Researcher basic information

• 博士（水産科学）, 北海道大学

• https://researchmap.jp/read0129269?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901061177354071
• https://nishioka48.wixsite.com/nishioka
• https://nishioka48.wixsite.com/nishioka/english

• 90371533

• 200901061177354071

• オホーツク海
• 北太平洋
• 化学海洋学
• Chemical Oceanography

• Environmental Science/Agriculture Science, Environmental dynamic analysis

• Master's degree program, Graduate School of Environmental Science
• Doctoral (PhD) degree program, Graduate School of Environmental Science

Research activity information

• Feb. 2025, 北海道大学, 令和6年度教育研究総長表彰
• Sep. 2024, 2024年度日本海洋学会, 2024年度日本海洋学会賞
  北西太平洋および縁辺海における鉄の輸送と生物生産との関わりの解明
  西岡 純
• Apr. 2023, 文部科学省, 令和5年度 科学技術分野の文部科学大臣表彰 科学技術賞（研究部門）
  北太平洋の生物生産を支える鉄分の供給過程に関する研究
  西岡 純
• 2016, 北海道大学, 北海道大学研究総長賞・奨励賞
  西岡 純
• 2015, 北海道大学, 北海道大学研究総長賞・奨励賞
  西岡 純
• 2014, 北海道大学, 北海道大学研究総長賞・奨励賞
  西岡 純
• Apr. 2005, 日本海洋学会, 岡田賞
  西岡 純

• Iron dynamics during spring phytoplankton bloom in the southern Sea of Okhotsk: The impact of sea ice melt on iron supply
  Momoka Imai; Aiko Murayama; Kazuya Ono; Youhei Yamashita; Koji Suzuki; Tomohiro Nakamura; Kay I. Ohshima; Humio Mitsudera; Jun Nishioka
  Progress in Oceanography, Jan. 2026, [Peer-reviewed]
  Scientific journal
• Formation of marine atmospheric organic aerosols associated with the spring phytoplankton bloom after sea ice retreat in the Sea of Okhotsk
  Yuzo Miyazaki; Yunhan Wang; Eri Tachibana; Koji Suzuki; Youhei Yamashita; Jun Nishioka
  Atmospheric Chemistry and Physics, 25, 24, 18325, 18340, Copernicus GmbH, 15 Dec. 2025
  Scientific journal, Abstract. The Sea of Okhotsk is one of the most biologically productive regions, where primary production during spring phytoplankton blooms after sea ice melting/retreat has the potential to contribute to the sea-to-air emission flux of atmospheric organic aerosols (OAs). To elucidate the effect of oceanic biological activity during blooms on the formation process of OAs, aerosol samples and surface seawater were collected during the bloom period of April 2021. Organic matter (OM) was the dominant component of submicrometer aerosols during both the bloom (53 ± 16 %) and bloom-decay periods (44 ± 12 %), with OM being highly water-soluble during the bloom. Stable carbon isotope ratios of aerosol organic carbon (OC) showed that 73 %–82 % of the observed aerosols were of marine origin. Relations between water-soluble OC (WSOC) and molecular tracers suggested that aerosol WSOC of marine origin was likely affected by secondary formation from precursors such as α-pinene and DMS-relevant compounds rather than primary emissions of sea spray aerosols. The amounts of water-soluble organic nitrogen (WSON) in aerosol and dissolved organic nitrogen (DON) in seawater during the bloom were larger than those during bloom-decay period, suggesting the preferential formation of N-containing water-soluble OAs of marine origin during the bloom. The increase in the amount of DON during the bloom was likely associated with the predominant diatoms, Thalassiosira spp. and Fragilariopsis spp. This study highlights the significant contribution of the secondary formation of marine biogenic OAs with increased N-containing components during the bloom after sea ice melting/retreat in the subarctic ocean.
• Sediment resuspension and its occurring conditions in the Soya warm current region observed from ADCP backscatter strength
  Mizuki Kuga; Kay I. Ohshima; Yasushi Fukamachi; Masato Ito; Jun Nishioka
  Journal of Oceanography, Springer Science and Business Media LLC, 17 Nov. 2025
  Scientific journal, Abstract
  
  One of the major sources of iron supply to the Okhotsk Sea and the Oyashio region, which both have high biological productivity, is thought to be regions of the East Sakhalin Current and its upstream, originating from the Amur River. This study suggests that the Soya Warm Current (SWC) region could also be a possible source of iron via resuspension of bottom sediments. We derived the volume backscatter strength from acoustic Doppler current profilers (ADCP) data that had previously been collected in the SWC region. The backscatter strength data indicate that prominent sediment resuspension occurs in both the upstream and downstream regions of the SWC when the bottom current exceeding 0.5 m/s continues to some extent. In the upstream region, strong current events that induced the sediment resuspension occurred through the SWC intensification caused by the increase in sea-level difference across the Soya Strait excited by the southerly winds. Such events frequently occur from September to December, because of frequent passages of cyclone. By contrast, in the downstream region, sediment resuspension occurred due to the strong northerly winds via the current increase caused by the coastal trapped waves over the shelf in winter. The sediment resuspension in the downstream region was also supported by direct observations of high turbidity near the bottom. High iron concentrations in the coastal Oyashio water possibly originate from the SWC water. The occurrence of the resuspension during the sea ice season suggests the potential local incorporation of sediment into sea ice.
• Photosynthetic carbon fixation capability of diatom communities in the southern Sea of Okhotsk from winter to spring as estimated using their rbcL genes
  Yanxu Sun; Jun Nishioka; Takenobu Toyota; Koji Suzuki
  Journal of Oceanography, Springer Science and Business Media LLC, 07 Oct. 2025
  Scientific journal
• Determining dominant phytoplankton assemblages and their controlling factors in the winter sea-ice-covered southern sea of okhotsk and the spring open water through a multiple analytical approach
  Yanxu Sun; Jun Nishioka; Takenobu Toyota; Koji Suzuki
  Marine Environmental Research, 210, 107297, 107297, Elsevier BV, Sep. 2025
  Scientific journal
• Melting processes of the marginal ice zone inferred from floe size distributions measured with a drone in the southern Sea of Okhotsk
  Takenobu Toyota; Yuriko Arihara; Takuji Waseda; Masato Ito; Jun Nishioka
  Polar Science, 101215, 101215, Elsevier BV, May 2025
  Scientific journal
• Decadal-scale reduction in net primary production in the western subarctic North Pacific: impact of lateral transport of dissolved iron from the Sea of Okhotsk
  Takuya Nakanowatari; Tomohiro Nakamura; Humio Mitsudera; Jun Nishioka; Hatsumi Nishikawa; Hiroshi Kuroda; Keisuke Uchimoto
  Environmental Research Letters, 20, 5, 054027, 054027, IOP Publishing, 11 Apr. 2025, [Peer-reviewed]
  Scientific journal, Abstract
  
  The subarctic North Pacific (SNP) is a high-nutrient low-chlorophyll region in which decoupling of dissolved iron (dFe) and macronutrient is an essential control of primary production. In this study, we evaluate the influence of decadal-scale climate change on the net primary production (NPP) in the SNP by performing a hindcast experiment for 1979–2016 using an ice–ocean coupled model with a simple biogeochemical model with iron cycle. Simulation results show a significant NPP decrease in the subtropical–subarctic gyre boundary (SGB) region since the 1990s; the trend is −48 mgC m⁻² d⁻¹/37 years with a magnitude that is 14.3% of the climatological mean NPP. The NPP decrease in the SGB is prominent during the spring, indicating weakening of the spring bloom. Diagnostic analysis of simulation data reveals that the NPP decrease in the SGB can be explained by the decrease in both dFe and light availability. Sensitivity experiments indicate that wind-driven circulation change mainly explains both the reduction in dFe and the light availability through the northward expansion of oligotrophic subtropical water, but the thermohaline change in the Sea of Okhotsk also has a non-negligible effect on the dFe reduction. Results from our numerical model simulations suggest the importance of lateral and vertical advection of dFe on the decadal-scale changes of NPP in the SNP.
• Phytoplankton community structure in relation to iron and macronutrient fluxes from subsurface waters in the western North Pacific during summer
  Huailin Deng; Koji Suzuki; Ichiro Yasuda; Hiroshi Ogawa; Jun Nishioka
  Biogeosciences, 19 Mar. 2025, [Peer-reviewed]
  Scientific journal
• Source and fate of atmospheric iron supplied to the subarctic North Pacific traced by stable iron isotope ratios
  Minako Kurisu; Kohei Sakata; Jun Nishioka; Hajime Obata; Tim M. Conway; Hannah R. Hunt; Matthias Sieber; Katsuhiko Suzuki; Teruhiko Kashiwabara; Sayuri Kubo; Makoto Takada; Yoshio Takahashi
  Geochimica et Cosmochimica Acta, 378, 168, 185, 01 Aug. 2024, [Peer-reviewed]
  Scientific journal
• In-situ analysis of sub-nanomolar level of Fe(II) in open-ocean waters
  Hajime Obata; Akira Mase; Toshitaka Gamo; Jun Nishioka; Kei Okamura
  Analytical Sciences, 40, 11, 2017, 2025, Springer Science and Business Media LLC, 30 Jul. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  Iron (Fe) in seawater is an essential micronutrient for marine phytoplankton, and Fe deficiency limits their growth in high-nutrient, low-chlorophyll areas. The bioavailability of Fe for phytoplankton largely depends on its chemical speciation in seawater. In surface water, the reduction of Fe(III) to Fe(II) is an important step in the uptake of Fe by phytoplankton. However, the marine biogeochemical cycle of Fe(II) in the open ocean has not been fully investigated. In oxic open-ocean waters, Fe(II) is rapidly oxidized and exists at sub-nanomolar levels, making it difficult to determine the Fe(II) concentration of seawater. In this study, we applied the flow analytical method of determining the Fe(II) concentration of seawater using luminol chemiluminescence in an in-situ analyzer (geochemical anomaly monitoring system, GAMOS). In the onboard laboratory, we successfully detected sub-nanomolar levels of Fe(II) in seawater using the GAMOS. In the central Indian Ocean, this analyzer was deployed at a depth of 1000 m to determine the Fe(II) concentration in the water column. During deployment, the detection limit (0.48 nM) was insufficient to determine the concentration. Therefore, we need to lower the blank values and enhance the stability of signal of the in-situ analytical method for application to open-ocean seawater samples.
  
  Graphical abstract
• Steady nutrient upwelling around a biological hotspot of the confluence between the quasi-stationary jet and the Oyashio in the western North Pacific
  Itsuka Yabe; Shin-ichi Ito; Shigeho Kakehi; Takeyoshi Nagai; Jun Nishioka
  Scientific Reports, 14, 1, Springer Science and Business Media LLC, 30 Jul. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  The quasi-stationary jet, a branch of the Kuroshio Extension, transports warm saline water in the mixed water region of the western North Pacific. Around the subarctic front between the quasi-stationary jet and Oyashio and its downstream area is a biologically productive area including small pelagic fishes. However, how nutrient is supplied to the euphotic zone in this region remains elusive, especially into the quasi-stationary jet. Using high-resolution hydrography sections across the jet, we showed that Oyashio water isopycnally intrudes under the jet around 26.5–26.8 σ_θ and forms nutrient-rich intermediate water. Upwelling associated with ageostrophic secondary circulation across the front, caused by confluence, uplifts the intermediate water. A local nitrate maximum was also identified inside the jet by the hydrographic observation. Upwelling has been suggested as a precondition for nutrient supply from nutrient-rich intermediate water to the jet through water mixing which potentially sustains high biological production in the downstream.
• Long-term observation of the Soya Warm Current using HF ocean radars: relationship between the Soya Warm Current variability and the sea level anomalies in the Soya/La Perouse Strait
  Naoto Ebuchi; Yasushi Fukamachi; Kay I. Ohshima; Humio Mitsudera; Jun Nishioka; Toru Takatsuka; Kazuya Ono; Masao Ishikawa; Takaharu Daibo; Kunio Shirasawa; Masaaki Wakatsuchi
  Journal of Oceanography, Springer Science and Business Media LLC, 23 May 2024, [Peer-reviewed]
  Scientific journal
• Sea ice-melt amount estimated from spring hydrography in the Sea of Okhotsk: spatial and interannual variabilities
  Mariko Honda; Kay I. Ohshima; Vigan Mensah; Jun Nishioka; Masatoshi Sato; Stephen C. Riser
  Journal of Oceanography, 80, 4, 273, 290, Springer Science and Business Media LLC, 11 May 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  This study provides the first estimation of sea ice-melt amount in the Sea of Okhotsk based on spring hydrographic data accumulated for nearly a hundred years. Just after sea ice melts completely, a low-salinity layer appears on the ocean surface, overlying the layer of Winter Water at the freezing point. The integration of the salinity decrease from Winter Water should correspond to the total ice-melt amount. We developed an algorithm to extract the profiles that clearly show the salinity deficit and converted the salinity deficit to the ice-melt amount from all available data. The climatological map shows that ice-melt amount decreases toward the ice edge and exhibits large values around the northern Sakhalin Island, reflecting the ice thickness distribution. In the southern area (south of 48°N), where sea ice is transported from the north, the average ice-melt amount is estimated to be ~ 71 cm in thickness. It is clearly shown that the ice-melt amount has decreased by ~ 30% in the southern area since the 1990s. These changes possibly affect the regional climate through the decreased latent heat of sea ice and potentially affect biological production through weakened stratification caused by decreased ice melt. We also suggested that ice-melt amount did not show a significant trend during the 1930s–1970s, implying that our methodology could extract information on sea ice before the era of satellite observations.
• Classification of optical water groups in the subarctic Pacific and adjacent seas using satellite-derived light absorption spectra of chromophoric dissolved organic matter
  Joji Oida; Toru Hirawake; Youhei Yamashita; Hiroto Abe; Jun Nishioka; Hisatomo Waga; Daiki Nomura; Shigeho Kakehi
  Deep Sea Research Part I: Oceanographic Research Papers, 104313, 104313, Elsevier BV, Apr. 2024, [Peer-reviewed]
  Scientific journal
• Dissolved zinc in the western Bering Sea and near Kamchatka Strait: A coastal source and transport to the subarctic Pacific
  Kuo Hong Wong; Hajime Obata; Taejin Kim; Hirofumi Tazoe; Asami S. Mashio; Hiroshi Hasegawa; Jun Nishioka
  Marine Chemistry, 260, Mar. 2024, [Peer-reviewed]
  Scientific journal
• Origin and Transport of Dissolved Organic Matter in the Northwestern Margin of the North Pacific Inferred from Radiocarbon Signatures
  Shigeyoshi Otosaka; Yunxuan Hou; Masahide Wakita; Youhei Yamashita; Jun Nishioka; Hajime Obata; Yosuke Miyairi; Yusuke Yokoyama; Hiroshi Ogawa
  Journal of Coastal Research, 116, sp1, Coastal Education and Research Foundation, 04 Jan. 2024, [Peer-reviewed]
  Scientific journal
• Dissolved Fe(II) and its oxidation rates in the Kuroshio area, subarctic Pacific, and Bering Sea
  Hajime Obata; Akira Mase; Naoya Kanna; Shigenobu Takeda; Jun Nishioka; Kenshi Kuma
  GEOCHEMICAL JOURNAL, 58, 2, 71, 79, Geochemical Society of Japan, 2024, [Peer-reviewed]
  Scientific journal
• Backward-tracking simulations of sea ice in the Sea of Okhotsk toward understanding of material transport through sea ice
  Mizuki Kuga; Kay I. Ohshima; Sachiko Kishi; Noriaki Kimura; Takenobu Toyota; Jun Nishioka
  Journal of Oceanography, Springer Science and Business Media LLC, 17 Oct. 2023, [Peer-reviewed]
  Scientific journal
• Asian dust-deposition flux to the subarctic Pacific estimated using single quartz particles
  Kana Nagashima; Hajime Kawakami; Koji Sugie; Tetsuichi Fujiki; Jun Nishioka; Yoko Iwamoto; Toshihiko Takemura; Takuma Miyakawa; Fumikazu Taketani; Maki Noguchi Aita
  Scientific Reports, 13, 1, Springer Science and Business Media LLC, 29 Sep. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Abstract
  
  Iron availability limits marine ecosystem activities in large areas of the ocean. However, the sources and seasonal supply of iron, critically important for controlling surface ocean biogeochemistry and carbon cycling, are poorly understood. The western subarctic Pacific is a high-nutrient and low-chlorophyll region, and despite high concentrations of macronutrients, iron limits phytoplankton production in summer. Here, we determine the seasonal deposition flux of Asian dust using scanning electron microscope–cathodoluminescence analysis of single quartz particles derived from the western subarctic Pacific during 2003–2022 to trace provenance. We found a high (up to 6.9 mg m⁻² day⁻¹) deposition flux of Asian dust in May, June, and early July, with an annual average of 1.0 ± 0.2 mg m⁻² day⁻¹. The supply of dissolved-iron flux calculated from Asian dust was 0.9 ± 0.3 µg m⁻² day⁻¹ during the high productivity season (April–July), which is approximately half that from the deeper part of the ocean, calculated from vertical profiles of dissolved iron. Our study provides a reliable approach for estimating iron supply from dust to the surface ocean that may be critical for sustaining biological productivity under future ocean stratification, which suppresses nutrient supply from the subsurface ocean.
• Long-Term Observation of the Soya Warm Current Combining HF Ocean Radars with Coastal Tide Gauges and Satellite Altimetry
  N. Ebuchi; Y. Fukamachi; K.I. Ohshima; T. Takatsuka; H. Mitsudera; J. Nishioka; K. Ono; M. Ishikawa; T. Daibo; K. Shiwasawa; M. Wakatsuchi
  IGARSS 2023 - 2023 IEEE International Geoscience and Remote Sensing Symposium, IEEE, 16 Jul. 2023, [Peer-reviewed]
  International conference proceedings
• Different responses of phytoplankton to Fe manipulation in Fe-limited waters with contrasting surface mixed layer depths in the western subarctic Pacific
  Kazuhiro Yoshida; Jun Nishioka; Ichiro Yasuda; Koji Suzuki
  Journal of Oceanography, Springer Science and Business Media LLC, 15 Jun. 2023, [Peer-reviewed]
  Scientific journal
• Dissolved Iron Concentration and the Solubility Inferred by Humic‐Like Fluorescent Dissolved Organic Matter in the Intermediate Water in the North Pacific Including the Marginal Seas
  Youhei Yamashita; Jun Nishioka
  Journal of Geophysical Research: Biogeosciences, Mar. 2023, [Peer-reviewed]
  Scientific journal
• Role of nutrients and temperature in shaping distinct summer phytoplankton and microzooplankton population dynamics in the western North Pacific and Bering Sea
  Liu, Kailin; Jun Nishioka; Bingzhang Chen; Koji Suzuki; Shunyan Cheung; Lu, Yanhong; Huijun Wu; Hongbin Liu
  Limnology and Oceanography, Wiley, 16 Jan. 2023, [Peer-reviewed], ［Internationally co-authored］
  English, Scientific journal
• The Interannual Variability of Sea Ice Area, Thickness, and Volume in the Southern Sea of Okhotsk and Its Likely Factors
  Takenobu Toyota; Noriaki Kimura; Jun Nishioka; Masato Ito; Daiki Nomura; Humio Mitsudera
  Journal of Geophysical Research: Oceans, 127, 12, American Geophysical Union (AGU), Dec. 2022, [Peer-reviewed]
  English, Scientific journal
• Meltwater Discharge From Marine‐Terminating Glaciers Drives Biogeochemical Conditions in a Greenlandic Fjord
  Naoya Kanna; Shin Sugiyama; Takuto Ando; Yefan Wang; Yuta Sakuragi; Toya Hazumi; Kohei Matsuno; Atsushi Yamaguchi; Jun Nishioka; Youhei Yamashita
  Global Biogeochemical Cycles, 36, 11, American Geophysical Union (AGU), Nov. 2022
  Scientific journal
• Number‐Size Distribution and CCN Activity of Atmospheric Aerosols in the Western North Pacific During Spring Pre‐Bloom Period: Influences of Terrestrial and Marine Sources
  Kaori Kawana; Yuzo Miyazaki; Yuko Omori; Hiroshi Tanimoto; Sara Kagami; Koji Suzuki; Youhei Yamashita; Jun Nishioka; Yange Deng; Hikari Yai; Michihiro Mochida
  Journal of Geophysical Research: Atmospheres, 127, 19, American Geophysical Union (AGU), 16 Oct. 2022, [Peer-reviewed]
  Scientific journal
• High biomass turnover rates of endosymbiotic nitrogen-fixing cyanobacteria in the western Bering Sea
  Shunyan Cheung; Kailin Liu; Kendra A. Turk-Kubo; Jun Nishioka; Koji Suzuki; Michael R. Landry; Jonathan; P. Zehr; Szeki Leung; Lixia Deng; Hongbin Liu
  Limnology and Oceanography Letters, 05 Jul. 2022, [Peer-reviewed], ［Internationally co-authored］
  Scientific journal
• Winter microalgal communities of the southern Sea of Okhotsk: A comparison of sea ice, coastal, and basinal seawater
  Dong Yan; Jun Nishioka; Takenobu Toyota; Koji Suzuki
  Progress in Oceanography, 204, 102806, 102806, Elsevier BV, Jun. 2022, [Peer-reviewed]
  Scientific journal
• Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean
  Hirofumi Tazoe; Hajime Obata; Takuya Hara; Mutsuo Inoue; Takahiro Tanaka; Jun Nishioka
  Frontiers in Marine Science, 9, Frontiers Media SA, 31 May 2022, [Peer-reviewed]
  Scientific journal, The vertical activity concentration distributions of the radium isotopes, ²²⁶Ra and ²²⁸Ra, which are useful as radiotracers, were obtained for the first time in the western Subarctic Pacific Gyre (WSAG). It was possible to detect short-lived ²²⁸Ra present from the surface to 400 m depth by analyzing large seawater samples. Low ²²⁸Ra and high ²²⁶Ra activity concentrations in the surface layer in the WSAG were strongly influenced by upwelled deeper water with nutrients. The activity concentration distribution of ²²⁶Ra especially was in good agreement with the silicate concentration distribution, which was consistent with previous reported findings. These distributions were uniform from the surface to 100 m of the dichothermal layer due to vertical mixing in winter. ²²⁸Ra activity concentration decreased with water depth below the pycnocline and reached the undetectable level at 600 m which was within the oxygen minimum layer. Estimations of vertical fluxes of ²²⁸Ra and nitrate according to ²²⁸Ra decay indicated that the vertical transport by eddy diffusion was a minor process for the ²²⁸Ra and nitrate fluxes, and lateral transport mainly affected ²²⁸Ra in the intermediate warm water, that is, the mesothermal layer below the main pycnocline. Vertical mixing or submarine underground water and lateral transport to the WSAG could yield this ²²⁸Ra in the intermediate depth.
• Subarctic Pacific Intermediate Water: An Oceanic Highway for the Transport of Trace Metals in the North Pacific
  Kuo Hong Wong; Hajime Obata; Jun Nishioka; Youhei Yamashita; Yoshiko Kondo; Taejin Kim; Asami Mashio; Hiroshi Hasegawa
  Limnology and Oceanography Bulletin, 31, 2, 31, 36, Wiley, May 2022, [Peer-reviewed]
  Scientific journal
• Biogeochemical and physical linkages between the Arctic Ocean and Sub-Arctic Pacific through marginal seas
  Jun Nishioka; Ichiro Yasuda; Toru Hirawake; Tomohiro Nakamura; Yoshiko Kondo; Yuri N. Volkov
  Progress in Oceanography, 203, Apr. 2022, [Peer-reviewed]
  Scientific journal
• Long‐Range Lateral Transport of Dissolved Manganese and Iron in the Subarctic Pacific
  Kuo Hong Wong; Jun Nishioka; Taejin Kim; Hajime Obata
  Journal of Geophysical Research: Oceans, 127, 2, American Geophysical Union (AGU), Feb. 2022, [Peer-reviewed]
  Scientific journal
• Fate of dissolved black carbon in the deep Pacific Ocean
  Youhei Yamashita; Motohiro Nakane; Yutaro Mori; Jun Nishioka; Hiroshi Ogawa
  Nature Communications, 13 Jan. 2022, [Peer-reviewed]
  Scientific journal
• Decadal vision in oceanography 2021: Air―sea boundary
  Yoko Iwamoto; Hidenori Aiki; Osamu Isoguchi; Yumiko Obayashi; Fumiyoshi Kondo; Yoshiko Kondo; and Jun Nishioka
  Oceanography in Japan, 30, 5, 199, 225, The Oceanographic Society of Japan, 15 Nov. 2021, [Peer-reviewed], [Invited]
  Japanese, Scientific journal
• Decadal vision in oceanography 2021: Polar oceans
  Michiyo Yamamoto-Kawai; Takeshi Tamura; Eiji Watanabe; Jun Nishioka; Daiki Nomura; Ryusuke Makabe; Kohei Mizobata; Yasunaka Sayaka
  Oceanography in Japan, 30, 5, 159, 178, The Oceanographic Society of Japan, 15 Nov. 2021, [Peer-reviewed]
  Scientific journal
• Diatoms contributing to new production in surface waters of the northern Bering and Chukchi Seas during summer with reference to water column stratification
  Koji Suzuki; Yuta Yoshino; Yuichi Nosaka; Jun Nishioka; Stanford B. Hooker; Toru Hirawake
  199, 102692, Oct. 2021, [Peer-reviewed]
  English
• Change of nitrogen chemical tracer N2* between the Okhotsk Sea and the subarctic North Pacific
  Yutaka W. Watanabe; Yuto Nakano; Jun Nishioka; Masanori Ito
  Progress in Oceanography, 102693, 102693, Elsevier BV, Oct. 2021, [Peer-reviewed]
  English, Scientific journal
• Water mass distribution in the northern Bering and southern Chukchi seas using light absorption of chromophoric dissolved organic matter
  Toru Hirawake; Joji Oida; Youhei Yamashita; Hisatomo Waga; Hiroto Abe; Jun Nishioka; Daiki Nomura; Hiromichi Ueno; Atsushi Ooki
  Progress in Oceanography, 197, 102641, 102641, Elsevier BV, Sep. 2021, [Peer-reviewed]
  English, Scientific journal, 12352893;12352899
• Interannual to decadal variability of phosphate in the Oyashio region: Roles of wind-driven ocean current and tidally induced vertical mixing in the Sea of Okhotsk
  Takuya Nakanowatari; Tomohiro Nakamura; Humio Mitsudera; Jun Nishioka; Hiroshi Kuroda; Keisuke Uchimoto
  Progress in Oceanography, 197, 102615, 102615, Elsevier BV, Sep. 2021, [Peer-reviewed]
  Scientific journal
• Iron and nutrient dynamics along the East Kamchatka Current, western Bering Sea Basin and Gulf of Anadyr
  Jun Nishioka; Toru Hirawake; Daiki Nomura; Youhei Yamashita; Kazuya Ono; Aiko Murayama; Alexey Shcherbinin; Yuri N. Volkov; Humio Mitsudera; Naoto Ebuchi; Masaaki Wakatsuchi; Ichiro Yasuda
  Progress in Oceanography, 198, 102662, 102662, Elsevier BV, Aug. 2021, [Lead author]
  English, Scientific journal, 12352893;12352898;12352899
• Formation of dense shelf water associated with sea ice freezing in the Gulf of Anadyr estimated with oxygen isotopic ratios
  Daiki Nomura; Hiroto Abe; Toru Hirawake; Atsushi Ooki; Youhei Yamashita; Aiko Murayama; Kazuya Ono; Jun Nishioka
  Progress in Oceanography, 196, 102595, 102595, Elsevier BV, Aug. 2021, [Last author]
  Scientific journal, 12352893;12352899
• A review: iron and nutrient supply in the subarctic Pacific and its impact on phytoplankton production
  Jun Nishioka; Hajime Obata; Toru Hirawake; Yoshiko Kondo; Youhei Yamashita; Kazuhiro Misumi; Ichiro Yasuda
  Journal of Oceanography, 77, 4, 561, 587, Springer Science and Business Media LLC, 13 May 2021, [Peer-reviewed], [Lead author]
  Scientific journal, 12352893;12352899
• Determination of Nd isotopic composition in seawater using newly developed solid phase extraction and MC-ICP-MS
  Hirofumi Tazoe; Hiroshi Amakawa; Katsuhiko Suzuki; Jun Nishioka; Takuya Hara; Hajime Obata
  Talanta, 232, 122435, 122435, Elsevier BV, Apr. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Determination of neodymium (Nd) isotopic composition in seawater is useful for tracing water masses and geochemical cycles for lithogenic elements in the ocean. A new separation procedure for determination of the Nd isotopic composition of in seawater samples was developed that offers enhanced sample throughput and improved measurement reliability. The procedure consists of conventional Fe hydroxide coprecipitation, solid phase extraction using DGA chelating resin column chromatography, and Ln Resin column chromatography to preconcentrate samples. High selectivity in HNO3 medium and elution by low concentration HCl medium for Nd are characteristics of extraction using DGA Resin®, and they allowed an evaporation step to be omitted between the chromatographic steps. These chromatographic steps, using DGA Resin to separate REEs and Ln Resin® to remove Sm, were refined from a previous study. The procedural blank value of Nd was obtained as 2 pg (n = 6) from 3 L of water samples. Chemical yield of Nd from 3 L of seawater ranged within 90-95%. The developed procedure was combined with multiple collector-ICP-MS and applied to analysis of vertical seawater samples obtained from the western subarctic gyre of the North Pacific Ocean, where εNd ranged from -1.29 ± 0.42 at the surface to -3.80 ± 0.41 at 4000 m depth. These results were validated by comparing them with results obtained by the conventional method verified in the GEOTRACES inter-calibration program., 12352893
• Chemical speciation of iron in the euphotic zone along the Kuroshio Current
  Mitsuhide Sato; Jun Nishioka; Kazuyuki Maki; Shigenobu Takeda
  Marine Chemistry, 233, 103966, 103966, Elsevier BV, Apr. 2021, [Peer-reviewed]
  Scientific journal, 12352899;12352893
• Slowly Sinking Particles Underlie Dissolved Iron Transport Across the Pacific Ocean
  K. Misumi; J. Nishioka; H. Obata; D. Tsumune; T. Tsubono; M. C. Long; K. Lindsay; J. K. Moore
  Global Biogeochemical Cycles, 35, 4, American Geophysical Union (AGU), Apr. 2021, [Peer-reviewed]
  Scientific journal, 12352893;12352899
• Transport of dissolved black carbon from marginal sea sediments to the western North Pacific
  Yutaro Mori; Jun Nishioka; Shinzou Fujio; Youhei Yamashita
  Progress in Oceanography, 193, 102552, 102552, Apr. 2021, [Peer-reviewed]
  English, Scientific journal, 12352893;12352899
• Observations of anticyclonic eddies in the western subarctic North Pacific
  Ryo Dobashi; Hiromichi Ueno; Yuki Okada; Takahiro Tanaka; Jun Nishioka; Toru Hirawake; Atushi Ooki; Sachihiko Itoh; Daisuke Hasegawa; Yoshikazu Sasai; Hideharu Sasaki; Ichiro Yasuda
  Journal of Oceanography, 77, 2, 229, 242, Springer Science and Business Media LLC, Apr. 2021, [Peer-reviewed]
  Scientific journal, 12352899
• New insights into the biogeochemical cycling of copper in the subarctic Pacific: Distributions, size fractionation, and organic complexation
  Kuo Hong Wong; Hajime Obata; Taejin Kim; Yoshiko Kondo; Jun Nishioka
  Limnology and Oceanography, 66, 4, 1424, 1439, Wiley, Apr. 2021, [Peer-reviewed], [Last author]
  Scientific journal, 12352893
• The Prominent Spring Bloom and Its Relation to Sea‐Ice Melt in the Sea of Okhotsk, Revealed by Profiling Floats
  S. Kishi; K. I. Ohshima; J. Nishioka; N. Isshiki; S. Nihashi; S. C. Riser
  Geophysical Research Letters, 48, 6, 28 Mar. 2021, [Peer-reviewed]
  English, Scientific journal, 12352893;9968759
• Wide-range detection of Cu-binding organic ligands in seawater using reverse titration
  Wiwit; Kuo Hong Wong; Hideki Fukuda; Hiroshi Ogawa; Asami S. Mashio; Yoshiko Kondo; Jun Nishioka; Hajime Obata
  Marine Chemistry, 230, 103927, 103927, Elsevier BV, Mar. 2021, [Peer-reviewed]
  Scientific journal, 12352893
• Widespread distribution of allochthonous fluorescent dissolved organic matter in the intermediate water of the North Pacific
  Youhei Yamashita; Tetsu Tosaka; Rise Bamba; Ryuichi Kamezaki; Shuji Goto; Jun Nishioka; Ichiro Yasuda; Toru Hirawake; Joji Oida; Hajime Obata; Hiroshi Ogawa
  Progress in Oceanography, 191, 102510, 102510, Elsevier BV, Feb. 2021, [Peer-reviewed]
  Scientific journal, 12352893
• Enhanced vertical turbulent nitrate flux in the intermediate layer of the Kuroshio in the Tokara Strait
  T. Tanaka; D. Hasegawa; I. Yasuda; D. Yanagimoto; S. Fujio; H. Nakamura; R. Inoue; J. Nishioka
  Journal of Oceanography, 77, 1, 45, 53, Springer Science and Business Media LLC, Feb. 2021, [Peer-reviewed], [Last author]
  Scientific journal, 12352899;12352893
• Ocean mixing processes (OMIX): impact on biogeochemistry, climate and ecosystem
  Ichiro Yasuda; Shuhei Masuda; Jun Nishioka; Xinyu Guo; Naomi Harada; Shin-ichi Ito; Toshiyuki Hibiya; Hiroyasu Hasumi
  Journal of Oceanography, 77, 1, 1, 1, Feb. 2021
  English, Scientific journal, 12352899
• Author Correction: New index of organic mass enrichment in sea spray aerosols linked with senescent status in marine phytoplankton (Scientific Reports, (2020), 10, 1, (17042), 10.1038/s41598-020-73718-5)
  Miyazaki, Y.; Suzuki, K.; Tachibana, E.; Yamashita, Y.; M{\"u}ller, A.; Kawana, K.; Nishioka, J.
  Scientific Reports, 11, 1, 2021, [Peer-reviewed]
  Scientific journal
• Dynamics of dissolved iron and dissolved organic matter in a glacial fjord; Inglefield Bredning in northwest Greenland.
  Kanna Naoya; Sugiyama Shin; Ando Takuto; Asaji Izumi; Yefan Wang; Sakuragi Yuta; Nishioka Jun; Yamashita Yohei
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 68, 41, GEOCHEMICAL SOCIETY OF JAPAN, 2021
  Japanese, 海洋における腐植様蛍光物質(FDOMH)は、海洋の微量栄養物質である鉄と有機錯体を形成し、海水中に鉄を溶解させる役割を担う。FDOMHは、陸由来のものと海洋自生性のものに区別されるが、北大西洋では、北極海に注ぐ河川からのFDOMHの影響が大きいため、塩分とFDOMHの蛍光強度に負の相関がみられる。北大西洋に面するグリーンランド沿岸では、河川水に加えて陸氷(氷河、氷山)の融解水が流入する。この融解水が、海洋におけるFDOMHや鉄の動態にどのような影響を与えるかは不明である。本研究では、グリーンランド北西部のフィヨルドにおいて、氷河の融解水が海水中のFDOMHと鉄の動態に与える影響を調べた。
• Distinct profiles of size-fractionated iron-binding ligands between the eastern and western subarctic Pacific
  Yoshiko Kondo; Rise Bamba; Hajime Obata; Jun Nishioka; Shigenobu Takeda
  Scientific Reports, 11, 1, Springer Science and Business Media LLC, Jan. 2021, [Peer-reviewed]
  Scientific journal, Iron (Fe) is well known as a limiting factor to control primary productivity especially in high-nutrient and low chlorophyll area such as the subarctic Pacific. The solubility of Fe is believed to be controlled by its complexation with natural organic ligands, while the distribution of organic ligands is poorly understood. Here, we report that dissolved (< 0.2 µm) organic ligands were unevenly distributed between the western and eastern stations in the subarctic Pacific. The concentration of dissolved organic ligands around the lower part of subarctic Pacific intermediate water was higher in the western station, suggesting that Fe complexation with these organic ligands supports a lateral transport within the water mass. However, a more detailed size-fractionated treatment indicated no significant difference in the soluble (< 1000 kDa) ligands’ distribution between the western and eastern stations. These results suggest that organic and inorganic colloid formations are potentially essential for Fe transport mechanisms in the subarctic Pacific., 12352893;12352899
• New index of organic mass enrichment in sea spray aerosols linked with senescent status in marine phytoplankton
  Yuzo Miyazaki; Koji Suzuki; Eri Tachibana; Youhei Yamashita; Astrid Müller; Kaori Kawana; Jun Nishioka
  Scientific Reports, 10, 1, Dec. 2020, [Peer-reviewed]
  English, Scientific journal
• Iron Supply by Subglacial Discharge Into a Fjord Near the Front of a Marine‐Terminating Glacier in Northwestern Greenland
  Naoya Kanna; Shin Sugiyama; Yasushi Fukamachi; Daiki Nomura; Jun Nishioka
  Global Biogeochemical Cycles, 34, 10, American Geophysical Union (AGU), Oct. 2020, [Peer-reviewed], [Last author]
  Scientific journal
• Cold Water Upwelling Near the Anadyr Strait: Observations and Simulations
  Yusuke Kawaguchi; Jun Nishioka; Shigeto Nishino; Shinzou Fujio; Keunjong Lee; Amane Fujiwara; Daigo Yanagimoto; Humio Mitsudera; Ichiro Yasuda
  Journal of Geophysical Research: Oceans, 125, 9, American Geophysical Union (AGU), Sep. 2020, [Peer-reviewed]
  Scientific journal
• Distributions of radiocesium and radium isotopes in the western Bering Sea in 2018
  Mutsuo Inoue; Ryosei Takehara; Shotaro Hanaki; Hiroaki Kameyama; Jun Nishioka; Seiya Nagao
  Marine Chemistry, 225, 103843, 103843, Elsevier BV, Sep. 2020, [Peer-reviewed]
  Scientific journal
• Response to Sea Ice Melt Indicates High Seeding Potential of the Ice Diatom Thalassiosira to Spring Phytoplankton Blooms: A Laboratory Study on an Ice Algal Community From the Sea of Okhotsk
  Dong Yan; Kazuhiro Yoshida; Jun Nishioka; Masato Ito; Takenobu Toyota; Koji Suzuki
  Frontiers in Marine Science, 7, 24 Jul. 2020, [Peer-reviewed]
  English, Scientific journal
• Subpolar marginal seas fuel the North Pacific through the intermediate water at the termination of the global ocean circulation
  Jun Nishioka; Hajime Obata; Hiroshi Ogawa; Kazuya Ono; Youhei Yamashita; Keunjong Lee; Shigenobu Takeda; Ichiro Yasuda
  Proceedings of the National Academy of Sciences U.S.A, 117, 23, 202000658, 12673, 27 May 2020, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Response of Arctic biodiversity and ecosystem to environmental changes: Findings from the ArCS project
  Toru Hirawake; Masaki Uchida; Hiroto Abe; Irene D. Alabia; Tamotsu Hoshino; Shota Masumoto; Akira S. Mori; Jun Nishioka; Bungo Nishizawa; Atsushi Ooki; Akinori Takahashi; Yukiko Tanabe; Motoaki Tojo; Masaharu Tsuji; Hiromichi Ueno; Hisatomo Waga; Yuuki Y. Watanabe; Atsushi Yamaguchi; Youhei Yamashita
  Polar Science, in press, 100533, 100533, Elsevier BV, May 2020, [Peer-reviewed]
  English, Scientific journal
• Size fractionation and bioavailability of iron released from melting sea ice in a subpolar marginal sea
  Naoya Kanna; Delphine Lannuzel; Pier van der Merwe; Jun Nishioka
  Marine Chemistry, 221, 103774, 103774, Elsevier BV, Apr. 2020, [Peer-reviewed]
  Scientific journal
• Community Composition and Photosynthetic Physiology of Phytoplankton in the Western Subarctic Pacific Near the Kuril Islands With Special Reference to Iron Availability
  Kazuhiro Yoshida; Suzu Nakamura; Jun Nishioka; Stanford B. Hooker; Koji Suzuki
  Journal of Geophysical Research: Biogeosciences, 125, 3, American Geophysical Union ({AGU}), 11 Mar. 2020, [Peer-reviewed]
  Scientific journal
• Shelf humic substances as carriers for basin-scale iron transport in the North Pacific
  Youhei Yamashita; Jun Nishioka; Hajime Obata; Hiroshi Ogawa
  Scientific Reports, 10, 1, Mar. 2020
  English, Scientific journal
• Influence of Coastal Oyashio water on massive spring diatom blooms in the Oyashio area of the North Pacific Ocean
  Kuroda, H; Y. Toya; T. Watanabe; J. Nishioka; D. Hasegawa; Y. Taniuchi; A. Kuwata
  Progress in Oceanography, 175, 328, 344, May 2019, [Peer-reviewed]
• Enhanced vertical turbulent nitrate flux in the Kuroshio across the Izu Ridge
  Tanaka, T; D Hasegawa; I Yasuda; H Tsuji; S Fujio; Y Goto; J Nishioka
  Journal of Oceanography, 75, 2, 195, 203, Jan. 2019, [Peer-reviewed]
• Accumulation processes of trace metals into Arctic sea ice: distribution of Fe, Mn and Cd associated with ice structure
  Evans,L.K; J. Nishioka
  Marine Chemistry, 209, 36, 47, Jan. 2019, [Peer-reviewed]
  English, Scientific journal
• Winter iron supply processes fueling spring phytoplankton growth in a sub-polar marginal sea, the Sea of Okhotsk
  Kanna,Naoya; Yusuke Sibano; Tkenobu Toyota; Jun Nishioka
  Marine Chemistry, Aug. 2018, [Peer-reviewed], [Last author]
  English
• Quantitative analysis of Fe, Mn and Cd from sea ice and seawater in the Chukchi Sea, Arctic Ocean
  La Kenya Evansa; Jun Nishioka
  Polar Science, 17, 50, 58, Aug. 2018, [Peer-reviewed], [Last author]
  English, Scientific journal
• Chemical transfer of dissolved organic matter from surface seawater to sea spray water-soluble organic aerosol in the marine atmosphere
  Yuzo Miyazaki; Youhei Yamashita; Kaori Kawana; Eri Tachibana; Sara Kagami; Michihiro Mochida; Koji Suzuki; Jun Nishioka
  Scientific reports, 8, 1, 14861, 2018, [Peer-reviewed]
  English, Scientific journal
• Responses of phytoplankton assemblages to iron availability and mixing water masses during the spring bloom in the Oyashio region, NW Pacific
  T Isada; A Hattori‐Saito; H Saito; Y Kondo; J Nishioka, K Kuma; H Hattori; RML McKay; K Suzuki
  Limnology and Oceanography, 2018, [Peer-reviewed]
  English, Scientific journal
• The GEOTRACES Intermediate Data Product 2017
  Reiner Schlitzer; Robert F. Anderson; Elena Masferrer Dodas; Maeve Lohan; Walter Geibert; Alessandro Tagliabue; Andrew Bowie; Catherine Jeandel; Maria T. Maldonado; William M. Landing; Donna Cockwell; Cyril Abadie; Wafa Abouchami; Eric P. Achterberg; Alison Agather; Ana Aguliar-Islas; Hendrik M. van Aken; Morten Andersen; Corey Archer; Maureen Auro; Hein J. de Baar; Oliver Baars; Alex R. Baker; Karel Bakker; Chandranath Basak; Mark Baskaran; Nicholas R. Bates; Dorothea Bauch; Pieter van Beek; Melanie K. Behrens; Erin Black; Katrin Bluhm; Laurent Bopp; Heather Bouman; Katlin Bowman; Johann Bown; Philip Boyd; Marie Boye; Edward A. Boyle; Pierre Branellec; Luke Bridgestock; Guillaume Brissebrat; Thomas Browning; Kenneth W. Bruland; Hans-Jürgen Brumsack; Mark Brzezinski; Clifton S. Buck; Kristen N. Buck; Ken Buesseler; Abby Bull; Edward Butler; Pinghe Cai; Patricia Cámara Mor; Damien Cardinal; Craig Carlson; Gonzalo Carrasco; Núria Casacuberta; Karen L. Casciotti; Maxi Castrillejo; Elena Chamizo; Rosie Chance; Matthew A. Charette; Joaquin E. Chaves; Hai Cheng; Fanny Chever; Marcus Christl; Thomas M. Church; Ivia Closset; Albert Colman; Tim M. Conway; Daniel Cossa; Peter Croot; Jay T. Cullen; Gregory A. Cutter; Chris Daniels; Frank Dehairs; Feifei Deng; Huong Thi Dieu; Brian Duggan; Gabriel Dulaquais; Cynthia Dumousseaud; Yolanda Echegoyen-Sanz; R. Lawrence Edwards; Michael Ellwood; Eberhard Fahrbach; Jessica N. Fitzsimmons; A. Russell Flegal; Martin Q. Fleisher; Tina van de Flierdt; Martin Frank; Jana Friedrich; Francois Fripiat; Henning Fröllje; Stephen J.G. Galer; Toshitaka Gamo; Raja S. Ganeshram; Jordi Garcia-Orellana; Ester Garcia-Solsona; Melanie Gault-Ringold; Ejin George; Loes J.A. Gerringa; Melissa Gilbert; Jose M. Godoy; Steven L. Goldstein; Santiago R. Gonzalez; Karen Grissom; Chad Hammerschmidt; Alison Hartman; Christel S. Hassler; Ed C. Hathorne; Mariko Hatta; Nicholas Hawco; Christopher T. Hayes; Lars-Eric Heimbürger; Josh Helgoe; Maija Heller; Gideon M. Henderson; Paul B. Henderson; Steven van Heuven; Peng Ho; Tristan J. Horner; Yu-Te Hsieh; Kuo-Fang Huang; Matthew P. Humphreys; Kenji Isshiki; Jeremy E. Jacquot; David J. Janssen; William J. Jenkins; Seth John; Elizabeth M. Jones; Janice L. Jones; David C. Kadko; Rick Kayser; Timothy C. Kenna; Roulin Khondoker; Taejin Kim; Lauren Kipp; Jessica K. Klar; Maarten Klunder; Sven Kretschmer; Yuichiro Kumamoto; Patrick Laan; Marie Labatut; Francois Lacan; Phoebe J. Lam; Myriam Lambelet; Carl H. Lamborg; Frédéric A.C. Le Moigne; Emilie Le Roy; Oliver J. Lechtenfeld; Jong-Mi Lee; Pascale Lherminier; Susan Little; Mercedes López-Lora; Yanbin Lu; Pere Masque; Edward Mawji; Charles R. Mcclain; Christopher Measures; Sanjin Mehic; Jan-Lukas Menzel Barraqueta; Pier van der Merwe; Rob Middag; Sebastian Mieruch; Angela Milne; Tomoharu Minami; James W. Moffett; Gwenaelle Moncoiffe; Willard S. Moore; Paul J. Morris; Peter L. Morton; Yuzuru Nakaguchi; Noriko Nakayama; John Niedermiller; Jun Nishioka; Akira Nishiuchi; Abigail Noble; Hajime Obata; Sven Ober; Daniel C. Ohnemus; Jan van Ooijen; Jeanette O'Sullivan; Stephanie Owens; Katharina Pahnke; Maxence Paul; Frank Pavia; Leopoldo D. Pena; Brian Peters; Frederic Planchon; Helene Planquette; Catherine Pradoux; Viena Puigcorbé; Paul Quay; Fabien Queroue; Amandine Radic; S. Rauschenberg; Mark Rehkämper; Robert Rember; Tomas Remenyi; Joseph A. Resing; Joerg Rickli; Sylvain Rigaud; Micha J.A. Rijkenberg; Stephen Rintoul; Laura F. Robinson; Montserrat Roca-Martí; Valenti Rodellas; Tobias Roeske; John M. Rolison; Mark Rosenberg; Saeed Roshan; Michiel M. Rutgers van der Loeff; Evgenia Ryabenko; Mak A. Saito; Lesley A. Salt; Virginie Sanial; Geraldine Sarthou; Christina Schallenberg; Ursula Schauer; Howie Scher; Christian Schlosser; Bernhard Schnetger; Peter Scott; Peter N. Sedwick; Igor Semiletov; Rachel Shelley; Robert M. Sherrell; Alan M. Shiller; Daniel M. Sigman; Sunil Kumar Singh; Hans A. Slagter; Emma Slater; William M. Smethie; Helen Snaith; Yoshiki Sohrin; Bettina Sohst; Jeroen E. Sonke; Sabrina Speich; Reiner Steinfeldt; Gillian Stewart; Torben Stichel; Claudine H. Stirling; Johnny Stutsman; Gretchen J. Swarr; James H. Swift; Alexander Thomas; Kay Thorne; Claire P. Till; Ralph Till; Ashley T. Townsend; Emily Townsend; Robyn Tuerena; Benjamin S. Twining; Derek Vance; Sue Velazquez; Celia Venchiarutti; Maria Villa-Alfageme; Sebastian M. Vivancos; Antje H.L. Voelker; Bronwyn Wake; Mark J. Warner; Ros Watson; Evaline van Weerlee; M. Alexandra Weigand; Yishai Weinstein; Dominik Weiss; Andreas Wisotzki; E. Malcolm S. Woodward; Jingfeng Wu; Yingzhe Wu; Kathrin Wuttig; Neil Wyatt; Yang Xiang; Ruifang C. Xie; Zichen Xue; Hisayuki Yoshikawa; Jing Zhang; Pu Zhang; Ye Zhao; Linjie Zheng; Xin-Yuan Zheng; Moritz Zieringer; Louise A. Zimmer; Patrizia Ziveri; Patricia Zunino; Cheryl Zurbrick
  Chemical Geology, 493, 210, 223, Elsevier B.V., 2018, [Peer-reviewed]
  English, Scientific journal
• Dynamics of particulate and dissolved organic and inorganic phosphorus during the peak and declining phase of an iron-induced phytoplankton bloom in the eastern subarctic Pacific
  Takeshi Yoshimura; Jun Nishioka; Hiroshi Ogawa; Atsushi Tsuda
  JOURNAL OF MARINE SYSTEMS, 177, 1, 7, Jan. 2018, [Peer-reviewed]
  English, Scientific journal
• Phytoplankton community responses to iron and CO2 enrichment in different biogeochemical regions of the Southern Ocean
  Hisashi Endo; Hiroshi Hattori; Tsubasa Mishima; Gen Hashida; Hiroshi Sasaki; Jun Nishioka; Koji Suzuki
  Polar Biology, 41, 3, 397, Springer Verlag, 01 Nov. 2017, [Peer-reviewed]
  English, Scientific journal
• Phytoplankton community responses to iron and CO2 enrichment in different biogeochemical regions of the Southern Ocean
  Hisashi Endo; Hiroshi Hattori; Tsubasa Mishima; Gen Hashida; Hiroshi Sasaki; Jun Nishioka; Koji Suzuki
  POLAR BIOLOGY, 40, 11, 2143, 2159, Nov. 2017, [Peer-reviewed]
  English, Scientific journal
• Dissolved iron distribution in the western and central subarctic Pacific: HNLC water formation and biogeochemical processes
  Jun Nishioka; Hajime Obata
  Limnology and Oceanography, 62, 5, 2004, 2022, Wiley Blackwell, 01 Sep. 2017, [Peer-reviewed]
  English, Scientific journal
• Dissolved iron distribution in the western and central subarctic Pacific: HNLC water formation and biogeochemical processes
  Jun Nishioka; Hajime Obata
  LIMNOLOGY AND OCEANOGRAPHY, 62, 5, 2004, 2022, Sep. 2017, [Peer-reviewed]
  English, Scientific journal
• Distribution of Dissolved Zinc in the Western and Central Subarctic North Pacific
  Taejin Kim; Hajime Obata; Jun Nishioka; Toshitaka Gamo
  GLOBAL BIOGEOCHEMICAL CYCLES, 31, 9, 1454, 1468, Sep. 2017, [Peer-reviewed]
  English, Scientific journal
• Evaluation of the biogeochemical impact of iron-rich shelf water to the Green Belt in the southeastern Bering Sea
  T. Tanaka; I. Yasuda; K. Kuma; J. Nishioka
  CONTINENTAL SHELF RESEARCH, 143, 130, 138, Jul. 2017, [Peer-reviewed]
  English, Scientific journal
• Geographic Distribution of Ammonia-Oxidizing Archaea along the Kuril Islands in the Western Subarctic Pacific
  Hongmei Jing; Shunyan Cheung; Xiaomin Xia; Koji Suzuki; Jun Nishioka; Hongbin Liu
  FRONTIERS IN MICROBIOLOGY, 8, Jun. 2017, [Peer-reviewed]
  English, Scientific journal
• Dissolved iron and zinc in Sagami Bay and the Izu-Ogasawara Trench
  Hajime Obata; Jun Nishioka; Taejin Kim; Kazuhiro Norisuye; Shigenobu Takeda; Yohei Wakuta; Toshitaka Gamo
  JOURNAL OF OCEANOGRAPHY, 73, 3, 333, 344, Jun. 2017, [Peer-reviewed]
  English, Scientific journal
• Estimation of ocean primary production from satellite remote sensing
  Toru Hirawake; Shintaro Takao; Koji Suzuki; Jun Nishioka; Yutaka W. Watanabe; Tomonori Isada
  Oceanography in Japan, 26, 3, 65, 77, The Oceanographic Society of Japan, 15 May 2017
  Scientific journal
• Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific
  Takuya Nakanowatari; Tomohiro Nakamura; Keisuke Uchimoto; Jun Nishioka; Humio Mitsudera; Masaaki Wakatsuchi
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 122, 5, 4364, 4391, May 2017, [Peer-reviewed]
  English, Scientific journal
• Observations of frazil ice formation and upward sediment transport in the Sea of Okhotsk: A possible mechanism of iron supply to sea ice
  Masato Ito; Kay I. Ohshima; Yasushi Fukamachi; Genta Mizuta; Yoshimu Kusumoto; Jun Nishioka
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 122, 2, 788, 802, Feb. 2017, [Peer-reviewed]
  English, Scientific journal
• 衛星による海洋基礎生産力の推定
  平譯 享; 高尾信太郎; 鈴木光次; 西岡 純; 渡邉 豊; 伊佐田 智規
  海の研究, 26, 3, -, -, 2017, [Peer-reviewed]
• 北太平洋亜寒帯における鉄の供給過程
  小畑 元; 金 泰辰; 西岡 純
  海の研究, 26, 3, 79, 93, 2017, [Peer-reviewed]
• Novel method for low level Sr-90 activity detection in seawater by combining oxalate precipitation and chelating resin extraction
  Hirofumi Tazoe; Hajime Obata; Masatoshi Tomita; Shinya Namura; Jun Nishioka; Takeyasu Yamagata; Zin'ichi Karube; Masatoshi Yamada
  GEOCHEMICAL JOURNAL, 51, 2, 193, 197, 2017, [Peer-reviewed]
  English, Scientific journal
• Bio-availability of iron derived from subarctic first-year sea ice
  Naoya Kanna; Jun Nishioka
  MARINE CHEMISTRY, 186, 189, 197, Nov. 2016, [Peer-reviewed]
  English, Scientific journal
• Iron in sea ice: Review & new insights
  D. Lannuzel; M. Vancoppenolle; P. Van Der Merwe; J. De Jong; K. M. Meiners; M. Grotti; J. Nishioka; V. Schoemann
  Elementa, 4, BioOne, 27 Oct. 2016, [Peer-reviewed]
  English
• Migration of the FDNPP-derived Cs-134 and Cs-137 along with Ra-226 and Ra-228 concentrations across the northwestern North Pacific Ocean
  M. Inoue; Y. Shirotani; S. Nagao; H. Kofuji; Y. N. Volkov; J. Nishioka
  JOURNAL OF ENVIRONMENTAL RADIOACTIVITY, 162, 33, 38, Oct. 2016, [Peer-reviewed]
  English, Scientific journal
• The conservative behavior of dissolved organic carbon in surface waters of the southern Chukchi Sea, Arctic Ocean, during early summer
  Kazuki Tanaka; Nobuyuki Takesue; Jun Nishioka; Yoshiko Kondo; Atsushi Ooki; Kenshi Kuma; Toru Hirawake; Youhei Yamashita
  SCIENTIFIC REPORTS, 6, Sep. 2016, [Peer-reviewed]
  English, Scientific journal
• Observations of frazil ice formation and sediment upward transport off the northeast coast of Sakhalin
  Ito, M; K. I. Ohshima; J. Nishioka; Y. Kusumoto; Y. Fukamachi
  Proceedings of the 31th International Symposium on Okhotsk Sea & Sea Ice, 124, 127, Feb. 2016
  English, International conference proceedings
• べーリング海南東部陸棚縁辺域での潮汐混合と溶存鉄輸送
  田中雄大; 安田一郎; 久万健志; 西岡純; 田中祐希; 大西広二; 上野洋路; 増島雅親
  月刊海洋 号外, 58, 47, 55, 2016
  Japanese, Scientific journal
• Application of an in situ fluorometer to determine the distribution of fluorescent organic matter in the open ocean
  Y. Yamashita; C. -J. Lu; H. Ogawa; J. Nishioka; H. Obata; H. Saito
  MARINE CHEMISTRY, 177, 298, 305, Dec. 2015, [Peer-reviewed]
  English, Scientific journal
• The GEOTRACES Intermediate Data Product 2014
  Edward Mawji; Reiner Schlitzer; Elena Masferrer Dodas; Cyril Abadie; Wafa Abouchami; Robert F. Anderson; Oliver Baars; Karel Bakker; Mark Baskaran; Nicholas R. Bates; Katrin Bluhm; Andrew Bowie; Johann Bown; Marie Boye; Edward A. Boyle; Pierre Branellec; Kenneth W. Bruland; Mark A. Brzezinski; Eva Bucciarelli; Ken Buesseler; Edward Butler; Pinghe Cai; Damien Cardinal; Karen Casciotti; Joaquin Chaves; Hai Cheng; Fanny Chever; Thomas M. Church; Albert S. Colman; Tim M. Conway; Peter L. Croot; Gregory A. Cutter; Hein J. W. de Baar; Gregory F. de Souza; Frank Dehairs; Feifei Deng; Huong Thi Dieu; Gabriel Dulaquais; Yolanda Echegoyen-Sanz; R. Lawrence Edwards; Eberhard Fahrbach; Jessica Fitzsimmons; Martin Fleisher; Martin Frank; Jana Friedrich; Francois Fripiat; Stephen J. G. Galer; Toshitaka Gamo; Ester Garcia Solsona; Loes J. A. Gerringa; Jose Marcus Godoy; Santiago Gonzalez; Emilie Grossteffan; Mariko Hatta; Christopher T. Hayes; Maija Iris Heller; Gideon Henderson; Kuo-Fang Huang; Catherine Jeandel; William J. Jenkins; Seth John; Timothy C. Kenna; Maarten Klunder; Sven Kretschmer; Yuichiro Kumamoto; Patrick Laan; Marie Labatut; Francois Lacan; Phoebe J. Lam; Delphine Lannuzel; Frederique le Moigne; Oliver J. Lechtenfeld; Maeve C. Lohan; Yanbin Lu; Pere Masque; Charles R. McClain; Christopher Measures; Rob Middag; James Moffett; Alicia Navidad; Jun Nishioka; Abigail Noble; Hajime Obata; Daniel C. Ohnemus; Stephanie Owens; Frederic Planchon; Catherine Pradoux; Viena Puigcorbe; Paul Quay; Amandine Radic; Mark Rehkaemper; Tomas Remenyi; Micha J. A. Rijkenberg; Stephen Rintoul; Laura F. Robinson; Tobias Roeske; Mark Rosenberg; Michiel Rutgers van der Loeff; Evgenia Ryabenko; Mak A. Saito; Saeed Roshan; Lesley Salt; Geraldine Sarthou; Ursula Schauer; Peter Scott; Peter N. Sedwick; Lijuan Sha; Alan M. Shiller; Daniel M. Sigman; William Smethie; Geoffrey J. Smith; Yoshiki Sohrin; Sabrina Speich; Torben Stichel; Johnny Stutsman; James H. Swift; Alessandro Tagliabue; Alexander Thomas; Urumu Tsunogai; Benjamin S. Twining; Hendrik M. van Aken; Steven van Heuven; Jan van Ooijen; Evaline van Weerlee; Celia Venchiarutti; Antje H. L. Voelker; Bronwyn Wake; Mark J. Warner; E. Malcolm S. Woodward; Jingfeng Wu; Neil Wyatt; Hisayuki Yoshikawa; Xin-Yuan Zheng; Zichen Xue; Moritz Zieringer; Louise A. Zimmer
  MARINE CHEMISTRY, 177, 1, 8, Dec. 2015, [Peer-reviewed]
  English, Scientific journal
• Vertical segregation and population structure of ontogenetically migrating copepods Neocalanus cristatus, N-flemingeri, N-plumchrus, and Eucalanus bungii during the ice-free season in the Sea of Okhotsk
  Atsushi Tsuda; Hiroaki Saito; Hiromi Kasai; Jun Nishioka; Takeshi Nakatsuka
  JOURNAL OF OCEANOGRAPHY, 71, 3, 271, 285, Jun. 2015, [Peer-reviewed]
  English, Scientific journal
• Methods for biogeochemical studies of sea ice: The state of the art, caveats, and recommendations
  Lisa A. Miller; Francois Fripiat; Brent G.T. Else; Jeff S. Bowman; Kristina A. Brown; R. Eric Collins; Marcela Ewert; Agneta Fransson; Michel Gosselin; Delphine Lannuzel; Klaus M. Meiners; Christine Michel; Jun Nishioka; Daiki Nomura; Stathys Papadimitriou; Lynn M. Russell; Lise Lotte Sørensen; David N. Thomas; Jean-Louis Tison; Maria A. van Leeuwe; Martin Vancoppenolle; Eric W. Wolff; Jiayun Zhou
  Elementa: Science of the Anthropocene, 3, 000038, 000038, University of California Press, 23 Jan. 2015, [Peer-reviewed]
  Scientific journal
• Sampling and onboard analytical methods for determining subnanomolar concentrations of zinc in seawater
  Taejin Kim; Hajime Obata; Toshitaka Gamo; Jun Nishioka
  LIMNOLOGY AND OCEANOGRAPHY-METHODS, 13, 1, 30, 39, Jan. 2015, [Peer-reviewed]
  English, Scientific journal
• Organic matter production response to CO2 increase in open subarctic plankton communities: Comparison of six microcosm experiments under iron-limited and -enriched bloom conditions
  Takeshi Yoshimura; Koji Sugie; Hisashi Endo; Koji Suzuki; Jun Nishioka; Tsuneo Ono
  DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, 94, 1, 14, Dec. 2014, [Peer-reviewed]
  English, Scientific journal
• Laterally spreading iron, humic-like dissolved organic matter and nutrients in cold, dense subsurface water of the Arctic Ocean
  Nanako Hioki; Kenshi Kuma; Yuichirou Morita; Ryouhei Sasayama; Atsushi Ooki; Yoshiko Kondo; Hajime Obata; Jun Nishioka; Youhei Yamashita; Shigeto Nishino; Takashi Kikuchi; Michio Aoyama
  SCIENTIFIC REPORTS, 4, Oct. 2014, [Peer-reviewed]
  English, Scientific journal
• Dissolved organic phosphorus production and decomposition during open ocean diatom blooms in the subarctic Pacific
  Takeshi Yoshimura; Jun Nishioka; Hiroshi Ogawa; Kenshi Kuma; Hiroaki Saito; Atsushi Tsuda
  MARINE CHEMISTRY, 165, 46, 54, Oct. 2014, [Peer-reviewed]
  English, Scientific journal
• Application of chemical tracers to an estimate of benthic denitrification in the Okhotsk Sea
  Masanori Ito; Yutaka W. Watanabe; Masahito Shigemitsu; Shinichi S. Tanaka; Jun Nishioka
  JOURNAL OF OCEANOGRAPHY, 70, 5, 415, 424, Oct. 2014, [Peer-reviewed]
  English, Scientific journal
• Community structure of mesozooplankton in the western part of the Sea of Okhotsk in summer
  Hiroshi Itoh; Jun Nishioka; Atsushi Tsuda
  PROGRESS IN OCEANOGRAPHY, 126, 224, 232, Aug. 2014, [Peer-reviewed]
  English
• Internal tides and turbulent mixing observed in the Bussol Strait
  Yuki Tanaka; Ichiro Yasuda; Satoshi Osafune; Takahiro Tanaka; Jun Nishioka; Yuri N. Volkov
  PROGRESS IN OCEANOGRAPHY, 126, 98, 108, Aug. 2014, [Peer-reviewed]
  English
• Simulation of high concentration of iron in dense shelf water in the Okhotsk Sea
  Keisuke Uchimoto; Tomohiro Nakamura; Jun Nishioka; Humio Mitsudera; Kazuhiro Misumi; Daisuke Tsumune; Masaaki Wakatsuchi
  PROGRESS IN OCEANOGRAPHY, 126, 194, 210, Aug. 2014, [Peer-reviewed]
  English
• Quantitative evaluation of iron transport processes in the Sea of Okhotsk
  Jun Nishioka; Takeshi Nakatsuka; Kazuya Ono; Yu. N. Volkov; Alexey Scherbinin; Takayuki Shiraiwa
  PROGRESS IN OCEANOGRAPHY, 126, 180, 193, Aug. 2014, [Peer-reviewed]
  English
• Biogeochemical and physical processes in the Sea of Okhotsk and the linkage to the Pacific Ocean Preface
  Jun Nishioka; Humio Mitsudera; Ichiro Yasuda; Hongbin Liu; Takeshi Nakatsuka; Yuri N. Volkov
  PROGRESS IN OCEANOGRAPHY, 126, 1, 7, Aug. 2014, [Peer-reviewed]
  English
• Chemical evidence for the origin of the cold water belt along the northeastern coast of Hokkaido
  Kenshi Kuma; Ryohei Sasayama; Nanako Hioki; Yuichiroh Morita; Yutaka Isoda; Tohru Hirawake; Keiri Imai; Takafumi Aramaki; Tomohiro Nakamura; Jun Nishioka; Naoto Ebuchi
  JOURNAL OF OCEANOGRAPHY, 70, 4, 377, 387, Aug. 2014, [Peer-reviewed]
  English, Scientific journal
• Iron and macro-nutrient concentrations in sea ice and their impact on the nutritional status of surface waters in the southern Okhotsk Sea
  Naoya Kanna; Takenobu Toyota; Jun Nishioka
  PROGRESS IN OCEANOGRAPHY, 126, 44, 57, Aug. 2014, [Peer-reviewed]
  English
• Direct breaking of large-amplitude internal waves in the Urup Strait
  Sachihiko Itoh; Yuki Tanaka; Satoshi Osafune; Ichiro Yasuda; Masahiro Yagi; Hitoshi Kaneko; Shunsuke Konda; Jun Nishioka; Yuri. N. Volkov
  PROGRESS IN OCEANOGRAPHY, 126, 109, 120, Aug. 2014, [Peer-reviewed]
  English
• Spatial variability in iron nutritional status of large diatoms in the Sea of Okhotsk with special reference to the Amur River discharge
  K. Suzuki; A. Hattori-Saito; Y. Sekiguchi; J. Nishioka; M. Shigemitsu; T. Isada; H. Liu; R. M. L. McKay
  BIOGEOSCIENCES, 11, 9, 2503, 2517, 2014, [Peer-reviewed]
  English, Scientific journal
• Dissolved iron and zinc in the Sagami Bay and Izu-Ogasawara Trench area
  Obata Hajime; Nishioka Jun; Kim Taejin; Norisuye Kazuhiro; Takeda Shigenobu; Wakuta Yohei; Gamo Toshitaka
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 61, 67, 67, GEOCHEMICAL SOCIETY OF JAPAN, 2014
  Japanese, 国際GEOTRACES計画の進行に伴い、海洋における微量元素の研究は急速に進みつつある。日本では、2013年度から運用を開始した学術研究船新青丸に国際GEOTRACES計画レベルのクリーン採水が可能なシステムが導入された。この新しい採水システムを用いて、実際にクリーンな海水が採取できるかどうかを検討した。さらに、相模湾、伊豆小笠原海溝域で得られた海水中の溶存鉄・亜鉛の結果から、日本近海における鉄・亜鉛の挙動についての議論を行った。
• Disitribution of hydrogen peroxide in the Arctic Ocean
  Kondo Yoshiko; Obata Hajime; Ooki Atsushi; Yamashita Youhei; Nishioka Jun; Kuma Kenshi
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 61, 199, 199, GEOCHEMICAL SOCIETY OF JAPAN, 2014
  Japanese, 過酸化水素は、大気中ではその酸性度を高める物質として、海水中では微量金属の酸化還元反応や溶存有機物の循環および微生物群集の生物生産に影響を与える因子として重要な物質である。海水中の過酸化水素のソースとシンクは光化学反応や生物活動と密接に関わるためその挙動は動的で一様ではない。これまで、海洋における過酸化水素の分布は外洋域・沿岸域様々な海域で報告されているが、北極海におけるデータは限られている。本発表では、これまでの海洋における過酸化水素の分布動態に関するレビューを含め、GRENE北極海研究プロジェクト（http://www.nipr.ac.jp/grene/）の一環として2013年夏期に実施された北海道大学練習船おしょろ丸航海で得られた北極海（チャクチ海）における過酸化水素の分布について紹介する。
• Biogeochemical study using icebreaker for sea ice and polar oceans
  Nomura Daiki; Nishioka Jun; Kawai Michiyo; Ooki Atsushi; Tamura Takeshi
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 61, 132, 132, GEOCHEMICAL SOCIETY OF JAPAN, 2014
  Japanese, 我が国におけるこれまでの海氷研究は、主に物理過程を明らかにすることに主眼が置かれ、海氷の物理的動態を実測や衛星観測、モデリングから明らかにする研究が精力的に進められてきた。一方で、海氷に関わる化学過程や生物過程に関しては、これまで十分な研究が展開されていなかった。海氷の生成が生み出す独特の海洋循環を介して、他海域の物質循環にまで多大な影響を与えているシステムの存在が指摘されており、これらのシステムを理解するためには、海氷の存在する時期から消失していくまでの詳細な時系列観測、ポリニヤにおける海氷の生成が起こっている現場での観測が欠かせない。また、地球規模で起こっている環境変動を理解するためには、通年観測する必要があり、海洋研究プラットフォームを生物地球化学分野で最大限活用すると同時に、厳冬期でも観測が続けられる本格的な観測研究用の砕氷船が欠かせないだろう。
• Distribution and transport processes of detritus from the Amur River in the northwestern shelf of the Okhotsk Sea revealed by the Sr and Nd isotopes and chemical compositions.
  Yasuda Tomoki; Asahara Yoshihiro; Ichikawa Ryo; Nakatsuka Takeshi; Nishioka Jun; Minami Hideki; Nagao Seiya
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 61, 88, 88, GEOCHEMICAL SOCIETY OF JAPAN, 2014
  Japanese, オホーツク海は、生物生産の高い海域として知られている。中でも特に、北西陸棚域及びサハリン島東岸において高い生物生産を誇っており、世界最大級の河川であるアムール川から供給される栄養塩及び溶存態鉄の供給によってこの海域の生物生産が支えられていることが指摘されてきた。しかしながら、アムール川供給物質がオホーツク海をどのように輸送され、分布しているかは明らかにされていないこなかった。そこで、本研究ではアムール川懸濁物及びオホーツク海懸濁物、表層堆積物に含まれる珪酸塩砕屑物成分のSr、Nd同位体比及び微量・希土類元素組成分析からを行うことで、アムール川供給砕屑物の分布及び輸送過程の解明を試みた。本研究の結果、オホーツク海北西陸棚域の砕屑物は3つの供給源物質によって構成されており、また北西陸棚域のSakhalinsky Bay及びサハリン島東岸の生物生産の高い海域にアムール川供給物質が輸送されていることが明らかになった。
• Fe/Al ratios of suspended particulate matter from intermediate water in the Okhotsk Sea: Implications for long-distance lateral transport of particulate Fe
  Masahito Shigemitsu; J. Nishioka; Y. W. Watanabe; Y. Yamanaka; T. Nakatsuka; Y. N. Volkov
  Marine Chemistry, 157, 41, 48, 20 Dec. 2013, [Peer-reviewed]
  English, Scientific journal
• Synergistic effects of pCO₂ and iron availability on nutrient consumption ratio of the Bering Sea phytoplankton community
  K. Sugie; H. Endo; K. Suzuki; J. Nishioka; H. Kiyosawa; T. Yoshimura
  Biogeosciences, 10, 10, 6309, Copernicus {GmbH}, Oct. 2013, [Peer-reviewed]
• Impacts of elevated CO2 on particulate and dissolved organic matter production: microcosm experiments using iron-deficient plankton communities in open subarctic waters
  Takeshi Yoshimura; Koji Suzuki; Hiroshi Kiyosawa; Tsuneo Ono; Hiroshi Hattori; Kenshi Kuma; Jun Nishioka
  JOURNAL OF OCEANOGRAPHY, 69, 5, 601, 618, Oct. 2013, [Peer-reviewed]
  English, Scientific journal
• Intensive mixing along an island chain controls oceanic biogeochemical cycles
  Jun Nishioka; Takeshi Nakatsuka; Yutaka W. Watanabe; Ichiro Yasuda; Kenshi Kuma; Hiroshi Ogawa; Naoto Ebuchi; Alexey Scherbinin; Yuri N. Volkov; Takayuki Shiraiwa; Masaaki Wakatsuchi
  GLOBAL BIOGEOCHEMICAL CYCLES, 27, 3, 920, 929, Sep. 2013, [Peer-reviewed]
  English, Scientific journal
• Report of Working Group 22 on Iron Supply and its Impact on Biogeochemistry and Ecosystems in the North Pacific Ocean
  S. Takeda; F. Chai; J. Nishioka
  PICES Scientific Report, 42, 1, 60, Jul. 2013
  English, Research institution
• Availability of particulate Fe to phytoplankton in the Sea of Okhotsk
  Koji Sugie; Jun Nishioka; Kenshi Kuma; Yuri N. Volkov; Takeshi Nakatsuka
  Marine Chemistry, 152, 20, 31, 20 May 2013, [Peer-reviewed]
  English, Scientific journal
• Influence of Amur River discharge on phytoplankton photophysiology in the Sea of Okhotsk during late summer
  Tomonori Isada; Takahiro Iida; Hongbin Liu; Sei-Ichi Saitoh; Jun Nishioka; Takeshi Nakatsuka; Koji Suzuki
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 118, 4, 1995, 2013, Apr. 2013, [Peer-reviewed]
  English, Scientific journal
• Synergistic effects of pCO₂ and iron availability on nutrient consumption ratio of the Bering Sea phytoplankton community
  K. Sugie; H. Endo; K. Suzuki; J. Nishioka; H. Kiyosawa; T. Yoshimura
  Biogeosciences Discussions, 10, 3, 4331, Copernicus {GmbH}, Mar. 2013
• Growth stimulation and inhibition of natural phytoplankton communities by model organic ligands in the western subarctic Pacific
  Yoshiko Kondo; Shigenobu Takeda; Jun Nishioka; Mitsuhide Sato; Hiroaki Saito; Koji Suzuki; Ken Furuya
  JOURNAL OF OCEANOGRAPHY, 69, 1, 97, 115, Feb. 2013, [Peer-reviewed]
  English, Scientific journal
• Resuspension and transport processes of Amur River particulate iron settling in the northwestern continental shelf of the Okhotsk Sea: Application of Fe and Nd isotope tracers to sediments and suspend
  Yasuda Tomoki; Asahara Yoshihiro; Ichikawa Ryo; Nakatsuka Takeshi; Nishioka Jun; Minami Hideki; Nagao Seiya; Tanimizu Masaharu; Kicheol Shin; Kono Makiko
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 60, 212, GEOCHEMICAL SOCIETY OF JAPAN, 2013
  Japanese, HNLC海域の一つである西部北太平洋亜寒帯域 (WSP) は生物生産が高い海域であり、鉄の供給源としては主にユーラシア大陸からの大気ダストによる供給が考えられてきた。一方、溶存鉄濃度が海洋よりも高い河川は、河口域の塩析で溶存鉄の大部分が沈殿するため、WSPなど外洋の鉄の供給源としては重要視されてこなかった。しかし近年、河川起源の鉄がWSPへの鉄の供給源となる可能性が高まっている。WSP縁海のオホーツク海に流入するアムール川の河口域の北西陸棚域は潮汐混合が激しく、沈殿した粒子態鉄が固定されにくい環境にある。再懸濁された粒子態鉄は、陸棚底層水塊の高密度陸棚水(DSW)によってオホーツク海中層水(OSIW)へと運び出され、WSPまで輸送されている可能性がある。本研究では鉄・ネオジム同位体比から粒子態鉄の輸送過程を検証することを試みた。その結果、アムール川起源の粒子態鉄がオホーツク海南域の千島列島周辺まで輸送されている可能性が高いことが明らかになった。
• Influence of Amur River discharge on phytoplankton photophysiology in the Sea of Okhotsk during late summer
  Tomonori Isada; Takahiro Iida; Hongbin Liu; Sei-Ichi Saitoh; Jun Nishioka; Takeshi Nakatsuka; Koji Suzuki
  Journal of Geophysical Research: Oceans, 118, 4, 1995, 2013, Blackwell Publishing Ltd, 2013, [Peer-reviewed]
  English, Scientific journal
• Synergistic effects of p CO2 and iron availability on nutrient consumption ratio of the Bering Sea phytoplankton community
  K. Sugie; H. Endo; K. Suzuki; J. Nishioka; H. Kiyosawa; T. Yoshimura
  Biogeosciences, 10, 10, 6309, 6321, 2013
  English, Scientific journal
• Evidence of an extensive spread of hydrothermal dissolved iron in the Indian Ocean
  Jun Nishioka; Hajime Obata; Daisuke Tsumune
  EARTH AND PLANETARY SCIENCE LETTERS, 361, 26, 33, Jan. 2013, [Peer-reviewed]
  English, Scientific journal
• Decadal time evolution of oceanic uptake of anthropogenic carbon in the Okhotsk Sea
  Yutaka W. Watanabe; Jun Nishioka; Takeshi Nakatsuka
  GEOPHYSICAL RESEARCH LETTERS, 40, 2, 322, 326, Jan. 2013, [Peer-reviewed]
  English, Scientific journal
• Development of a one-dimensional ecosystem model including the iron cycle applied to the Oyashio region, western subarctic Pacific
  M. Shigemitsu; T. Okunishi; J. Nishioka; H. Sumata; T. Hashioka; M. N. Aita; S. L. Smith; N. Yoshie; N. Okada; Y. Yamanaka
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 117, Jun. 2012, [Peer-reviewed]
  English, Scientific journal
• Vertical turbulent iron flux sustains the Green Belt along the shelf break in the southeastern Bering Sea
  T. Tanaka; I. Yasuda; K. Kuma; J. Nishioka
  GEOPHYSICAL RESEARCH LETTERS, 39, Apr. 2012, [Peer-reviewed]
  English, Scientific journal
• Development of a one-dimensional ecosystem model including the iron cycle applied to the Oyashio region, western subarctic Pacific
  M. Shigemitsu; T. Okunishi; J. Nishioka; H. Sumata; T. Hashioka; M. N. Aita; S. L. Smith; N. Yoshie; N. Okada; Y. Yamanaka
  Journal of Geophysical Research: Oceans, 117, 6, Blackwell Publishing Ltd, 2012, [Peer-reviewed]
  English, Scientific journal
• Mechanisms controlling dissolved iron distribution in the North Pacific: A model study
  K. Misumi; D. Tsumune; Y. Yoshida; K. Uchimoto; T. Nakamura; J. Nishioka; H. Mitsudera; F. O. Bryan; K. Lindsay; J. K. Moore; S. C. Doney
  Journal of Geophysical Research: Biogeosciences, 116, 3, G03005, Blackwell Publishing Ltd, 01 Sep. 2011, [Peer-reviewed]
  English, Scientific journal
• Strong vertical mixing in the Urup Strait
  Sachihiko Itoh; Ichiro Yasuda; Masahiro Yagi; Satoshi Osafune; Hitoshi Kaneko; Jun Nishioka; Takeshi Nakatsuka; Yuri N. Volkov
  GEOPHYSICAL RESEARCH LETTERS, 38, Aug. 2011, [Peer-reviewed]
  English, Scientific journal
• Mechanisms controlling dissolved iron distribution in the North Pacific: A model study
  K. Misumi; D. Tsumune; Y. Yoshida; K. Uchimoto; T. Nakamura; J. Nishioka; H. Mitsudera; F. O. Bryan; K. Lindsay; J. K. Moore; S. C. Doney
  JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES, 116, doi:10.1029/2010JG001541, Jul. 2011, [Peer-reviewed]
  English, Scientific journal
• Simulations of chlorofluorocarbons in and around the Sea of Okhotsk: Effects of tidal mixing and brine rejection on the ventilation
  K. Uchimoto; T. Nakamura; J. Nishioka; H. Mitsudera; M. Yamamoto-Kawai; K. Misumi; D. Tsumune
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 116, C02034, doi:10.1029/2010JG001541, Feb. 2011, [Peer-reviewed]
  English, Scientific journal
• Oceanic iron supply mechanisms which support the spring diatom bloom in the Oyashio region, western subarctic Pacific
  Jun Nishioka; Tsuneo Ono; Hiroaki Saito; Keiichiro Sakaoka; Takeshi Yoshimura
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 116, Feb. 2011, [Peer-reviewed]
  English, Scientific journal
• 気候工学（ジオエンジニアリング)
  杉山昌広; 西岡 純; 藤原正智
  天気, 58, 7, 3, 24, 2011, [Peer-reviewed]
  Japanese, Scientific journal
• Full depth section profile of dissolved iron in the Indian Ocean
  Nishioka Jun; Obata Hajime; Tsumune Daisuke
  Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 160, 160, GEOCHEMICAL SOCIETY OF JAPAN, 2011
  海洋における微量金属元素は、供給過程、物理的な海洋循環と混合、生物生産、粒状・溶存物質などと密接に関連し、分布や循環が支配されている。また、観測には厳密なクリーン技術と分析技術が必要となる。これまで実施されてきた微量金属元素の観測は、その困難さから、十分な空間スケールを網羅しておらず、各大洋における微量金属の分布の全貌を捉えるには至っていない。GEOTRACES計画では、大洋縦断（横断）観測を実施し、微量元素および同位体の全海洋の分布とそれを支配する要因を明らかにすることを目的としている。2009年11月から2010年1月に、国際GEOTRACES計画の一環として、白鳳丸KH09-5次航海でインド洋の縦断観測が実施された。本報告では、Key Parameterの一つである溶存鉄濃度の船上分析の結果を報告する。
• Simulations of chlorofluorocarbons in and around the Sea of Okhotsk: Effects of tidal mixing and brine rejection on the ventilation
  K. Uchimoto; T. Nakamura; J. Nishioka; H. Mitsudera; M. Yamamoto-Kawai; K. Misumi; D. Tsumune
  Journal of Geophysical Research: Oceans, 116, 2, Blackwell Publishing Ltd, 2011, [Peer-reviewed]
  English, Scientific journal
• Oceanic iron supply mechanisms which support the spring diatom bloom in the Oyashio region, western subarctic Pacific
  Jun Nishioka; Tsuneo Ono; Hiroaki Saito; Keiichiro Sakaoka; Takeshi Yoshimura
  Journal of Geophysical Research: Oceans, 116, 2, Blackwell Publishing Ltd, 2011, [Peer-reviewed]
  English, Scientific journal
• Simulations of chlorofluorocarbons in and around the Sea of Okhotsk: Effects of tidal mixing and brine rejection on the ventilation
  Uchimoto, K; T. Nakamura; J. Nishioka; H. Mitsudera; M. Yamamoto-Kawai; K. Misumi; D. Tsumune
  Journal of Geophysical Research, 116, C2, C02034, 2011, [Peer-reviewed]
  English, Scientific journal
• Iron nutritional status of the phytoplankton assemblage in the Okhotsk Sea during summer
  Takeshi Yoshimura; Jun Nishioka; Takeshi Nakatsuka
  DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, 57, 11, 1454, 1464, Nov. 2010, [Peer-reviewed]
  English, Scientific journal
• Impacts of elevated CO2 on organic carbon dynamics in nutrient depleted Okhotsk Sea surface waters
  Takeshi Yoshimura; Jun Nishioka; Koji Suzuki; Hiroshi Hattori; Hiroshi Kiyosawa; Yutaka W. Watanabe
  JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 395, 1-2, 191, 198, Nov. 2010, [Peer-reviewed]
  English, Scientific journal
• Significant portion of dissolved organic Fe complexes in fact is Fe colloids
  Marie Boye; Jun Nishioka; Peter Croot; Patrick Laan; Klaas R. Timmermans; Volker H. Strass; Shigenobu Takeda; Hein J. W. de Baar
  MARINE CHEMISTRY, 122, 1-4, 20, 27, Oct. 2010, [Peer-reviewed]
  English, Scientific journal
• Fine- and microstructure observations in the Urup Strait, Kuril Islands, during August 2006
  S. Itoh; I. Yasuda; T. Nakatsuka; J. Nishioka; Y. N. Volkov
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 115, C08004, doi:10.1029/2009JC005629., Aug. 2010, [Peer-reviewed]
  English, Scientific journal
• Fluorescence characteristics of dissolved organic matter in the deep waters of the Okhotsk Sea and the northwestern North Pacific Ocean
  Youhei Yamashita; Rose M. Cory; Jun Nishioka; Kenshi Kuma; Eiichiro Tanoue; Rudolf Jaffe
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 57, 16, 1478, 1485, Aug. 2010
  English, Scientific journal
• Status and trends of the Sea of Okhotsk region, 2003-2008
  Radchenko, V.I; Dulepova, E.P; Figurkin, A.L; Katugin, O.N; Ohshima, K; Nishioka, J; McKinnell, S.M; Tsoy, A.T
  Marine Ecosystems of the North Pacific Ocean, 2003-2008. PICES Special Publication 4, 393 p., 393, May 2010, [Peer-reviewed]
• Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk
  Daiki Nomura; Jun Nishioka; Mats A. Granskog; Andreas Krell; Sumito Matoba; Takenobu Toyota; Hiroshi Hattori; Kunio Shirasawa
  MARINE CHEMISTRY, 119, 1-4, 1, 8, Apr. 2010, [Peer-reviewed]
  English, Scientific journal
• Iron Deficiency in Micro-Sized Diatoms in the Oyashio Region of the Western Subarctic Pacific during Spring
  Ai Hattori-Saito; Jun Nishioka; Tsuneo Ono; R. Michael L. Mckay; Koji Suzuki
  JOURNAL OF OCEANOGRAPHY, 66, 1, 105, 115, Feb. 2010, [Peer-reviewed]
  English, Scientific journal
• Response of lower trophic organisms to nutrient input and effects on carbon budget: A mesocosm experiment
  Atsushi Tsuda; Kimio Fukami; Hiroshi Kiyosawa; Koji Suzuki; Shigenobu Takeda; Jun Nishioka; Masayuki Takahashi; Keith Johnson; Chi-Shing Wong
  Plankton and Benthos Research, 5, 4, 144, 155, 2010
  English, Scientific journal
• Iron deficiency in micro-sized diatoms in the Oyashio region of the Western subarctic Pacific during spring
  Ai Hattori-Saito; Jun Nishioka; Tsuneo Ono; R. Michael L. McKay; Koji Suzuki
  Journal of Oceanography, 66, 1, 105, 115, Jan. 2010
  English, Scientific journal
• Fine- and microstructure observations in the Urup Strait, Kuril Islands, during August 2006
  S. Itoh; I. Yasuda; T. Nakatsuka; J. Nishioka; Y. N. Volkov
  Journal of Geophysical Research: Oceans, 115, 8, Blackwell Publishing Ltd, 2010, [Peer-reviewed]
  English, Scientific journal
• The annual cycle of surface iron and the source of iron supporting the spring diatom bloom in the Oyashio region, western subarctic Pacific
  Nishioka J; Ono T; Saito H; Sakaoka K; Yoshimura T; Matoba
  AGU Fall Meeting Abstracts, 1, 0331, 2010, [Peer-reviewed]
• Community compositions of Bacteria and Archaea in the Sea of Okhotsk during summer
  Hongmei Jing; Hongbin Liu; Koji Suzuki; Rumi Sohrin; Jun Nishioka
  AQUATIC MICROBIAL ECOLOGY, 61, 2, 191, 204, 2010, [Peer-reviewed]
  English, Scientific journal
• Temporal and spatial variations in photosynthetic physiology of diatoms during the spring bloom in the western subarctic Pacific
  Naoki Yoshie; Koji Suzuki; Akira Kuwata; Jun Nishioka; Hiroaki Saito
  MARINE ECOLOGY PROGRESS SERIES, 399, 39, 52, 2010, [Peer-reviewed]
  English, Scientific journal
• Physical behaviors of the iron-fertilized patch in SEEDS II
  Daisuke Tsumune; Jun Nishioka; Akifumi Shimamoto; Yutaka W. Watanabe; Takafumi Aramaki; Yukihiro Nojiri; Shigenobu Takeda; Atsushi Tsuda; Takaki Tsubono
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2948, 2957, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• Behaviors of dissolved and particulate Co, Ni, Cu, Zn, Cd and Pb during a mesoscale Fe-enrichment experiment (SEEDS II) in the western North Pacific
  Seiji Nakatsuka; Kei Okamura; Shigenobu Takeda; Jun Nishioka; M. Lutfi Firdaus; Kazuhiro Norisuye; Yoshiki Sohrin
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2822, 2838, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• Community structure and photosynthetic physiology of phytoplankton in the northwest subarctic Pacific during an in situ iron fertilization experiment (SEEDS-II)
  Koji Suzuki; Hiroaki Saito; Tomonori Isada; Ai Hattori-Saito; Hiroshi Kiyosawa; Jun Nishioka; R. Michael. L. McKay; Akira Kuwata; Atsushi Tsuda
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2733, 2744, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• Dynamics and elemental stoichiometry of carbon, nitrogen, and phosphorus in particulate and dissolved organic pools during a phytoplankton bloom induced by in situ iron enrichment in the western subarctic Pacific (SEEDS-II)
  Takeshi Yoshimura; Hiroshi Ogawa; Keiri Imai; Takafumi Aramaki; Yukihiro Nojiri; Jun Nishioka; Atsushi Tsuda
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2863, 2874, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• Biogeochemical cycling of N and Si during the mesoscale iron-enrichment experiment in the western subarctic Pacific (SEEDS-II)
  Hiroaki Saito; Atsushi Tsuda; Yukihiro Nojiri; Takafumi Aramaki; Hiroshi Ogawa; Takeshi Yoshimura; Keiri Imai; Isao Kudo; Jun Nishioka; Tsuneo Ono; Koji Suzuki; Shigenobu Takeda
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2852, 2862, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• The response of the virus community to the SEEDS II mesoscale iron fertilization
  Julie L. Higgins; Isao Kudo; Jun Nishioka; Atsushi Tsuda; Steven W. Wilhelm
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2788, 2795, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• Changes in iron concentrations and bio-availability during an open-ocean mesoscale iron enrichment in the western subarctic Pacific, SEEDS II
  Jun Nishioka; Shigenobu Takeda; Yoshiko Kondo; Hajime Obata; Takashi Doi; Daisuke Tsumune; C. S. Wong; W. Keith Johnson; N. Sutherland; Atsushi Tsuda
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 56, 26, 2796, 2809, Dec. 2009, [Peer-reviewed]
  English, Scientific journal
• Impacts of elevated CO2 on phytoplankton community composition and organic carbon dynamics in nutrient-depleted Okhotsk Sea surface waters
  Yoshimura T.; Nishioka J.; Suzuki K.; Hattori H.; Kiyosawa H.; Watanabe Y. W.
  Biogeosciences Discussions, 6, 2, 4143, 4163, Copernicus Publications, 15 Apr. 2009
  English, Impacts of the increasing CO2 in seawater (i.e. ocean acidification) on phytoplankton physiology may have various and potentially adverse effects on phytoplankton dynamics and the carbon cycle. We conducted a CO2 manipulation experiment in the Sea of Okhotsk in summer 2006 to investigate the response of the phytoplankton assemblage and dynamics of organic carbon. During the 14-day incubation of nutrient-depleted surface water with a natural phytoplankton assemblage under 150, 280, 480, and 590μatm pCO2, the relative abundance of fucoxanthin-containing phytoplankton such as diatoms and prymnesiophytes decreased with increasing pCO2. The amount of DOC accumulation also decreased with increasing pCO2, while differences in POC accumulation between the treatments were small and did not show a clear trend with the pCO2. Change in the phytoplankton community composition under different pCO2 conditions will alter the organic carbon dynamics as found in the present experiment. Compared to results in the literature from nutrient-replete conditions indicating a potential enhancement of phytoplankton production with elevated pCO2, the present results indicated a different physiological response of phytoplankton under nutrient-depleted conditions. These results indicate that the continuing increase in atmospheric CO2 can significantly affect the structure of marine ecosystems and carbon cycle in nutrient-depleted subpolar surface waters.
• Phytoplankton growth and microzooplankton grazing in the Sea of Okhotsk during late summer of 2006
  Hongbin Liu; Koji Suzuki; Jun Nishioka; Rumi Sohrin; Takeshi Nakatsuka
  DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, 56, 4, 561, 570, Apr. 2009
  English, Scientific journal
• Size dependence of iron solubility of Asian mineral dust particles
  Atsushi Ooki; Jun Nishioka; Tsuneo Ono; Shinichiro Noriki
  Journal of Geophysical Research Atmospheres, 114, 3, Blackwell Publishing Ltd, 16 Feb. 2009, [Peer-reviewed]
  English, Scientific journal
• Size dependence of iron solubility of Asian mineral dust particles
  Atsushi Ooki; Jun Nishioka; Tsuneo Ono; Shinichiro Noriki
  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 114, D03202, doi:10.1029/2008JD010804--, Feb. 2009
  English, Scientific journal
• Increases of alkalinity and pH in the Okhotsk Sea during the 1990s and 2000s
  Watanabe; Y. W,, J; Nishioka, S; Shigemitsu, A; Mimura; T. Nakatsuka
  Geophys. Res. Lett, doi:10.1029/2009GL038520, 2009, [Peer-reviewed]
  English, Scientific journal
• Organic iron(III) complexing ligands during an iron enrichment experiment in the western subarctic North Pacific
  Yoshiko Kondo; Shigenobu Takeda; Jun Nishioka; Hajime Obata; Ken Furuya; William Keith Johnson; C. S. Wong
  GEOPHYSICAL RESEARCH LETTERS, 35, 12, doi:10.1029/2008GL033354--, Jun. 2008
  English, Scientific journal
• Evidence for the grazing hypothesis: Grazing reduces phytoplankton responses of the HNLC ecosystem to iron enrichment in the western subarctic pacific (SEEDS II)
  Atsushi Tsuda; Shigenobu Takeda; Hiroaki Saito; Jun Nishioka; Isao Kudo; Yukihiro Nojiri; Koji Suzuki; Mitsuo Uematsu; Mark L. Wells; Daisuke Tsumune; Takeshi Yoshimura; Tatsuo Aono; Takafumi Aramaki; William P. Cochlan; Maki Hayakawa; Keiri Imai; Tomoshi Isada; Yoko Iwamoto; William K. Johnson; Sohiko Kameyama; Shungo Kato; Hiroshi Kiyosawa; Yoshiko Kondo; Maurice Levasseur; Ryuji J. Machida; Ippei Nagao; Fumiko Nakagawa; Takahiro Nakanish; Seiji Nakatsuka; Akira Narita; Yoshifumi Noiri; Hajime Obata; Hiroshi Ogawa; Kenji Oguma; Tsuneo Ono; Tomofumi Sakuragi; Motoki Sasakawa; Mitsuhide Sato; Akifumi Shimamoto; Hyoe Takata; Charles G. Trick; Yutaka W. Watanabe; Chi Shing Wong; Naoki Yoshie
  JOURNAL OF OCEANOGRAPHY, 63, 6, 983, 994, Dec. 2007
  English, Scientific journal
• Iron supply to the western subarctic Pacific: Importance of iron export from the Sea of Okhotsk
  Jun Nishioka; Tsuneo Ono; Hiroaki Saito; Takeshi Nakatsuka; Shigenobu Takeda; Takeshi Yoshimura; Koji Suzuki; Kenshi Kuma; Shigeto Nakabayashi; Daisuke Tsumune; Humio Mitsudera; W. Keith Johnson; Atsushi Tsuda
  Journal of Geophysical Research: Oceans, 112, 10, Blackwell Publishing Ltd, 08 Oct. 2007, [Peer-reviewed]
  English, Scientific journal
• Iron supply to the western subarctic Pacific: Importance of iron export from the Sea of Okhotsk
  Jun Nishioka; Tsuneo Ono; Hiroaki Saito; Takeshi Nakatsuka; Shigenobu Takeda; Takeshi Yoshimura; Koji Suzuki; Kenshi Kuma; Shigeto Nakabayashi; Daisuke Tsumune; Humio Mitsudera; W. Keith Johnson; Atsushi Tsuda
  JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 112, C10, Oct. 2007, [Peer-reviewed]
  English, Scientific journal
• Distributions of particulate and dissolved organic and inorganic phosphorus in North Pacific surface waters
  Takeshi Yoshimura; Jun Nishioka; Hiroaki Saito; Shigenobu Takeda; Atsushi Tsuda; Mark L. Wells
  MARINE CHEMISTRY, 103, 1-2, 112, 121, Jan. 2007, [Peer-reviewed]
  English, Scientific journal
• Effect of high iron concentrations on iron uptake and growth of a coastal diatom Chaetoceros sociale
  Shouei Iwade; Kenshi Kuma; Yutaka Isoda; Masahiko Yoshida; Isao Kudo; Jun Nishioka; Koji Suzuki
  AQUATIC MICROBIAL ECOLOGY, 43, 2, 177, 191, Jun. 2006, [Peer-reviewed]
  English, Scientific journal
• Role of heterotrophic dinoflagellate Gyrodinium sp. in the fate of an iron induced diatom bloom
  Hiroaki Saito; Takashi Ota; Koji Suzuki; Jun Nishioka; Atsushi Tsuda
  Geophysical Research Letters, 33, 9, 16 May 2006
  English, Scientific journal
• Speciation of Iron and the Role of Iron for Phytoplankton Growth in the Subarctic North Pacific(The Paper for the 2005 Okada Prize of the Oceanographic Society of Japan)
  NISHIOKA Jun; Jun Nishioka; Central Research Institute of Electric Power Industry:(Present address)Pan-Okhotsk research center Institute of low temperature science Hokkaido University
  Oceanography in Japan, 15, 1, 19, 36, 日本海洋学会, 2006, [Peer-reviewed]
  Japanese, サイズ分画測定法を用いて外洋海域における鉄の存在状態を研究した。その結果, 従来"溶存態"と定義されてきた画分中にはコロイド状鉄が含まれており, 海水中の植物プランクトンによる鉄の利用過程や地球化学的鉄の循環を理解するために重要な画分であることを示した。また, 国際共同プロジェクトとして, 北太平洋亜寒帯域の西部および東部で現場鉄散布実験を行ない, 大気から供給される鉄が他海域より多いと考えられる西部海域においても, 鉄の不足が生物生産を制限する要因であることを明らかにした。さらに, 西部海域が鉄制限海域になるプロセスとして, 供給された鉄が, 速やかに植物プランクトンが利用しづらい形態に変化してしまうことが重要であることを示した。海洋における鉄の生物地球化学的な研究は, 自然海域における生物生産の諸過程を理解するためには欠かせない分野と成りつつある。本稿では, 著者がこれまでに展開してきた, 海水中の鉄の存在状態と鉄が生物生産に果たす役割に関する研究の一部を紹介した。A size-fractionation technique was used for observation and experimental studies to investigate iron speciation in oceanic seawater. The results showed that we need to consider the existence of colloidal Fe in the dissolved fraction to better understand Fe availability and the Fe biogeochemical cycle in the ocean. Moreover, an Fe-enrichment experiment in the western subarctic Pacific clearly demonstrated that iron availability controls phytoplankton growth in this region, even though there is a higher iron supply from atmospheric dust here than in the eastern region. Our results also suggested that Fe transformation is an important process in understanding how phytoplankton becomes iron limited in the western subarctic Pacific. Research on the biogeochemistry of Fe is becoming indispensable in understanding the processes of phytoplankton growth in a natural open-ocean environment. In this paper, the research results on Fe speciation and the role of Fe in phytoplankton growth in oceanic seawater are presented.
• Effect of high iron level on iron uptake and growth of marine phytoplankton
  Iwade, S; K. Kuma; Y. Isoda; M. Yoshida; I. Kudo; J. Nishioka; K. Suzuki
  Aquatic Microbial Ecology, 43, 177, 191, 2006, [Peer-reviewed]
  English, Scientific journal
• Phytoplankton community response to Fe and temperature gradients in the NE (SERIES) and NW (SEEDS) subarctic Pacific Ocean
  Isao Kudo; Yoshifumi Noiri; Jun Nishioka; Yousuke Taira; Hiroshi Kiyosawa; Atsushi Tsuda
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 53, 20-22, 2201, 2213, 2006, [Peer-reviewed]
  English, Scientific journal
• Mesozooplankton response to iron enrichment during the diatom bloom and bloom decline in SERIES (NE Pacific)
  Atsushi Tsuda; Hiroaki Saito; Jun Nishioka; Tsuneo Ono; Yoshifumi Noiri; Isao Kudo
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 53, 20-22, 2281, 2296, 2006, [Peer-reviewed]
  English, Scientific journal
• Nutrient and phytoplankton dynamics during the stationary and declining phases of a phytoplankton bloom induced by iron-enrichment in the eastern subarctic Pacific
  Hiroaki Saito; Atsushi Tsuda; Yukihiro Nojiri; Jun Nishioka; Shigenobu Takeda; Hiroshi Kiyosawa; Isao Kudo; Yoshifumi Noiri; Tsuneo Ono; Yousuke Taira; Koji Suzuki; Takeshi Yoshimura; Philip W. Boyd
  DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 53, 20-22, 2168, 2181, 2006, [Peer-reviewed]
  English, Scientific journal
• Synthesis of iron fertilization experiments: From the iron age in the age of enlightenment
  Hein J.W. de Baar; Philip W. Boyd; Kenneth H. Coale; Michael R. Landry; Atsushi Tsuda; Philipp Assmy; Dorothee C.E. Bakker; Yann Bozec; Richard T. Barber; Mark A. Brzezinski; Ken O. Buesseler; Marie Boyé; Peter L. Croot; Frank Gervais; Maxim Y. Gorbunov; Paul J. Harrison; William T. Hiscock; Patrick Laan; Christiane Lancelot; Cliff S. Law; Maurice Levasseur; Adrian Marchetti; Frank J. Millero; Jun Nishioka; Yukihiro Nojiri; Tim van Oijen; Ulf Riebesell; Micha J.A. Rijkenberg; Hiroaki Saito; Shingenobu Takeda; Klaas R. Timmermans; Marcel J.W. Veldhuis; Anya M. Waite; Chi-Shing Wong
  Journal of Geophysical Research C: Oceans, 110, 9, 1, 24, 08 Sep. 2005, [Peer-reviewed]
  English
• Major deviations of iron complexation during 22 days of a mesoscale iron enrichment in the open Southern Ocean
  M Boye; J Nishioka; PL Croot; P Laan; KR Timmermans; HJW de Baar
  MARINE CHEMISTRY, 96, 3-4, 257, 271, Sep. 2005, [Peer-reviewed]
  English, Scientific journal
• Changes in the concentration of iron in different size fractions during an iron enrichment experiment in the open Southern Ocean
  J Nishioka; S Takeda; HJW de Baar; PL Croot; M Boye; P Laan; KR Timmermans
  MARINE CHEMISTRY, 95, 1-2, 51, 63, May 2005, [Peer-reviewed]
  English, Scientific journal
• Spatial and temporal distribution of Fe(II) and H2O2 during EisenEx, an open ocean mescoscale iron enrichment
  PL Croot; P Laan; J Nishioka; Strass, V; B Cisewski; M Boye; KR Timmermans; RG Bellerby; L Goldson; P Nightingale; HJW de Baar
  MARINE CHEMISTRY, 95, 1-2, 65, 88, May 2005, [Peer-reviewed]
  English, Scientific journal
• Dynamics of trace metals during the subarctic Pacific iron experiment for ecosystem dynamics study (SEEDS2001)
  M Kinugasa; T Ishita; Y Sohrin; K Okamura; S Takeda; J Nishioka; A Tsuda
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 129, 147, 2005
  English
• Physical behavior of the SEEDS iron-fertilized patch by sulphur hexafluoride tracer release
  D Tsumune; J Nishioka; A Shimamoto; S Takeda; A Tsuda
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 111, 127, 2005, [Peer-reviewed]
  English, Scientific journal
• Effect of iron enrichment on the dynamics of transparent exopolymer particles in the western subarctic Pacific
  N Ramaiah; S Takeda; K Furuya; T Yoshimura; J Nishioka; T Aono; Y Nojiri; K Imai; Kudo, I; H Saito; A Tsuda
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 253, 261, 2005, [Peer-reviewed]
  English, Scientific journal
• Responses of diatoms to iron-enrichment (SEEDS) in the western subarctic Pacific, temporal and spatial comparisons
  A Tsuda; H Kiyosawa; A Kuwata; M Mochizuki; N Shiga; H Saito; S Chiba; K Imai; J Nishioka; T Ono
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 189, 205, 2005, [Peer-reviewed]
  English, Scientific journal
• Noiri,Y., I. Kudo, H. Kiyosawa, J. Nishioka, and A. Tsuda, (2005) Iron and Temperatue, two factors influencing phytoplankton species composition in the western subarctic Pacific Ocean. Progress in Oceanography 64. 149-166.*
  2005
• Influence of iron and temperature on growth, nutrient utilization ratios and phytoplankton species composition in the western subarctic Pacific Ocean during the SEEDS experiment
  Y Noiri; Kudo, I; H Kiyosawa; J Nishioka; A Tsuda
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 149, 166, 2005, [Peer-reviewed]
  English, Scientific journal
• Mesozooplankton responses to iron-fertilization in the western subarctic Pacific (SEEDS2001)
  A Tsuda; H Saito; J Nishioka; T Ono
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 237, 251, 2005, [Peer-reviewed]
  English, Scientific journal
• Primary productivity and nitrogenous nutrient assimilation dynamics during the Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study
  Kudo, I; Y Noiri; K Imai; Y Nojiri; J Nishioka; A Tsuda
  PROGRESS IN OCEANOGRAPHY, 64, 2-4, 207, 221, 2005, [Peer-reviewed]
  English, Scientific journal
• Enhanced carbohydrate production by Southern Ocean phytoplankton in response to in situ iron fertilization
  T van Oijen; MJW Veldhuis; MY Gorbunov; J Nishioka; MA van Leeuwe; HJW de Baara
  MARINE CHEMISTRY, 93, 1, 33, 52, Jan. 2005, [Peer-reviewed]
  English, Scientific journal
• Spatial variability of iron in the surface water of the northwestern North Pacific Ocean
  H Takata; K Kuma; S Iwade; Y Yamajyoh; A Yamaguchi; S Takagi; K Sakaoka; Y Yamashita; E Tanoue; T Midorikawa; K Kimura; J Nishioka
  MARINE CHEMISTRY, 86, 3-4, 139, 157, May 2004, [Peer-reviewed]
  English, Scientific journal
• The decline and fate of an iron-induced subarctic phytoplankton bloom
  PW Boyd; CS Law; CS Wong; Y Nojiri; A Tsuda; M Levasseur; S Takeda; R Rivkin; PJ Harrison; R Strzepek; J Gower; RM McKay; E Abraham; M Arychuk; J Barwell-Clarke; W Crawford; D Crawford; M Hale; K Harada; K Johnson; H Kiyosawa; Kudo, I; A Marchetti; W Miller; J Needoba; J Nishioka; H Ogawa; J Page; M Robert; H Saito; A Sastri; N Sherry; T Soutar; N Sutherland; Y Taira; F Whitney; SKE Wong; T Yoshimura
  NATURE, 428, 6982, 549, 553, Apr. 2004, [Peer-reviewed]
  English, Scientific journal
• Sources and fate of organic matter in Khung Krabaen Bay (Thailand) as traced by delta C-13 and C/N atomic ratios
  W Thimdee; G Deein; C Sangrungruang; J Nishioka; K Matsunaga
  WETLANDS, 23, 4, 729, 738, Dec. 2003, [Peer-reviewed]
  English, Scientific journal
• Iron(III) hydroxide solubility and humic-type fluorescent organic matter in the deep water column of the Okhotsk Sea and the northwestern North Pacific Ocean
  H Tani; J Nishioka; K Kuma; H Takata; Y Yamashita; E Tanoue; T Midorikawa
  DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, 50, 9, 1063, 1078, Sep. 2003, [Peer-reviewed]
  English, Scientific journal
• Size-fractionated iron distributions and iron-limitation processes in the subarctic NW Pacific
  Jun Nishioka; Shigenobu Takeda; Isao Kudo; Daisuke Tsumune; Takeshi Yoshimura; Kenshi Kuma; Atsushi Tsuda
  GEOPHYSICAL RESEARCH LETTERS, 30, 14, Jul. 2003, [Peer-reviewed]
  English, Scientific journal
• A mesoscale iron enrichment in the western Subarctic Pacific induces a large centric diatom bloom
  A Tsuda; S Takeda; H Saito; J Nishioka; Y Nojiri; Kudo, I; H Kiyosawa; A Shiomoto; K Imai; T Ono; A Shimamoto; D Tsumune; T Yoshimura; T Aono; A Hinuma; M Kinugasa; K Suzuki; Y Sohrin; Y Noiri; H Tani; Y Deguchi; N Tsurushima; H Ogawa; K Fukami; K Kuma; T Saino
  SCIENCE, 300, 5621, 958, 961, May 2003, [Peer-reviewed]
  English, Scientific journal
• Grazing impact of microzooplankton on a diatom bloom in a mesocosm as estimated by pigment-specific dilution technique
  K Suzuki; A Tsuda; H Kiyosawa; S Takeda; J Nishioka; T Saino; M Takahashi; CS Wong
  JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 271, 1, 99, 120, May 2002, [Peer-reviewed]
  English, Scientific journal
• Multi-decadal decrease of net community production in western subarctic North Pacific
  T Ono; K Tadokoro; T Midorikawa; J Nishioka; T Saino
  GEOPHYSICAL RESEARCH LETTERS, 29, 8, 10.1029/2001 GL014332, Apr. 2002, [Peer-reviewed]
  English, Scientific journal
• Size-fractionated iron concentrations in the northeast Pacific Ocean: distribution of soluble and small colloidal iron
  J Nishioka; S Takeda; CS Wong; WK Johnson
  MARINE CHEMISTRY, 74, 2-3, 157, 179, May 2001, [Peer-reviewed]
  English, Scientific journal
• Change in the concentrations of iron in different size fractions during a phytoplankton bloom in controlled ecosystem enclosures
  J Nishioka; S Takeda; CS Wong
  JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 258, 2, 237, 255, Apr. 2001, [Peer-reviewed]
  English, Scientific journal
• Evaluation of Fertilization Effects of Deep Ocean Water on Surface Water Phytoplankton community by Mesocosm Experiments in Subtropical Ocean
  IKEYA Tohru; NAKAYA Seiji; FUKABORI Yoshio; NISHIOKA Jun; TAKEDA Shigenobu; KAWANOBE Kyoko; TAKAHASH Masayuki Mac
  Deep Ocean Water Research, 2, 1, 73, 86, DEEP OCEAN WATER APPLICATION SOCIETY, 2001, [Peer-reviewed]
  English, Scientific journal, Responses of phytoplankton community in subtropical surface waters by the addition of deep ocean water (DOW) were examined under natural sunlight. Two culture experiments were carried out in September and October, 1999; DOW collected from ca 800 m was mixed into the surface water at high concentrations (13 and 27% (v/v)) in 9 l polycarbonate bottles and incubated in an outdoor incubator (EXP 1), and DOW from ca 400 m was daily added to ca 800 l of surface water at low concentrations (0.6 and 1.2%) in polyethylene bags moored in a harbor (EXP 2). Both experiments showed that the DOW enrichment, equivalent to more than 0.15 μmol nitrate l^-1 day^-1, increased concentrations of chlorophyll a (Chl a) after a lag period of 5 to 7 days and reached maximum concentrations at 10 to 12 days after the start of the experiments. The maximum levels of Chl a were proportional to the total addition of nitrate; 1 mol nitrate = around 1.4 g Chl a. The specific rates of increase of Chl a concentration were also in proportion to the amount of added DOW. Low Chl a share percentage of>2 μm fraction, such as 15% of total Chl a, in the initial surface water was changed to more than 70%. These results indicated that the DOW enrichment effectively enhanced the growth of nano- and microphytoplankton. Within those phytoplankton, some diatom species, being extremely less abundant in the subtropical surface water, increased rapidly. Results indicate primary production even in subtropical ocean can be raised effectively to enhance effective phytoplankton community for fish production by the DOW enrichment. Since the enhancement of the phytoplankton growth by the DOW enrichment was observed after 5 to 7 days, DOW should be added to keep at least 0.1 μmol nitrate l^-1 day^-1 during the lag period for initialing the fertilization effects in the subtropical waters.
• Change in the concentrations of iron in different size fractions during growth of the oceanic diatom Chaetoceros sp.: importance of small colloidal iron
  J Nishioka; S Takeda
  MARINE BIOLOGY, 137, 2, 231, 238, Sep. 2000, [Peer-reviewed]
  English, Scientific journal
• Riverine input of bioavailable iron supporting phytoplankton growth in Kesennuma Bay (Japan)
  K Matsunaga; J Nishioka; K Kuma; K Toya; Y Suzuki
  WATER RESEARCH, 32, 11, 3436, 3442, Nov. 1998, [Peer-reviewed]
  English, Scientific journal
• Size-fractionated iron concentrations and Fe(III) hydroxide solubilities in various coastal waters
  K Kuma; A Katsumoto; J Nishioka; K Matsunaga
  ESTUARINE COASTAL AND SHELF SCIENCE, 47, 3, 275, 283, Sep. 1998, [Peer-reviewed]
  English, Scientific journal
• Controls on iron(III) hydroxide solubility in seawater: The influence of pH and natural organic chelators
  K Kuma; J Nishioka; K Matsunaga
  LIMNOLOGY AND OCEANOGRAPHY, 41, 3, 396, 407, May 1996, [Peer-reviewed]
  English, Scientific journal
• Determination of the freshwater origin of Coastal Oyashio Water using humic-like fluorescence in dissolved organic matter
  Yu Mizuno; Jun Nishioka; Takahiro Tanaka; Yuya Tada; Koji Suzuki; Yuta Tsuzuki; Atsuko Sugimoto; Youhei Yamashita
  Journal of Oceanography, 74, 5, 509, 521, [Peer-reviewed]
  English, Scientific journal

• 海氷に含まれる鉄の生物利用能に関する研究
  漢那 直也; 西岡 純, 低温科学, 82, 93, 101, Mar. 2024
• Coastal Monitoring, Shipboard Observations, and Mooring Observations around the Shiretoko Area
  中村知裕; 野別貴博; 嶋田宏; 美坂正; 美坂正; 西岡純; 藤尾伸三; 柳本大吾; 三谷曜子; 山村織生; 三寺史夫, 低温科学, 82, 2024
• 夏季オホーツク海北海道沿岸の水塊:タタール海峡水・海底混合層・北部根室海峡に注目して
  中村知裕; 植田純生; 野別貴博; 美坂正; 三谷曜子; 西岡純; 三寺史夫, 日本水産学会大会講演要旨集(CD-ROM), 2023, 2023
• Year-round observation of the East Sakhalin Coastal Current using a mooring system
  FUJIO Shinzou; YANAGIMOTO Daigo; NAKAMURA Tomohiro; NISHIOKA Jun; MITSUDERA Humio, Proceedings of the International Symposium on Okhotsk Sea & Polar Oceans, 37th, 2023
• Decadal vision in oceanography 2021 : Mid-latitude ocean
  橋濱 史典; 纐纈 慎也; 近藤 能子; 佐々木 克徳; 杉本 周作; 高橋 一生; 長井 健容; 西岡 純; 林田 博士; 平井 惇也, 海の研究, 30, 5, 131, 158, Nov. 2021
  日本海洋学会, Japanese
• Decadal vision in oceanography 2021: Coastal oceans
  木田新一郎; 栗原晴子; 大林由美子; 川合美千代; 近藤能子; 西岡純, 海の研究, 30, 5, 2021
• Spatial distribution and size composition of the genus Clione (Pteropoda: Gymnosomata) in the southern part of the Okhotsk Sea in winter
  山崎友資; 西岡純; 豊田威信; 桑原尚司; 高橋邦夫, 日本貝類学会大会研究発表要旨集, 2020 (Web), 2020
• 千島ブッソル海峡において観測された流速変動特性
  柳本大吾; 安田一郎; 藤尾伸三; 田中雄大; 後藤恭敬; 西岡純, 日本海洋学会大会講演要旨集, 2020, 2020
• 天皇海山列北端を通過する深層流
  藤尾伸三; 柳本大吾; 川口悠介; 安田一郎; 李根淙; 西岡純, 日本海洋学会大会講演要旨集, 2020, 2020
• アナディル海峡における冷水湧昇:ロシア船・「みらい」による現場観測と数値実験
  川口悠介; 西岡純; 西岡純; 西野茂人; 藤尾伸三; 藤原周; 李根淙; 柳本大吾; 三寺史夫; 安田一郎, 日本海洋学会大会講演要旨集, 2020, 2020
• 湿原起源の鉄の海洋への輸送プロセスの解明
  加藤寛己; 芳村毅; 伊佐田智規; 黒田寛; 白岩孝行; 長尾誠也; 西岡純; 村山愛子; 山下洋平, 日本海洋学会大会講演要旨集, 2020, 2020
• The water mass structure and nutrients distribution were revealed using colored dissolved organic matter (CDOM) in the western north Pacifiic Ocean and the northern Bering Sea
  大井田穣示; 平譯享; 山下洋平; 阿部泰人; 西岡純; 和賀久朋; 野村大樹, 日本地球惑星科学連合大会予稿集(Web), 2020, 2020
• Observation of coastal regions using satellite ocean color remote sensing
  平譯享; 山下洋平; 鈴木光次; 西岡純, 日本地球惑星科学連合大会予稿集(Web), 2020, 2020
• 有色溶存有機物(CDOM)の光学的特性から見る西部北太平洋及び北部ベーリング海の水塊構造と栄養塩分布
  大井田穣示; 平譯享; 平譯享; 山下洋平; 阿部泰人; 西岡純; 西岡純; 和賀久朋; 和賀久朋; 野村大樹; 野村大樹, 日本海洋学会大会講演要旨集, 2020, 2020
• 有色溶存有機物(CDOM)の光吸収係数により分類したベーリング海北部およびチュクチ海南部の水塊の分布
  平譯享; 平譯享; 大井田穣示; 和賀久朋; 和賀久朋; 山下洋平; 阿部泰人; 西岡純; 西岡純, 日本海洋学会大会講演要旨集, 2020, 2020
• 酸素安定同位体比を用いたベーリング海北部アナディール湾における高密度陸棚水形成の評価
  野村大樹; 野村大樹; 野村大樹; 阿部泰人; 平譯享; 平譯享; 大木淳之; 大木淳之; 山下洋平; 村山愛子; 小野数也; 西岡純; 西岡純, 日本海洋学会大会講演要旨集, 2020, 2020
• 北太平洋における中層水循環に伴う外来性溶存有機物の輸送
  山下洋平; 森雄太郎; 遠坂哲; 亀崎龍一; 後藤周史; 後藤周史; 西岡純; 馬場梨世; 馬場梨世; 安田一郎; 藤尾伸三; 平譯享; 大井田穣示; 小畑元; 小川浩史, 日本海洋学会大会講演要旨集, 2020, 2020
• ロシア船を用いた西部ベーリング海の観測研究-航海の概要-
  西岡純; 西岡純; 安田一郎; 平譯享; 平譯享; 小野数也; 村山愛子; 山下洋平; 李勃豊; 森雄太郎; 野村大樹; 野村大樹; 阿部泰人; 和賀久朋; 和賀久朋; 和賀久朋; 田副博文; 藤尾伸三; 柳本大吾; 川口悠介; 李根淙; 木村詩乃; 宋智暎; 島崎智広; 野口真希; 林央之; 宗林留美; 近藤拓斗; 三好友子; 三好友子; 岡崎裕典; CHEUNG Shun Yan; LIU Kailin; SCHERBININ A.; LIU Hongbin; 近藤能子; 角皆潤; 長尾誠也; 井上睦夫; 原田尚美; 小川浩史; 小畑元; 乙坂重嘉; 乙坂重嘉; 鈴木崇史; 鈴木光次; 渡辺豊; 亀山宗彦; 関宰; 深町康; 江淵直人; 大島慶一郎; 大島慶一郎; 三寺史夫; 若土正暁; VOLKOV Y. N., 日本海洋学会大会講演要旨集, 2020, 2020
• 大気/海洋を通じた北太平洋亜寒帯域への鉱物粒子輸送に関する研究~個別石英粒子のカソードルミネッセンス分析より~
  長島佳菜; 藤木徹一; 原田尚美; 西岡純, 日本地球化学会年会要旨集(Web), 65th, 2018
• 基礎生産量の季節性から推察される北太平洋亜寒帯域の栄養物質循環
  金子拓郎; 平譯享; 西岡純, 日本地球惑星科学連合大会予稿集(Web), 2018, ROMBUNNO.ACG41‐08 (WEB ONLY), 2018
  Japanese
• Strong vertical turbulent nitrate flux in the Kuroshio across the Tokara Strait and the Izu Ridge
  Tanaka T; Hasegawa D; Yasuda I; Tsuji H; Yanagimoto D; Fujio S; Goto Y; Ito S; Nishioka J; Saito R; Nishina K, JpGU-AGU Joint Meeting 2017 Abstracts, AOS15-P08, May 2017
  English, Summary international conference
• 海氷変動を軸とした両極の環境変動の解明
  田村岳史; 溝端浩平; 渡邉英嗣; 三瓶真; 山本正伸; 野村大樹; 西岡純; 渡邉豊; 末吉哲雄, 日本地球惑星科学連合大会予稿集(Web), 2017, 2017
• 西部北太平洋亜寒帯域における基礎生産量の季節性の経年変動
  金子拓郎; 平譯享; 西岡純, 日本地球惑星科学連合大会予稿集(Web), 2017, ROMBUNNO.ACG52‐07 (WEB ONLY), 2017
  Japanese
• 春季親潮・沿岸親潮水の光学的性質と海色クロロフィルa濃度推定への影響
  平譯享; 和賀久朋; 金子拓郎; 鈴木光次; 山下洋平; 西岡純, 日本地球惑星科学連合大会予稿集(Web), 2017, ROMBUNNO.ACG52‐06 (WEB ONLY), 2017
  Japanese
• GEOTRACES計画エンジン全開ヘ―躍進する微量元素海洋学―ベーリング海南東部陸棚縁辺域での潮汐混合と溶存鉄輸送
  田中雄大; 安田一郎; 久万健志; 西岡純; 田中祐希; 大西広二; 上野洋路; 増島雅親, 月刊海洋, 47‐55, 01 Nov. 2016
  Japanese
• ロシア船を用いた親潮源流域の観測研究―航海の概要と親潮上流の栄養物質分布―
  西岡純; 安田一郎; 小野数也; 中村知裕; 鈴木光次; 渡辺豊; 山下洋平; 平譯享; LIU Hongbin; 藤尾伸三; 柳本大吾; 田中雄大; 原田尚美; 関宰; 岡崎裕典; 長尾誠也; 井上睦夫; 小畑元; 田副博文; 小川浩史; 宗林留美; 三寺史夫; 江淵直人; 若土正暁; VOLKOV Y.N, 日本海洋学会大会講演要旨集, 2016, 107, Aug. 2016
  Japanese
• 鉄の海洋内循環におけるコロイド態画分の重要性 (総特集 微量元素・同位体の生物地球化学研究) -- (「微量元素海洋学」事始 : GEOTRACES計画)
  西岡 純; 武田 重信, 月刊地球 = Chikyu monthly : カラー版, 38, 6, 352, 357, Jun. 2016
  海洋出版, Japanese
• The role of Pacific marginal seas in linking adjacent land with ocean
  西岡純; 三寺史夫; 白岩孝行; 関宰; 中村知裕; 的場澄人; 江淵直人, 低温科学, 74, 175, 180, 31 Mar. 2016
  日本は，オホーツク海，日本海，東シナ海といった「縁辺海」と「北太平洋」に面しており，太平洋からみると縁辺海と大洋を隔てる列島の一部である．さらにベーリング海を含めたこれら北太平洋の縁辺海は，自然科学的視点からみても，人間活動の場として見ても多くの共通性と特異性を持ち合わせている．これらのすべての縁辺海には，大河川や，規模は小さいが数多くの中・小河川が流れ込むことで，陸域の影響が大きく現れる．これら河川を通じて陸からの物質を受け取り，縁辺海内部で起こる様々な物理的プロセスと生物的・化学的反応を介して物質循環が活発に起こっている場所である．これらの各縁辺海は，陸域の影響を大洋に伝える間の緩衝作用も担うと同時に，大洋の影響も強く受け，物質的にも暖流（黒潮）や寒流（親潮）で結ばれている．縁辺海の自然科学的な機能を明らかにすることは，東シナ海，日本海，オホーツク海を経由して，北太平洋へと至る，長大な物質循環システムを理解することに繋がる．本稿では，環オホーツク域の「陸海結合システム」という概念に焦点を当て，環オホーツク域で進めてきた研究で残されている課題と，日本の周辺領域も含めたさらに大きなスケールで陸海結合システムをとらえるための研究展開について記す．Linkage between land and ocean is one of important issue for understanding earth system, and marginal seas are a key place for this linkage. The South China Sea, the East China Sea, the Japan Sea, the Sea of Okhotsk and the Bering Sea are marginal seas located on the north/west rim of the Pacific Ocean. These marginal seas received strong influence from the land via large and small scale river discharge, which include human influence. The marginal seashave high productivity and active biogeochemical cycles relative to those in oceanic regions, which are controlled by individual local processes, such as fresh water discharge, interior current systems, tidal mixing, local upwelling, continental shelves interactions, sea ice production/melting, and flows through straits. Further, recent studies indicated that some of the marginal seas strongly influence to the Pacific Ocean on physical and biogeochemicalprocesses. Therefore, clarifying roles of the marginal seas for linkage between land and oceanic region is one of the major remaining issue for understanding whole Pacific Ocean. In this paper, we discuss remaining issue to understand not only pan-Okhotsk biogeochemical system but also the role of Pacific marginal seas in linking adjacent land with ocean., 低温科学第74巻編集委員会, Japanese
• オホーツク海における海氷が関わる鉄の供給過程 の解明
  漢那直也; 西岡純; 豊田威信, 低温科学, 74, 105, 114, Mar. 2016, [Peer-reviewed]
  Japanese, Introduction research institution
• 千島カムチャツカ海溝における深層流量の推定
  藤尾伸三; 柳本大吾; 安田一郎; 田中雄大; 後藤恭敬; 西岡純; VOLKOV Y., 日本海洋学会大会講演要旨集, 2016, 2016
• 千島ブッソル海峡での乱流観測:ロシア船マルタノフスキー観測から
  安田一郎; 田中雄大; 柳本大吾; 藤尾伸三; 後藤恭敬; 西岡純; VOLKOV Y., 日本海洋学会大会講演要旨集, 2016, 2016
• Iron biogeochemical cycle in the subarctic Pacific
  西岡 純; 小畑 元, 海洋. 号外 = Kaiyo monthly : カラー版, 58, 38, 46, 2016
  海洋出版, Japanese
• 海洋酸性化と温暖化の複合ストレスに因る亜寒帯北太平洋のプランクトン群集動態の変化
  杉江恒二; 亀山宗彦; 芳村毅; 内田裕; 西岡純; 原田尚美; 村田昌彦, 日本海洋学会大会講演要旨集, 2016, 2016
• 海氷変動を軸とした両極の環境変動の解明
  田村岳史; 溝端浩平; 渡邉英嗣; 三瓶真; 山本正伸; 野村大樹; 西岡純; 渡邉豊, 極域科学シンポジウム(Web), 7th, 2016
• 海氷変動を軸とした両極の環境変動の解明
  田村岳史; 溝端浩平; 渡邉英嗣; 三瓶真; 山本正伸; 野村大樹; 西岡純; 渡邉豊, 日本地球惑星科学連合大会予稿集(Web), 2016, 2016
• 季節海氷域における鉄の供給過程
  漢那直也; 西岡純, 月刊海洋, 31, 37, 2016
  Japanese, Introduction scientific journal
• Potential source areas of dissolved iron to dense shelf water in the Sea of Okhotsk
  内本 圭亮; 中村 知裕; 西岡 純; 三寺 史夫; 三角 和弘; 津旨 大輔; 若土 正暁, 低温科学, 74, 95, 104, 2016
  Recent observations have elucidated that a source region of iron to the northwestern North Pacific is the northern part of the shelf region in the Sea of Okhotsk, and that the iron is transported with dense shelf water (DSW). The high concentration of iron in DSW is successfully simulated. In this paper, we summarize the model of iron cycle in the Sea of Okhotsk, and discusses potential source regions of iron to DSW based on numerical experiments. In the experiments, the continental shelf in the Sea of Okhotsk is divided into 4 regions: the northwestern shelf (NW), the central part of the northern shelf (NC), the northeastern shelf (NE), and the other (OT). The experiments suggest that the contribution of NW to the high concentration of iron in DSW is the largest, and is followed by NC and OT. The contribution of NE is small, 低温科学第74巻編集委員会, Japanese
• Biogeochemical properties of seawater in Lützow-Holm Bay in February 2011 during the 52nd Japanese Antarctic Research Expedition
  Kunio T. TAKAHASHI; Tomomi R. TAKAMURA; Takahiro IIDA; Jun NISHIOKA; Tsuneo ODATE, JARE DATA REPORT (Marine Biology) = JARE DATA REPORT (Marine Biology), 51, 1, 8, Jul. 2015
  English
• Responses of marine organisms to ocean acidification, part 4-Incubation experiments using open ocean plankton communities-
  芳村毅; 杉江恒二; 鈴木光次; 西岡純, 電力中央研究所環境科学研究所研究報告, V13018, 25P, 3,1-19, Apr. 2014
  電力中央研究所, Japanese
• Biogeochemical data and chlorophyll a concentrations of phytoplankton during a cruise of the 53rd Japanese Antarctic Research Expedition in the austral summer of 2011-2012
  Takahashi Kunio T.; Iida Takahiro; Nishioka Jun; Odate Tsuneo, JARE data reports. Marine biology, 44, 1, 19, Mar. 2014
  National Institute of Polar Research, English
• Vertical section observation of dissolved iron in the Indian Ocean
  西岡 純; 小畑 元; 津旨 大輔, 海洋. 号外 = Kaiyo monthly : カラー版, 55, 59, 64, 2014
  海洋出版, Japanese
• 化学成分からみた宗谷暖流沖冷水帯水塊の起源
  久万健志; 笹山了平; 日置菜々子; 森田雄一朗; 磯田豊; 平譯享; 今井圭理; 荒巻能史; 中村知裕; 西岡純; 江淵直人, 日本海洋学会大会講演要旨集, 2013, 94, 30 Aug. 2013
  Japanese
• 生物地球化学過程に果たす環オホーツク圏の海洋循環・物質循環の役割 オホーツク海の鉄循環シミュレーション
  内本圭亮; 中村知裕; 西岡純; 三寺史夫; 三角和弘; 津旨大輔, 月刊海洋, 44, 9, 504, 510, 01 Sep. 2012
  Japanese
• 生物地球化学過程に果たす環オホーツク圏の海洋循環・物質循環の役割 北太平洋北西部における堆積物起源の鉄の輸送過程―数値モデルによる考察―
  三角和弘; 津旨大輔; 吉田義勝; 内本圭亮; 中村知裕; 西岡純; 三寺史夫, 月刊海洋, 44, 9, 496, 503, 01 Sep. 2012
  Japanese
• Distribution of mesozooplankton in the western Sea of Okhotsk : The origin of Clione limacina of the Hokkaido coast
  津田 敦; 西岡 純; 伊東 宏, 海洋と生物, 34, 1, 25, 33, Feb. 2012
  生物研究社, Japanese
• 南部オホーツク海域の海氷に含まれる栄養塩と鉄の定量的評価
  漢那直也; 西岡純; 村山愛子; 豊田威信, 月刊海洋, 44, 10, 517, 523, 2012
  Japanese, Introduction scientific journal
• 夏季オホーツク西部海域における動物プランクトンの分布
  海洋と生物, 198, 34, 25, 32, 2012
• 親潮域の生物生産を支える環オホーツク海域の物質循環
  海洋と生物, 198, 34, 10, 17, 2012
• 潮汐混合とオホーツク海・ベーリング海の物理・化学・生物過程―白鳳丸KH09‐4航海・おしょろ丸・クロモフ2006/2007シンセシス―オホーツク海物質循環モデリング
  内本圭亮; 中村知裕; 西岡純; 三寺史夫; 川合美千代; 三角和弘; 津旨大輔, 月刊海洋, 43, 11, 682, 687, 01 Nov. 2011
  Japanese
• 潮汐混合とオホーツク海・ベーリング海の物理・化学・生物過程―白鳳丸KH09‐4航海・おしょろ丸・クロモフ2006/2007シンセシス―親潮域・混合域の鉄濃度の季節的変動を支配するプロセス―海洋循環・潮汐混合・大気ダスト―
  西岡純; 的場澄人; 小埜恒夫; 齊藤宏明; 坂岡桂一郎, 月刊海洋, 43, 11, 648, 654, 01 Nov. 2011
  Japanese
• Oceanic iron supply mechanisms which support the spring diatom bloom in the Oyashio region, western subarctic Pacific (vol 116, C04007, 2011)
  Jun Nishioka; Tsuneo Ono; Hiroaki Saito; Keiichiro Sakaoka; Takeshi Yoshimura, JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 116, doi:10.1029/2010JC006321, Apr. 2011
  English, Others
• Climate Geoengineering
  SUGIYAMA Masahiro; NISHIOKA Jun; FUJIWARA Masatomo, 天気, 58, 7, 577, 598, 2011
  Climate geoengineering is defined as "deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change." The slow progress of greenhouse gas emissions reduction and a heightened recognition of the risk of dangerous global warming have led to increasing attention to this novel approach, although it cannot substitute for mitigation nor adaptation. The IPCC will review geoengineering as part of its fifth assessment report. There are two main categories of climate engineering options: carbon dioxide removal (CDR), which reduces the concentration of the atmospheric carbon dioxide, a primary cause of global warming; and solar radiation management (SRM) that reduces the incoming solar radiation, thereby cooling the earth system. An example of the CDR approach is to add iron to the ocean to increase photosynthesis. Amongst many proposed approaches, the most promising is arguably the stratospheric aerosol injection, an SRM option. Its physics is similar to that of global cooling following volcanic eruptions. Research has shown that it would be accompanied with undesired effects such as changes in precipitation patterns. The GeoMIP, an international effort to climate model intercomparison on this approach, has recently been launched. Though intended as a cure of global warming, climate geoengineering confronts the human society with a number of problems. It would require an international framework since, if conducted unilaterally, it would affect the global climate as a whole. In the short run, guidelines for experiments in the natural environment would be crucial, on which international discussions just commenced., 日本気象学会, Japanese
• アリューシャン列島海峡部における鉄供給過程と植物プランクトン増殖応答
  月刊海洋, 729, 2011
• 親潮域・混合域の鉄濃度の季節変動を支配するプロセス
  月刊海洋, 493, 143, 648, 2011
• Fe^*を用いた親潮域中層におけるオホーツク海からの鉄移送量の評価
  西岡純; 小埜恒夫; 齊藤宏明; 坂岡桂一郎; 芳村毅, 日本海洋学会大会講演要旨集, 2010, 73, 25 Aug. 2010
  Japanese
• Fluorescence characteristics of dissolved organic matter in the deep waters of the Okhotsk Sea and the northwestern North Pacific Ocean
  Youhei Yamashita; Rose M. Cory; Jun Nishioka; Kenshi Kuma; Eiichiro Tanoue; Rudolf Jaffe, DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, 57, 16, 1478, 1485, Aug. 2010
  English
• Fe(II) distribution in the Arabian Sea oxygen minimum zone and Western tropical Indian Ocean from GEOTRACES KH-09-5
  Yoshiko Kondo; James W. Moffett; Hajime Obata; Jun Nishioka, GEOCHIMICA ET COSMOCHIMICA ACTA, 74, 12, A528, A528, Jun. 2010
  English, Summary international conference
• 低次生態系モデルを用いた親潮域における海洋表層鉄循環の解析
  重光雅仁; 奥西武; 西岡純; 須股浩; 橋岡豪人; 相田真希; 相田真希; SMITH S.L.; 吉江直樹; 山中康裕, 日本海洋学会大会講演要旨集, 2010, 2010
• 鉄の海洋内循環におけるコロイド態画分の重要性
  西岡 純; 武田 重信, 月刊海洋, 42, 1, .., 19, 2010
  海洋出版, Japanese
• Responses of marine organisms to ocean acidification: incubation experiment using a natural plankton assemblage
  芳村 毅; 杉江 恒二; 西岡 純, 電力中央研究所報告 研究報告, 9005, 1, 15,巻頭1〜3, Nov. 2009
  電力中央研究所, Japanese
• 親潮域春季ブルームの空間変動要因
  齊藤宏明; 近藤能子; 西岡純; 高橋一生; 中町美和; 岡崎雄二; 伊佐田智規; 桑田晃; 清水勇吾; 鈴木光次, 日本海洋学会大会講演要旨集, 2009, 183, 11 Sep. 2009
  Japanese
• Influence of riverine alkalinity on carbonate species in the Okhotsk Sea
  Y. W. Watanabe; J. Nishioka; M. Shigemitsu; A. Mimura; T. Nakatsuka, Geophysical Research Letters, 36, 15, L15604, 16 Aug. 2009
  American Geophysical Union, English
• Impact of sea ice production and its recent reduction on overturning and material circulation in the Okhotsk Sea and North Pacific
  Ohshima, K.I; T. Nakanowatari; S. Nihashi; J. Nishioka; T. Nakatsuka; M. Wakatsuchi, Report on Amur-Okhotsk Project, No. 6, Research Institute for Humanity and Nature, 21, 29, 2009
• Modeling the circulation of the intermediate layer in the Sea of Okhotsk
  Uchimoto, K; T. Nakamura; J. Nishioka; H. Mitsudera, PICES Sci. Rep., 36, 97, 101, 2009
  English, Introduction other
• 千島海橋の混合過程の生物地球化学的重要性―西部北太平洋亜寒帯域の鉄：栄養塩比に与える影響―
  西岡純, 月刊海洋, 50, 99, 114, 2009
• An improvement of iron supply process in a marine biogeochemical cycle model: effects of iron export from the Sea of Okhotsk on the iron concentrations in the Western Subarctic North Pacific
  三角 和弘; 津旨 大輔; 西岡 純, 電力中央研究所報告 研究報告, 8004, 1, 18,巻頭1〜3, Nov. 2008
  電力中央研究所, Japanese
• Linkage between inland and open ocean ecosystems by material transport through river, shelf and intermediate water layer background of 2006/2007 research expeditions in the Sea of Okhotsk
  中塚 武; 西岡 純; 白岩 孝行, Kaiyo monthly, 50, 68, 76, 2008
  海洋出版, Japanese
• Importance of mixing process at Kuril Strait for biogeochemical cycle: influence on iron to nitrate ratio in the western subartic Pacific
  西岡 純; 中塚 武; 小野 数也, Kaiyo monthly, 50, 107, 114, 2008
  海洋出版, Japanese
• Nutrient status of sea-ice and snow cover in the southern Sea of Okhotsk
  Daiki Nomura; Takenobu Toyota; Sumito Matoba; Jun Nishioka; Kunio Shirasawa, Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2008, 44, 2008
  English
• Iron supply to the western subarctic Pacific: Importance of iron export from the Sea of Okhotsk
  Jun Nishioka; Tsuneo Ono; Hiroaki Saito; Takeshi Nakatsuka; Shigenobu Takeda; Takeshi Yoshimura; Koji Suzuki; Kenshi Kuma; Shigeto Nakabayashi; Daisuke Tsumune; Humio Mitsudera; W. Keith Johnson; Atsushi Tsuda, JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 112, C10, -, Oct. 2007
  English
• Physicochemical speciation of trace metals during the mesoscale iron enrichment (SEEDS II) in the western North Pacific
  S. Nakatsuka; Y. Sohpjn; K. Norisuye; K. Okamura; S. Takeda; J. Nishioka, GEOCHIMICA ET COSMOCHIMICA ACTA, 71, 15, A704, A704, Aug. 2007
  English, Summary international conference
• Iron speciation and dynamics during SERIES, a mesoscale iron enrichment experiment in the NE Pacific
  C. S. Wong; W. K. Johnson; N. Sutherland; J. Nishioka; D. A. Timothy; M. Robert; S. Takeda, Deep-Sea Research Part II: Topical Studies in Oceanography, 53, 20-22, 2075, 2094, Oct. 2006
  English
• Biological carbon dioxide fixation in the ocean by iron supply; Part 2-Improvement of a tracing method of water mass at an iron fertilization experiment-
  津旨大輔; 芳村毅; 西岡純, 電力中央研究所環境科学研究所研究報告, V05026, 19P, 16,巻頭1〜3, Aug. 2006
  電力中央研究所, Japanese
• 海域毎の鉄散布に対する植物プランクトン増殖の応答性の違いとその要因の検討
  西岡純; 津旨大輔; 芳村毅, 電力中央研究所環境科学研究所研究報告, V04033, 24P, 22,巻頭1〜4, Jun. 2005
  電力中央研究所, Japanese
• Biological carbon fixation during iron enrichment experiments in the subarctic north Pacific
  芳村毅; 西岡純; 津旨大輔, 電力中央研究所環境科学研究所研究報告, V04020, 17P, 12,巻頭1〜3, Jun. 2005
  電力中央研究所, Japanese
• 親潮海域春季ブルーム期における亜酸化窒素の挙動
  今村正裕; 西岡純; 芳村毅; 斉藤宏明; 小埜恒夫, 日本海洋学会大会講演要旨集, 2005, 2005
• 海洋鉄散布による二酸化炭素固定化の試みとその評価
  中塚清次; 西岡純; 宗林由樹, 第66回分析化学討論会 展望とトピックス, 3, 2005
  Japanese, Introduction other
• Dissolved organic matter dynamics during an iron enrichment experiment in the western north Pacific
  芳村毅; 西岡純, 電力中央研究所環境科学研究所研究報告, V04002 (Web), 2004
• Literature surveys on the role of dissolved organic matter in the biological carbon fixation into the ocean.
  芳村毅; 西岡純, 電力中央研究所我孫子研究所報告, U03004, 20P, 15,巻頭1〜4, May 2003
  電力中央研究所, Japanese
• Processes of iron limitation in the subarctic NW Pacific-Higher particulate iron concentration than that in the subarctic NE Pacific
  NISHIOKA J., Geophys. Res. Lett., 30, 2003
• Influence of iron supply to oceanic phytoplankton ecosystem.
  西田純; 津旨大輔; 芳村毅; 武田重信; 津田敦, 電力中央研究所我孫子研究所報告, 2017, 1, 15,巻頭1〜4, Jan. 2003
  電力中央研究所, Japanese
• 海洋の植物プランクトンを介入したC02吸収量の見積もり
  西岡 純, 農業電化, 54, 6, 11, 15, Jun. 2001
  農業電化協会, Japanese
• 海洋における鉄の存在状態 (総特集 現代海洋化学・2) -- (3章 海洋表層の生物地球化学)
  武田 重信; 西岡 純, 号外海洋, 25, 83, 89, 2001
  海洋出版, Japanese
• 東部北太平洋亜寒帯域における生物的な炭素移送量評価のための海洋プランクトン生態系モデルの構築
  西岡 純; 武田 重信, 電力中央研究所報告 研究報告, 10, 1, 17,巻頭1〜4, Nov. 2000
  電力中央研究所, Japanese

• 化学海洋学特論, 2024年, 修士課程, 環境科学院
• 海洋生物地球化学特論, 2024年, 修士課程, 環境科学院
• 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育
• 環境と人間, 2024年, 学士課程, 全学教育
• 環境と人間, 2024年, 学士課程, 全学教育

• 日本地球化学会
• 日本海洋学会
• American Society of Limnoligy and Oceanography
• American Geophysical Union
• PICES IFEP Advisory Panel

• Impact of basal melting of ice shelf and marine heat wave on iron supply and phytoplankton communities in the Southern Ocean
  Grants-in-Aid for Scientific Research
  01 Apr. 2024 - 31 Mar. 2029
  平譯 享; 西岡 純; 高尾 信太郎; 吉田 和広; 真壁 竜介
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), National Institute of Polar Research, 24H00758
• Research promotion for Macroscale Coastal Oceanography
  Grants-in-Aid for Scientific Research Grant-in-Aid for Transformative Research Areas (A)
  16 Jun. 2022 - 31 Mar. 2027
  羽角 博康; 伊藤 幸彦; 杉本 亮; 黒田 寛; 松村 義正; 西岡 純; 郭 新宇; 纐纈 慎也; 山崎 大; 安田 一郎; 小畑 元; 田中 潔; 平譯 享; 中田 聡史; 西川 悠
  Japan Society for the Promotion of Science, Grant-in-Aid for Transformative Research Areas (A), The University of Tokyo, 22H05200
• Material exchange between coastal area and the subarctic North Pacific and biological production
  Grants-in-Aid for Scientific Research Grant-in-Aid for Transformative Research Areas (A)
  16 Jun. 2022 - 31 Mar. 2027
  西岡 純; 小畑 元; 平譯 享; 安田 一郎; 山下 洋平
  Japan Society for the Promotion of Science, Grant-in-Aid for Transformative Research Areas (A), Hokkaido University, 22H05205
• Study of the internal cycles of trace metals in the western North Pacific by using ship observation and modeling
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2026
  小畑 元; 則末 和宏; 岡 顕; 西岡 純
  海水中の鉄をはじめとするいくつかの微量金属元素は植物プランクトンにとっての必須栄養素であり、その循環プロセスは海洋の一次生産にも影響を及ぼす。本研究では、親潮・黒潮の生態系を維持するためのメカニズムの一つとして、海水中の微量金属元素の生物地球化学的循環を研究する。本年度は、国際GEOTRACES計画の一環として、2023年6月に白鳳丸KH-23-2次研究航海を西部北太平洋において実施した。昨年度実施できなかった北太平洋亜寒帯域において鉛直採水を行った。繊維索ケーブルにCTD多重採水システムを接続し、クリーン洗浄したニスキン-X採水器を24本搭載した。 採取した溶存態用試料はクリーンエリアで加圧濾過し、酸添加して保存した。一方、全可溶態用試料は未濾過のまま酸添加した。懸濁粒子試料も採取し、冷凍保存した。海水試料中の溶存態微量金属元素については、キレート樹脂カラムで濃縮・分離を行い、高分解能誘導結合プラズマ質量分析計により測定を行っている。さらに、懸濁粒子試料についても測定を行い、その鉛直分布を明らかにした。本年度は、同じ方法により過去にサンプリングしたベンガル湾東部の海水中の微量金属元素(鉄・銅・亜鉛・マンガン・カドミウム・鉛)を分析した。ベンガル湾東部におけるこれらの元素の鉛直断面分布を明らかにすることに成功した。特にベンガル湾の沿岸域および縁辺海に複数の鉄の供給源が存在していることが示された。一方、海水中の微量金属元素の生物地球化学循環の数値モデル化についても検討を行った。西部ベーリング海などの縁辺海から供給される亜鉛について、その影響を定量的に議論した。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 23K24982
• Study of the internal cycles of trace metals in the western North Pacific by using ship observation and modeling
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2026
  小畑 元; 則末 和宏; 岡 顕; 西岡 純
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 22H03728
• Formation of water nutritional property including iron and silicate at the termination of global ocean conveyor belt
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)
  Jul. 2021 - Mar. 2026
  西岡 純
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 21H05056
• Global redistribution of heat, salt and materials induced by sea-ice processes
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)
  Aug. 2020 - Mar. 2025
  大島 慶一郎; 深町 康; 西岡 純; 二橋 創平; 三谷 曜子; 木村 詞明
  高海氷生産域であるフラジルアイス域を検知できるマイクロ波放射計AMSRのアルゴリズムを開発し、南大洋全域で初めてフラジルアイス域のマッピングを行った。フラジルアイス域を検知できたことで、今まで過小評価されていた沿岸ポリニヤでの海氷生産量をより高精度で見積もることができ、従来のアルゴリズムより、20－50％高い海氷生産量が示された。30年あまり継続してあるマイクロ波放射計SSM/I-SSMISデータに対し、薄氷タイプを識別することでより高精度の薄氷厚が推定できるアルゴリズムを開発した。南大洋をベースに開発したこのアルゴリズムは北極海でも適用可能であることも示され、全球に汎用性のあるアルゴリズムであることが示された。この開発により、長期間での全球での沿岸ポリニヤの海氷生産量の見積もりに道が開けた。プロファイリングフロートの溶存酸素量の変動から、初めてオホーツク海の広範囲で正味の生物生産量（純群集生産量）を見積もることに成功し、春の植物プランクトンの大増殖（春季ブルーム）は海氷融解によってもたらされていることを定量的指標をもって明らかにした。さらに、海氷融解時に放出される物質（鉄分）がブルームを誘起していることを示唆し、海氷による物質輸送の重要性を示した。観測としては、2021年3月に小型砕氷船ガリンコ号を傭船し、海氷サンプリングや氷縁での観測を実施し、海氷による物質輸送の観測研究に着手した。この他、CTDタグを購入し、データ通信用のアルゴスシステムに登録するなど、アザラシ、トドによるバイオロギング観測を行う準備を整えた。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 20H05707
• Chemical properties of North Pacific intermediate water and its impact to biological production
  Grants-in-Aid for Scientific Research Challenging Research (Exploratory)
  Jul. 2020 - Mar. 2022
  Nishioka Jun
  The results obtained from this study clearly show that the Sub-Antarctic intermediate water becomes an area where Fe and Silicic acid are insufficient to support the growth of diatoms in the surface layer, while the North Pacific intermediate water is a Si-rich water mass and the supply of Fe is relatively high in its western part (NPIE-W), which also supports the production of diatoms in the surface layer. The results of the study indicated the need for a quantitative evaluation of the entire material circulation system, including the marginal seas in the North Pacific.
  Japan Society for the Promotion of Science, Challenging Research (Exploratory), Hokkaido University, 20K21838
• 海氷融解水を介した極域－亜寒帯域海洋の生物地球化学的リンケージの解明
  基盤研究(A)
  Apr. 2017 - Mar. 2021
  西岡 純
  科学研究費, Principal investigator, Competitive research funding
• ポリニヤを起点とする熱塩／物質循環
  基盤研究(A)
  Apr. 2017 - Mar. 2020
  大島慶一郎
  科研費補助金, Competitive research funding
• カムチャツカ半島の淡水供給が制御する環オホーツク陸海結合システム
  基盤研究(A)
  Apr. 2017 - Mar. 2020
  三寺史夫
  科研費補助金, Competitive research funding
• 海洋混合学の創設：物質循環・気候・生態系をつなぐ統合的理解の推進
  新学術領域研究(研究領域提案型)
  Jun. 2015 - Mar. 2020
  安田一郎
  科研費補助金, Competitive research funding
• オホーツク海・ベーリング海における混合と物質循環の解明
  新学術領域研究(研究領域提案型)
  Jun. 2015 - Mar. 2020
  西岡 純
  科研費補助金, Principal investigator, Competitive research funding
• Disosolved iron transport process and its mechanism driven by sea ice formation and melting in polar oceans
  Grants-in-Aid for Scientific Research
  01 Apr. 2016 - 31 Mar. 2019
  Nakanowatari Takuya; Mitsudera Humio; Nakamura Tomoyuki; Uchimoto Keisuke; Nishioka Jun; Watanabe Eiji
  By using an ice-ocean coupled model with an biogeochemical model, the transport process of dissolved iron and its variability in the subarctic North Pacific including the Sea of Okhotsk were investigated. Seasonal to interannual variability of dissolved iron and macro nutrient concentration in the Oyashio and northwestern subarctic North Pacific is controlled by the wind-driven transport from the Okhotsk Sea and the Bering Sea as well as the local transport from the subsurface layer due to winter convection. Such lateral transport process has an essential role on the determination of primary production in the subarctic North Pacific. On the other hand, the impact of sea ice formation and melting process on the primary production is limited to the Sea of Okhotsk.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), 16K21586
• Nanoparticulate metal sulfides and their importance of stability of trace metals in oxygenated seawater
  Grants-in-Aid for Scientific Research
  01 Apr. 2015 - 31 Mar. 2018
  Nakayama Noriko; OBATA Hajime; NISHIOKA Jun
  Concentrations of acid volatile sulfides (AVS) as metal sulfides were studied over the submarine hydrothermal fields with an emphasis on the stability and preservation of trace metal. These studies find several important aspects of metal sulfide nanoparticles. Dissolved metal sulfide originating from hydrothermal vents contributes to a large portion of the observed high dissolved total sulfide concentration even in the surface water, indicating that metal-sulfide complex is quite stable in preventing its rapid removal from the water column by metal precipitation and/or oxidation in an oxic environment.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), 15K00516
• 表層と中層を繋ぐ北太平洋の子午面循環：その三次元構造と変動メカニズムの新たな描像
  基盤研究(A)
  Apr. 2014 - Mar. 2017
  三寺 史夫
  科研費補助金, Competitive research funding
• 北太平洋HNLC海域形成過程の解明
  基盤研究(B)
  Apr. 2014 - Mar. 2017
  西岡 純
  科研費補助金, Principal investigator, Competitive research funding
• オホーツク海太平洋交換流・混合と太平洋深層構造観測研究
  基盤研究(A)
  Apr. 2013 - Mar. 2016
  安田一郎
  科研費補助金, Competitive research funding
• 海氷融解過程を考慮した極域海洋像の構築
  新学術領域研究(公募研究)
  Apr. 2013 - Mar. 2015
  西岡 純
  本課題では、海氷が栄養物質の循環と植物プランクトン増殖にどのような役割を果たしているのかを、生物・化学的視点から明らかにする事を目的として取り組んだ。これまでの知見では、季節海氷域では春季に海氷が融けることで海洋表層に低温・低塩分水を供給し、密度成層を発達させ、植物プランクトンにとって光環境の整った安定な生息域を形成する点で、春季から夏季の植物プランクトンの増殖に大きな影響を与える事が指摘されていた。一方で、表層の低温・低塩分水の形成が、窒素・リン・ケイ素などの主要な栄養塩や、海水中で不足しがちな鉄分などの濃度にどのような影響を与え、植物プランクトン増殖に影響しているのかについては知見が不足していた。そこで我々は、海氷内に含まれる化学物質と、海氷融解水が表層の栄養物質環境に与える影響を調べるため、2013年夏季の北極海において、海氷をクリーンにサンプリングし、海氷の中に含まれる窒素・リン・ケイ素などの栄養塩や鉄分の分析を実施した。その結果、海氷には表層の海水にくらべて１-２オーダー以上高い濃度で鉄分が含まれていること、一方で主要な栄養塩は海氷結氷時に排出されて海氷内の濃度が著しく低いことが明らかとなった。さらに、北極海の氷縁域で海洋表面水のマッピングを実施し、アルカリ度と鉄分および栄養塩を測定することで、北極海表層の広範囲に海氷融解水由来の鉄分が供給されていて、主要な栄養塩である硝酸塩が消費されている様子を捉えることに成功した。河川水由来の鉄分供給の及ぶ範囲に比べ、海氷融解水由来の鉄分の及ぶ範囲は各段に大きいと考えられ、北極海季節海氷域だけでなく、海氷融解水の及ぶ範囲の植物プランクトン生態系に大きな影響を与えていることが示唆された。
  科研費補助金, 新学術領域研究(研究領域提案型), 北海道大学, Principal investigator, Competitive research funding, 25121501
• 凍る海の豊な生態系を生み出す機構の解明
  理想の追求
  Apr. 2012 - Mar. 2015
  西岡 純
  キャノン財団, Principal investigator, Competitive research funding
• オホーツク海と北太平洋亜寒帯域をつなぐ熱塩／物質循環システムの実態解明
  基盤研究(S)
  Apr. 2010 - Mar. 2015
  若土 正曉
  科研費補助金, Competitive research funding
• Development of clean technique for trace metal measurement method in the sea ice
  Grants-in-Aid for Scientific Research
  Apr. 2011 - Mar. 2013
  NISHIOKA Jun; MATOBA Sumito
  We developed two clean analytical procedure for determining iron and aluminium concentrations in the sea ice. One is the method that removed contaminated outer layer of sea ice. The sea ice corer is collected by a lightweight filament tube with an aluminum cutting shoe and heat-treated steel cutting teeth. The outer layers of core were carefully removed using a ceramic knife to remove contaminated part during coring. The other method is comprised by ice meltar and in-line sampling and Fe analytical system. These method were applied to oridinary a sea ice collected from the Sea of Okhotsk.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, Principal investigator, Competitive research funding, 23651001
• The feedback system of gas exchange in the ocean
  Grants-in-Aid for Scientific Research
  Apr. 2010 - Mar. 2013
  WATANABE Yutaka; NISHIOKA Jun; SAKAOKA Keiichiro; YOSHIKAWA Hisayuki; MINAMI Hideki; ONO Tsuneo
  ：In order to clarify how the nitrogen and carbon cycles in the ocean change spatiotemporally, we carried out the developments of the new estimations about these changes with a new sampling system. Applying the new estimations with the new sampling system to ocean observation, we had significant distributions of spatiotemporal distributions of nitrogen and carbon parameters in the North Pacific and the global ocean, indicating a possibility that we can obtain the detailed spatiotemporal distributions of change in ocean biogeochemical cycles.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, Competitive research funding, 22241001
• Pivotal roles of sea ice on biogeochemical iron cycles in the Pan-Okhotsk area
  Grants-in-Aid for Scientific Research
  Apr. 2010 - Mar. 2013
  NISHIOKA Jun
  Iron (Fe) data in the water column and in the sea ice which were collected during sea ice retreat season indicate that the ice melting processes supply substantial Fe to the surface of the water column. These results clearly indicate that the additional Fe input from melting sea ice could be biologically important. Variability in sea ice dynamics are likely to result in a varying supply of Fe to the southern part of the Sea of Okhotsk in early spring, and to contribute to changes in the timing of termination and community composition of the spring phytoplankton bloom, especially around the Kuril Islands.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, Competitive research funding, 22310001
• Direct observations of tidal mixing and studies on ocean/climate variability synchronized with 18.6-year period nodal tidal cycle
  Grants-in-Aid for Scientific Research
  Apr. 2008 - Mar. 2013
  YASUDA Ichiro; HASUMI Hiroyasu; KOMATSU Kosei; NISHIOKA Jun; WATANABE Yutaka; NAKATSUKA Takeshi; ITOH Sachihiko; TATEBE Hiroaki; KATSUMATA Katsurou; NAKAMURA Tomohiro; HIROE Yutaka; OSAFUNE Satoshi; TANAKA Yuki; IKEYA Tohru; NISHIKAWA Haruka; TOMOSADA Akira
  Intense tide-induced turbulent mixing that reached deep ocean around the Kuril or Aleutian Straits was observationally evidenced. This strong vertical mixing affects marine ecosystem in the subarctic North Pacific through circulations of nutrients such as iron. Furthermore, observations and climate model experiments revealed that oceanic variations originated from the 18.6-year period modulation of the tidal mixing in those regions are amplified by air-sea interactions such as SST east of Japan and the Aleutian Low Pressure system and regulate bi-decadal climate and ocean variations.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), The University of Tokyo, Competitive research funding, 20221002
• 海洋表層マッピングによる親潮域の鉄供給過程の評価
  特定領域研究 （公募研究）
  Apr. 2009 - Mar. 2011
  西岡 純
  親潮域の生物生産を支える鉄の供給過程を明らかにするために下記の研究を進めた。
  本年度は、これまでに実施してきた観測研究の結果に基づき、大気ダスト由来と海洋循環由来の鉄の供給過程が、親潮域・混合域の植物プランクトン増殖に対してどのような役割を果たしているのかについて、定量的・定性的に評価する事を試みた。また、それぞれの供給過程に関わる重要なプロセスやパラメータを抽出した。
  その結果、海洋内部の循環は、明瞭な季節的変動を駆動する供給過程であり、中層の循環によるオホーツク海からの高い鉄濃度水塊の移送、千島海峡の混合過程を介した鉄濃度の再分配、冬季の混合層発達による高鉄濃度水塊の表層への回帰などが重要なプロセスとして挙げられた。この海洋循環で供給されている鉄分は、毎年春季に起こる植物プランクトンのブルームを生み出すために利用されている。一方、大気ダスト経由の鉄は、冬季～春季にイベント的に供給されており、バックグランドにある海洋循環で決まる鉄濃度の周年変動に上乗せして、突発的に、また空間的には不均一に供給されるものであると推察された。表層鉄濃度の周年変動に影響を与えるレベルの供給量ではないが、年間に数回から十回程度、植物プランクトン増殖にインパクトを与えるレベルの鉄を供給するイベントが発生している可能性があることが分かった。以上の研究結果から、それぞれの鉄供給過程は、海洋の生物生産に対してそれぞれの役割を持ち、違った特徴の生態系の応答を導いていると考えられる。
  科研費補助金, 特定領域研究, 北海道大学, Principal investigator, Competitive research funding, 21014001
• Iron transformation and transportation in the Pan-Okhotsk region
  Grants-in-Aid for Scientific Research
  Apr. 2007 - Mar. 2010
  NISHIOKA Jun
  We found extremely high concentrations of dissolved and particulate iron in the Okhotsk Sea Intermediate Water (OSIW) and the North Pacific Intermediate Water (NPIW), which are affected by water ventilation processes caused by sea ice formation in the north-western continental shelf region of the Sea of Okhotsk. We can estimate the amount of diss-Fe in the intermediate layer. The Fe flux section cross the Oyashio is as 3.1×10^5~6.3×10^5μmol Fe/m^2/yr. The estimated annual upward flux is 28.6μmol Fe/m^2/yr in this region. Our data suggests that the consideration of this source of iron is essential in our understanding of the spring biological production and biogeochemical cycles in the western subarctic Pacific.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (A), Hokkaido University, Principal investigator, Competitive research funding, 19681001
• Iron behavior and sources regulating primary production in marginal seas (Bering Sea, Okhotsk Sea, Japan Sea)
  Grants-in-Aid for Scientific Research
  Apr. 2006 - Mar. 2010
  KUMA Kenshi; SAITOH Seiichi; ISODA Yutaka; NAGAO Seiya; NAKATSUKA Takeshi; SUZUKI Koji; WATANABE yutaka; NISHIOKA Jun
  Surface mixed layer of the basin region in the Bering Sea is under a typical iron-deficient and nutrient-rich condition with low primary production because of low atmospheric iron input. However, phytoplankton bloom (Breen Belt) is observed at the shelf break region of the Southeastern Bering Sea for a long period in summer. It is suggested that the Green Belt is maintained by the supply of nutrient-rich basin water and iron-rich shelf deep water to the surface water of the shelf break. The tidal mixing in the straits of the Kuril Islands is an important role on supplying nutrient and iron to the surface water of the northwestern North Pacific Ocean and maintaining the high primary production in the Oyashio region. On the contrary, the surface mixed layer in the Japan Sea is characterized by low nutrient and high iron concentrations, resulting from high atmospheric iron input to nutrient-depleted surface water of the Japan Sea close to the Asian continent.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, Competitive research funding, 18201001
• Geochemical ocean sections study focusing on trace elements and isotopes in the Indian Ocean and the Japan Sea (GEOTRACES Program)
  Grants-in-Aid for Scientific Research
  2007 - 2010
  GAMO Toshitaka; OBATA Hajime; AMAKAWA Hiroshi; SOHRIN Yoshiki; HASUMI Hiroyasu; OKAMURA Kei; ZHANG Jing; NAKAGUCHI Yuzuru; YAMADA Masatoshi; SHIRAIWA Yoshihiro; NORIKI Shinichiro; MINAMI Hideki; NISHIOKA Jun; SHITASHIMA Kiminori; KATO Yoshihisa; MINAGAWA Masao; MARUO Masahiro; OTOSAKA Shigeyoshi; NAKAYAMA Noriko; NAGAI Hisao; MURAYAMA Masafumi
  研究成果の概要(英文):As part of the international GEOTRACES (Global marine biogeochemical cycles of trace elements and their isotopes) program, we successfully conducted meridional research cruises in the Indian Ocean (from Arabian Sea to the Antarctic Ocean) and in the Japan Sea using the research vessel Hakuho Maru. We took clean seawater samples (total ～300 samples) for the measurement of GEOTRACES key paremeters(Fe,Al,Zn,Mn,Cd,Cu,δ^<15>N,δ^<13>C,^<230>Th,^<231>Pa, Pb isotopes,Nd isotopes), and their analyses are now ongoing in shorebased laboratories.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), The University of Tokyo, 19253006
• 西部北太平洋亜寒帯域(親潮域)表層の鉄濃度の変動と大気ダスト供給量との関係
  特定領域研究 （公募研究）
  Apr. 2007 - Mar. 2009
  西岡 純
  本研究の目的は、大気ダスト経由の鉄供給が亜寒帯域表層の鉄濃度の変動にどのように寄与しているかを定量的に評価することである。研究期間内に次のI)〜III)の項目について研究を行った。I)親潮海域の定線観測(Aライン観測)において、表層鉄濃度の季節的変動を含めた時系列観測を継続して行った。II)実海域の海表層付近の大気ダスト中に含まれる鉄量の季節的な変化を観測するとともに、海水中で大気ダストから鉄がどの程度溶出してくるかを、室内実験および船上実験において検討した。III)IIのデータおよび、季節毎の親潮海域へのダストの沈着量を、Iで得られる表層鉄濃度の季節的な変動とともに解析することで、大気ダスト経由の鉄供給が亜寒帯域表層の鉄濃度の変動にどのように寄与しているかを定量的に評価した。
  これらの内容を含む本研究の結果より、当概海域の季節的な鉄濃度の変動とダストおよび海洋内循環の供給過程の寄与が明らかになってきた。親潮域表層の鉄濃度の季節的な変動は概ね次のように説明できる。親潮域では, 冬季の鉛直混合の活発な時期に下層から表層に供給され, 春季のブルーム期にほぼ枯渇するまで減少する主要栄養塩と同様のサイクルを示す。しかし, 各観測時の測点間のばらつきは明瞭であり, 冬季に詳細なマッピングを行った結果, 鉄濃度の変化は水塊の違い(混合層の発達過程の違い)にも支配されていることが分かってきた。これらの結果は, これまで考えられてきた大気経由の鉄供給に加えて, 冬季の混合過程, 水塊の水平移動, 亜表層の鉄循環などのプロセスが海洋表層の鉄濃度の変化を引き起こす重要な要因になっていることを示している。これらの結果は, 大気から海洋表層への鉄供給を評価するためには, まず海洋循環で決まる鉄濃度のバックグランド変動を把握した上で, 大気からのシグナルを抽出することが重要であることを示している。
  科研費補助金, 特定領域研究, 北海道大学, Principal investigator, Competitive research funding, 19030002
• Modeling of the Intermediate Circulation and Material Transferin the Pan-Okhotsk Region
  Grants-in-Aid for Scientific Research
  Apr. 2006 - Mar. 2009
  EBUCHI Naoto; NAKATSUKA Takeshi; NISHIOKA Jun; MITSUDERA Humio; OHSHIMA Keiichirou; NAKAMURA Tomohiro
  オホーツク海および北西北太平洋親潮域の高い海洋生物生産性を支えている物質循環のメカニズムを,海洋中層(400~800m)の循環と鉄の輸送過程に注目して,現場観測と数値モデルによる研究を行った.その結果,オホーツク海北西大陸棚起源の鉄分が,海氷の生成とともに作られるオホーツク海中層水によって移送され,千島海峡で広い深度層に分配された後,西部北太平洋に送り出されている様子が定量的に明らかとなった.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, Competitive research funding, 18201002
• 海洋表層における微量栄養物質(鉄)の広域水平分布観測技術の開発
  若手研究(B)
  Apr. 2005 - Mar. 2007
  西岡 純
  船速度15ノットにて曳航できる曳航体を作成し、テフロンインライン採水装置と組み合わせることで「表層海水連続クリーン採水システム」を作成した。
  キレート樹脂濃縮-ルミノール化学発光系の微量栄養物質(鉄)分析装置を改良し、連続自動分析が可能な装置の作成を行った。装置にはサンプルを溜め込んで前処理を行うユニットを作成し、自動で15分に一度サンプルをフローセルに溜め込み、分析に供するシーケンスを設定した。また、実験室内において、上記「表層海水連続クリーン採水システム」のテフロンインライン採水装置より「微量栄養物質連続自動分析装置」にサンプルを引き込めるようにしてシステム化を行った。テストの結果、ブランク値も十分に低く、自動連続分析が出来ることを確認した。
  さらに北海道水産研究所が運行の研究調査航海に(1月、釧路発着、航海日数各14日)に乗船し、実海域において「表層海水連続クリーン採水システム」と「微量栄養物質連続自動分析装置」の統合(観測システム化)テストを行った。ここでは、サンプル間の入れ替わり時の汚染など、実海域で用いた場合の問題点・改良すべき点等を抽出した。
  18年度は構築した表層海水連続自動微量栄養物質(鉄)分析システムをさらに実用化に向けて改良した。サンプルの導入のシークエンスを組み替えて,前サンプルの汚染を抑えることで実用にも耐える装置とした。構築した本システムを,北海道区水産研究所の行ったHK0701航海で使用し,北海道沿岸から親潮域にかけての観測を行った。その結果,本装置を用いて船の走行中約15分から20分毎に表層海水の鉄濃度を観測し,親潮外洋から北海道陸棚域にかけての鉄濃度の広域の水平分布を把握する事に成功した。
  科研費補助金, 若手研究(B), 北海道大学, Principal investigator, Competitive research funding, 17710021
• Observational research for iron, biological productivity, and carbon cycle in the subarctic northwestern Pacific
  Grants-in-Aid for Scientific Research
  Apr. 2004 - Mar. 2007
  ONO Tsuneo; KASAI Hiromi; NISHIOKA Jun; WATANABE Yutaka; YOSHIMURA Takeshi
  2-D iron distribution in the subarctic northwestern Pacific was investigated repeatedly from 2003 to 2006 with high spacio-temporal resolution equally to major nutrients. Seasonal and interannual variations of iron observed in the Oyashio domain brought us the following information :
  1] Monthly-mean concentration of dissolved iron (DFe) in the Oyashio mixed layer varies in parallel with nitrate, with its maximum anteceding the Kosa season. Ratio of DFe to the nitrate is fairly constant throughout the year (ΔDFe/ΔN=27×10^<-6>[mol/mol]), and this ratio resembles those of North Pacific intermediate water (NPIW). Based on these observation results and a simple model calculation, it is concluded that the seasonal variation of Dfe in the Oyashio mixed layer is mainly governed by spring-summer biological consumption and winter recirculation from the NPIW. Iron input from the dust deposition is implied to have small effect to the mixed-layer iron cycle, although small-scale high iron patch might sometimes be generated by local iron deposition.
  2] More than half of the DFe data observed in Oyashio mixed layer at the bloom-termination period shows roughly constant value of 0.25 nM, implying that the bloom-forming diatoms incur significant iron limitation below this iron level. In spring, iron reaches this lower-limit faster than nitrate, forming iron-limited ecosystem conditions at the end of spring bloom. In summer, however, the ultimate depletion of mixed layer nitrate occurs faster than that of DFe at July, forming nitrate-limited ecosystem in the summer Oyashio domain.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Fisheries Research Agency, Competitive research funding, 16310019