Researcher Profile and Settings

Master

Affiliation (Master)

• Field Science Center for Northern Biosphere　Forest Research Station　Tomakomai Experimental Forest

Affiliation (Master)

• Field Science Center for Northern Biosphere　Forest Research Station　Tomakomai Experimental Forest

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Profile and Settings

Affiliation

• Hokkaido University, Field Science Center for Northern Biosphere

Profile and Settings

• Name (Japanese)

  Uetake

• Name (Kana)

  Jun

• Name

  201201010170698354

Alternate Names

http://kaken.nii.ac.jp/d/r/40455473.ja.html

Affiliation

• Hokkaido University, Field Science Center for Northern Biosphere

Achievement

Research Interests

• Environmental DNA   Glacier ecosystem   bioaerosol   好冷性微生物   

Research Areas

• Environmental science/Agricultural science / Environmental dynamics

Research Experience

• 2021/02 - Today Hokkaido University Field Science Center for Northern Biosphere Forest Research Station Associate Professor
• 2017/04 - 2020/12 Colorado State University Department of Atmospheric Science Researcher
• 2016/04 - 2017/03 National Institute of Polar Research Arctic Environment Research Center
• 2007/04 - 2016/03 Research Organization of Information and Systems

Published Papers

• Microbiomic Analysis of Bacteria Associated with Rock Tripe Lichens from Alpine Areas in Eastern Alps and Equatorial Africa

  Zichen He, Takeshi Naganuma, Ryosuke Nakai, Jun Uetake, Martin W. Hahn

  Current Microbiology 81 (5) 0343-8651 2024/03/14 

  Abstract The diversity of bacteria associated with alpine lichens was profiled. Lichen samples belonging to the Umbilicariaceae family, commonly known as rock tripe lichens, were gathered from two distinct alpine fellfields: one situated on Mt. Brennkogel located in the Eastern European Alps (Austria), and the other on Mt. Stanley located in the Rwenzori mountains of equatorial Africa (Uganda). The primary aim of this research was to undertake a comparative investigation into the bacterial compositions, and diversities, identifying potential indicators and exploring their potential metabolisms, of these lichen samples. Bulk genomic DNA was extracted from the lichen samples, which was used to amplify the 18S rRNA gene by Sanger sequencing and the V3-V4 region of the 16S rRNA gene by Illumina Miseq sequencing. Examination of the fungal partner was carried out through the analysis of 18S rRNA gene sequences, belonging to the genus Umbilicaria (Ascomycota), and the algal partner affiliated with the lineage Trebouxia (Chlorophyta), constituted the symbiotic components. Analyzing the MiSeq datasets by using bioinformatics methods, operational taxonomic units (OTUs) were established based on a predetermined similarity threshold for the V3-V4 sequences, which were assigned to a total of 26 bacterial phyla that were found in both areas. Eight of the 26 phyla, i.e. Acidobacteriota, Actinomycota, Armatimonadota, Bacteroidota, Chloroflexota, Deinococcota, Planctomycetota, and Pseudomonadota, were consistently present in all samples, each accounting for more than 1% of the total read count. Distinct differences in bacterial composition emerged between lichen samples from Austria and Uganda, with the OTU frequency-based regional indicator phyla, Pseudomonadota and Armatimonadota, respectively. Despite the considerable geographic separation of approximately 5430 km between the two regions, the prediction of potential metabolic pathways based on OTU analysis revealed similar relative abundances. This similarity is possibly influenced by comparable alpine climatic conditions prevailing in both areas.
• Dense spatial variation of the eukaryotic and prokaryotic communities on the Gulkana Glacier, Alaska

  Jun Uetake, Masato Ono, Suzunosuke Usuba, Akane Tsushima, Nozomu Takeuchi

  2023/05/15
• Spatiotemporal changes in communities of snow-ice microbes living on Gulkana Glacier, Alaska

  Masato Ono, Nozomu Takeuchi, Akane Tsushima, Yukihiko Onuma, Kino Kobayashi, Daiki Seto, Suzunosuke Usuba, Fuki Konishi, Jun Uetake

  2023/05/15
• Modeling seasonal growth of phototrophs on bare ice on the Qaanaaq Ice Cap, northwestern Greenland

  Onuma, Y, Takeuchi, N, Uetake, J, Niwano, M, Tanaka, S, Nagatsuka, N, Aoki, T

  Journal of Glaciology 2022/09 [Refereed]
  
• Spatial Distribution of Unique Biological Communities and Their Control Over Surface Reflectivity of the Stanley Glacier, Uganda

  Jun Uetake, Denis Samyn, Simon Anguma, Nozomu Takeuchi

  Frontiers in Earth Science 10 2022/02/17 [Refereed]
   

  Diverse microbes have been revealed to live in glaciers worldwide, but only a few biological studies were dedicated to glaciers in tropical Africa. These glaciers are shrinking rapidly and are expected to disappear shortly. In this study, we carried out biological and glaciological field observations on Stanley Glacier, the largest remaining glacier in the Rwenzori Mountains, Uganda, Africa. Microbial aggregates ranging from micrometer to centimeter in size were found on the glacier surface and contained moss and various types of Chlorophyta, among which a new endemic species of green alga. Concentrations of total impurities on the glacier surface, including microbial aggregates, varied spatially and decreased as altitude increased. The large microbial aggregates (larger than 4 cm in diameter) were found only at the glacier surface near the terminus and side margins, where the surface was less frequently covered with snow. It is also shown that the total organic matter on the glacier surface is determined by the timing of snow cover, which affects the quantity of solar radiation reaching the glacier ice surface. Furthermore, the total impurity content was negatively correlated with surface reflectivity, revealing their potential role in albedo reduction at the glacier surface through positive feedback between enhanced meltwater and increased biological growth.
• Cryoconite - From minerals and organic matter to bioengineered sediments on glacier's surfaces.

  Piotr Rozwalak, Paweł Podkowa, Jakub Buda, Przemysław Niedzielski, Szymon Kawecki, Roberto Ambrosini, Roberto S Azzoni, Giovanni Baccolo, Jorge L Ceballos, Joseph Cook, Biagio Di Mauro, Gentile Francesco Ficetola, Andrea Franzetti, Dariusz Ignatiuk, Piotr Klimaszyk, Edyta Łokas, Masato Ono, Ivan Parnikoza, Mirosława Pietryka, Francesca Pittino, Ewa Poniecka, Dorota L Porazinska, Dorota Richter, Steven K Schmidt, Pacifica Sommers, Juliana Souza-Kasprzyk, Marek Stibal, Witold Szczuciński, Jun Uetake, Łukasz Wejnerowski, Jacob Yde, Nozomu Takeuchi, Krzysztof Zawierucha

  The Science of the total environment 150874 - 150874 2021/10/07 [Refereed]
   

  Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier's surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-dust interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite included various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite. Moreover, a major driver of cryoconite colouring was the concentration of organic matter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceae were the most common. The most of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cementing matter and form granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to >40%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb and Hg in cryoconite collected from European glaciers near industrialized regions, corroborating cryoconite as element-specific collectors and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may be more than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystems.
• Spatial and Temporal Variations in Pigment and Species Compositions of Snow Algae on Mt. Tateyama in Toyama Prefecture, Japan

  Tomomi Nakashima, Jun Uetake, Takahiro Segawa, Lenka Procházková, Akane Tsushima, Nozomu Takeuchi

  Frontiers in Plant Science 12 2021/07/05 [Refereed]
   

  Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.
• Visualization of the seasonal shift of a variety of airborne pollens in western Tokyo

  Jun Uetake, Yutaka Tobo, Satoshi Kobayashi, Keisuke Tanaka, Satoru Watanabe, Paul J. DeMott, Sonia M. Kreidenweis

  Science of The Total Environment 788 147623 - 147623 0048-9697 2021/05 [Refereed]
  
• A hole in the nematosphere: tardigrades and rotifers dominate the cryoconite hole environment, whereas nematodes are missing

  K. Zawierucha, D. L. Porazinska, G. F. Ficetola, R. Ambrosini, G. Baccolo, J. Buda, J. L. Ceballos, M. Devetter, R. Dial, A. Franzetti, U. Fuglewicz, L. Gielly, E. Łokas, K. Janko, T. Novotna Jaromerska, A. Kościński, A. Kozłowska, M. Ono, I. Parnikoza, F. Pittino, E. Poniecka, P. Sommers, S. K. Schmidt, D. Shain, S. Sikorska, J. Uetake, N. Takeuchi

  Journal of Zoology 313 (1) 18 - 36 0952-8369 2021/01 [Refereed]
   

  The worldwide distribution of microinvertebrates on glaciers, the coldest biome, is poorly known. Owing to their tolerance to hostile conditions, small size and dispersal abilities, nematodes, tardigrades and rotifers are considered cosmopolitan and together inhabit various ecosystems. In this study, we investigated their global distribution in cryoconite holes – a type of freshwater reservoir forming directly in the glacial ice that creates biodiversity hotspots on glaciers. We analysed cryoconite samples (using classical microscopic observations and environmental DNA metabarcoding) from 42 glaciers located around the world (the Arctic, Subarctic, Scandinavia, the Alps, the Caucasus, Siberia, Central Asia, Africa, South America and Antarctica), as well as using literature data. Samples from Antarctic, Karakoram and the Alps were analysed using next-generation sequencing (NGS) and classical observations under microscopes, while all other samples were analysed by microscope alone. Three general outcomes were found: (1) tardigrades and rotifers represented the most common invertebrates in cryoconite holes; (2) tardigrades and rotifers often coexisted together, with one or the other dominating, but the dominant taxon varied by region or by glacier; (3) nematodes – the most abundant, hyperdiverse and widespread metazoans on Earth, including in environments surrounding and seeding glacial surfaces – were consistently absent from cryoconite holes. Despite the general similarity of environmental conditions in cryoconite holes, the distribution of tardigrades and rotifers differed among glaciers, but not in any predictable way, suggesting that their distribution mostly depended on the random dispersal, extreme changes of supraglacial zone or competition. Although nematodes have been found in supraglacial habitats, cryoconite hole environments seem not to provide the necessary conditions for their growth and reproduction. Lack of physiological adaptations to permanently low temperatures (~0°C) and competition for different food resources in the cryoconite hole environment may explain the absence of nematodes in cryoconite holes.
• Seasonal Trends of Atmospheric Ice Nucleating Particles Over Tokyo

  Yutaka Tobo, Jun Uetake, Hitoshi Matsui, Nobuhiro Moteki, Yasushi Uji, Yoko Iwamoto, Kazuhiko Miura, Ryohei Misumi

  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 125 (23) 2169-897X 2020/12 [Refereed]
   

  Ice nucleating particles (INPs) originating from Asia are expected to have large impacts on aerosol-cloud-precipitation interactions on local, regional, and global scales. However, their seasonal variability is poorly understood. Here, we present a year-round record of atmospheric INPs measured on Tokyo Skytree, which is the world's tallest broadcasting tower located in the Tokyo Metropolitan area. The INP number concentrations showed relatively small variations in the temperature regime below -20 degrees C, whereas the values were episodically enhanced by long-range transported Asian dusts. On the other hand, the INP spectra in the temperature regime warmer than -20 degrees C exhibited measurable seasonal variations. Notably, the INP number concentrations in the temperature regime between -15 degrees C and -10 degrees C tended to indicate higher values in warm/wet seasons and lower values in cold/dry seasons. Our results suggest that Asian dust events and seasonal variations in certain particles of biological origin linked to local/regional meteorology might influence the seasonal trends of the INP spectra over the Tokyo Metropolitan area.
• Thawing permafrost: an overlooked source of seeds for Arctic cloud formation

  Jessie M Creamean, Thomas C J Hill, Paul J DeMott, Jun Uetake, Sonia Kreidenweis, Thomas A Douglas

  Environmental Research Letters 15 (8) 084022 - 084022 2020/08/05 [Refereed]
  
• Airborne bacteria confirm the pristine nature of the Southern Ocean boundary layer

  Jun Uetake, Thomas C. J. Hill, Kathryn A. Moore, Paul J. DeMott, Alain Protat, Sonia M. Kreidenweis

  Proceedings of the National Academy of Sciences 117 (24) 13275 - 13282 0027-8424 2020/06/16 [Refereed]
   

  Microorganisms are ubiquitous and highly diverse in the atmosphere. Despite the potential impacts of airborne bacteria found in the lower atmosphere over the Southern Ocean (SO) on the ecology of Antarctica and on marine cloud phase, no previous region-wide assessment of bioaerosols over the SO has been reported. We conducted bacterial profiling of boundary layer shipboard aerosol samples obtained during an Austral summer research voyage, spanning 42.8 to 66.5°S. Contrary to findings over global subtropical regions and the Northern Hemisphere, where transport of microorganisms from continents often controls airborne communities, the great majority of the bacteria detected in our samples were marine, based on taxonomy, back trajectories, and source tracking analysis. Further, the beta diversity of airborne bacterial communities varied with latitude and temperature, but not with other meteorological variables. Limited meridional airborne transport restricts southward community dispersal, isolating Antarctica and inhibiting microorganism and nutrient deposition from lower latitudes to these same regions. A consequence and implication for this region’s marine boundary layer and the clouds that overtop it is that it is truly pristine, free from continental and anthropogenic influences, with the ocean as the dominant source controlling low-level concentrations of cloud condensation nuclei and ice nucleating particles.
• Glacially sourced dust as a potentially significant source of ice nucleating particles

  Yutaka Tobo, Kouji Adachi, Paul J. DeMott, Thomas C. J. Hill, Douglas S. Hamilton, Natalie M. Mahowald, Naoko Nagatsuka, Sho Ohata, Jun Uetake, Yutaka Kondo, Makoto Koike

  Nature Geoscience 12 (4) 253 - 258 1752-0894 2019/04 [Refereed]
   

  Aeolian dusts serve as ice nucleating particles in mixed-phase clouds, and thereby alter the cloud properties and lifetime. Glacial outwash plains are thought to be a major dust source in cold, high latitudes. Due to the recent rapid and widespread retreat of glaciers, high-latitude dust emissions are projected to increase, especially in the Arctic region, which is highly sensitive to climate change. However, the potential contribution of high-latitude dusts to ice nucleation in Arctic low-level clouds is not well acknowledged. Here we show that glacial outwash sediments in Svalbard (a proxy for glacially sourced dusts) have a remarkably high ice nucleating ability under conditions relevant for mixed-phase cloud formation, as compared with typical mineral dusts. The high ice nucleating ability of the sediments is probably governed by the presence of small amounts of organic matter (< 1 wt% organic carbon) rather than mineral components. In addition, our results from intensive field measurements and model simulations indicate that the concentrations of atmospheric ice nucleating particles over the Svalbard region are expected to be enhanced in the summertime under the influence of dust emissions from Svalbard and its surroundings. We suggest that high-latitude dust sources have the potential to significantly influence glaciation of Arctic low-level clouds.
• Bacterial community changes with cryoconite granule size and their susceptibility to exogenous nutrients on 10 glaciers in northwestern Greenland [preprint]

  Jun Uetake, Naoko Nagatsuka, Yukihiko Onuma, Nozomu Takeuchi, Hideaki Motoyama, Teruo Aoki

  2019/01/08 [Not refereed]
   

  Cryoconite granules, which are dark-colored biological aggregates on glaciers, effectively accelerate the melting of glacier ice. Bacterial community varies with granule size, however, community change in space and their susceptibility to environmental factors has not been described yet. Therefore, we focused on bacterial community from 4 different granule sizes (30-249 μm, 250-750 μm, 750-1599 μm, more than 1600 μm diameter) in 10 glaciers in northwestern Greenland and their susceptibility for exogenous nutrients in cryoconite hole. A filamentous cyanobacterium Phormidesmis priestleyi, which has been frequently reported from glaciers in Arctic was abundant (10-26%) across any size of granules on most of glaciers. Bacterial community across glaciers became similar with size increase, and whence smallest size fractions contain more unique genera in each glacier. Multivariate analysis suggests that phosphate, which is significantly higher in one glacier (Scarlet Heart Glacier), is primary associated with bacterial beta diversity. Correlation coefficients between abundance of major genera and nutrients largely changed with granule size, suggesting that nutrients susceptibility to genera changes with growth process of granule (e.g. P. priestleyi was affected by nitrate in early growth stage).
• Seasonal Changes of Airborne Bacterial Communities Over Tokyo and Influence of Local Meteorology.

  Jun Uetake, Yutaka Tobo, Yasushi Uji, Thomas C J Hill, Paul J DeMott, Sonia M Kreidenweis, Ryohei Misumi

  Frontiers in microbiology 10 1572 - 1572 1664-302X 2019 [Refereed]
   

  In order to study airborne bacterial community dynamics over Tokyo, including fine-scale correlations between airborne microorganisms and meteorological conditions, and the influence of local versus long-range transport of microbes, air samples were collected on filters for periods ranging from 48 to 72 h. The diversity of the microbial community was assessed by next generation sequencing. Predicted source regions of airborne particles, from back trajectory analyses, changed abruptly from the Pacific Ocean to the Eurasian Continent in the beginning of October. However, the microbial community composition and the alpha and beta diversities were not affected by this shift in meteorological regime, suggesting that long-range transport from oceanic or continental sources was not the principal determinant controlling the local airborne microbiome. By contrast, we found a significant correlation between the local meteorology, especially relative humidity and wind speed, and both alpha diversity and beta diversity. Among four potential local source categories (soil, bay seawater, river, and pond), bay seawater and soil were identified as constant and predominant sources. Statistical analyses point toward humidity as the most influential meteorological factor, most likely because it is correlated with soil moisture and hence negatively correlated with the dispersal of particles from the land surface. In this study, we have demonstrated the benefits of fine-scale temporal analyses for understanding the sources and relationships with the meteorology of Tokyo's "aerobiome."
• Bacterial community changes with granule size in cryoconite and their susceptibility to exogenous nutrients on NW Greenland glaciers

  Uetake, J., Nagatsuka, N., Onuma, Y., Takeuchi, N., Motoyama, H., Aoki, T.

  FEMS microbiology ecology 95 (7) fiz075  2019 [Refereed][Not invited]
  
• Temporal variations of cryoconite holes and cryoconite coverage on the ablation ice surface of Qaanaaq Glacier in northwest Greenland

  Nozomu Takeuchi, Ryutaro Sakaki, Jun Uetake, Naoko Nagatsuka, Rigen Shimada, Masashi Niwano, Teruo Aoki

  Annals of Glaciology 59 (77) 21 - 30 0260-3055 2018/12 [Refereed]
   

  Cryoconite holes are water-filled cylindrical holes formed on ablation ice surfaces and commonly observed on glaciers worldwide. Temporal changes of cryoconite holes characteristically <5 cm in diameter were monitored with a time-lapse interval camera over 15 d during the melting season on Qaanaaq Glacier in northwest Greenland. The holes drastically changed their dimensions and synchronously collapsed twice during the study period. When the holes collapsed, the coverage of cryoconite on the ice surface increased from 1.0 to 3.5% in the field of view of the camera, and then decreased again to 0.4% after the holes reformed. Comparison with meteorological data showed that the collapses occurred in cloudy and rainy or windy weather conditions, corresponding to low shortwave solar radiation (68–126 W m⁻², 40–55% of the incoming flux). In contrast, holes developed in sunny conditions correspond to high solar radiation (186–278 W m⁻², 63–88%). Results suggest that the dimensions of holes drastically changed depending on the weather conditions and that frequent cloudy, warm and windy conditions would cause a decay of holes and weathering crust, inducing an increase in the cryoconite coverage on the ice, consequently darkening the glacier surface.
• Development and decay of cryoconite holes on Qaanaaq Glacier in northwest Greenland

  Takeuchi, N, R. Sakaki, J. Uetake, N. Nagatsuka, R. Shimada, M. Niwano, T. Aoki

  Ann. Glaciol. 59 1 - 10 2018 [Refereed][Not invited]
  
• Biogeography of cryoconite forming cyanobacteria on polar and Asian glaciers

  Takahiro Segawa, Takahiro Yonezawa, Arwyn Edwards, Ayumi Akiyoshi, Sota Tanaka, Jun Uetake, Tristram Irvine-Fynn, Kotaro Fukui, Zhongqin Li, Nozomu Takeuchi

  JOURNAL OF BIOGEOGRAPHY 44 (12) 2849 - 2861 0305-0270 2017/12 [Refereed][Not invited]
   

  AimCryoconite, a microbe-mineral aggregate found on glaciers worldwide, is formed by microbial phototrophs, principally cyanobacteria. Despite their ecological importance in supraglacial environments, the phylogeographical distributions of supraglacial cyanobacteria are poorly understood. Here, we investigate the biogeographical distribution of cyanobacteria on glaciers in the Antarctic, Arctic and Asia. LocationGlaciers in the Antarctic, Arctic and Asia. MethodsWe analysed contiguous sequences of 16S rRNA genes and 16S-23S internal transcribed spacer (ITS) regions, determined by a long read strategy and single-filament PCR analysis in 38 glacial samples. We analysed cyanobacterial distribution patterns and genetic differentiation. ResultsThe cyanobacterial 16S rRNA gene sequences were grouped into 20 operational taxonomic units (OTUs), and the six major OTUs that accounted for 88% of sequences were distributed broadly from polar to Asian glaciers, suggesting that they are cosmopolitan at the species level. However, analysis of the more variable ITS region revealed geographical differentiation at the strain level. Nineteen OTUs, including the six major OTUs, showed considerable genetic differentiation among geographical regions; at the population level, they are, thus, geographically restricted. Only one of the phylotype exhibits a population structure which does not show a relationship with geographical distribution, suggesting that is cosmopolitan, even at the strain level. Main conclusionsOur 16S rRNA gene analyses suggest a global distribution of species of cyanobacteria colonizing glacier surfaces; however, the 16S-23S ITS regions revealed that most of the phylotypes are fundamentally endemic to particular areas at the population level and indicate limited migration among regions. Our result suggests that selection pressures among geographical regions are strong driving forces shaping genetic structure in cyanobacteria.
• Changes in the fungal community of Austre Broggerbreen deglaciation area, Ny-Alesund, Svalbard, High Arctic

  Masaharu Tsuji, Jun Uetake, Yukiko Tanabe

  MYCOSCIENCE 57 (6) 448 - 451 1340-3540 2016/11 [Refereed][Not invited]
   

  Austre Broggerbreen is located in Ny-Alesund in the Svalbard archipelago, Norway, and is known as one of the most retreating glaciers in the world. We selected five sites in the retreating area and investigated the mycoflora in each of them. A total of 58 fungal strains were isolated and classified into 14 species (Cryptococcus gilvescens, Cryptococcus victoriae, Mrakia gelida, Mrakia robertii, Mrakia psychrophila, Rhodotorula glacialis, Rhodotorula psychrophenolica, Cladosporium cladosporioides, Thelebolus microsporus, Mortierella alpina, Mortierella polygonia, Mortierella elongata, Mortierella horticola, and Mucor hiemalis). We showed that the mycoflora clearly changes with distance from the glacier terminus in Austre Broggerbreen deglaciation area. (C) 2016 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved.
• Microbial community variation in cryoconite granules on Qaanaaq Glacier, NW Greenland

  Uetake, J, S. Tanaka, T. Segawa, N. Takeuchi, N. Nagatsuka, H. Motoyama, T. Aoki

  FEMS Microbiology Ecology 92 (9) 2016/06 [Refereed][Not invited]
   

  Cryoconite granules are aggregations of microorganisms with mineral particles that form on glacier surfaces. To understand the processes by which the granules develop, this study focused on the altitudinal distribution of the granules and photosynthetic microorganisms on the glacier, bacterial community variation with granules size and environmental factors affecting the growth of the granules. Size-sorted cryoconite granules collected from five different sites on Qaanaaq Glacier were analyzed. C and N contents were significantly higher in large (diameter greater than 250 μm) granules than in smaller (diameter 30-249 μm) granules. Bacterial community structures, based on 16S rRNA gene amplicon sequencing, were different between the smaller and larger granules. The filamentous cyanobacterium Phormidesmis priestleyi was the dominant bacterial species in larger granules. Multivariate analysis suggests that the abundance of mineral particles on the glacier surface is the main factor controlling growth of these cyanobacteria. These results show that the supply of mineral particles on the glacier enhances granule development, that P. priestleyi is likely the key species for primary production and the formation of the granules and that the bacterial community in the granules changes over the course of the granule development.
• Variations in Sr and Nd isotopic ratios of mineral particles in cryoconite in western Greenland

  Nagatsuka, N., Takeuchi, N., Uetake, J., Shimada, R., Onuma, Y., Tanaka, S., Nakano, T.

  Frontiers in Earth Science 4 (93) 2016 [Refereed][Not invited]
   

  © 2016 Nagatsuka, Takeuchi, Uetake, Shimada, Onuma, Tanaka and Nakano. In order to better understand the source of minerals on the dark-colored ice, located in the Greenland ice sheet ablation zone, we analyzed the Sr and Nd isotopic ratios of minerals in cryoconite, which were collected from glaciers in northwest and southwest Greenland. We focused on the following: (i) comparison of the isotopes of minerals in cyroconite with those in sediments from local and distant areas, (ii) regional variations in western Greenland, and (iii) spatial variations across an individual a glacier. The mineral components of the cryoconite showed variable Sr and Nd isotopic ratios (87Sr/86 Sr: 0.711335 to 0.742406, εNd (0): −33.1 to −22.9), which corresponded to those of the englacial dust and moraine on and around the glaciers but were significantly different from those of the distant deserts that have been considered to be primary sources of mineral dust on the Greenland Ice Sheet. This suggests that the minerals within the cryoconites were mainly derived from local sediments, rather than from distant areas. The Sr ratios in the northwestern region were significantly higher than those in the southwestern region. This is probably due to geological differences in the source areas, such as the surrounding glaciers in each region. The isotopic ratios further varied spatially within a glacier (Qaanaaq and Kangerlussuaq areas), indicating that the silicate minerals on the glaciers were derived not from a single source but from multiple sources, such as englacial dust and wind-blown minerals from the moraine surrounding the glaciers.
• Geographical variations in cryoconite on Greenland Icesheet

  Takeuchi Nozomu, Nagatsuka Naoko, Uetake Jun, Tanaka Sota, Onuma Yukihiko, Shimada Rigen

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2015 71 - 71 2015
• Spatial variations in abundance and composition of snow algal pigments in Mt. Tateyama in Toyama prefecture, Japan in melting season of 2015

  Nakashima Tomomi, Takeuchi Nozomu, Uetake Jun, Segawa Takahiro, Tanabe Yukiko, Watanabe Kenichi, Tsuji Masaharu, Miyauchi Kenshiro, Okamoto Chika, Hori Yoichiro

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2015 181 - 181 2015
• A snow community on a mountain glacier (Condpriri glacier) in Bolivia

  Tanaka Sota, Takeuchi Nozomu, Asaoka Yoshihiro, Uetake Jun

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2015 2 - 2 2015
• Impurities and snow algal communities of Conejeras Glacier in the Andes Mountains in Colombia, South America

  Konno Yudai, Takeuchi Nozomu, Uetake Jun, Hara Kousuke

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2015 1 - 1 2015
• Novel Biogenic Aggregation of Moss Gemmae on a Disappearing African Glacier

  Jun Uetake, Sota Tanaka, Kosuke Hara, Yukiko Tanabe, Denis Samyn, Hideaki Motoyama, Satoshi Imura, Shiro Kohshima

  PLOS ONE 9 (11) 1932-6203 2014/11 [Refereed][Not invited]
   

  Tropical regions are not well represented in glacier biology, yet many tropical glaciers are under threat of disappearance due to climate change. Here we report a novel biogenic aggregation at the terminus of a glacier in the Rwenzori Mountains, Uganda. The material was formed by uniseriate protonemal moss gemmae and protonema. Molecular analysis of five genetic markers determined the taxon as Ceratodon purpureus, a cosmopolitan species that is widespread in tropical to polar region. Given optimal growing temperatures of isolate is 20-30 degrees C, the cold glacier surface might seem unsuitable for this species. However, the cluster of protonema growth reached approximately 10 degrees C in daytime, suggesting that diurnal increase in temperature may contribute to the moss's ability to inhabit the glacier surface. The aggregation is also a habitat for microorganisms, and the disappearance of this glacier will lead to the loss of this unique ecosystem.
• Light-absorbing snow impurity concentrations measured on Northwest Greenland ice sheet in 2011 and 2012

  Aoki, T, S. Matoba, S. Yamaguchi, T. Tanikawa, M. Niwano, K. Kuchiki, K. Adachi, J. Uetake, H. Motoyama, M. Hori

  Bulletin of Glaciological Research 32 (0) 21 - 31 1345-3807 2014/03 [Refereed][Not invited]
  
• Spatial variations in impurities (cryoconite) on glaciers in northwest Greenland

  Nozomu Takeuchi, Naoko Nagatsuka, Jun Uetake, Rigen Shimada

  Bulletin of Glaciological Research 32 (1) 85 - 94 1345-3807 2014 [Refereed][Not invited]
   

  Spatial variations in impurities (cryoconite) on the glacier surface were investigated on Qaanaaq Ice Cap and Tugto Glacier in the northwest Greenland in the melting season of 2012. Abundance of impurities ranged from 0.36 to 119 gm-2 (dry weight, mean: 18.8 gm-2) on bare ice and from 0.01 to 8.7 gm-2 (mean: 3.6 gm-2) on snow surface at the study sites. On Qaanaaq Glacier (an outlet glacier of Qaanaaq Ice Cap) impurity abundance was greatest at mid-elevations, with fewer impurities at upper and lower sites. Surface reflectivity was lowest in the mid-elevation area, suggesting that impurities substantially reduce ice surface albedo at mid-elevations on glacier surfaces. Organic matter content in the impurities ranged from 1.4 to 12.0% (mean: 5.4%) on the ice and from 3.2 to 10.6% (mean: 6.7%) on the snow surface. Microscopy revealed that impurities in the ice areas mainly consisted of cryoconite granules, which are aggregations of mineral particles, filamentous cyanobacteria and other microbes and organic matter, while those in snow areas consisted of mineral particles and snow algae. Results suggest that the spatial variation in the abundance of impurities is caused by supply of mineral particles both from air and ice, and microbial production of organic matter on the glacier surface.© Japanese Society of Snow and Ice.
• Mineralogical composition of cryoconite on glaciers in northwest Greenland

  Naoko NAGATSUKA, Nozomu TAKEUCHI, Jun UETAKE, Rigen SHIMADA

  Bulletin of Glaciological Research 32 107 - 114 1345-3807 2014
• Field activities of “Snow Impurities and Glacial Microbe effects on abrupt warming in the Arctic” (SIGMA) Project in Greenland in 2011-2013

  Aoki, T, S. Matoba, J. Uetake, N. Takeuchi, H. Motoyama

  Bulletin of Glaciological Research The Japanese Society of Snow and Ice = 日本雪氷学会 32 3 - 20 1345-3807 2014 [Refereed][Not invited]
   

  Field activities of the "Snow Impurity and Glacial Microbe effects on abrupt warming in the Arctic" (SIGMA) Project in Greenland in the summer season of 2011-2013 are reported; this consists of (1) glaciological and meteorological observations and (2) biological observations. In 2011, we conducted a field reconnaissance in the Qaanaaq, Ilulissat and Kangerlussuaq areas to enable continuous meteorological observations with automatic weather stations (AWS), campaign observations for glaciology, meteorology and Biology and shallow ice core drilling, which were planned for 2012-2014. Based on the results, we chose the Qaanaaq area in northwest Greenland as our main activity area and the Kangerlussuaq area in mid-west Greenland partly for biological observations. In 2012, we conducted field observations for (1) and (2) mentioned above together with installations of two AWSs at site SIGMA-A on The Greenland ice sheet (GrIS) and at site SIGMA-B on the Qaanaaq ice cap (QIC) from June to August. Surface snow and ice over all of the QIC melted in July and August 2012, and most of the Glacier surface appeared to be dark-colored, probably due to mineral dust and glacial microbial products. In 2013, we carried out similar observations in the Qaanaaq area. However, the weather and Glacier surface conditions were considerably different from those in 2012. Snow cover over the summer of 2013 remained over large areas with elevations higher than about 700 m on QIC. Biological activity on the Glacier surface appears to be substantially lower as compared to that in 2012. ? Japanese Society of Snow and Ice.
• Numerical simulation of spectral albedos of glacier surfaces covered with glacial microbes in Northwestern Greenland

  Teruo Aoki, Katsuyuki Kuchiki, Masashi Niwano, Sumito Matoba, Jun Uetake, Kazuhiko Masuda, Hiroshi Ishimoto

  2013
• DNA analysis for section identification of individual Pinus pollen grains from Belukha glacier, Altai Mountains, Russia

  Fumio Nakazawa, Jun Uetake, Yoshihisa Suyama, Ryo Kaneko, Nozomu Takeuchi, Koji Fujita, Hideki Motoyama, Satoshi Imura, Hiroshi Kanda

  Environmental Research Letters 8 (1) 014032  2013/01 [Refereed][Not invited]
  
• Isolation of oligotrophic yeasts from supraglacial environments of different altitude on the Gulkana Glacier (Alaska)

  Jun Uetake, Yoshitaka Yoshimura, Naoko Nagatsuka, Hiroshi Kanda

  FEMS MICROBIOLOGY ECOLOGY 82 (2) 279 - 286 0168-6496 2012/11 [Refereed][Not invited]
   

  Psychrophilic yeasts have been isolated from supra- and subglacial ice at many sites worldwide. To understand the ecology of psychrophilic yeasts on glaciers, we focused on their adaptation to wide range of nutrient concentrations and their distribution with altitude on the Gulkana Glacier in Alaska. We found various culturable psychrophilic yeasts on the ice surfaces of the glacier, and 11 species were isolated with incubation at 4 degrees C in four different dilutions of agar medium. Some of our isolated species (Rhodotorula psychrophenolica, Rhodotorula aff. psychrophenolica, Rhodotorula glacialis, and Basidiomycota sp. 1) can grow on the low dissolved organic matter (DOC) concentrations medium (7.6mgL-1) which is close to the typical level of supraglacial melt water, suggesting that these species can inhabit in any supraglacial meltwater. Otherwise, most of other species were isolated only from higher DOC concentration medium (183mgL-118.3gL-1), suggesting that these are inhabitant around the cryoconite, because DOC concentrations in melted surface-ice contained cryoconite is much higher than in melted water. Similarity of altitudinal distribution between culturable yeast and algal biomass suggests that the ecological role played by the cold-adapted yeasts is as organic matter decomposers and nutrient cyclers in glacier ecosystem.
• Chemical properties of snow cover at the northwestern Greenland Ice Sheet

  Matoba Sumito, Uetake Jun, Aoki Teruo

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2012 151 - 151 2012
• Glacial Biological Research on Ruwenzori mountains, Tropical Africa

  HARA KOSUKE, TANAKA SOTA, UETAKE JUN, KOHSHIMA SHIRO

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2012 216 - 216 2012
• Microbial composition changes in cryoconite formation process in Northwestern Greenland

  Uetake Jun, Motoyama Hideaki, Aoki Teruo

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2012 155 - 155 2012
• Seasonal variation of bacteria from surface snow pit at NEEM, Greenland

  Uetake Jun, Azuma Kumiko, Kuramoto Takayuki, Hirabayashi Motohiro, Miyake Takayuki, Motoyama Hideaki

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2012 219 - 219 2012
• Aggregation of bryophyte (Moss) on glacier surface in Rwenzori Mts., Uganda

  Uetake Jun, Tanabe Yukiko, Hara Kosuke, Tanaka Sota, Motoyama Hideaki, Kohshima Shiro

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2012 54 - 54 2012
• Variations in spectral reflectance of snow surface in thawing season in Tateyama, Mountains,Japan

  Tanaka Monami, Takeuchi Nozomu, Onua yukihiko, Uetake Jun

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2012 201 - 201 2012
• Establishing the Timing of Chemical Deposition Events on Belukha Glacier, Altai Mountains, Russia, Using Pollen Analysis

  Fumio Nakazawa, Takayuki Miyake, Koji Fujita, Nozomu Takeuchi, Jun Uetake, Toshiyuki Fujiki, Vladimir Aizen, Masayoshi Nakawo

  ARCTIC ANTARCTIC AND ALPINE RESEARCH 43 (1) 66 - 72 1523-0430 2011/02 [Refereed][Not invited]
   

  In this study, we used a 4.00-m pit on Belukha glacier in Russia's Altai region and attempted to establish the timing of chemical deposition events by analyzing pollen profiles. As the pollen deposition of each examined taxon on the glacier surfaces followed a distinct seasonal phenology, seasonal layers could be identified over a two-year period. The seasonal layer boundaries reconstructed from the pollen analyses were in close agreement with the in situ observations and indicated that the snow deposition on the glacier originates mainly from summer precipitation. The record of oxygen isotope ratios showed a relatively high mean value of 13.3 parts per thousand, which was attributed to the absence of winter depositions. The formate (HCOO-) concentration records displayed seasonal variation with the highest emissions occurring in the spring, and a dust event in the spring of 2003 was detected from the Mg2+, Ca2+, and dust concentration profiles. Taken together, these results suggest the analysis of pollen profiles in combination with chemical data in snow pits and ice cores may lead to better reconstruction of seasonal variation.
• Evidence for propagation of cold-adapted yeast in an ice core from a Siberian Altai glacier

  Jun Uetake, Shiro Kohshima, Fumio Nakazawa, Nozomu Takeuchi, Koji Fujita, Takayuki Miyake, Hideki Narita, Vladimir Aizen, Masayoshi Nakawo

  JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES 116 (1) 0148-0227 2011/02 [Refereed][Not invited]
   

  Cold environments, including glacier ice and snow, are known habitats for cold-adapted microorganisms. We investigated the potential for cold-adapted yeast to have propagated in the snow of the high-altitude Belukha glacier. We detected the presence of highly concentrated yeast (over 10(4) cells mL(-1)) in samples of both an ice core and firn snow. Increasing yeast cell concentrations in the same snow layer from July 2002 to July 2003 suggests that the yeast cells propagated in the glacier snow. A cold-adapted Rhodotorula sp. was isolated from the snow layer and found to be related to psychrophilic yeast previously found in other glacial environments (based on the D1/D2 26S rRNA domains). 26S rRNA clonal analysis directly amplified from meltwater within the ice core also revealed the presence of genus Rhodotorula. Analyses of the ice core showed that all peaks in yeast concentration corresponded to the peaks in indices of surface melting. These results support the hypothesis that occasional surface melting in an accumulation area is one of the major factors influencing cold-adapted yeast propagation.
• Reevaluation of the reconstruction of summer temperatures from melt features in Belukha ice cores, Siberian Altai

  Sachiko Okamoto, Koji Fujita, Hideki Narita, Jun Uetake, Nozomu Takeuchi, Takayuki Miyake, Fumio Nakazawa, Vladimir B. Aizen, Stanislav A. Nikitin, Masayoshi Nakawo

  JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 116 (2) D02110  2169-897X 2011/01 [Refereed][Not invited]
   

  In a previous study, past summer temperatures were reconstructed from melt features in the Belukha ice core, Siberian Altai. We evaluated the climatic representativeness of net accumulation and melt features by comparing two Belukha ice cores retrieved at neighboring sites by different institutions and dated by different methods. Melt features in both cores showed a significant correlation, but the trends of net accumulation were different between the cores. Melt features corresponded to the retreat rate of a glacier terminus in a neighboring mountain range. These findings demonstrate the spatial representativeness of melt features in the ice cores. We reevaluated an equation formulated for reconstructions of summer temperature, as used in a previous study, and found that it underestimates temperature. We propose an alternative equation to obtain more reliable summer temperatures from melt features and net accumulation records for the period from 1914 to 2003.
• Microorganisms variation in snow fall on mountainside of Mt. Tokachi

  Jun Uetake, Hideaki Motoyama, Takayuki Miyake, Teruya Maki, Atsushi Matsuki, Tomoya Baba

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2011 104  1883-0889 2011 [Refereed][Not invited]
  
• Seasonal variations of snow chemistry at NEEM, Greenland

  Takayuki Kuramoto, Kumiko Goto-Azuma, Motohiro Hirabayashi, Takayuki Miyake, Hideaki Motoyama, Jun Uetake

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2010 86  1883-0889 2010 [Refereed][Not invited]
  
• Preliminary study of microorganisms analysis in North Greenland Eemian Ice Driling site

  Jun Uetake, Jun Uetake, Kumiko Azuma, Takayuki Kuramoto, Hideaki Motoyama, Hiroshi Kanda

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2010 148  1883-0889 2010 [Refereed][Not invited]
  
• Psychrophilic yeast communities on the Gulkana glacier, Alaska

  UETAKE JUN, Nagatsuka Naoko, Yoshimura Yoshitaka

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2009 136 - 136 1883-0870 2009
• Stratigraphy analysis focused on air bubbles in Belukha ice core, Russian Altai

  Okamoto Sachiko, Fujita Koji, Narita Hideki, Uetake Jun, Takeuchi Nozomu, Miyake Takayuki, Nakazawa Fumio, Aizen Vladimir, Nikitin Stanislav, Nakawo Masayoshi

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2009 134 - 134 1883-0870 2009
• Distribution of surface dust in the bare ice area of the Greenland Ice Sheet derived from Landsat ETM images.:Presumption of surface condition from spectral characteristics

  Ito Hiroki, Takeuchi Nozomu, Kohshima Shiro, Uetake Jun

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 公益社団法人 日本雪氷学会／日本雪工学会 2009 25 - 25 1883-0870 2009
• DNA analysis of a single Pinus pollen grain in a glacier

  Fumio Nakazawa, Jun Uetake, Hiroshi Kanda, Yoshihisa Suyama, Nozomu Takeuchi, Koji Fujita

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2009 127  1883-0889 2009 [Refereed][Not invited]
  
• Pollen analysis of snow samples from Antarctica

  Fumio Nakazawa, Jun Uetake, Hiroshi Kanda

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2008 78  1883-0889 2008 [Refereed][Not invited]
  
• Microorganisms density changes during glacial-interglacial cycle in Dome Fuji ice core

  Jun Uetake, Hideaki Motoyama, Hiroshi Kanda

  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research 2008 146  1883-0889 2008 [Refereed][Not invited]
  
• Estimation of net accumulation rate at a Patagonian glacier by ice core analyses using snow algae

  Shiro Kohshima, Nozomu Takeuchi, Jun Uetake, Takayuki Shiraiwa, Ryu Uemura, Naohiro Yoshida, Sumito Matoba, Maria Angelica Godoi

  Global and Planetary Change 59 (1-4) 236 - 244 0921-8181 2007/10 [Refereed][Not invited]
   

  Snow algae in a 45.97-m-long ice core from the Tyndall Glacier (50°59′05″S, 73°31′12″W, 1756 m a.s.l.) in the Southern Patagonian Icefield were examined for potential use in ice core dating and estimation of the net accumulation rate. The core was subjected to visual stratigraphic observation and bulk density measurements in the field, and later to analyses of snow algal biomass, water isotopes (18O, D), and major dissolved ions. The ice core contained many algal cells that belonged to two species of snow algae growing in the snow near the surface: Chloromonas sp. and an unknown green algal species. Algal biomass and major dissolved ions (Na+, K+, Mg2+, Ca2+, Cl-, SO42-) exhibited rapid decreases in the upper 3 m, probably owing to melt water elution and/or decomposition of algal cells. However, seasonal cycles were still found for the snow algal biomass, 18O, D-excess, and major ions, although the amplitudes of the cycles decreased with depth. Supposing that the layers with almost no snow algae were the winter layers without the melt water essential to algal growth, we estimated that the net accumulation rate at this location was 12.9 m a- 1 from winter 1998 to winter 1999, and 5.1 m from the beginning of winter to December 1999. These estimates are similar to the values estimated from the peaks of 18O (17.8 m a- 1 from summer 1998 to summer 1999 and 11.0 m from summer to December 1999) and those of D-excess (14.7 m a- 1 from fall 1998 to fall 1999 and 8.6 m a- 1 from fall to December 1999). These values are much higher than those obtained by past ice core studies in Patagonia, but are of the same order of magnitude as those predicted from various observations at ablation areas of Patagonian glaciers. © 2006 Elsevier B.V. All rights reserved.
• Reconstruction of summer temperature by using melt features in an ice core at Belukha Glacier, Russian Altai Mountains

  Okamoto Sachiko, Fujita Koji, Narita Hideki, Uetake Jun, Takeuchi Nozomu, Miyake Takayuki, Nakazawa Fumio

  Preprints of the Annual Conference, Japanese Society of Snow and Ice 公益社団法人 日本雪氷学会 2007 7 - 7 0919-7346 2007
• Spatial distribution and abundance of red snow algae on the Harding Icefield, Alaska derived from a satellite image

  Nozomu Takeuchi, Roman Dial, Shiro Kohshima, Takahiro Segawa, Jun Uetake

  GEOPHYSICAL RESEARCH LETTERS 33 (21) 0094-8276 2006/11 [Refereed][Not invited]
   

  Red snow caused by algal bloom is common on glaciers and snowfields worldwide. Description of spatial distributions of snow algal blooms is important for understanding snow algae's unique life in an extremely cold environment and for determining the effect of algae through the reduction of surface albedo. Here we present the spatial distribution of red snow algae on the Harding Icefield, Alaska retrieved from a satellite image. Field observations on the icefield conducted in August 2001 revealed visible red snow, particularly near the snowline. Field measurements of spectral reflectance on the surface revealed the specific spectral absorption of algal pigments. We found a significant correlation between snow algal biomass and a reflectance ratio of SPOT ( Satellite Probatoire d' Observation de la Terre) satellite band of wavelength 610 - 680 nm to band 500 - 590 nm. Using this relationship between the reflectance ratio and algal biomass, we estimated the distribution and abundance of red snow across the icefield using a SPOT satellite image. The spatial distribution of red snow on the icefield obtained by mapping the reflectance ratio matched field observations across the icefield with more red algal blooms on the continental than the maritime side of the icefield. Area averaged mean carbon content estimated from the red algal biomass for the icefield on the image was 1.2 kg km(-2).
• A snow algal community on Akkem glacier in the Russian Altai mountains

  Nozomu Takeuchi, Jun Uetake, Koji Fujita, Vladimir B. Aizen, Stanislav D. Nikitin

  ANNALS OF GLACIOLOGY, VOL 43, 2006 43 378 - + 0260-3055 2006 [Not refereed][Not invited]
   

  Snow algae are cold-tolerant algae growing on snow and ice and have been reported on glaciers in many parts of the world. Blooms of snow algae can reduce the surface albedo of snow and ice and significantly affect their melting. In addition, snow algae found in ice cores can be potential indicators of the paleo-environment, making them of great interest both to the biology and the geophysics of glaciers. A snow algal community was investigated in 2002 and 2003 on Akkem glacier in the Russian Altai mountains, where no information on its biological community has previously been available. Five species of snow algae including green algae and cyanobacteria were observed on the glacier. Red snow due to a bloom of algae (Chloromonas sp.) was visually apparent in the snow area during our study periods. The total algal cell-volume biomass on the glacier ranged from 97 to 1156 mu L m(-2), which is equivalent to that reported previously on glaciers in the Himalaya and Alaska. The community structure showed that Mesotaenium berggrenii and/or Ancylonema nordenskioeldii, which are common species on glaciers in the Northern Hemisphere, were dominant in the ice area, while Chloromonas sp. was dominant in the snow area. Such community structures are similar to those on Alaskan and Arctic glaciers but differ from those on Himalayan and Tibetan glaciers, even though the Altai mountains are geographically closer to the Himalaya and Tibet than to Alaska. The difference in algal communities between the Altaic and other glaciers is discussed together with physical and chemical conditions affecting the algae.
• Chemical composition of surface ice at July 1st Glacier, Qilian Mountains, China

  Miyake Takayuki, Uetake Jun, Matoba Sumito, Sakai Akiko, Fujita Koji, Fujii Yoshiyuki, Yao Tandong, Nakawo Masayoshi

  Preprints of the Annual Conference, Japanese Society of Snow and Ice 公益社団法人 日本雪氷学会 2006 202 - 202 0919-7346 2006
• Glacio-biological ice cores analyses from Belukha Glacier.

  Uetake Jun, Kohshima Shiro, Nakazawa Fumio, Segawa Takahiro, Miyake Takayuki, Yoshimura Yoshitaka, Narita Hideki, Fujita Koji, Takeuchi Nozomu, Nakao Masayoshi

  Preprints of the Annual Conference, Japanese Society of Snow and Ice 公益社団法人 日本雪氷学会 2006 206 - 206 0919-7346 2006
• A snow algal community and pH on Qiyi Glacier in the Qilian Mountains, China

  Takeuchi Nozomu, Uetake Jun, Segawa Takahiro

  Preprints of the Annual Conference, Japanese Society of Snow and Ice 公益社団法人 日本雪氷学会 2006 205 - 205 0919-7346 2006
• Dating of seasonal snow/firn accumulation layers using pollen analysis

  Fumio Nakazawa, Koji Fujita, Nozomu Takeuchi, Toshiyuki Fujiki, Jun Uetake, Vladimir Aizen, Masayoshi Nakawo

  JOURNAL OF GLACIOLOGY 51 (174) 483 - 490 0022-1430 2005 [Not refereed][Not invited]
   

  Reliable chronologies in ice cores and snow pits from many alpine glaciers in latitudes between 60 degrees N and 60 degrees S are often difficult to establish owing to problems with annual-layer. counting. Problems arise from melting, wind erosion and the negligible amount of precipitation in some seasons, all of which tend to obscure the seasonal variations in delta(18)O and chemical concentrations that are typically used to date ice cores. However, alpine glaciers contain many species of pollen grains that peak at particular times of the year. We used the peaks in Betulaceae, Pinus, Artemisia and a combination of Abies and Picea pollen species to determine the four seasonal layers of a snow pit on Belukha glacier in Russia's Altai Mountains. Comparing the pollen-dated profiles with wind and precipitation records allows us to determine where a seasonal layer is missing. Thus, the pollen-dating method described here may be a useful tool to measure the annual snow deposition on alpine glaciers, even when some seasonal layers are eroded by wind or missing due to negligible precipitation.

MISC

• Studies on Atmosphere, Snow/Ice, and Glacial Microbes on Greenland Ice Sheet by SIGMA and relevant projects: ─A linkage to the ArCS II Project─

  AOKI Teruo, MATOBA Sumito, NIWANO Masashi, KUCHIKI Katsuyuki, TANIKAWA Tomonori, TAKEUCHI Nozomu, YAMAGUCHI Satoru, MOTOYAMA Hideaki, FUJITA Koji, YAMASAKI Tetsuhide, IIZUKA Yoshinori, HORI Masahiro, SHIMADA Rigen, UETAKE Jun, NAGATSUKA Naoko, ONUMA Yukihiko, HASHIMOTO Akihiro, ISHIMOTO Hiroshi, TANAKA Taichu Yasumich, OSHIMA Naga, KAJINO Mizuo, ADACHI Kouji, KUROSAKI Yutaka, SUGIYAMA Shin, TSUTAKI Shun, GOTO-AZUMA Kumiko, HACHIKUBO Akihiro, KAWAKAMI Kaoru, KINASE Takeshi  Journal of the Japanese Society of Snow and Ice  83-  (2)  169  -191  2021/03  [Not refereed]
   

  Currently occurring rapid warming in the Arctic could affect global environmental changes through sea level rise and remote atmospheric effect. The surface melting of the Greenland Ice Sheet (GrIS) involves various uncertainties, which are issues to be elucidated for accurate climate projections. To clarify how the atmosphere, snow/ice, and glacial microbes in the GrIS affect the ice sheet change under global warming, the SIGMA and SIGMA-II projects were conducted from FY2011 to FY2019. In parallel, big Arctic research projects such as GRENE and ArCS were also done, which accelerated the Japanese Greenland researches. This paper describes the research results of the SIGMA and SIGMA-II projects as well as the related research projects in the categories of (1) in-situ observations of the atmosphere, snow/ice, and glacial microbes, (2) ice core drilling, (3) satellite observation, and (4) numerical modeling. Furthermore, we discuss current issues in these studies, a linkage to the Cryosphere subject of recently launched ArCS II Project, and the importance of capacity building.
• Greenland records of aerosol source and atmospheric lifetime changes from the Eemian to the Holocene

  S. Schüpbach, H. Fischer, M. Bigler, T. Erhardt, G. Gfeller, D. Leuenberger, O. Mini, R. Mulvaney, N. J. Abram, N. J. Abram, L. Fleet, M. M. Frey, E. Thomas, A. Svensson, D. Dahl-Jensen, E. Kettner, H. Kjaer, I. Seierstad, J. P. Steffensen, S. O. Rasmussen, P. Vallelonga, M. Winstrup, A. Wegner, B. Twarloh, K. Wolff, K. Schmidt, K. Goto-Azuma, T. Kuramoto, T. Kuramoto, M. Hirabayashi, J. Uetake, J. Uetake, J. Zheng, J. Bourgeois, D. Fisher, D. Zhiheng, C. Xiao, M. Legrand, A. Spolaor, J. Gabrieli, C. Barbante, J. H. Kang, S. D. Hur, S. B. Hong, H. J. Hwang, S. Hong, M. Hansson, Y. Iizuka, I. Oyabu, R. Muscheler, F. Adolphi, F. Adolphi, O. Maselli, J. McConnell, E. W. Wolff  Nature Communications  9-  (1)  2018/12/01  [Not refereed][Not invited]
   

  © 2018 The Author(s). The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. Separating source and transport effects, we find strongly reduced terrestrial biogenic emissions during glacial times reflecting net loss of vegetated area in North America. Rapid climate changes during the glacial have little effect on terrestrial biogenic aerosol emissions. A strong increase in terrestrial dust emissions during the coldest intervals indicates higher aridity and dust storm activity in East Asian deserts. Glacial sea salt aerosol emissions in the North Atlantic region increase only moderately (50%), likely due to sea ice expansion. Lower aerosol concentrations in Eemian ice compared to the Holocene are mainly due to shortened atmospheric residence time, while emissions changed little.
• Characteristics of droplet size distributions in low-level stratiform clouds observed from Tokyo skytree

  Ryohei Misumi, Yasushi Uji, Yutaka Tobo, Kazuhiko Miura, Jun Uetake, Yoko Iwamoto, Takeshi Maesaka, Koyuru Iwanami  Journal of the Meteorological Society of Japan  96-  (4)  405  -413  2018  

  Continuous observations of cloud droplet size distributions (DSDs) in low-level stratiform clouds have been conducted at a height of 458 m from Tokyo Skytree (a 634-m-high broadcasting tower in Tokyo) using a cloud droplet spectrometer. In this report, the characteristics of cloud parameters related to the cloud DSD from June to December 2016 are presented. The mean cloud droplet number concentration (Nc), average diameters, and effective diameters of cloud droplets in non-drizzling clouds were 213 cm−3, 7.3 μm, and 9.5 μm, respectively, which are close to the reported values for continental stratiform clouds. The relationship between liquid water content (LWC; g m−3), Nc (cm−3), and radar reflectivity (Z; mm6 m−3) was estimated as LWC = 0.17 Nc0.50Z0.45, with a coefficient of determination (R2) of 0.93. The observed cloud DSDs were well fitted by a lognormal distribution, and the average median diameter of the fitted DSD was 6.6 μm.
• Biological studies on the Greenland ice sheet

  永塚 尚子, 竹内 望, 植竹 淳  月刊地球  37-  (3)  72  -82  2015/03
• 2011年及び2012年に北西グリーンランド氷床上で観測された光吸収性積雪不純物濃度

  AOKI Teruo, MATOBA Sumito, YAMAGUCHI Satoru, TANIKAWA Tomonori, NIWANO Masashi, KUCHIKI Katsuyuki, ADACHI Kouji, UETAKE Jun, MOTOYAMA Hideaki, HORI Masahiro  Bulletin of Glaciological Research  (32)  21  -31  2014/08
• Chemical composition of surface snow and ice, and precipitation on Qiyi Glacier, Qilian Mountains, western China

  三宅 隆之, 植竹 淳, 的場 澄人  雪氷  76-  (1)  3  -17  2014/01
• O34-06 グリーンランド、カナック氷河上のクリオコナイト粒の形成プロセスと分布(口頭発表)

  植竹 淳, 瀬川 高弘, 永塚 尚子, 田中 聡太, 竹内 望, 本山 秀明, 青木 輝夫  日本微生物生態学会講演要旨集  2014-  125  -125  2014
• Eemian interglacial reconstructed from a Greenland folded ice core

  D. Dahl-Jensen, M. R. Albert, A. Aldahan, N. Azuma, D. Balslev-Clausen, M. Baumgartner, A. M. Berggren, M. Bigler, T. Binder, T. Blunier, J. C. Bourgeois, E. J. Brook, S. L. Buchardt, C. Buizert, E. Capron, J. Chappellaz, J. Chung, H. B. Clausen, I. Cvijanovic, S. M. Davies, P. Ditlevsen, O. Eicher, H. Fischer, D. A. Fisher, L. G. Fleet, G. Gfeller, V. Gkinis, S. Gogineni, K. Goto-Azuma, A. Grinsted, H. Gudlaugsdottir, M. Guillevic, S. B. Hansen, M. Hansson, M. Hirabayashi, S. Hong, S. D. Hur, P. Huybrechts, C. S. Hvidberg, Y. Iizuka, T. Jenk, S. J. Johnsen, T. R. Jones, J. Jouzel, N. B. Karlsson, K. Kawamura, K. Keegan, E. Kettner, S. Kipfstuhl, H. A. Kjær, M. Koutnik, T. Kuramoto, P. Köhler, T. Laepple, A. Landais, P. L. Langen, L. B. Larsen, D. Leuenberger, M. Leuenberger, C. Leuschen, J. Li, V. Lipenkov, P. Martinerie, O. J. Maselli, V. Masson-Delmotte, J. R. McConnell, H. Miller, O. Mini, A. Miyamoto, M. Montagnat-Rentier, R. Mulvaney, R. Muscheler, A. J. Orsi, J. Paden, C. Panton, F. Pattyn, J. R. Petit, K. Pol, T. Popp, G. Possnert, F. Prié, M. Prokopiou, A. Quiquet, S. O. Rasmussen, D. Raynaud, J. Ren, C. Reutenauer, C. Ritz, T. Röckmann, J. L. Rosen, M. Rubino, O. Rybak, D. Samyn, C. J. Sapart, A. Schilt, A. M.Z. Schmidt, J. Schwander, S. Schüpbach, I. Seierstad, J. P. Severinghaus, S. Sheldon, S. B. Simonsen, J. Sjolte, A. M. Solgaard, T. Sowers, P. Sperlich, H. C. Steen-Larsen, K. Steffen, J. P. Steffensen, D. Steinhage, T. F. Stocker, C. Stowasser, A. S. Sturevik, W. T. Sturges, A. Sveinbjörnsdottir, A. Svensson, J. L. Tison, J. Uetake, P. Vallelonga, R. S.W. Van De Wal, G. Van Der Wel, B. H. Vaughn, B. Vinther, E. Waddington, A. Wegner, I. Weikusat, J. W.C. White, F. Wilhelms, M. Winstrup, E. Witrant, E. W. Wolff, C. Xiao, J. Zheng  Nature  493-  (7433)  489  -494  2013/01/24  [Not refereed][Not invited]
   

  Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future. © 2013 Macmillan Publishers Limited. All rights reserved.
• Improved direct-count method by fluorescence microscope for low-biomass ice core (in Japanese)

  Jun Uetake, Kumiko Goto-Azuma, Hideaki Motoyama  Antarctic record  56-  (1)  57  -67  2012/03/30  [Not refereed][Not invited]
   

  Ice cores recovered from ice sheets contain microorganisms that were transported to the surface of the ice sheet along with airborne dust. The abundance of microorganisms in ice cores, as measured by direct cell count under a fluorescence microscope, is generally lower than that in other aquatic environments. It is possible that the abundance of microorganisms in ice cores is underestimated due to the degradation of fluorescent dye or because non-specific fluorescence from mineral particles inhibits the fluorescence signal from microorganisms. To investigate this possibility, we tested 4 ty...
• 「北極域における積雪汚染及び雪氷微生物が急激な温暖化に及ぼす影響評価に関する研究」(SIGMAプロジェクト)の紹介

  青木輝夫, 朽木勝幸, 庭野匡思, 田中泰宙, 保坂征宏, 橋本明弘, 本山秀明, 兒玉裕二, 植竹淳, 竹内望, 的場澄人, 杉山慎, 山口悟, 本吉弘岐, 岩田幸良, 杉浦幸之助, 八久保晶弘, 堀雅裕, 谷川朋範, 本谷研, 山崎哲秀  日本気象学会大会講演予稿集  (102)  2012
• Depth distribution of microorganisms in the surface pit from accumulation area in McCall Glacier, Alaska

  Jun Uetake, Jun Uetake, Hideaki Motoyama, Fujii Yoshiyuki, Kazuhide Satow, Matt Nolan, Shuhei Takahashi  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2011-  (0)  199  -199  2011  [Not refereed][Not invited]
  
• グリーンランドNEEMにおける観測報告

  東久美子, 青木周司, 東信彦, 飯塚芳徳, 植竹淳, 川村賢二, 神田啓史, 倉元隆之, 小端拓郎, 笹公和, 佐藤基之, 瀬川高弘, 高村近子, 中澤高清, 平林幹啓, 藤井理行, 藤田秀二, 堀彰, 堀内一穂, 三宅隆之, 三宅隆之, 宮本淳, 本山秀明  極域科学・宙空圏・気水圏・生物・地学シンポジウム講演予稿集(CD-ROM)  2011-  2011
• Measurement of crystal size in Belukha ice core, Siberian Altai

  Sachiko Okamoto, Koji Fujita, Hideki Narita, Jun Uetake, Fumio Nakazawa, Nozomu Takeuchi, Takayuki Miyake, V. B. Aizen, S. A. Nikitin, Masayoshi Nakawo  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2011-  (0)  207  -207  2011  [Not refereed][Not invited]
  
• The use of DNA analysis in sectional identification of a Pinus pollen grain found in Belukha Glacier, Altain Mountains, Russia

  Nakazawa Fumio, Uetake Jun, Suyama Yoshihisa, Kaneko Ryou, Takeuchi Nozomu, Fujita Koji, Motoyama Hideaki, Kanda Hiroshi  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2011-  (0)  55  -55  2011  [Not refereed][Not invited]
  
• Communities of algae and cyanobacteria on glaciers in west Greenland

  Uetake Jun, Naganuma Takeshi, Hebsgaard Martin Bay, Kanda Hiroshi, Kohshima Shiro  Polar science  4-  (1)  71  -80  2010/05  

  Communities of algae and cyanobacteria on two glaciers in west Greenland (the Qaanaaq and Russel glaciers) were analyzed and compared with the aim of explaining why the Qaanaaq Glacier (in northwestern Greenland) has a dark-colored surface in satellite images whereas the Russel Glacier (in western central Greenland) has a light-colored surface. We found that algal andcyanobacterial communities differed between the glaciers and that the amount of biomass was higher on the colder glacier (Qaanaaq Glacier). The community on the Qaanaaq Glacier was composed mainly of green algae, whereas that on the Russel Glacier was dominated by cyanobacteria. Despite the shorter melting period (due to colder air temperature) for the QaanaaqGlacier, the biovolume of algae and cyanobacteria was 2.35 times higher than that on the Russel Glacier at a similar altitude, suggesting greater primary production on the Qaanaaq Glacier. We discuss the possible effects of temperature, nutrient concentrations, and cryoconite holes (melt-holes in the glacier) on the community structure and productivity of algae and cyanobacteria on each glacier, and consider the influence of the identified differences in algal and cyanobacterial communities on the amount of surface melt.
• グリーンランド深層氷床コア掘削計画(NEEM計画)における微生物解析の検討

  植竹淳, 植竹淳, 東久美子, 倉元隆之, 本山秀明, 神田啓史  雪氷研究大会講演要旨集  2010-  2010
• グリーンランド・NEEMにおける積雪中の化学成分の季節変化

  倉元隆之, 植竹淳, 植竹淳, 東久美子, 平林幹啓, 三宅隆之, 本山秀明  雪氷研究大会講演要旨集  2010-  2010
• グリーンランド深層氷床コア掘削計画(NEEM計画)の展望

  東久美子, 青木周司, 東信彦, 飯塚芳徳, 植竹淳, 川村賢二, 神田啓史, 倉元隆之, 小端拓郎, 笹公和, 佐藤基之, 瀬川高弘, 高村近子, 中澤高清, 平林幹啓, 藤井理行, 藤田秀二, 堀彰, 堀内一穂, 三宅隆之, 宮本淳, 本山秀明  極域科学・宙空圏・気水圏・生物・地学シンポジウム講演予稿集(CD-ROM)  2010-  2010
• Distribution of surface albedo in the Western bare ice area of the Greenland Ice Sheet derived from MODIS images

  Hiroki Ito, Nozomu Takeuchi, Shiro Kohshima, Jun Uetake  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2010-  (0)  95  -95  2010  [Not refereed][Not invited]
  
• Reconstructed summer temperature in Belukha ice core and neighbor glacier changes

  Sachiko Okamoto, Koji Fujita, Hideki Narita, Jun Uetake, Takayuki Miyake, Fumio Nakazawa, Nozomu Takeuchi, Vladimir B. Aizen, Stanislav A. Nikitin, Masayoshi Nakowo  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2010-  (0)  94  -94  2010  [Not refereed][Not invited]
  
• P-68 Diversity of eukaryotes in cryoconite on Greenland Ice sheet(Poster Session)

  UETAKE JUN, KANEKO RYO, MOTOYAMA HIDEAKI  日本微生物生態学会講演要旨集  (26)  128  -128  2010
• DNA analysis of a single Pinus pollen grain in a glacier (Part 2)

  Nakazawa Fumio, Uetake Jun, Suyama Yoshihisa, Kaneko Ryou, Takeuchi Nozomu, Fujita Koji, Motoyama Hideaki, Kanda Hiroshi  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2010-  (0)  93  -93  2010  [Not refereed][Not invited]
  
• North Greenland Eemian Ice Driling

  Kumiko Goto-Azuma, Jun Uetake, Kenji Kawamura, Hiroshi Kanda, Takayuki Kuramoto, Takuro Kobashi, Takahiro Segawa, Chiikako Takamura, Motohiro Hirabayashi, Yoshiyuki Fujii, Shuji Fujita, Takayuki Miyake, Hideaki Motoyama, Shuji Aoki, Takakiyo Nakazawa, Nobuhiko Azuma, Motoyuki Sato, Yoshinori Iizuka, Atsushi Miyamoto, Kimikazu Sasa, Akira Hori, Kazuho Horiuchi  Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research  2010-  4  2010/01/01  [Not refereed][Not invited]
  
• Spore-forming halophilic bacteria isolated from Arctic terrains: Implications for long-range transportation of microorganisms

  Yukimura Kise, Nakai Ryosuke, Kohshima Shiro, Uetake Jun, Kanda Hiroshi, Naganuma Takeshi  Polar science  3-  (3)  163  -169  2009/11  

  Organisms living in the Arctic terrains such as Greenland have to deal with low temperature conditions. The mechanisms by which bacteria resist to low temperature are largely unknown; however, a well-known survival strategy of the microorganisms inhabiting the Arctic is spore forming. Moreover, halophilic bacteria are often resistant to various stresses. We have attempted isolation of spore-forming halophilic bacteria from Arctic terrains. We isolated 10 strains of spore-forming halophilic bacteria from the samples collected from a glacial moraine in Qaanaaq, Greenland in July 2007. Identification based on 16S rRNA gene sequence similarities showed that the isolates were closely related to the Oceanobacillus, Ornithinibacillus, Virgibacillus, Gracilibacillus, and Bacillus genera. In addition, the 16S rRNA sequences of some isolates were extremely similar to those of strains from the desert sand in China (100% identity, near full length), the source of the so-called "yellow dust." Previous research indicated that yellow dust had been transported to Greenland by the wind. Our research implies the long-range transportation of these microorganisms to locations such as the Arctic.
• P-54 アラスカ、グルカナ氷河における好冷性酵母群集について(ポスター発表)

  植竹 淳, 永塚 尚子, 吉村 義隆  日本微生物生態学会講演要旨集  (25)  76  -76  2009
• 日本地球惑星科学連合2008年大会参加報告

  中澤 文男, 三宅 隆之, 紺屋 恵子, 田中 基樹, 五十嵐 誠, 植竹 淳  雪氷 : 日本雪氷協會雜誌  70-  (5)  507  -509  2008/09/15
• 04-062 Snow algal communities on the glaciers in West Greenland(Extremophiles)

  Uetake Jun, Naganuma Takeshi, Kanda Hiroshi, Kohshima Shiro  日本微生物生態学会講演要旨集  (24)  89  -89  2008
• Stratigraphical studies in accumulation area of McCall glacier, Alaska, 2004

  SATOW Kazuhide, Uetake Jun, Takahashi Shuhei, Sato Kengo, Yamazaki Tetsuhide, Takahashi Akiyoshi, Nolan Matt, Igarashi Makoto, Fujii Yoshiyuki  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2006-  (0)  105  -105  2006  [Not refereed][Not invited]
  
• Meteorological observation at July 1st Glacier in northwest China from 2002 to 2005

  SAKAI Akiko, MATSUDA Yoshihiro, FUJITA Koji, MATOBA Sumito, UETAKE Jun, SATOW Kazuhide, DUAN Keqin, PU Jianchen, NAKAWO Masayoshi, YAO Tandong  Bull. Glaciological Res.  23-  23  -32  2006/01/01
• Preliminary observations of sub-surface and shallow ice core at July 1st Glacier, China in 2002-2004

  UETAKE Jun, SAKAI Akiko, MATSUDA Yoshihiro, FUJITA Koji, NARITA Hideki, MATOBA Sumito, DUAN Keqin, NAKAWO Masayoshi, YAO Tandong  Bulletin of glaciological research  23-  85  -93  2006/01/01
• Biological ice-core analysis of Sofiyskiy glacier in the Russian Altai

  UETAKE J.  Ann. Glaciol.  43-  70  -78  2006
• Concentrations, deposition rates and source variations of n-alkanes in Sofiyskiy Glacier, Russian Altai Mountains

  MIYAKE Takayuki, NAKAZAWA Fumio, KOHNO Mika, UETAKE Jun, SUZUKI Keisuke, KAMEDA Takao, FUJII Yoshiyuki, NAKAWO Masayoshi, OHTA Keiichi  Bulletin of glaciological research  22-  81  -87  2005/03/01
• Size distribution and deposition rate of dust in an ice core at Belukha Glacier, Russian Altai Mountains

  Miyake Takayuki, Fujii Yoshiyuki, Nakazawa Fumio, Uetake Jun, Takeuchi Nozomu, Fujita Koji, Nakawo Masayoshi  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2005-  (0)  147  -147  2005  [Not refereed][Not invited]
  
• Glacio-biological ice cores analyses from Belukha Glacier

  Uetake Jun, Kohshima Shiro, Nalazawa Fumio, Takeuchi Nozomu, Miyake Takayuki, Fujita Koji, Nakawo Masayoshi  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2005-  (0)  148  -148  2005  [Not refereed][Not invited]
  
• Distribution of red snow on the Harding Icefield in Alaska, derived from a satellite image

  Takeuchi Nozomu, DIal Roman, Kohshima Shiro, Segawa Takahiro, Uetake Jun  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2005-  (0)  37  -37  2005  [Not refereed][Not invited]
  
• A report on ice core drilling on the western plateau of Mt. Belukha in the Russian Altai Mountains in 2003

  Takeuchi Nozomu, Takahashi Akiyoshi, Uetake Jun, Yamazaki Tetsuya, Aizen Vladimir B., Joswiak Daniel, Surazakov Arzhan, Nikitin Stanislav  Polar meteorology and glaciology  18-  121  -133  2004/11  

  A 171m deep ice core from the surface to the bottom has been successfully drilled on the West Belukha snow-firn Plateau in the Russian Altai Mountains in the summer of 2003. The drill system used in this project was an electro-mechanical drill with a barrel 135cm long and 9.5cm in inner diameter manufactured by Geo Tecs Co., Japan. The maximum core length for a drilling run is 55cm. It took 87.5 hours in actual working time of 7 working days to drill the core down to the bottom of the glacier. The total number of drilling runs was 325. The mean length of the drilled core was 48.6cm. Most of the cores were not brittle and had a good cylindrical shape. High air temperature above the melting point in the drilling shelter caused some trouble in drilling. One of the major troubles was slip of cutters due to adhesion of cutting tips to the cutters and shoes.
• ロシア・アルタイ山脈ベルーハ氷河でのアイスコア掘削

  植竹 淳  雪氷  66-  (1)  89  -93  2004/01/15
• Glacio-biological research on Qiyi Glacier, Qi-lian Mountains, China

  Uetake Jun, Khoshima Shiro, Takeuchi Nozomu, sakai akiko, Matsuda Yoshihiro  Preprints of the Annual Conference, Japanese Society of Snow and Ice  2004-  (0)  103  -103  2004  [Not refereed][Not invited]
  
• Application of pollen analysis to dating of ice cores from lower-latitude glaciers

  Nakazawa Fumio, Fujita Koji, Uetake Jun, Kohno Mika, Fujiki Toshiyuki, Serguei M. Arkhipov, Kameda Takao, Suzuki Keisuke, Fujii Yoshiyuki  Journal of Geophysical Research  109-  (4)  F04001  2004
• Stratigraphy and ice grains of a 25.3m ice core from Sofiyskiy Glacier, Russian Altai Mountains, in 2001

  KAMEDA Takao, FUJII Yoshiyuki, SUZUKI Keisuke, KOHNO Mika, NAKAZAWA Fumio, UETAKE Jun, SAVATYUGIN Lev M., ARKHIPOV Serguei M., PONOMAREV Ivan A., MIKHAILOV Nikolay N.  Bulletin of glaciological research  21-  65  -69  2004/01/01
• Meteorological observations on Sofiyskiy Glacier, Russian Altai Mountains

  Suzuki Keisuke, Kameda Takao, Kohno Mika, Nakazawa Fumio, Uetake Jun, Fujii Yoshiyuki  Polar meteorology and glaciology  16-  140  -148  2002/11  

  Meteorological observations were carried out on Sofiyskiy Glacier from July 7 to 17, 2001. Air temperature, relative humidity, wind direction, wind speed, atmospheric pressure and global radiation were measured with automatic instruments every ten minutes. Snow surface height was measured using a stake installed in the surface snow several times a day. The net gain of snow surface during the observation period was 268 mm. In the first half of the observation period, air temperature exceeded 3°C during the daytime, but air temperature never became positive during the latter half of the observation period. The heat balance was examined from the meteorological data. The values of estimated snowmelt and observed snowmelt correspond almost exactly.
• Outline of Japan-Russia joint Glaciological Research on Sofiyskiy Glacier, Russian Altai Mountains in 2000 and 2001

  FUJII Yoshiyuki, KAMEDA Takao, NISHIO Fumihiko, SUZUKI Keisuke, KOHNO Mika, NAKAZAWA Fumio, UETAKE Jun, SAVATYUGIN Lev M., ARKHIPOV Serguei M., PONOMAREV lvan A., MIKHAILOV Nikolay N.  Bulletin of glaciological research  19-  53  -58  2002/02/01
• High net accumulation rates at Campo de Hielo Patagonico Sur, South America, revealed by analysis of a 45.97 m long ice core

  T Shiraiwa, S Kohshima, R Uemura, N Yoshida, S Matoba, J Uetake, MA Godoi  ANNALS OF GLACIOLOGY, VOL 35  35-  84  -90  2002  [Not refereed][Not invited]
   

  A 45.97 in long ice core was recovered in the accumulation area of Glaciar Tyndall (50degrees59'05" S, 73degrees31'12" W, 1756 in a.s.l.), Campo de Hielo Patagonico Sur (southern Patagonia icefield), during December 1999. The firn core was subjected to visual stratigraphic observation and bulk density measurements in the field, and later to analyses of water isotopes (delta(18)O, deltaD), major dissolved ions and snow algal biomass. The drillhole remained dry down to about 43 in depth, where a water-soaked layer appeared. Seasonal cycles were found for delta(18)O, deltaD and the D-excess, although the amplitudes of the cycles decreased with depth. Major dissolved ions (Na+, K+, Mg2+, Ca2+, Cl-, SO42-) and algal biomass exhibit rapid decreases in the upper 3 in, probably due to meltwater elution. Annual increments defined by the 518 0 and D-excess peaks suggest that the minimum net accumulation rates at this location were 17.8 in a(-1) in 1997/98-1998/99 and > 11.0 in a(-1) in 1998/99-1999/2000. These are much higher values than those previously obtained from past ice-core studies in Patagonia, but are of the same order of magnitude as those predicted from various observations in ablation areas of Patagonian glaciers.

Research Projects

• International joint research on Arctic natural aerosols under warm conditions in Southern Greenland

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2023/09 -2026/03 

  Author : 當房 豊, 吉田 淳, 植竹 淳, 大畑 祥, 足立 光司
• 氷河・積雪生態系における雪氷藻類へのツボカビ感染症の動態解明

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2022/04 -2026/03 

  Author : 鏡味 麻衣子, 三木 健, 竹内 望, 植竹 淳, 村上 正志, 瀬川 高弘
• Seasonal change and the origins of bioaerosol in the forest.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2022/04 -2025/03 

  Author : 植竹 淳
• Expansion of microbial blooming on glaciers induced by abrupt environmental changes

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2019/04 -2024/03 

  Author : 竹内 望, 植竹 淳, 瀬川 高弘, 米澤 隆弘, 幸島 司郎, 服部 祥平

   

  当初2020年度に予定していたアラスカ氷河の野外調査は，2021年度に予算繰り越しを行い実施する計画を立てていた．しかしながら，新型コロナ感染症の流行は収まることはなく，2021年度も海外野外調査を実施することはできなかった．その代わり，国内の積雪表面を対象に野外調査を実施し，さらに過去に採取された試料の分析をすすめた．国内の積雪では，雪氷藻類の繁殖が進んだ表面には，藻類お捕食者となるクマムシやワムシも多く存在することを発見し，論文で発表した（Ono et al., 2021）．またアラスカの赤雪の分析を進めたところ，赤雪細胞の表面に大量の多糖類が分泌されていることが明らかになり，この多糖類が細胞の凝集効果を持っていることが明らかになり，論文に発表した（Folika et al., 2020）．氷河表面の暗色化の原因物質の一つ，クリオコナイトについても過去に採取したサンプルの分析を進めた．クリオコナイトの粒構造分析を行なった結果，内部では嫌気条件となっており，そこに繁殖する嫌気的細菌類が特に窒素循環に重要な役割を果たしていることが明らかになった（Segawa et al., 2020）．中央アジアの氷河ではアルベドの時空間変動が，クリオコナイトの表面量の変動で説明できることが明らかになった（Yue et al., 2020）． さらに，クリオコナイトには放射性元素が特異的に濃縮していることも明らかになった（Baccolo et al., 2020）．2021年度に繰り越した予算は，研究遂行に必須である雪氷試料の化学成分を分析するイオンクロマトグラフィーが故障したため，一部を新しく購入するために利用した．
• Elucidation of Changes in the fungal communities in seasonal variations using by next generation sequence

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2016/04 -2018/03 

  Author : Tsuji Masaharu

   

  In this study, we investigated the changes of fungal community in soil collected from different season at the same sampling point of East Ongul Island, East Antarctica using by next generation sequencer. As a result of next generation sequence analysis, the fungal sequence data were classified to 128 OTU. By detailed analysis of the OTU about changes of the fungal community by different seasons (Spring and Autumn), the fungal community was dramatically changed by seasons. This is a first report about changes of the fungal community by seasons in Antarctica.
• Effects of global environmental changes on glacier ecosystems

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2014/04 -2018/03 

  Author : Kohshima Shiro

   

  We genetically analyzed microorganisms collected from the glaciers in various part of the world and found regional difference in species composition of bacteria and cyanobacteria in cryoconites, biogenic dark granules on the glacier that accelerate glacier melting. We could also identify symbiotic bacteria of glacier animals. We developed mathematical model simulating changes in cryoconite holes, melt holes on the glacier formed by cryoconite, to establish the mass valance model of the glacier including biological albedo reducing process.
• 消え行く熱帯氷河の微生物多様性の解明

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2015/04 -2017/03 

  Author : 植竹 淳

   

  昨年度に行ったケニア山の氷河に生息している微生物の多様性に関する予備調査を踏まえ、氷河上での不均一性や同一地点での経年変化、また氷河周辺土壌に与える影響を評価するために、ルイス氷河において観測機器の回収、観測、サンプルの採取を行った。現地に設置したインターバルカメラの結果から、本氷河の融解による表面低下が非常に大きいことがわかり、設置期間中の２０１７年２月に氷河中流部の岩が露出し、ルイス氷河が上下に分断する様子を記録することができた。 DNA分析の結果、同氷河が隣国のウガンダ、ルウェンゾリ山の氷河よりも中国、天山山脈や北極、スバールバードの氷河に生息している微生物の群集構造に近いことがわかり、氷河上の微生物が全球的な粒子の移動と循環の影響を受けている可能性を示した。
• Effects of snow impurities and glacial microbes on abrupt warming in the Arctic

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2011/04 -2016/03 

  Author : Aoki Teruo, MOTOYAMA Hideaki, TAKEUCHI Nozomu, MATOBA Sumito, HORI Masahiro, HACHIKUBO Akihiro, YAMAGUCHI Satoru, TANAKA Yasumichi, IWATA Yukiyoshi, SUGIURA Konosuke, KODAMA Yuji, FUJITA Koji, KUCHIKI Katsuyuki, NIWANO Masashi, HOSAKA Masahiro, HASHIMOTO Akihiro, TANIKAWA Tomonori, TANAKA Yasumichi, UETAKE Jun, NAGATSUKA Naoko, SUGIYAMA Shin, MOTOYOSHI Hiroki, SHIMODA Seiji, MOTOYA Ken

   

  From field observations on Greenland ice sheet, it was found that the contribution to albedo reduction in accumulation area by snow impurities such as black carbon (BC) is smaller than that by snow grain growth. Drastic surface melting event in July 2012 was accelerated by downward longwave radiation from low cloud. In ablation area, glacial microbes were contained in surface impurities and could contribute to the albedo reduction remarkably. Satellite remote sensing confirmed that the cause of darkening of ice sheet surface after 2000 is snow grain growth in accumulation area and the expansions of bare ice and dark area including glacial microbes in ablation area. We drilled a 223 m ice core in northwest Greenland ice sheet and analyzed the BC concentrations since 1660, which has a peak around 1920-1930 several times higher than the present value.
• Warming events and their impacts during the past 150,000 years viewed from Greenland ice

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2010/04 -2016/03 

  Author : Azuma Kumiko, KAWAMURA Kenji, FUJITA Shuji, UETAKE Jun, MOTOYAMA Hideaki, HIRABAYASHI Motohiro, KOBASHI Takuro, TAKAMURA Chikako, KURAMOTO Takayuki, SEGAWA Takahiro, AOKI Shuji, AZUMA Nobuhiko, IIZUKA Yoshinori

   

  We analyzed the ice core drilled under the international project North Greenland Eemian Ice Drilling. The air temperature during the warmest period of Eemian interglacial was warmer than the present by 8℃±４℃, which caused extensive surface melt in north Greenland. The thickness of the northwest Greenland ice sheet decreased by 400±250ｍ during 6000 years, which was much smaller than that had been expected. Mass loss of Antarctic ice sheet should have played a role in sea-level rise during the Eemian. Variations of methane, nitrous oxide, noble gases in the air extracted from the ice core, and those of ionic species and bacterial cell concentrations in ice provided us with valuable information on changes in atmospheric circulation, vegetation, microbial activities, mean ocean temperature etc during the warm periods and abrupt warming events.
• Accelerate the melting of tropical glacier by glacier organisms

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2013/04 -2015/03 

  Author : UETAKE Jun

   

  Tropical regions are not well represented in glacier biology, yet many tropical glaciers are under threat of disappearance due to climate change. Here we report a novel biogenic aggregation at the terminus of a glacier in the Rwenzori Mountains, Uganda. The material was formed by uniseriate protonemal moss gemmae and protonema. Molecular analysis of five genetic markers determined the taxon as Ceratodon purpureus, a cosmopolitan species that is widespread in tropical to polar region. Given optimal growing temperatures of isolate is 20–30℃, the cold glacier surface might seem unsuitable for this species. However, the cluster of protonema growth reached approximately 10℃ in daytime, suggesting that diurnal increase in temperature may contribute to the moss’s ability to inhabit the glacier surface. The aggregation is also a habitat for microorganisms, and the disappearance of this glacier will lead to the loss of this unique ecosystem.
• Biological analysis of ice core from Antarctica and reconstruction of past environment

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2010 

  Author : UETAKE Jun

   

  In Dome Fuji ice core, filamentous bacteria-like particle, had not been observed in the surface, were found in some layers. As concentration of coccoid bacteria is high in the end of glacial age when dust particle concentration is high, these match suggest coccoid bacteria are transported by wind with other particles like dust. This result indicate similar tendency as previous study in Vostok, and support them. Otherwise, concentration of filamentous bacteria-like particle is high in mid-last glacial age and early-Holocene, and these have no relationship with dust particle.