Faculty Profiles - UEMURA Ryu

Papers - UEMURA Ryu

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A 180-year-long isotopic record of tree-ring cellulose on Okinawa Island, Japan Reviewed

Ryu Uemura, Miki Uemura, Masaki Sano, Takeshi Nakatsuka

Geochemical Journal Vol. 52 ( 6 ) page： e21 - e27 2018.11

Asynchrony between Antarctic temperature and CO2 associated with obliquity over the past 720,000 years Reviewed

Uemura Ryu, Motoyama Hideaki, Masson-Delmotte Valerie, Jouzel Jean, Kawamura Kenji, Goto-Azuma Kumiko, Fujita Shuji, Kuramoto Takayuki, Hirabayashi Motohiro, Miyake Takayuki, Ohno Hiroshi, Fujita Koji, Abe-Ouchi Ayako, Iizuka Yoshinori, Horikawa Shinichiro, Igarashi Makoto, Suzuki Keisuke, Suzuki Toshitaka, Fujii Yoshiyuki

Nature Communications Vol. 9 2018.3

Spatial variation of isotopic compositions of snowpack nitrate related to post-depositional processes in eastern Dronning Maud Land, East Antarctica Reviewed

Noro Kazushi, Hattori Shohei, Uemura Ryu, Fukui Kotaro, Hirabayashi Motohiro, Kawamura Kenji, Motoyama Hideaki, Takenaka Norimichi, Yoshida Naohiro

GEOCHEMICAL JOURNAL Vol. 52 ( 2 ) page： E7-E14 2018.3

A 60 Year Record of Atmospheric Aerosol Depositions Preserved in a High-Accumulation Dome Ice Core, Southeast Greenland Reviewed

Yoshinori Iizuka, Ryu Uemura, Koji Fujita, Shohei Hattori, Osamu Seki, Chihiro Miyamoto, Toshitaka Suzuki, Naohiro Yoshida, Hideaki Motoyama, Sumito Matoba

Journal of Geophysical Research: Atmospheres Vol. 123 ( 1 ) page： 574 - 589 2018.1

Publishing type：Research paper (scientific journal) Publisher：Wiley-Blackwell

©2017. American Geophysical Union. All Rights Reserved. The Southeastern Greenland Dome (SE-Dome) has both a high elevation and a high accumulation rate (1.01 m we yr−1), which are suitable properties for reconstructing past environmental changes with a high time resolution. For this study, we measured the major ion fluxes in a 90 m ice core drilled from the SE-Dome region in 2015 and present the records of annual ion fluxes from 1957 to 2014. From 1970 to 2010, the trend of nonsea-salt (nss) SO42− flux decreases, whereas that for NH4+ increases, tracking well with the anthropogenic SOx and NH3 emissions mainly from North America. The result suggests that these fluxes reflect histories of the anthropogenic SOx and NH3 emissions. In contrast, the decadal trend of NO3− flux differs from the decreasing trend of anthropogenic NOx emissions. Although the cause of this discrepancy remains unclear, it may be related to changes in particle formation processes and chemical scavenging rates caused by an increase in sea salt and dust and/or a decrease in nssSO42−. We also find a high average NO3− flux (1.13 mmol m−2 yr−1) in the ice core, which suggests a negligible effect from postdepositional NO3− loss. Thus, the SE-Dome region is an excellent location for reconstructing nitrate fluxes. Over a decadal time scale, our NO3− flux record is similar to those from other ice cores in Greenland high-elevation sites, suggesting that NO3− concentration records from these ice cores are reliable.

DOI： 10.1002/2017JD026733

Web of Science

Scopus

Seasonal-Scale Dating of a Shallow Ice Core From Greenland Using Oxygen Isotope Matching Between Data and Simulation Reviewed

Ryoto Furukawa, Ryu Uemura, Koji Fujita, Jesper Sjolte, Kei Yoshimura, Sumito Matoba, Yoshinori Iizuka

JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Vol. 122 ( 20 ) page： 10873 - 10887 2017.10

Publishing type：Research paper (scientific journal) Publisher：AMER GEOPHYSICAL UNION

A precise age scale based on annual layer counting is essential for investigating past environmental changes from ice core records. However, subannual scale dating is hampered by the irregular intraannual variabilities of oxygen isotope (delta O-18) records. Here we propose a dating method based on matching the delta O-18 variations between ice core records and records simulated by isotope-enabled climate models. We applied this method to a new delta O-18 record from an ice core obtained from a dome site in southeast Greenland. The close similarity between the delta O-18 records from the ice core and models enables correlation and the production of a precise age scale, with an accuracy of a few months. A missing delta O-18 minimum in the 1995/1996 winter is an example of an indistinct delta O-18 seasonal cycle. Our analysis suggests that the missing delta O-18 minimum is likely caused by a combination of warm air temperature, weak moisture transport, and cool ocean temperature. Based on the age scale, the average accumulation rate from 1960 to 2014 is reconstructed as 1.02 m yr(-1) in water equivalent. The annual accumulation rate shows an increasing trend with a slope of 3.6 mm yr(-1), which is mainly caused by the increase in the autumn accumulation rate of 2.6 mm yr(-1). This increase is likely linked to the enhanced hydrological cycle caused by the decrease in Arctic sea ice area. Unlike the strong seasonality of precipitation amount in the ERA reanalysis data in the southeast dome region, our reconstructed accumulation rate suggests a weak seasonality.

DOI： 10.1002/2017JD026716

Web of Science

A global multiproxy database for temperature reconstructions of the Common Era Reviewed

Julien Emile-Geay, Nicholas P. McKay, Darrell S. Kaufman, Lucien von Gunten, Jianghao Wang, Kevin J. Anchukaitis, Nerilie J. Abram, Jason A. Addison, Mark A.J. Curran, Michael N. Evans, Benjamin J. Henley, Zhixin Hao, Belen Martrat, Helen V. McGregor, Raphael Neukom, Gregory T. Pederson, Barbara Stenni, Kaustubh Thirumalai, Johannes P. Werner, Chenxi Xu, Dmitry V. Divine, Bronwyn C. Dixon, Joelle Gergis, Ignacio A. Mundo, Takeshi Nakatsuka, Steven J. Phipps, Cody C. Routson, Eric J. Steig, Jessica E. Tierney, Jonathan J. Tyler, Kathryn J. Allen, Nancy A.N. Bertler, Jesper BjÃ¶rklund, Brian M. Chase, Min-Te Chen, Ed Cook, Rixt de Jong, Kristine L. DeLong, Daniel A. Dixon, Alexey A. Ekaykin, Vasile Ersek, Helena L. Filipsson, Pierre Francus, Mandy B. Freund, Massimo Frezzotti, Narayan P. Gaire, Konrad Gajewski, Quansheng Ge, Hugues Goosse, Anastasia Gornostaeva, Martin Grosjean, Kazuho Horiuchi, Anne Hormes, Katrine Husum, Elisabeth Isaksson, Selvaraj Kandasamy, Kenji Kawamura, K. Halimeda Kilbourne, Nalan Ko{\c{c}}, Guillaume Leduc, Hans W. Linderholm, Andrew M. Lorrey, Vladimir Mikhalenko, P. Graham Mortyn, Hideaki Motoyama, Andrew D. Moy, Robert Mulvaney, Philipp M. Munz, David J. Nash, Hans Oerter, Thomas Opel, Anais J. Orsi, Dmitriy V. Ovchinnikov, Trevor J. Porter, Heidi A. Roop, Casey Saenger, Masaki Sano, David Sauchyn, Krystyna M. Saunders, Marit-Solveig Seidenkrantz, Mirko Severi, Xuemei Shao, Marie-Alexandrine Sicre, Michael Sigl, Kate Sinclair, Scott St. George, Jeannine-Marie St. Jacques, Meloth Thamban, Udya Kuwar Thapa, Elizabeth R. Thomas, Chris Turney, Ryu Uemura, Andre E. Viau, Diana O. Vladimirova, Eugene R. Wahl, James W.C. White, Zicheng Yu, Jens Zinke

Scientific Data Vol. 4 page： 170088 2017.7

State dependence of climatic instability over the past 720,000 years from Antarctic ice cores and climate modeling Reviewed

and Kenji Kawamura, Ayako Abe-Ouchi, Hideaki Motoyama, Yutaka Ageta, Shuji Aoki, Nobuhiko Azuma, Yoshiyuki Fujii, Koji Fujita, Shuji Fujita, Kotaro Fukui, Teruo Furukawa, Atsushi Furusaki, Kumiko Goto-Azuma, Ralf Greve, Motohiro Hirabayashi, Takeo Hondoh, Akira Hori, Shinichiro Horikawa, Kazuho Horiuchi, Makoto Igarashi, Yoshinori Iizuka, Takao Kameda, Hiroshi Kanda, Mika Kohno, Takayuki Kuramoto, Yuki Matsushi, Morihiro Miyahara, Takayuki Miyake, Atsushi Miyamoto, Yasuo Nagashima, Yoshiki Nakayama, Takakiyo Nakazawa, Fumio Nakazawa, Fumihiko Nishio, Ichio Obinata, Rumi Ohgaito, Akira Oka, Jun'ichi Okuno, Junichi Okuyama, Ikumi Oyabu, Fr{\'{e}}d{\'{e}}ric Parrenin, Frank Pattyn, Fuyuki Saito, Takashi Saito, Takeshi Saito, Toshimitsu Sakurai, Kimikazu Sasa, Hakime Seddik, Yasuyuki Shibata, Kunio Shinbori, Keisuke Suzuki, Toshitaka Suzuki, Akiyoshi Takahashi, Kunio Takahashi, Shuhei Takahashi, Morimasa Takata, Yoichi Tanaka, Ryu Uemura, Genta Watanabe, Okitsugu Watanabe, Tetsuhide Yamasaki, Kotaro Yokoyama, Masakazu Yoshimori, Takayasu Yoshimoto

Science Advances Vol. 3 ( 2 ) page： e1600446 2017.2

Climate dependent contrast in surface mass balance in East Antarctica over the past 216 ka Reviewed

F. PARRENIN, S. FUJITA, A. ABE-OUCHI, K. KAWAMURA, V. MASSON-DELMOTTE, H. MOTOYAMA, F. SAITO, M. SEVERI, B. STENNI, R. UEMURA, E. W. WOLFF

Journal of Glaciology Vol. 62 ( 236 ) page： 1037 2016.12

Physicochemical properties of bottom ice from Dome Fuji, inland East Antarctica Reviewed

Ohno Hiroshi, Iizuka Yoshinori, Hori Akira, Miyamoto Atsushi, Hirabayashi Motohiro, Miyake Takayuki, Kuramoto Takayuki, Fujita Shuji, Segawa Takahiro, Uemura Ryu, Sakurai Toshimitsu, Suzuki Toshitaka, Motoyama Hideaki

JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE Vol. 121 ( 7 ) page： 1230-1250 2016.7

Spatial distributions of soluble salts in surface snow of East Antarctica Reviewed

Yoshinori Iizuka, Hiroshi Ohno, Ryu Uemura, Toshitaka Suzuki, Ikumi Oyabu, Yu Hoshina, Kotaro Fukui, Motohiro Hirabayashi, Hideaki Motoyama

Tellus B Vol. 68 ( 0 ) 2016.7

Sulfur isotopic composition of surface snow along a latitudinal transect in East Antarctica Reviewed

Ryu Uemura, Kosuke Masaka, Kotaro Fukui, Yoshinori Iizuka, Motohiro Hirabayashi, Hideaki Motoyama

Geophys. Res. Lett. Vol. 43 ( 11 ) page： 5878 2016.6

Acquisition of isotopic composition for surface snow in East Antarctica and the links to climatic parameters Reviewed

Alexandra Touzeau, AmaÃ«lle Landais, Barbara Stenni, Ryu Uemura, Kotaro Fukui, Shuji Fujita, Sarah Guilbaud, Alexey Ekaykin, Mathieu Casado, Eugeni Barkan, Boaz Luz, Olivier Magand, Gr{\'{e}}gory Teste, Emmanuel Le~Meur, M{\'{e}}lanie Baroni, JoÃ«l Savarino, Ilann Bourgeois, Camille Risi

The Cryosphere Vol. 10 ( 2 ) page： 837 2016.4

Precise oxygen and hydrogen isotope determination in nanoliter quantities of speleothem inclusion water by cavity ring-down spectroscopic techniques Reviewed

Ryu Uemura, Masashi Nakamoto, Ryuji Asami, Satoru Mishima, Masakazu Gibo, Kosuke Masaka, Chen Jin-Ping, Chung Che Wu, Yu Wei Chang, Chuan Chou Shen

Geochimica et Cosmochimica Acta Vol. 172 page： 159-176 2016.1

Late Holocene coral reef environment recorded in Tridacnidae shells from archaeological sites in Okinawa-jima, subtropical southwestern Japan Reviewed

Asami R, Konishi M, Tanaka K, Uemura R, Furukawa M, Shinjo R

Island Arc Vol. 24 ( 1 ) page： 61-72 2015

Chemical compositions of sulfate and chloride salts over the last termination reconstructed from the Dome Fuji ice core, inland Antarctica Reviewed

Oyabu I, Iizuka Y, Uemura R, Miyake T, Hirabayashi M, Motoyama H, Sakurai T, Suzuki T, Hondoh T

Journal of Geophysical Research Atmospheres Vol. 119 ( 24 ) page： 14045-14058 2014

日本-スウェーデン共同南極トラバース2007/2008実施報告(1)企画立案・事前準備と科学研究成果の概要 Reviewed

藤田秀二, 福井幸太郎, 中澤文男, 榎本浩之, 杉山慎, 藤井理行, 藤田耕史, 古川晶雄, 原圭一郎, 保科優, 五十嵐誠, 飯塚芳徳, 伊村智, 本山秀明, スーディクスィルヴィアン, 植村立

南極資料 Vol. 58 ( 3 ) page： 352 - 392 2013.3

Direct linking of Greenland and Antarctic ice cores at the Toba eruption (74 ka BP) Reviewed

A. Svensson, M. Bigler, T. Blunier, H. B. Clausen, D. Dahl-Jensen, H. Fischer, S. Fujita, K. Goto-Azuma, S. J. Johnsen, K. Kawamura, S. Kipfstuhl, M. Kohno, F. Parrenin, T. Popp, S. O. Rasmussen, J. Schwander, I. Seierstad, M. Severi, J. P. Steffensen, R. Udisti, R. Uemura, P. Vallelonga, B. M. Vinther, A. Wegner, F. Wilhelms, and M. Winstrup

Climate of the Past Vol. 9 ( 2 ) page： 749-766 2013

Ranges of moisture-source temperature estimated from Antarctic ice cores stable isotope records over glacial-interglacial cycles Reviewed

Ryu Uemura, Valérie Masson-Delmotte, Jean Jouzel, Amaelle Landais, Hideaki Motoyama, Barbara Stenni

Climate of the Past Vol. 8 page： 1109-1125 2012.6

Factors controlling isotopic composition of precipitation on Okinawa Island, Japan: Implications for paleoclimate reconstruction in the East Asian Monsoon region Reviewed

Ryu Uemura, Nao Yonezawa, Kei Yoshimura, Ryuji Asami, Hisashi Kadena, Keita Yamada, Naohiro Yoshida

Journal of Hydrology Vol. 475 page： 314–322 2012

Sulphate-climate coupling over the past 300,000 years in inland Antarctica Reviewed

Yoshinori Iizuka, Ryu Uemura, Hideaki Motoyama, Toshitaka Suzuki, Takayuki Miyake, Motohiro Hirabayashi, and Takeo Hondoh

Nature Vol. 490 ( 7418 ) page： 81-84 2012

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