ArCS Arctic Challenge for Sustainability Project

International Collaborative Researches
Study atmospheric climate forcers in the Arctic

Theme 3
Atmospheric climate forcers in the Arctic

Dr. Makoto Koike (NIPR)

PI : Makoto Koike (NIPR)Implementation Structure

Study Sites : Ny-Ålesund (Norway), Barrow (US), Baranova (Russia) , Nord (Greenland), Siberia, Bering Sea, Arctic Sea, Northern Pacific, Alaska, Tomsk, Surgut / Yakutsk, Elgeeii (Siberia), Fairbanks (Alaska, US), Churchill (Canada), and Narita-Paris Aircraft

Background of the Research

The Arctic is warming. The main driver is an increase in the global atmospheric concentration of carbon dioxide (CO2), which is a long-lived greenhouse gas (GHG). In addition, short-lived climate forcers (SLCFs), such as black carbon aerosol (BC) and gaseous methane (CH4), potentially make a large contribution to Arctic climate change. BC efficiently absorbs solar radiation, potentially leading to an acceleration of ice-albedo feedback. CH4 emissions from thawing permafrost will potentially enhance Arctic warming, thus leading to positive feedback. However, there are large uncertainties in their behaviors and impacts. The Arctic Council’s AMAP (Arctic Monitoring and Assessment Programme) has reported that there is a need for further systematic studies of GHGs and SLCFs.

Overview of the Research

The aim of this study is to characterize behaviors of SLCFs (such as BC and CH4) and other GHGs in the Arctic atmosphere and to quantify contributions of individual sources/sinks or fluxes of these compounds. We measure atmospheric BC (at selected sites, by aircraft and ship) in the Arctic using high-accuracy instruments, which we have developed. A technique to measure BC in precipitation (rain and snow) and snow on the ground has also been developed, and we evaluate wet deposition flux of BC in the Arctic. Using advanced numerical models, we evaluate contributions of individual BC sources (regions and source types). We also characterize behaviors of clouds using in-situ, radar/lidar, and satellite measurements.

To study GHG flux, we combine top-down and bottom-up approaches. In the former method, we estimate fluxes from atmospheric concentration measurements using numerical models. In the latter method, we directly measure fluxes at a number of representative sites and estimate fluxes from a wide area over the Arctic. By conducting these high-accuracy measurements and using advanced numerical models, we characterize temporal and spatial variations in sources/sinks of GHGs. We also estimate responses of sources and sinks with respect to climate/environmental changes.
We would like to enhance international collaborations, in which we have been working with many institutions and universities around the world, and make significant contributions to Arctic communities. We would also like to provide a scientific basis for examining strategies to mitigate Arctic climate change.

Transport of BC from source regions to the Arctic and aging and removal processes during transport

BC mass concentrations observed in Barrow (Alaska) and Ny-Ålesund (Norway)

In situ cloud measurements at Mt Zeppelin, Ny-Ålesund

Temporal variations in atmospheric CO2 concentrations observed at Ny-Ålesund, Svalbard and Syowa Station, Antarctica.

Platforms for the atmospheric observations: commercial airliner, research vessel, ground observatory and tower.

Observations of terrestrial greenhouse gas fluxes and soil organic carbon.

Conceptual figure of SLCF assesment

Cooperative Institutions / International Projects

Alfred Wegener Institute (Germany), Norwegian Polar Institute (Norway), National Oceanic and Atmospheric Administration (US), Arctic and Antarctic Research Institute (Russia), Stockholm University (Sweaden), Norwegian Institute for Air Research (Norway), The Institute of Atmospheric Sciences and Climate (Italy), University of Florence (Italy), MSC-EC (Canada), University of East Anglia (UK), University of Alaska (US), IARC (US), Russian Academy of Sciences (Russia), IBPC (Russia), MPI (Russia), Moscow State University (Russia), Central Aerological Observatory (Russia)

Implementation Structure


Name Institutes
Makoto Koike National Institute of Polar Research/The University of Tokyo
Shinji Morimoto Tohoku University
Tetsuya Hiyama Nagoya University
Masayuki Takigawa JAMSTEC
Yutaka Kondo National Institute of Polar Research
Yutaka Tobo National Institute of Polar Research
Daisuke Goto National Institute of Polar Research
Nobuhiro Moteki The University of Tokyo
Shuji Aoki Tohoku University
Yoichi Inai Tohoku University
Ayumi Kotani Nagoya University
Hironari Kanamori Nagoya University
Hitoshi Matsui Nagoya University
Hajine Okamoto Kyushu University
Kaori Sato Kyushu University
Name Institutes
Kazuyo Yamaji Kobe University
Masahito Ueyama Osaka Prefecture University
Yoshinobu Harazono Osaka Prefecture University
Hiroshi Ohno Kitami Institute of Technology
Konosuke Sugiura University of Toyama
Kazuyuki Saito JAMSTEC
Shin Nagai JAMSTEC
Yugo Kanaya JAMSTEC
Prabir K. Patra JAMSTEC
Hideki Kobayashi JAMSTEC
Fumikazu Taketani JAMSTEC
Kazuyuki Miyazaki JAMSTEC
Takuma Miyakawa JAMSTEC
Hisashi Sato JAMSTEC
Keiko Konya JAMSTEC
Petr Mordovskoi JAMSTEC
Masahiro Yamaguchi JAMSTEC


Name Institutes
Kumiko Goto-Azuma National Institute of Polar Research
Hisashi Nakamura The University of Tokyo
Masaki Sato The University of Tokyo
Takaaki Takano Chiba University
Nobuyuki Takegawa Tokyo Metropolitan University
Jinro Ukita Niigata University
Hiroki Iwata Shinshu University
Tempei Hashino Kochi University of Technology
Teruo Aoki National Institute of Polar Research
Naruki Hiranuma West Texas A&M University
Taro Nakai National Taiwan University
Name Institutes
Go Iwahana University of Alaska Fairbanks
Naga Oshima Meteorological Research Institute
Hidekazu Matsueda Meteorological Research Institute
Toshinobu Machida National Institute for Environmental Studies
Yasunori Tohjima National Institute for Environmental Studies
Akihiko Ito National Institute for Environmental Studies
S. Maksyutov National Institute for Environmental Studies
Tomoaki Nishizawa National Institute for Environmental Studies
Shohei Murayama National Institute of Advanced Industrial Science and Technology (AIST)
Shigeyuki Ishidoya National Institute of Advanced Industrial Science and Technology (AIST)

Study Sites (Map)

  • Ny-Ålesund (Norway)
  • Barrow (Alaska, US)
  • Baranova (Russia)
  • Nord (Greenland)
  • Siberia
  • Bering Sea
  • Arctic Sea
  • Northern Pacific
  • Alaska

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