Black carbon and iron oxide aerosols in Arctic Snowpack, based on advanced techniques

• Project/Area Number: 19K20441
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Tokyo University of Science
• Principal Investigator: Mori Tatsuhiro 東京理科大学, 理学部第一部物理学科, 助教 (60801181)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2019: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
• Keywords: 北極 / 黒色炭素粒子 / 黒色酸化鉄粒子 / レーザー誘起白熱法 / 粒径別質量濃度 / 沈着量 / 広域分布 / 北極圏 / 積雪中質量・数濃度 / 粒径 / 北極広域分布 / ブラックカーボン / 湿性除去 / ネブライザー / 積雪 / 沈着

Outline of Research at the Start

雪面に沈着した光吸収性粒子は太陽光を吸収し、雪面の融解を促進させるため、北極域の温暖化に強く影響を与える。その影響を正しく予測するためには、北極域に沈着した光吸収性粒子の質量濃度を高精度に測定し、その空間分布を解明する必要がある。本研究では、光吸収性粒子の中でも黒色炭素粒子と黒色酸化鉄粒子に着目し、積雪中に含まれる光吸収性粒子の粒径別質量濃度を高精度に測定する手法を確立する。さらに、北極広域（フィンランド、アラスカ、シベリア、グリーンランド、スピッツベルゲン）で採取した積雪試料を分析し、光吸収性粒子の質量濃度、粒径、沈着量の空間分布を解明する。

Outline of Final Research Achievements

Black carbon (BC) and iron oxide (FeOx) aerosols deposited on snow lowers its albedo, potentially contributing to warming in the Arctic. Atmospheric distributions of BC and FeOx, which contribute directly and indirectly to radiative forcing, are also greatly influenced by depositions. To quantify these effects, we developed an improved technique for measuring the size distributions of BC and FeOx aerosols in liquid water and made an accurate measurement of the spatial distributions of BC and FeOx in snowpack in Arctic regions. Our measurements revealed that BC mass concentrations in the snowpack were lower by a factor of ~ 13 than previous measurements. The average size distributions of BC in Arctic snowpack shifted to smaller sizes with decreasing BC concentration in snowpack due to an increase in the removal efficiency of larger BC particles during transport from lower latitudes.

Academic Significance and Societal Importance of the Research Achievements

北極広域に沈着したBCやFeOx粒子の質量濃度、粒径、沈着量の高精度な測定データは、北極圏の気候を予測するモデルの検証に非常に有効である。特に、積雪中BC質量濃度の測定技術の確立により、従来法ではBC濃度が10倍程度も過大評価し、雪面反射率の予測値にも波及的に不確実性を含む可能性を明らかにした。この結果は、次回の北極評議会の作業部会の報告書でも重要な知見として取り上げられる見込みである。本研究成果は今後の北極圏の気候変動への理解に貢献するだけでなく、適切な社会政策を行う上でも重要な知見となりうる。

Research Products

• [Journal Article] Studies on Arctic aerosols and clouds during the ArCS project (2021)
  • Author(s): M. Koike, K. Goto-Azuma, Y. Kondo, H. Matsui, T. Mori, N. Moteki, S. Ohata, H. Okamoto, N. Oshima, K. Sato, T. Takano, Y. Tobo, J. Ukita, and A. Yoshida
  • Journal Title: Polar Science Volume: 27 Pages: 1-11
  • DOI: 10.1016/j.polar.2020.100621
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] 積雪中のブラックカーボンの北極広域分布 (2021)
  • Author(s): 森樹大
  • Journal Title: 大気化学研究 Volume: 44
  • Peer Reviewed / Open Access
• [Journal Article] Seasonal Variation of Wet Deposition of Black Carbon in Arctic Alaska (2020)
  • Author(s): Mori T.、Kondo Y.、Ohata S.、Zhao Y.、Sinha P. R.、Oshima N.、Matsui H.、Moteki N.、Koike M.
  • Journal Title: Journal of Geophysical Research: Atmospheres Volume: 125 Issue: 16 Pages: 1-24
  • DOI: 10.1029/2019jd032240
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Abundances and Microphysical Properties of Light‐Absorbing Iron Oxide and Black Carbon Aerosols Over East Asia and the Arctic (2020)
  • Author(s): Yoshida Atsushi、Moteki Nobuhiro、Ohata Sho、Mori Tatsuhiro、Koike Makoto、Kondo Yutaka、Matsui Hitoshi、Oshima Naga、Takami Akinori、Kita Kazuyuki
  • Journal Title: Journal of Geophysical Research: Atmospheres Volume: 125 Issue: 15 Pages: 1-21
  • DOI: 10.1029/2019jd032301
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] 2019年度 エアロゾル・雲・降水の相互作用に関する研究会 報告 (2020)
  • Author(s): 佐藤陽祐, 當房 豊, 山下克也, 荒木健太郎, 岩崎杉紀, 三隅良平, 大竹秀明, 茂木信宏, 齋藤 泉, 川合秀明, 中島 孝, 中野 諭, 森 樹大, 橋本明弘, 郭威鎮, 勝山祐太, 瀬戸里枝, 古藤慎之, 山田怜史, 折笠成宏, 田尻拓也, 遠藤幸生, 近藤 誠, 大畑 祥, 松嶋俊樹
  • Journal Title: 天気 Volume: 67 Pages: 665-671
  • Peer Reviewed / Open Access
• [Journal Article] Black Carbon and Inorganic Aerosols in Arctic Snowpack (2019)
  • Author(s): Mori, T., Goto-Azuma, K., Kondo, Y., Ogawa-Tsukagawa, Y., Miura, K., Hirabayashi, M., Oshima, N., Koike, M., Kupiainen, K., Moteki, N., Ohata, S., Sinha, P. R., Sugiura, K., Aoki, T., Schneebeli, M., Steffen, K., Sato, A., Tsushima, A., Makarov, V., Omiya, S., Sugimoto, A., Takano, S., Nagatsuka
  • Journal Title: Journal of Geophysical Research: Atmospheres Volume: 124 Issue: 23 Pages: 13325-13356
  • DOI: 10.1029/2019jd030623
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Wet Deposition of Black Carbon at Ny-Alesund, Svalbard (2021)
  • Author(s): Tatsuhiro Mori
  • Organizer: JpGU-AGU Joint Meeting 2021
• [Presentation] A biomass burning record over the past 350 years in an ice core from Northwest Greenland (2021)
  • Author(s): 東久美子
  • Organizer: JpGU-AGU Joint Meeting 2021
• [Presentation] Seasonal Variations of Wet Deposition of Black Carbon at Ny-Alesund in Svalbard and at Barrow in Alaska (2021)
  • Author(s): Tatsuhiro Mori
  • Organizer: PACES 4th Open Science Meeting (IGAC 2021)
  • Int'l Joint Research
• [Presentation] Seasonal Variation of Wet Deposition of black Carbon at Ny-Alesund, Svalbard (2020)
  • Author(s): Tatsuhiro Mori
  • Organizer: The Ninth Symposium on Polar Science 13th
  • Int'l Joint Research
• [Presentation] Seasonal Variation of Wet Deposition of Black Carbon at Ny-Alesund in Svalbard and Barrow in Alaska (2020)
  • Author(s): Tatsuhiro Mori
  • Organizer: Joint International Symposium: Challenging the Research Development and Collaboration Through Online Discussion
  • Int'l Joint Research
• [Presentation] Black Carbon and Inorganic Aerosols in Arctic Snowpack (2020)
  • Author(s): Tatsuhiro Mori
  • Organizer: Sixth International Symposium on Arctic Research (ISAR-6)
  • Int'l Joint Research
• [Presentation] Seasonal Variation of Wet Deposition of Black Carbon in Arctic Alaska (2020)
  • Author(s): Tatsuhiro Mori
  • Organizer: JpGU-AGU Joint Meeting 2020
  • Int'l Joint Research
• [Presentation] ニーオルスンに沈着した黒色炭素粒子濃度の季節変化 (2020)
  • Author(s): 森樹大
  • Organizer: 第37回エアロゾル科学・技術討論会
• [Presentation] BarrowにおけるBC粒子の湿性沈着に関する研究 (2020)
  • Author(s): 森樹大
  • Organizer: 2019年度エアロゾル・雲・降水の相互作用に関する研究会
• [Presentation] Changes in concentrations and size distributions of black carbon in Northwest Greenland over the past 350 years (2020)
  • Author(s): 東久美子
  • Organizer: Sixth International Symposium on Arctic Research (ISAR-6)
  • Int'l Joint Research
• [Presentation] BarrowにおけるBC粒子の湿性沈着に関する研究 (2020)
  • Author(s): 森樹大、近藤豊、大畑祥、Y. Zhao, P. R. Sinha, 大島長, 松井仁志, 茂木信宏, 小池真
  • Organizer: エアロゾル・雲・降水の相互作用に関する研究会
• [Presentation] Black carbon and inorganic aerosols in snowpack over the Arctic (2019)
  • Author(s): Mori, T., Goto-Azuma, K., Kondo, Y., Ogawa-Tsukagawa, Y., Miura, K., Hirabayashi, M., Oshima, N., Koike, M., Kupiainen, K., Moteki, N., Ohata, S., Sinha, P. R., Sugiura, K., Aoki, T., Schneebeli, M., Steffen, K., Sato, A., Tsushima, A., Makarov, V., Omiya, S., Sugimoto, A., Takano, S., Nagatsuka
  • Organizer: 日本地球惑星科学連合大会2019年大会
• [Presentation] 北極域に沈着した黒色炭素粒子と無機エアロゾルの空間分布 (2019)
  • Author(s): 森樹大, 東久美子, 近藤豊, 塚川佳美, 平林幹啓, 小池 真, Kaarle Kupiainen, 茂木信宏, 大畑 祥, 大島 長, 三浦和彦, 杉浦幸之助, 青木輝夫, Konrad Steffen, Martin Schneebeli, 佐藤篤司, 對馬あかね, Vladimir Makarov, 大宮 哲, 杉本敦子, 鷹野真也,
  • Organizer: 日本エアロゾル学会
• [Presentation] BarrowにおけるBC粒子の湿性沈着フラックスの季節変動 (2019)
  • Author(s): 森樹大, 近藤豊, 大畑祥, Y. Zhao, P.R.Sinha, 大島長, 松井仁志, 茂木信宏, 小池真
  • Organizer: 大気化学討論会
• [Presentation] Black Carbon and Inorganic Aerosols in Arctic Snowpack (2019)
  • Author(s): Mori, T., Goto-Azuma, K., Kondo, Y., Ogawa-Tsukagawa, Y., Miura, K., Hirabayashi, M., Oshima, N., Koike, M., Kupiainen, K., Moteki, N., Ohata, S., Sinha, P. R., Sugiura, K., Aoki, T., Schneebeli, M., Steffen, K., Sato, A., Tsushima, A., Makarov, V., Omiya, S., Sugimoto, A., Takano, S., Nagatsuka
  • Organizer: Sixth International Symposium on Arctic Research (ISAR-6)
  • Int'l Joint Research