Permalink : http://hdl.handle.net/2115/91847

JaLCDOI : 10.14943/lowtemsci.82.45

KEYWORDS : 海氷;ブライン;二酸化炭素;気体交換;Sea ice;brine;carbon dioxide;gas exchange

従来，海氷は大気—海洋間の物質交換を阻む存在と考えられてきた．しかし，海氷は高塩分水であるブラインを含む多孔性の物質であり，大気との二酸化炭素（CO2）交換が起きる可能性がある．本稿では，海氷の物理特性と気体交換の関係性，室内実験や野外観測による海氷—大気間のCO2交換に関する理解の進展について述べる．また，近年進めつつあるデータ統合によるグローバルスケールでの海氷域の炭素収支評価，海氷上でのCO2交換に関する計測手法の確立のための取り組みについて紹介する．
Sea-ice has not been considered in estimations of biogeochemical cycles, especially in gas exchange, in icecovered seas because of the assumption that sea-ice acts as a barrier for atmosphere—ocean exchange. However, recent works have shown that sea ice cover play an active role in the carbon dioxide (CO2) exchange between the ocean and atmosphere. This paper describes the relationship between the physical properties of sea ice and gas exchange, laboratory experiments and field observation efforts, and progress in our understanding for sea ice—atmosphere CO2 exchange. We also introduce our recent efforts to evaluate the carbon budget of sea ice areas on a global scale by integrating data and to establish methods for CO2 exchange with the atmosphere in sea ice areas.