棚氷と海洋の相互作用とそのモデリング

• Main Author: 草原, 和弥
• Format: Article in Journal/Newspaper
• Language: Japanese
• Published: 低温科学第76巻編集委員会
• Subjects: 氷床／棚氷-海洋相互作用; 棚氷底面融解; 棚氷-海洋結合モデル; ice self-ocean interaction; basal melting of ice shelves; coupled ice shelf-ocean models; 452; Antarctic; The Antarctic; Antarc*; Ice Shelf; Ice Shelves; Sea ice
• Online Access: http://hdl.handle.net/2115/70324; https://doi.org/10.14943/lowtemsci.76.33

棚氷とは，氷床の末端で海に浮遊している部分である．南極棚氷の底面融解は南極氷床の質量収支を考える上で重要な消耗過程である．南極棚氷底面融解は南極沿岸大陸棚上の三つ水塊によって引き起こされる．一つ目は南極沿岸ポリニヤで形成される高密度陸棚水．二つ目は南極周極流域から大陸棚上に流入する周極深層水．三つ目は夏季海氷融解によって形成される表層水である．この概説では，これらの水塊が棚氷底面融解を引き起こすプロセスを説明し，さらに観測データと数値モデル結果から，南極棚氷毎にその底面融解の熱源が大きく異なることを示す． Antarctic ice shelves are the floating part of Antarctic ice sheets, and its basal melting plays a major role in ablation mechanisms in the Antarctic ice sheets mass balance. There are three key water masses controlling the basal melt process over the Antarctic coastal margins: cold dense shelf water formed in Antarctic coastal polynyas, warm Circumpolar Deep Water originating from the Antarctic Circumpolar Current regions, and Antarctic Surface Water from sea-ice meltwater in summer. We briefly review roles of these water masses on basal melting of Antarctic ice shelves and show that heat sources for basal melting are largely different from one ice shelf to another, based on observational data and numerical model results.