[A-OS09] Climate variability and predictability on subseasonal to multidecadal timescales

[AOS09-08] Summertime sea-ice prediction in the Weddell Sea improved by sea-ice thickness initialization

*森岡 優志¹、Iovino Doroteaciro ²、Cipollone Andrea²、Masina Simona²、Behera Swadhin¹ (1.海洋研究開発機構 付加価値情報創生部門 アプリケーションラボ、2.CMCC/ODA)

キーワード：ウェッデル海、海氷、予測可能性、大気海洋海氷結合モデル

Skillful sea-ice prediction in the Antarctic Ocean remains a big challenge due to paucity of sea-ice observations and insufficient representation of sea-ice processes in climate models. Using a coupled general circulation model, this study demonstrates skillful prediction of the summertime sea-ice concentration (SIC) in the Weddell Sea with wintertime SIC and sea-ice thickness (SIT) initializations. During low sea-ice years of the Weddell Sea, negative SIT anomalies initialized in June retain the memory throughout austral winter owing to horizontal advection of the SIT anomalies. The SIT anomalies continue to develop in austral spring owing to more incoming solar radiation and the associated warming of mixed layer, contributing to further sea-ice decrease during late austral summer-early autumn. Concomitantly, the model reasonably reproduces atmospheric circulation anomalies during austral spring in the Amundsen-Bellingshausen Seas besides the Weddell Sea. These results provide evidence that the wintertime SIT initialization benefits skillful summertime sea-ice prediction in the Antarctic Seas.