日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS07] 季節内から十年規模の気候変動と予測可能性

2019年5月30日(木) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:望月 崇(国立研究開発法人海洋研究開発機構)、V Ramaswamy(NOAA GFDL)、Doug Smith(Met Office)、森岡 優志(海洋研究開発機構)

[AOS07-P13] Role of sea-ice initialization in climate predictability over the Weddell Sea

*森岡 優志1土井 威志1Doroteaciro Iovino2Simona Masina2Swadhin Behera1 (1.海洋研究開発機構、2.Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC))

キーワード:Air-sea-ice interaction、Climate predictability、Weddell Sea

Potential impact of sea-ice initialization on the interannual climate predictability over the Weddell Sea is investigated using a coupled general circulation model. Climate variability in the Weddell Sea is generally believed to have association with remote forcing such as El Niño-Southern Oscillation and the Southern Annual Mode. However, sea-ice variability in the Weddell Sea has been recently suggested to play additional roles in modulating local atmospheric variability through changes in surface air temperature and near-surface baroclinicity. When both the model’s sea-surface temperature (SST) and sea-ice concentration (SIC) are initialized with observations using nudging schemes, reforecast experiments from September 1st show improvements in predicting the observed SIC anomalies in the Weddell Sea up to four months ahead, compared to the other experiments with only SST initialization. During austral spring (Oct-Dec) of lower-than-normal sea-ice years in the Weddell Sea, reforecast experiments with the SST and SIC initializations reasonably predict high surface air temperature anomalies in the Weddell Sea and high sea-level pressure anomalies over the Atlantic sector of the Southern Ocean. These results suggest that accurate initialization of sea-ice conditions during austral winter is necessary for skillful prediction of climate variability over the Weddell Sea during austral spring.