Permalink : http://hdl.handle.net/2115/20449

オホーツク海は大河が注ぐ中緯度の浅海で、その西方と北方をアジア大陸が囲むという地理学的特徴を有する。これを反映し、夏季には加熱される大陸との間に顕著な地表傾度が形成され、冬季にはその気温傾度は反転し、最南に位置する大規模海氷域となる。これら特徴的な地表の熱的状況とその変動が、半球規模の大気循環変動と如何に関連するかという観点から、冬季海氷域の経年変動が大規模な大気循環変動に及ぼし得る影響、並びに夏季の冷涼なオホーツク海高気圧の形成について、データの力学診断と数値モデリングに基づき解説する。
The Sea of Okhotsk is a shallow mid-latitude marginal sea bordered by the Asian Continent to its west and north. A strong thermal contrast forms in summer between the cool sea surface and the heated landmass, while the thermal gradient is reversed in winter. Under the influence of the continuous spill of extremely cold air form the continent and fresh water supplied by the Amur River, the Okhotsk region becomes the southernmost ice-covered maritime region in the Northern Hemisphere. With regard to how these seasonal characteristics of the surface thermal condition and their interannual variability in and around the Okhotsk region can be related to the variability in hemispheric-scale atmospheric circulation, we discuss the possible in fluence of the anomalous sea-ice extent on large-scale atmospheric circulation and the formation of the summertime cool surface Okhotsk High, based on data analysis and numerical experiments.