open access

https://hdl.handle.net/2115/20451

Decadal variability in the Okhotsk Sea : Sea-ice and upper ocean temperature

日本語

2007-03-23

北海道大学低温科学研究所

Low Temperature Science

65

21-30

1章 10年～100年スケールの気候変動の観測, 気候復元とモニタリング

We investigate decadal-scale variations in the wintertime (February-March) sea-ice concentration and warm-season (May-October) water temperature in the upper 200m of the Okhotsk Sea, as well as their relation to atmospheric circulation. Large decadal-scale variation in wintertime sea-ice occurs in the northern Okhotsk Sea; this variability showed a decreasing trend from 1980 to the mid-1990s and an increasing trend from the mid-1990s to the early 2000s. This sea-ice variation is thermodynamically influenced by the atmospheric conditions during the late autumn (October-November). The atmospheric conditions in late autumn for the positive sea-ice anomalies exhibit cold air-temperature anomalies over the Okhotsk Sea from Siberia. These atmospheric conditions in late autumn are related to 700-hPa geopotential height differences between the Bering Sea and northern Eurasia. The dominant upper-ocean temperature fluctuations in the southern Okhotsk Sea have a monopole structure with the maximum amplitude in the Kuril Basin; corresponding time series exhibit prominent quasi-decadai variability over the period 1958-94. This variability is closely related to wintertime differences in sea-level pressure between northern Eurasia and the northern North Pacific.

紀要論文

Version of Record

1880-7593

AA12122962