北极海冰快速减退前后的北冰洋上层海洋热含量变化OA北大核心CSTPCD

Arctic sea ice has been rapidly declining since 1997,which has a significant impact on the Arctic Ocean.Based on the numerical model results,the long-term trend of heat content in the upper ocean(0～150 m)of the Arctic Ocean during 1990 to 2014 is analyzed.The study found that only the western Chukchi Sea and the Barents Sea showed a significant increase trend in the continental shelf area,while the other sea areas showed a small change.The upper heat content of the Canada Basin was on the rise,which made a major contribution to the increasing trend of heat content of the Arctic Ocean basins,and mainly depended on the change of heat content of Pacific summer water.With the loss of sea ice,Pacific summer water continues to warm,but its heat content has not always increased.Corre-sponding to the rapid decline of Arctic sea ice,the Pacific summer water heat content showed two differ-ent long-term changes around 1997.From 1990 to 1997,the decrease trend was mainly attributed to the decrease of its volume,which was related to the weakened ability of Beaufort vortex to pump downward into the upper Pacific water due to the decrease of Arctic oscillation index during this period.From 1998 to 2014,there was a rapid growth trend,and its change rate was more than twice that of the previous period.Although there was no obvious change trend in the Arctic oscillation index during this period,the accelerated reduction of sea ice resulted in the increase of the direct forcing of the atmosphere on the ocean,and the strengthening of the downward pumping capacity of the Beaufort vortex,which increased the volume of Pacific summer water.Under the joint action of sea water warming,contributing to the rapid increase of heat content of the Pacific summer water.