Weak Vertical Diffusion Allows Maintenance of Cold Halocline in the Central Arctic  

作　　者：Ilker FER 

机构地区：[1]Geophysical Institute, University of Bergen & Bjerknes Centre for Climate Research,Bergen, Norway

出　　处：《Atmospheric and Oceanic Science Letters》2009年第3期148-152,共5页大气和海洋科学快报（英文版）

基　　金：funded by the Research Council of Norway, through NORKLIMA Young Investigator grant

摘　　要：In spring preceding the record minimum summer ice cover detailed microstructure measurements were made from drifting pack ice in the Arctic Ocean, 110 km from the North Pole. Profiles of hydrography, shear, and temperature microstructure collected in the upper water column covering the core of the Atlantic Water are analyzed to determine the diapycnal eddy diffusivity, the eddy diffusivity for heat, and the turbulent flux of heat. Turbulence in the bulk of the cold halocline layer was not strong enough to generate significant buoyancy flux and mixing. Resulting turbulent heat flux across the upper cold halocline was not significantly different than zero. The results show that the low levels of eddy diffusivity in the upper cold halocline lead to small vertical turbulent transport of heat, thereby allowing the maintenance of the cold halocline in the central Arctic.In spring preceding the record minimum summer ice cover detailed microstructure measurements were made from drifting pack ice in the Arctic Ocean, 110 km from the North Pole. Profiles of hydrography, shear, and temperature microstructure collected in the upper water column covering the core of the Atlantic Water are analyzed to determine the diapycnal eddy diffusivity, the eddy diffusivity for heat, and the turbulent flux of heat. Turbulence in the bulk of the cold halocline layer was not strong enough to generate significant buoyancy flux and mixing. Resulting turbulent heat flux across the upper cold halocline was not significantly different than zero. The results show that the low levels of eddy diffusivity in the upper cold halocline lead to small vertical turbulent transport of heat, thereby allowing the maintenance of the cold halocline in the central Arctic.

关 键 词：Arctic Ocean cold halocline layer turbulence mixing heat flux Atlantic Water 

分 类 号：P434.5[天文地球—大气科学及气象学]