Outflow of Pacific water from the Chukchi Sea to the Arctic Ocean

作     者：Robert S Pickart Greg Stossmeister 

作者机构：Woods Hole Oceanographic Institution Woods HoleMAUSA National Center for Atmospheric Research/Earth Observing Laboratory BoulderCOUSA 

出 版 物：《Chinese Journal of Polar Science》 (极地研究（英文版）)

年 卷 期：2008年第19卷第2期

页      面：135-148页

学科分类：07[理学] 0707[理学-海洋科学] 

基　　金：supported by the National Science Foundation under grants OPP-0731928 and OPP-0713250 

主　　题：Chukchi Sea Arctic Ocean outflow of Pacific water. 

摘      要：Pacific water exits the Chukchi Sea shelf through Barrow Canyon in the east and Herald Canyon in the west, forming an eastward-directed shelfbreak boundary current that flows into the Beaufort Sea. Here we summarize the transformation that the Pacific water undergoes in the two canyons, and describe the characteristics and variability of the resulting shelfbreak jet, using recently collected summertime hydrographic data and a year-long mooting data set. In both canyons the northward-flowing Pacific winter water switches from the western to the eastern flank of the canyon, interacting with the northward-flowing summer water. In Barrow canyon the vorticity structure of the current is altered, while in Herald canyon a new water mass mode is created. In both instances hydraulic effects are believed to be partly responsible for the observed changes. The shelfl）reak jet that forms from the canyon outflows has distinct seasonal configurations, from a bottom-intensified flow carrying cold, dense Pacific water in spring, to a surface-intensified current advecting warm, buoyant water in summer. The current also varies significantly on short timescales, from less than a day to a week. In fall and winter much of this mesoscale variability is driven by storm events, whose easterly winds reverse the current and cause upwelling. Different types of eddies are spawned from the current, which are characterized here using hydrographic and satellite data.