Variations of the Atlantic Water and Pacific Winter Water under the influ-ence of the shifting Beaufort Gyre in the western Arctic Ocean
The Chukchi Borderland served as the critical gateway for the inflow of Atlantic Water(AW,which is the most important heat storage layer in the Arctic Ocean)into the Canada Basin in the western Arctic Ocean.One of the key issues is how the AW and Pacific Winter Water(PWW)interacts in this complex topography region.The answer to this question will shed light on the important role of AW in the Arctic Ocean.In this study,based on the multi-sources'quality controlled hydrographic data during 1999-2021,the variation of AW,PWW and the double-diffusive staircases in the Chukchi Borderland are studied in details.We identified three anomalous warm events of AW that occurred in year 2000,2012 and 2018 with the maximum potential temperature over 1℃.The vertical aver-aged heat content between the PWW and AW shows a warming trend in the central and eastern region of the Chuk-chi Borderland.The major reason for this is the warming of PWW.The depth of PWW is more sensitive to the shift-ing of the Beaufort Gyre(BG)than that of the AW.The combined changes of PWW and AW lead to the variation of double-diffusive staircases,which show a regime shift from large to small thickness and to largely decayed in the Canada Basin.Our results suggest that the major mechanism for this transition is the cooling of AW along with the stronger stratification that restricts the vertical mixing for all.
万方数据
维普
