2011/2012年夏季南极半岛北端周边海域的水团与水交换

通过分析中国第28次南极考察队于2011年12月至2012年1月在南极半岛北端周边海域获得的5条断面CTD观测温盐剖面数据, 进一步认识了该海域的水团组成和水交换情况。观测区域南部的鲍威尔海盆及周边深海区, 可以观测到保持了较显著高温核心的威德尔深层水、密度大于28.27 kg·m^-3的威德尔海深层水以及温度低于－0.7 ℃的威德尔海底层水。周边陆坡上的威德尔海深层水则表现出因与周围水体发生混合而核心性质减弱的特征。在菲利普海岭、埃斯佩里兹海槽等复杂地形处, 观测到的对应于威德尔海深层水深度的混合与热盐入侵过程更为显著。威德尔海深层水能够到达南设得兰群岛以北的象岛东北面海域, 但是高盐核心加深至1 500 db, 并上覆温度基本不变但盐度随深度显著增大的较暖水体, 表明威德尔海深层水经历了不同的路径和变性过程。布兰斯菲尔德海峡中没有绕极深层水大规模侵入的迹象, 但是乔治王岛周边陆架上可能存在涡旋等中尺度过程, 会影响德雷克海峡与布兰斯菲尔德海峡之间的水交换。

Water masses and exchanges in the region around the northern tip of Antarctic Peninsula observed in summer of 2011/2012

Water masses and exchanges in the region around the northern tip of the Antarctic Peninsula were analyzed based on CTD (Conductivity-Temperature-Depth profiler) and XCTD (eXpendable CTD) data observed during the 28th Chinese National Antarctic Research Expedition in December 2011 to January 2012. The Weddell Deep Water (WDW) with significant warm core, the Weddell Sea Deep Water(WSDW) and Weddell Sea Bottom Water(WSBW, with potential temperature less than -0.7℃) with neutral density greater than 28.27 kg·m^-3 were found in the southern deep area of observing region, especially in Powell Basin.The WDW on the surrounding slope showed relative weaker core characteristics because of mixing with peripheral waters. In some locations with complex bottom topography, such as the Philip Ridge and Hesperides Trough, stronger mixing and a thermohaline intrusion occurred at the WDW layer. WDW with a deeper saline core at 1 500 db, overlaid by warm water with vertically uniform temperature and salinity, was observed to the northeast of Elephant Island, indicating that the WDW might have come from different sources and undergone different modifications. No Circumpolar Deep Water was found in the Bransfield Strait; however, some mesoscale processes, such as eddies on the shelf near King George Island, could influence exchange between the Drake Passage and Bransfied Strait.