埃默里冰架北缘海洋水文特征的变化

VARIABILITY OF MARINE HYDROLOGICAL FEATURES AT NORTHERN MARGIN OF AMERY ICE SHELF

利用中国第24次南极科学考察队(2007/2008)观测的CTD资料,分析了埃默里冰架北缘的温度、盐度、密度的空间分布,并与中国第22次南极科学考察队(2005/2006)观测的CTD资料进行了比较。比较后发现埃默里冰架北缘海域的最新变化是跃层深度明显变深,冰架北缘的东部海洋上层有明显的次表层暖水存在,但该暖水仅仅位于冰架北缘的最东端及其附近的站位,具有明显的局地性。此外,海洋的表层温度、盐度、密度都形成了明显的东西向梯度。这种梯度应与海表层浮冰的密集度有着密切的关系,是海-冰-气三者相互作用的结果。

CTD data observed by the 24th CHINARE（2007/2008）team are used to analyze the spatial distribution of temperature,salinity,and density at the northern margin of Amery Ice-shelf and to compare it with that of the 22nd CHINARE（2005/2006）team.It is discovered from the comparison that the new variation at the northern margin of Amery Ice Shelf is the thermocline deepening,there exists the subsurface warm water in the oceanic upper layer in the east part of the northern margin of Amery Ice Shelf,and the warm water is limited in a small area at the east end of the ice shelf and its adjacent locations.Therefore it is obviously a local feature.In addition,the temperature,salinity,and density have their east-west gradients in the surface layer,which might be closely related to the floe concentration in the sea surface.These local features result from ocean-ice-atmosphere interaction.