北冰洋浮冰站大气边界层结构的观测研究

利用2003年8月23日-9月3日我国第二次北极科学考察队在北冰洋浮冰站探测的50次大气廓线及相关资料,对北冰洋的大气边界层垂直结构进行了研究。结果显示,观测期间北冰洋(78°N附近,143°-148°W)浮冰区白天的对流边界层高度大于夜间的稳定边界层高度。大气边界层可分为稳定型、不稳定型和多层结构等几种类型。个例分析表明来自高空较强的暖湿气流与冰面近地层冷空气强烈相互作用,会形成强风切变和逆温、逆湿过程,有时100m高度内的风切变达10m/s,逆温达8℃。此种过程会导致北冰洋高纬度地区的大块海冰破裂,形成新的无冰海域,加强了海/冰/气的相互作用。该观测事实将有助于进一步提高对北冰洋高纬度边界层特征及其影响的认识。

ANALYSIS OF STRUCTURE OF ATMOSPHERIC LAYER IN ICE CAMP OVER ARCTIC OCEAN

The vertical structure of atmospheric boundary layer over Arctic floating ice is presented by using about 50 atmospheric profiles and relevant data sounded at ice camp over Arctic Ocean from 22 August to 3 September,2003.It shows that the height of the convective boundary layer on the day is greater than that of the stability boundary layer on the night.The boundary layer can be described as vertical structures of stability,instability and multiple.The interaction be- tween relative warm and wet down draft air from up level and cool air of surface layer is signifi- cant,which causes stronger wind shear,temperature and humidity inversion with typical wind shear of 10m·s~(-1)/100m,intensity of temperature inversion of 8℃/100m.While the larger pack ice is broken by such process and forms new ice free area in the high latitudes of arctic o- cean.Further the interactions between air/ice/water are enhanced.The fact helps us to under- stand characteristics of atmospheric boundary layer and its effect in Arctic floating ice region.