南极海冰与我国夏季天气的关系

南极各区海冰变化不同,这种不同的变化必然对各区局地大气环流产生不同的影响,进而可能对全球气候系统产生不同的作用。本文利用Hadley中心提供的1968年1月-2002年12月全球海冰密集度格点资料,结合中央气象台的北半球500hPa、100hPa高度场资料以及中国160站降水、温度资料,利用诊断分析方法,分别对南极Ross海区和Weddell海区海冰与我国夏季天气的关系进行了研究。研究表明,南极Ross海区和Weddell海区海冰对我国夏季天气均具有指示意义。Ross海区是影响我国夏季东北地区降水的海冰关键区,若该区上一年9月海冰偏多,则来年6月我国东北降水偏少;Weddell海区是影响我国夏季东北温度的海冰关键区,若该区上一年9月海冰偏多,则来年6月我国东北温度偏低。

A mesoscale model used in the Polar regions:modification and verification

The variations of the Antarctic sea-ice in each sea region are obviously different. This kind of different variations in each region may have different influence on a regional atmospheric circulation and further on global climate system. This study investigates that the relationship between variations of sea ice in the Ross Sea and Weddell Sea and the synoptic variations during summer in China using Northern Hemisphere monthly mean 500 hPa and 100 hPa geopotential and rainfall and temperature data at 160 stations in China. The results indicate that the sea ice variations in Ross Sea and Weddell Sea are both of indicative significance for the synoptic climate in summer of China. Ross Sea region is the crucial region where its proceeding sea ice variations in September show significant relation with the following June rainfall in Northeast China. If the sea ice of this crucial region in September is in heavy ice condition, the precipitation in Northeast China in the next June tends to be deficit. Weddell Sea region is the key region for summer temperature in Northeast China. If the sea ice of this key region in September is in light ice condition, the next June temperature in Northeast China also tends to be deficit.