宁夏春季沙尘暴与北极海冰之间的遥相关关系

根据宁夏沙尘暴发生次数资料、北极海冰密集度资料和NCEP／NCAR再分析500hPa、850hPa高度场、风场资料，得出了宁夏春季沙尘暴发生次数的变化规律及其与北极海冰面积之间的年代际和年际相关关系，发现宁夏春季沙尘暴发生次数与欧亚大陆北部的喀拉海、巴伦支海和格陵兰海冰面积之间存在较显著的年代际、年际相关关系。通过合成和相关分析知，宁夏春季沙尘暴偏多、偏少状况有明显不同的环流背景场，秋季格陵兰海冰异常变化通过影响其后一段时间的大气环流背景场，从而对宁夏沙尘暴产生影响。初步得出当格陵兰海秋季海冰面积增大(减小)，次年春季蒙古至西伯利亚一带500hPa、850hPa高压场降低(升高)，风场有明显的气旋性(反气旋性)特点，在宁夏至新疆一带西风明显偏强(偏弱)，说明冷空气活动次数偏多(少)，对应宁夏春季沙尘暴发生次数偏多(少)。通过海冰将全球气候变暖和宁夏(我国北方)沙尘暴总减少趋势联系起来，初次提出在环境总体恶化情况下，我国沙尘暴发生次数总体趋于减少，很可能是全球气候变暖所致。

Telecorrelation of Arctic Sea-Ice with Spring Sandstorm in Ningxia

Based on sandstorm records in Ningxia,Arctic sea-ice concentration data and 500,850hPa height and wind fields from NCEP/NCAR reanalysis dataset,the variations of sandstorm are investigated.It is found that there are significant interannual and interdecadal correlations between the spring sandstorm frequency and the sea-ice area indices of Kara,Barents and Greenland seas,which locate on the north of Eurasion continent.By using composite and correlation analysis,it is concluded that the circulation backgrounds between more and less spring sandstorm are evidently different,and the anomalies of autumn Greenland sea-ice can affect the occurrence of sandstorm in the following spring in Ningxia through impacting the atmospheric circulation background.When autumn Greenland sea-ice area increases(decreases),500 and 850hPa height fields from Mongolia to Siberian will become lower(higher) and the wind fields in following spring will exhibit cyclonic(anticyclonic) anomalies,and west winds from Ningxia to Xingjiang will be significantly stronger(weaker),which suggest the activities of cold air are active(inactive).As a result,the occurrence of spring sandstorm in Ningxia are more(less).It is possible to link the decreasing trend of sandstorm in Ningxia (North China) and the global warming through sea-ice,and it is concluded that the decreasing trend of sandstorm in China could be caused by the global warming.