盛夏副高东西位置异常变化对我国气候的影响及预测研究

Impact of anomalous latitudinal position of western pacific subtropical high on climate change in midsummer in China

利用1951—2008年全国160站盛夏(7—8月)气温和降水资料、北半球500 hPa高度场和北太平洋海温场资料及相关环流特征指数资料,分析了盛夏(7—8月)西太平洋副高东西位置异常变化对我国气候的影响及其与北半球500 hPa大气环流和北太平洋海温的关系。发现:盛夏副高东西位置异常偏西年主要集中出现在上世纪90年代和60年代,异常偏东年则集中出现在80年代、70年代和90年代。盛夏副高东西位置与长江流域及其以南地区气温存在着很好的负相关关系,与长江流域及其以北地区降水表现为负相关,与江南和华南地区降水表现为正相关。盛夏副高东西位置异常变化与北半球大范围环流形势调整相联系;前期春季(4—5月)北半球各副高单体强度变化,对盛夏副高东西位置变化具有很好的预测指示性。前期9—3月NINO4区和NINO3区海温,尤其是前期3月NINO4区海温,前期1月NINO3区海温对盛夏副高东西位置异常变化也具有很好的指示意义。

Based on air temperature,precipitation,500hPa geopotential height in the Northern Hemisphere,sea surface temperature in the Northern Pacific and the related circulation characteristic index in midsummer（from July to August） collected from the 160 nationwide stations from 1951 to 2008,the influence of latitudinal position anomaly of Western Pacific subtropical high in midsummer（from July to August） on the climate in our country and its relations to 500hPa atmospheric circulation of the Northern Hemisphere as well as sea surface temperature in the Northern Pacific is analyzed.It is found that the west-extending of the position of subtropical high in midsummer mainly appeared in 1990s and 1960s,while the east-extending mostly appeared in 1980s,1970s and 1990s.There is high negative correlation between latitudinal position of subtropical high in midsummer and the air temperature of Yangtze River Basin as well as its south area.There is negative correlation between latitudinal position and precipitation of Yangtze River Basin as well as its north area.There is positive correlation between latitudinal position and precipitation of Southern Yangtze as well as South China.Also,latitudinal position anomaly of subtropical high in midsummer is relative to large-scale adjustment of atmospheric circulation in the Northern Hemisphere.The intensity variation of the Northern Hemisphere subtropical high of the preceding spring（from April to May） always indicates the variation of the latitudinal position of the subtropical high in midsummer.The sea surface temperature of NINO04 and NINO03 area during the preceding September to March,especially the preceding March of NINO04 area and the preceding January of NINO03 area,also can effectively indicate the latitudinal position anomaly of subtropical high in midsummer.