冬春季格陵兰海冰变化与初夏中国气温/降水关系的初步分析

采用英国Hadley中心GISST海冰面积资料,NCEP／NCAR再分析资料以及中国地面降水和气温资料,运用EOF分解,小波分析和合成分析等方法,初步探讨了格陵兰岛两侧附近冬春季海冰面积变化特征及其与初夏6月中国气温和降水的关系,结果表明,格陵兰岛东西两侧海冰面积呈显著反相变化,并且具有明显的年际和年代际周期性振荡,冬春季格陵兰－寻威海海冰与初夏6月中国长江以北气温（降水）正相关（反相关）,与长江以南气温（降水）反相关（正相关）,而对于戴维斯海峡－拉布拉多海海冰则具有相反的相关型,大尺度500hPa环流合成分析初步表明,冬春季格陵兰附近海冰面积变化伴随着北极极涡环流和北半球阻塞高压的持续异常,海冰变化可能是影响初夏中国气温和降水的因子之一。

A Simple Study on Relation of Winter-Spring Greenland Sea Ice Chang with Air Temperature/Precipitation in Early Summer of China

The winter-spring mean sea ice extent oscillations nearby Greenland island and their relationships to surface air temperature and precipitation in early summer of China have been examined in the present paper using the GISST sea ice extent dataset released by Hadley center, UK, and NCEP/NCAR 40-year reanalysis as well as the recorded surface air temperature and rainfall in China, empirical orthogonal function (EOF) analysis and wavelet analysis, etc. The results point out that the sea ice extent oscillations on the west and east sides of Greenland island show inverse variation with distinct interannual and interdecadal circles. The winter-spring sea ice extent oscillation over Greenland-Norwegian Sea is positively correlated to June surface air temperature to the north and rainfall to the south along Yangtze River in China, whereas is negatively correlated to the reverse and vice versa to sea ice extent over Davis Strait-Labrador sea. The composed analyses based on the NH 500 hPa general circulation show that the winter-spring sea ice extent oscillations nearby Greenland island are in contact with the persistent Arctic polar vortex and northern hemisphere blocking high anomalies. The sea ice extent oscillations are one of factors to affect precipitation and surface air temperature in early summer of China.