作　　者： ; ; ;

机构地区： 中山大学环境科学与工程学院季风与环境中心大气科学系

出　　处： 《大气科学》 2006年第6期1138-1146,共9页

摘　　要： 通过区分ENSO外部影响和偶极子内部局地作用,探讨了前期春季的印度洋海温异常对南海夏季风建立早晚的可能影响途径。结果表明:在没有去除ENSO信号(外部作用)的情况下,全区一致型的海温分布主要通过影响热带印度洋上空纬向季风环流的强弱来影响南海夏季风建立的早晚。去除ENSO信号后,非ENSO全区一致型的海温分布则主要通过影响低层东西向的气压差异和对流层中上层的南北温度梯度的逆转,进而对南海夏季风建立的早晚产生影响;而南印度洋偶极子(SIODM)型的海温分布则主要通过影响亚洲大陆热低压、西太平洋副热带高压和高低层的辐合辐散运动影响南海夏季风的建立。 With 1953 - 1998 Reynolds ＆ Smith monthly sea surface temperature （SST） as well as NCEP/NCAR monthly re-analysis data and a picture in the mind that ENSO signal is culled or not from the Indian Ocean sea surface temperature anomaly （SSTA）, the possible impacts of Indian Ocean SSTA on the early or late onset of the South China Sea Summer Monsoon （SCSSM） have been analyzed based on Empirical Orthogonal Function （EOF）, the new statistical method CEOF （Conditional Empirical Orthogonal Function）. The results show that with the influence of ENSO, unipole pattern of the Indian Ocean SSTA mainly does favor to the unusual onset of SCSSM by affecting atmospheric vertical motion at 500 hPa, convergence/divergence motion in the low/high troposphere and the intensity of zonal monsoon circulation over the tropical Indian Ocean; while without the influence of ENSO, the unipole pattern may contribute to the unusual onset of SCSSM through affecting the reverse of meridional temperature gradient in the middle-upper troposphere. The Southern Indian Ocean Dipole Mode （SIODM） pattern also plays a role in the unusual onset of SCSSM by affecting the thermal depression over Asian landmass, the western Pacific subtropical high, and convergence/divergence in the low/high troposphere as well.

关 键 词： 印度洋 海温异常 南海夏季风 建立迟早

领　　域： [天文地球]