南海海温与我国夏季降水相关关系的研究

近20年来，气象工作者一直把赤道东太平洋海温对我国汛期降水的影响作为海-气相互作用中的重要研究课题。陈烈庭(1977)研究了赤道东太平洋地区海温异常变化对我国汛期降水的影响；黄嘉佑(1989)利用相关矩方法分析了赤道东太平洋海温与我国夏季雨日之间的关系；魏风英等(1992)研究了赤道东太平洋海温等因子与长江流域夏季旱、涝之间的关系及各因子在旱、涝形成中的贡献。研究结果表明，赤道东太平洋海温对我国降水有显著影响。南海地处赤道西太平洋边缘，是低纬热带海域，它位于季风气流上游，是我国夏季降水的水汽和各种能量的重要源地之一，因此该海域海表面温度(简称海温)的变化与季风环流的相互作用可直接影响我国东部低纬地区的降水。罗绍华等(1985)曾作过南海海温与长江中、下游夏季降水的相关分析，分析结果认为，南海前期海温变化与长江中、下游夏季降水有密切关系，即前期海温偏暖时，长江中、下游夏季降水往往偏多，反之，前期海温变冷时，降水少。但是，由于上述研究是利用1951-1972年的资料，而且仅限于长江中、下游地区与南海海温的相关分析，因而还不尽如人意。随着南海海温资料和我国降水资料的不断累积，为进一步深入研究南海海温变异与我国降水的关系提供更好的条件，本文试图通过分析南海前期各季海温与长江中、下游和东南沿海地区的降水关系，找出在海温影响下的降水分布特征及旱、涝出现规律，为长江中、下游和东南部地区旱、涝的长期预测提供依据。

STUDY ON RELATION OF SOUTH CHINA SEA SST TO PRECIPITATION OF CHINA IN SUMMER

The drought/flood index of precipitation in summer was determined based on the first component of precipitation total amount from June to August for 65 stations. Then, the relationship between the preceding South China Sea SST and the drought/flood in the middle and lower reaches of the Chang jiang River valleys and the southeastern region were studied by using the correlation matrix. The relationships were shown principally by the abnormal drought/flood years, the correlation of the preceding SST with the drought/flood were persistent for a certain period and indicated that the preceding SST contributed significantly to the formation of drought/flood in the middle and lower reaches of the Chang jiang River valleys. The results provide the reference for long-range forecast of drought/flood.