南海和青藏高原TBB的低频振荡与湖北省“二度梅”的关系

THE RELATIONSHIPS BETWEEN THE TBB’S LOW FREQUENCY SURGE OF THE SOUTH CHINA SEA AND THE TIBETAN PLATEAU AND THE SECONDARY MEIYU IN HUBEI PROVINCE

用GMS TBB和ECMWF的格点风资料,采用带通滤波、EOF分解和合成分析方法,对湖北省洪涝年出现“二度梅”年(1980、1998年)和无“二度梅”年(1991、1999年)的南海和青藏高原TBB的低频振荡特征进行了分析研究。结果表明:有(无)“二度梅”年,南海低频TBB在6～7月的振荡位相是相反的;在7月下旬～8月上旬,南海低频TBB为高(低)值位相,青藏高原低频TBB为低(高)值位相。南亚地区低频TBB场EOF1的空间分布形式呈“南负北正”(南正北负)。

This paper analyzed the character of the TBB＇s low frequency surge in the South China Sea and the Tibetan Plateau in years with a secondary Meiyu （1980,1998） and the years （1991,1999） without it in Hubei province by the band-pass filter, EOF analysis and composition analysis with the grid wind data of GMS TBB and ECMWF. The results show that the topology of low frequency TBB surge in the South China Sea from June to July is the opposite between the years with the secondary Meiyu and the years without. In the years with the secondary Meiyu, the low frequency TBB surge in the South China Sea is high and the low frequency TBB surge of the Tibetan Plateau is low from the last ten days of July to the first ten days of August. The case is reversed in the years without the secondary Meiyu. The dimensional distribution of the low frequency TBB EOF1 in south Asia is that the southward is negative and the northward is positive in years with the secondary Meiyu, and the distribution is adverse in the years without the secondary Meiyu.