中国春末夏初降水量异常的气候类型

选取中国大陆均匀分布的８０个测站１９５１—１９９４年历年５—６月月总降水量标准化距平资料，利用ＥＯＦ和ＲＥＯＦ方法对春末夏初降水量异常的空间结构及时间演变规律作了研究。结果表明，中国春末夏初降水异常在空间上主要表现为南北相反变化的差异（ＬＶ）。旋转载荷向量场（ＲＬＶ）反映出１１个主要降水异常类型区。旋转主分量（ＲＰＣ）揭示了４４年来春末夏初降水的时间演变特征：江淮和江南地区降水量减少，东北和南疆地区降水量增多；河套东部、华南、北疆、华北地区呈多雨—少雨—多雨的抛物线型，而河套西部、西南地区呈少雨—多雨—少雨的反抛物线型。

CLIMATIC PATTERNS OF PRECIPITATION ANOMALY DURING LATE SPRING AND EARLY SUMMER IN CHINA

The spatial structure and temporal evolution rule of late spring and early summer rainfall anomaly in chinese continent are studied by EOF and REOF using the nomalized sum precipitation of 80 observational stations during the period of May and June from 1951 to 1994. The results show that spatial rainfall anomaly is opposite from North to South (LV), and the rotated loading vector fields (RLV) represent 11 main anomaly regions. The rotated principal compontnt (RPC) reveals the temporal evolution features of late spring and early summer rainfall, and the basic trend in recent 44 years is the rainfall deereasing in Jianghuai and Jiangnan region and increasing in Northeast China and South Xinjiang, and the trend is a wet dry wet pattern in east hetao region, South China, North Xinjian and North China, and is a dry wet dry pattern in west hetao region and South west china.