中国冬季地温场变化特征及与夏季降水场的关系

Variation Features of Winter Soil Temperature Field in the Depth of 3.2 mand Its Relation to Summer Precipitation Field in China

利用我国 141个测站 1980— 1997年间 12月～ 2月 3.2m深度地温资料和中国 16 0个测站195 1— 1997年间 6～ 8月降水资料 ,采用主成分、旋转主成分分析 ,对冬季地温的空间异常特征、时间变化规律以及与夏季降水的关系进行分析。结果表明 :未旋转的前 3个载荷向量场可以较好地反映中国冬季地温整体异常结构 ,即全区一致的高温或低温 ;东西相反的东高 (低 )西低 (高 )型 ;南北相反的南高 (低 )北低 (高 )型。旋转后的前 4个载荷向量场可较好地代表中国冬季地温的 4个主要异常敏感区 :北方区、淮河区、西北区和江南区。旋转主分量和代表站资料反映出 90年代以来西北区、华南区冬季地温呈下降趋势 ,北方区、淮河区、江南区呈明显上升趋势。当北方冬季地温偏高时 ,有利于 7月黄河以北大部分地方降水偏多 ;当淮河区冬季地温偏高时 ,有利于 7月江淮流域降水偏多 ,而使黄河以北、长江以南降水偏少 ;当西北区冬季地温偏高时 ,有利于 7月江淮流域降水偏少 ;当江南冬季地温偏高时 ,有利于

With EOF and REOF analyse techniqne, the spatial anomalous features and time evolution rule and the relation between winter soil temperature and summer precipitation anomaly in China are studied using soil temperature date in the depth of 3.2 m in December, January and February of 1980_1997 in 141 stations and the precipitation date in June, July and August of 1951_1997 in 160 stations.The results show that before rotating the first three loading vector fields can reflect the whole anomaly pattern structures of soil temperature in China, i.e., the higher (or lower) soil temperatures in whole calculated area, higher (or lower) ones in east-west direction, higher (or lower) ones in north-south direction. After rotating, the first four rotated loading vector fields represent four principal soil temperature anomaly patterns: i.e., North China, Huaihe river, Northwest China and of Yangtze river to the south. The rotated principal components and some station data show that there is an increasing trend of soil temperature in patters like North China, Huaihe river and Yangtze river to the south from 1990s, but vice versa for Northwest and South China patterns. When winter soil temperature of North China is higher, the July precipitation in most part of North China is obviously increased; when winter soil temperature of Huaihe river is higher, the July precipitation in both the Yangtze and Huaihe rivers is obviously increased and vice versa for Yellow river to the North and South China; When winter soil temperature of Northwest China is higher, the July precipitation in both the Yangtze and Huaihe rivers is obviously decreased; when winter soil temperature of South China, the July precipitation in Sichuan and north Yunnan is obviously increased.