塔克拉玛干沙漠地表潜热时空特征分析

 利用1979年3月至2004年2月月平均的NCEP/DOE再分析地表潜热资料,在分析塔克拉玛干沙漠四季潜热基本气候特征的基础上,通过EOF方法,对沙漠地表潜热异常变化的空间结构和时间演变趋势作了诊断研究。结果表明：①沙漠地区夏季潜热最大,春季和秋季次之,冬季最小;靠近山区的沙漠西部、西北部地区四季明显大于中、东部地区。②根据四季地表潜热距平场的EOF分析,该区潜热异常主要有全区一致型、南北差异型以及西北—东南差异型三种常见的分布模态。③25 a期间,塔克拉玛干沙漠地表潜热在第一空间尺度上四季都有不同程度增强的趋势;在第二空间尺度上,春季沙漠北部、西北部有减弱的趋势,南部、东南部有增强的趋势,而冬、夏、秋季变化趋势不是很大。

Analysis on Space-time Characteristics of Surface Latent Heat Flux in Taklimakan Desert

The paper analyzed the basic climate characteristics of four seasonal latent heat based on the monthly mean NCEP/DOE surface latent heat flux data of Taklimakan Desert area from March in 1979 to February in 2004. Further, the paper made diagnose on the space-time distributing characteristics of surface latent heat flux by using the EOF analysis method. The results are as follows: ①The distributing surface latent heat flux on desert area has great space-time difference. The surface latent heat flux in summer is the largest, second is in spring and autumn, that in winter is the smallest; the seasonal latent heat fluxes in the west and north-west of the desert are remarkably larger than that in the center and east regions. ②There are three typical abnormal latent heat flux distribution patterns: “all-consistent pattern”, “south-north reversal pattern” and “northwest-southeast reversal pattern”. ③In the 25 years, the variation of surface latent heat flux on Taklimakan Desert has increscent trend on the first space scale in winter, spring, summer and autumn; on the second space scale, it has a descending trend in north and northwest of the desert and an increscent trend in the south and southeast in spring. However, the change trends of surface latent heat flux are less evident in winter, summer and autumn.