摘要
利用10年的TRMM卫星降水雷达观测资料,首次对青藏高原及其下游平原及海洋地区降水厚度的地区差异进行了对比分析,并对青藏高原及其周边地区对流和层云降水厚度的水平分布及其日变化和季节变化进行了统计分析,结果表明:(1)青藏高原地区对流和层云降水厚度都要比下游平原地区更为浅薄,东部海洋地区对流降水厚度比平原地区小,而层云降水厚度与平原地区相当。青藏高原及其下游平原地区对流降水厚度的日变化特征非常明显,海洋地区对流降水厚度日夜差异则不大。层云降水厚度在各地区的日变化特征都不明显。青藏高原、下游平原及海洋地区对流和层云降水厚度的季节变化都非常明显,从冬至夏,对流和层云降水逐渐变得深厚,而从夏入冬,对流和层云降水则逐渐变得浅薄。(2)青藏高原及其周边地区对流和层云平均降水厚度的分布形式和降水量分布具有较好的对应关系,降水量大的地区其降水厚度一般较为深厚,降水少的地区则降水厚度比较浅薄。对流和层云降水厚度存在明显差异,对流降水一般要比层云降水深厚。青藏高原及其周边地区降水厚度水平分布的日夜差距不大,但季节变化非常明显,且与气候系统的季节变化紧密相关。
The diurnal and seasonal climatology of the precipitation depth over the Tibetan Plateau and its downstream regions is investigated using the data of Tropical Rainfall Measuring Mission（TRMM）precipitation radar（PR）measurements from 1998 to 2007.Results demonstrate that both convective and stratiform precipitation depths are smaller in Tibet than in its downstream regions.The convective precipitation depth in the East China Sea region is smaller than that in the Yangtze Plain,while the stratiform precipitation depth is similar for these two regions.The diurnal amplitude of convective precipitation depth is large over both the Tibetan Plateau and the Yangtze Plain,while it is small over the East China Sea.The diurnal cycle of stratiform precipitation depth is not significant over these regions.There are prominent seasonal variations of convective precipitation depth and stratiform precipitation depth over the Tibetan Plateau,the Yangtze Plain,and the East China Sea.Both convective and stratiform precipitation systems gradually deepen from winter to summer,and vice versa.The horizontal distribution of precipitation depths over the Tibetan Plateau and its surrounding regions shows a close relationship with the spatial pattern of surface rainfall,i.e.,the area with more surface precipitation is generally corresponding to a large precipitation depth.There is a significant difference between the convective and stratiform precipitation depths,and the precipitation depth is generally larger for convective systems than for stratiform systems.The precipitation depths during the daytime and the nighttime over the Tibetan Plateau and its surrounding regions are similar,however,they have clear seasonal variations,which are consistent with the seasonal variation of the climate precipitation systems.
出处
《大气科学》
CSCD
北大核心
2010年第2期387-398,共12页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目40428002
国家自然科学基金资助项目40775058
