中国西北地区近20年云水路径时空分布特征

Temporal and spatial distributions of cloud water path over Northwestern China in the recent 20 years

利用国际卫星云计划D2资料集1990 2009年20年云水路径资料,分析了西北地区云水路径的时空分布特征,结果表明:西北地区云水路径总体上为上升趋势,时空分布特点明显;就20年变化情况看,昆仑山阿尔金山、祁连山云水路径增加,天山、阿尔泰山地区减少明显,具体变化情况随季节变化而变化;西北地区云水路径一致性变化特征中,包含"东正西负"的东西向变化差异和"北正南负"的反相位的特征;西北地区云水路径存在多重尺度嵌套现象,具有明显的4,7年周期,4年短周期与大气环流振荡准周期对应较好.

The temporal and spatial characteristics of cloud water path (CWP) over Northwestern China were analyzed by using the ISCCP monthly mean D2 data from July 1990 to December 2009. The results showed that, over the past 20 years, there was an increasing trend in the cloud water path over most of the region, especially over the Kunlun Mountains, A’erjin Mountains and Qilian Mountains, while a decreasing trend was observed over the Tianshan Mountains and A’ertai Mountains. The CWP exhibited very large seasonal variations. The cloud water path in Northwestern China was affected by large-scale weather systems. There were features such as the path being positive in the east and negative in the west, positive in the north and negative in the south. The cloud water path mainly had 4-year and 7-year short periods. And the 4-year period was consistent with the period of atmospheric circulation.