摘要
青藏高原云物理特征的认识对高原天气和气候的研究有重要意义。利用2006年6月—20l1年4月的CloudSat卫星资料，分析了青藏高原地区云的总云水路径、液态水路径、冰水路径及雷达反射率的分布特征，并对高原与东亚降水云的垂直结构进行对比，得到如下结论：（1）总云水路径的大值区分布在高原西南坡、东南部及高原中部低值区分布在昆仑山脉、祁连山脉及其以北地区；暖季大于冷季；（2）高原南部及东部为液水路径大值区，以液相云为主；高原中部、北部及西部为冰水路径大值区，以冰相云为主；（3）雷达反射率的垂直分布主要介于-27-17dBz，集中在3～9km；云粒子群随高度先增大后减小，在4km高度的大小和浓度最大；暖季云高大于冷季，对流活动旺盛；（4）高原与东亚降水云的结构不同，季节变化也与东亚有差别。（5）雷达反射率在近地面层随纬度的增大减小，垂直方向的递减率是暖季小于冷季；（6）冷季的高原上与周边相比为丰水区，南坡的冰水路径与低层雷达反射率大值区对应，表明南坡阻挡作用促进云中冰粒子的形成。
Cloud microphysical characteristics over the Tibetan Plateau have important significance for the plateau weather and climate research. Using the CloudSat satellite data from June 2006 to April 2011, this work analyzed the distributions of total water path （TWP）, liquid water path （LWP）, ice water path （IWP） and radar reflectivity （RRF） over the Tibetan Plateau and compared the vertical structure of precipitation clouds in the plateau and East Asia. The results are shown as follows. （1） The high-value areas of TWP distribute in the southwest and southeast slopes as well as the central part of the plateau, and Kunlun Mountains, Qilian Mountains and the area north of the Qilian Mountains are the regions of low TWP values, and it is larger in the warm season than that in the cold season. （2） The high-value areas of LWP are in the southern and eastern plateau, mostly due to the influence of the wet air delivery, and these areas mainly contain liquid-phase clouds. The high-value areas of IWP are in the central, northern and western plateau, and these areas mainly contain ice-phase clouds. （3） The vertical distribution of RRF is between -27 dBz and 17 dBz and concentrates from 3 to 9 km. Groups of cloud particles first increase and then decrease with increasing altitude and the size and concentration are the biggest at 4 km. The height of cloud top is larger in the warm season than in the cold season, showing that convection activity is stronger in the warm season. （4） Both the structure and seasonal variations of precipitation clouds differ between the plateau and East Asia. （5） The value of RRF decreases with increasing latitude in the ground layer and the decline rate in the vertical direction is smaller in the warm season than in the cold season. （6） The plateau appears to be a wet area compared to the surroundings in the cold season. The IWP in the plateau＇s southem slope is corresponding to the large value of RRF in the lower layers, reflecting that the obstructing effect of the southern slope can promote the formation of ice particles in the cloud.
出处
《热带气象学报》
CSCD
北大核心
2014年第2期239-248,共10页
Journal of Tropical Meteorology
基金
财政部/科技部公益性行业(气象)科研专项(GYHY201306005
GYHY201006014
GYHY201206039)
国家重点基础研究发展计划973项目(2012CB417204)
国家自然科学基金项目(41175064)共同资助
