冰川下垫面对夏季云结构和云水含量的影响——以祁连山区疏勒南山为例

云水含量和云结构参量是天气预报、高山区水循环过程分析的基础。基于2012-2015年夏季CloudSat卫星遥感资料的2B-CLDCLASS、2B-GEOPROF和2B-GEOPROF-LIDAR,结合中国第二次冰川编目数据及气象资料,对祁连山地区疏勒南山冰川区与非冰川区云水含量和云类型特征进行分析。结果表明:(1)云水含量的垂直分布受下垫面和云类型的影响,主要表现为有冰川覆盖的高山上空降水云类型以深对流云为主,无冰川覆盖的高山上空降水云类型以雨层云为主。(2)疏勒南山地区高含水量主要分布在5 km以下的中低层云中,且冰川区气流垂直运动较非冰川区活跃。(3)疏勒南山冰川区云水含量平均值为0.07 g·m^-3,非冰川区云水含量平均值为0.17 g·m^-3,云水的空间变化在一定程度上能够反映降水和水汽的分布状况。

Effects of glacial surface on cloud structure and cloud water content in summer:A case study of the Shulenan Mountain of Qilian Mountains

As a distinct underlying surface,glaciers directly affect water vapor flux,cloud,precipitation,and atmospheric circulation.Shulenan Mountain is rich in cloud water resources and is home to the glacier development center of the Qilian Mountains.It is of great significance for regional climate change,water resource development,and utilization for study of the interaction of glaciers,clouds,and precipitation at Shulenan Mountain.On the basis of the 2B-CLDCLASS,2B-GEOPROF,and 2B-GEOPROF-LIDAR product data of the CloudSat remote sensing satellite during the summers of 2012-2015,the second Chinese glacier inventory,and meteorological data,this paper first analyzed the current situation of the glaciers on Shulenan Mountain.Then,it studied the cloud water content and cloud structure in the summer at Shulenan Mountain,including the spatial distribution of cloud water content,cloud types,and height structure.Finally,the influence of the glacial surface of Shulenan Mountain on the cloud water content in summer was analyzed.The results showed the following:(1)The cloud water content at Shulenan Mountain could develop in the stratosphere in summer,and the vertical distribution of the cloud water content was affected by the glacial surface and cloud type,which mainly showed that the type of precipitation clouds over glacial-covered high mountains was largely deep convective clouds and that on the mountain without glacier cover was mainly nimbostratus.(2)The high water content in the Shulenan Mountain area was mainly distributed in the middle-and lower-layer clouds below 5 km,and the vertical movement of the airflow in the glacial area was more active than that in the non-glacial area.The development potential of the cloud water resources showed a decreasing trend from west to east,indicating that the change of cloud water can,to some extent,reflect the spatial distribution of the precipitation and water vapor.(3)The average cloud water content in the glacial area of Shulenan Mountain was 0.07 g·m^-3,and that in the non-glacial area was 0.17 g·m^-3.This showed that when the water vapor passed over the glacial area,the saturated water vapor pressure of the overhead water vapor decreased because of the cold storage of the glacial surface and water vapor was more likely to condense and cause rain,reflecting that the glacier has a certain traction effect on water vapor transportation.