青藏高原那曲地区夏季水汽来源及输送特征分析

Analysis on the Source and Transport Characteristics of Moisture in Naqu of the Qinghai-Tibetan Plateau in Summer

青藏高原作为“亚洲水塔”,研究其降水来源对我国水安全和水资源利用有重要意义。本文使用中国地面气候资料日值数据集,并用GDAS资料驱动HYSPLIT(Hybrid Single Particle Lagrangian Integrated Trajecto‐ry)拉格朗日模式,分析了那曲地区2014年夏季的水汽输送轨迹和不同等级降水的轨迹。结果表明:(1)夏季水汽输送轨迹有明显的月、旬变化,主要是由于夏季风的向北推进造成的。印度洋、阿拉伯海、孟加拉湾、大西洋和中亚为5条主要的水汽输送路径。(2)小雨和中雨存在南方路径和西方路径,而大雨只存在南方路径;海洋的水汽输送对降水等级具有决定性作用。(3)1天前水汽来源大值区为雅鲁藏布江流域;3天前水汽来源大值区为印度与不丹的交界;大雨的水汽来源较小雨和中雨更加集中;水汽贡献分布集中的区域与水汽轨迹追踪的终点有较好的对应关系。(4)水汽源地:小雨主要来自阿拉伯海、孟加拉湾、印度、新疆以及中亚地区;中雨主要来自印度洋、阿拉伯海、孟加拉湾、印度、新疆以及中亚地区;大雨主要来自阿拉伯海和孟加拉湾。

As the Asian Water Tower,it’s of great significance to study the precipitation sources of the QinghaiTibetan Plateau for water security and water resources utilization in China.In order to study the characteristics of summer moisture transport in the middle of the plateau and understand the regional water cycle.In this paper,the daily data set of China's surface climate data and the HYSPLIT Lagrangian model driven by GDAS data are used to analyze the moisture transport track and the track of different grades of precipitation in summer of 2014 in Naqu area.Using the cluster analysis to get the moisture passages and the paticle tracking analysis to calculate the moisture contribution.The results show that,There are obvious monthly and ten day changes in the moisture transport trajectories in summer,which is mainly caused by the northward advance of summer monsoon.The In‐dian Ocean,the Arabian Sea,the Bay of Bengal,the Atlantic Ocean and Central Asia are the five main moisture transport passages.There are southern and western paths for light rain and moderate rain,but only southern paths for heavy rain.The moisture transport in the ocean plays a decisive role in the precipitation level.The area with high moisture source one day ago is the Yarlung Zangbo River Basin.The area with high moisture source three days ago is the border between India and Badan.The moisture source of heavy rain is more concentrated than that of light rain and moderate rain.There is a good correspondence between the region of moisture contribution con‐centration and the end point of moiture trace.In a nutshell,the moisture sources of different grades of precipita‐tion are different.