三江源及其周边地区多源水汽资料对比检验

Comparative Analysis of Multi-Source Water Vapor Data in Three River Source and Nearby Areas

采用三江源人工增雨工程建设的35通道微波辐射仪、全球导航卫星系统气象观测(GNSS/Met)、L波段探空系统以及美国国家环境预报中心(NCEP)再分析资料,经多源连续监测和计算大气水汽含量,对比检验多源数据的差异性和影响因素,了解多源大气水汽含量在三江源及其周边地区的适用性。文中以L波段探空计算的大气水汽含量为基准值进行检验,结果表明GNSS/Met反演的大气水汽含量与基准值保持一致,总偏差为1. 45 mm,不受温度、降水、季节、地区的明显影响,可代表三江源及其周边地区的大气水汽特征; NCEP大气可降水量总趋势与基准值比较一致,其值明显偏小,仅为基准值的69%,且随降水越大偏差增大,温度、地区、季节对其有明显影响;微波辐射仪能代表无降水或弱降水条件下的大气水汽特征,其值明显偏大,且受温度、液态水含量等多种因素影响。对三江源及其周边地区的旬大气水汽分析表明,三江源核心区大气水汽含量差异较小,从东到西呈波谷型分布;周边地区分布差异巨大,东边最高,西边最低,此分布特征与地理位置、地形和年内天气过程等密切相关。这些监测数据的对比检验和分析为三江源及其周边地区的云水资源精确定量评估起到基础性作用,也为改善人工增雨(雪)技术和保护当地生态环境起到关键性作用。

The 35-channel microwave radiometer,global navigation satellite system meteorological observations( GNSS/Met),L-band sounding and National Center for Environmental Prediction( NCEP) reanalysis data constructed by enhancement precipitation project of Three Rivers Source were used to continuously monitor and calculated the precipitation water vapor( PWV) in this paper. The differences and influencing factors of multi-source data were compared,grasped and identified the applicability of multi-source data in Three River Source and nearby areas. The results showthat GNSS/Met PWV is basically consistent with the reference value,which is not affected by temperature,precipitation,seasons and regions,and the total deviation is 1. 45 mm. It can completely represent the water vapor characteristics of Three River Source and nearby areas. The general trend of NCEP PWV is consistent with the reference value,its value is obviously small,only 69% of the reference value,and with the larger deviation of precipitation increases. Temperature,region and season have a significant impact on its value. PWV of microwave radiometer can represent the water vapor characteristics of no or weak precipitation conditions,the value is significantly larger,and affected by the temperature,liquid water content and other factors,the data applicability need a lot of neural network training. The analysis of the ten-day PWV in Three River Source and nearby areas shows that there is little difference in the core area of Three River Source,and it is a trough-type distribution from east to west;the distribution characteristics of nearby areas are very different,with the highest in the east and the lowest in the west. the characteristics closely relate with geographic location,topography,and annual weather processes. These monitoring data analysis and comparative verification have played a fundamental role in the accurate quantitative assessment of cloud water resources in Three River Source and nearby areas. and also played a key role in protecting the ecological environment of the plateau ecology by enhancement precipitation.