利用卫星资料对青藏高原地区空中云水资源的研究

Analysis of cloud-water resources from satellite data over the Qinghai-Tibet Plateau region

利用青藏高原地区39个站的地面站逐日观测资料,采用泰森多边形法计算了青藏高原地区2007-2011年多年平均月降水量.利用美国环境预报中心逐月再分析资料,计算了2007-2011年各季节的高原季风指数,借助相关分析法分析了影响青藏高原地区降水量的环流因素.利用MOD08大气可降水量和云产品,用奇异值分解法分析了青藏高原地区可降水量与云参数的关系.将地面降水与量资料和MOD08大气可降水量资料结合,计算了青藏高原地区的降水效率.结果表明:西太平洋副热带高压面积指数、亚洲经向环流指数、亚洲纬向环流指数和高原季风指数均与降水量具有显著的相关关系;可降水量与云顶温度、云量、云顶气压和云光学厚度都有很显著的关系,通过奇异值分解,发现每对奇异向量场之间的相关系数,第一模态均达到5%显著性水平,方差贡献均超过989%,每组对应的可降水量的第一模态的异性相关系数在整个青藏高原地区都为正值,且都通过了95%的显著性水平检验,说明可降水量对各云参数的影响在整个研究区域都很大.青藏高原地区上空的云水资源具有较大的开发潜力,年降水效率为32.2%.

With daily observation data from 39 ground meteorologic observation stations and Taisen polygon method, the monthly mean precipitation from 2007 to 2011 over the Qinghai-Tibet-Plateau was obtained. The plateau monsoon indices in different seasons from 2007 to 2011 were figured out by using the data from the National Centers for Environmental Prediction monthly reanalysis and the circulation indices were analyzed with the help of correlational analysis method. Using the precipitable water vapor data and the cloud data provided by MOD08, and according to the singular value decomposition method, the relationship between the precipitation and cloud parameters were analyzed. Using the precipitation data from ground meteorologic observation stations and the precipitable water vapor data provided by MOD08, the precipitation efficiency in the region of the Qinghai-Tibet Plateau were calculated. The resuits showed that significant positive correlations were found between precipitation and the Western Pacific subtropical high, zonal circulation, meridional circulation and plateau monsoon. By singular value decomposition, it was found that the correlation coefficients of the first mode between pairs of singular vector field passed 5% significance level tests and contributions of variance were more than 98%, sug- gesting a significant relationship between precipitation, cloud top temperature, cloud cover, cloud top pressure and cloud optical thickness. The corresponding precipitation heterogeneous correlation coefficients of the first mode in the whole region of the Tibet-Plateau were positive and passed 95% significance level tests, suggesting that precipitable water vapor had a big effect on cloud parameters in the whole region; the annual precipitation efficiency in the Tibet-Plateau region was 32.2%, so cloud-water resources in the region should be of great exploitable potentials.