探空、地面及卫星资料反演水汽含量的比较

The comparison of water vapor content retrieved by radiosonde,ground station and satellite data

利用探空、地面等常规探测资料及卫星遥感资料计算了我国中西部地区2007年6月—2008年5月间水汽含量的空间分布和时间演变,结果显示:由探空资料计算的整层大气水汽含量的空间变化,总体形势是,纬度低的地区水汽含量多,纬度高的地区水汽含量少;各探空站上空水汽分布的季节演变规律比较一致,夏季水汽含量最大,冬季最小,春秋季节基本相当。根据探空资料建立地面水汽压与大气总水汽量的经验关系,利用地面站资料确定水汽分布,与同时次探空站资料估算的水汽场相比,两者分布趋势基本一致。利用FY-2C卫星的可见光和红外分裂窗通道资料,建立反演大气水汽含量的回归关系式,与探空资料计算的结果相比,总体上变化趋势较一致。

The radiosonde,ground station and satellite remote sensing data are used to calculate the spatial distribution and temporal evolution of the water vapor content over the central and western regions of China during June 2007 and July 2008.It shows that there is great spatial difference among the total water vapor content calculated by the radiosonde data.The overall trend is that in the low-latitude area there is more water vapor content than that in the high-latitude;the seasonal evolution over different sounding stations is consistent,that is,water vapor content in the summer is the most,in the winter it is the least,in the spring and fall,they are almost the same.Meanwhile the radiosonde data are also used to build empirical relationship between the surface water vapor pressure and the total water vapor content,which made it possible to estimate water vapor distribution by ground station data.The FY-2C data at channels of infrared split windows and visible light are applied to retrieve water vapor distribution,in order to compare with the result calculated by sounding data,it proved to be credible.