COSMIC反演大气温湿廓线与模式客观分析场的比较

利用2009年不同季节COSMIC湿反演的大气温度和相对湿度廓线数据,分别与时、空相匹配的ECMWF(European Centre for Medium-Range Weather Forecasts,欧洲中尺度天气预报中心)、NCEP(National Centers for Environmental Prediction,美国环境预报中心)模式客观分析场和无线电探空观测数据,进行全球范围的比较分析.初步研究表明,无论夏季还是冬季,各种资料源之间相互比较的偏差和标准差分布相似,与季节无关.就温度而言,三种资料源的温度水平、垂直分布都很接近,ECMWF模式数据比NCEP不论是温度廓线还是湿度廓线都更接近COSMIC反演值.模式的水汽客观分析场在对流层基本上都比无线电探空观测值偏湿,对流层中高层在大部分海洋地区也比COSMIC反演场偏湿.COSMIC反演的相对湿度相对于无线电探空整层偏大,具有明显正偏差,在300 hPa偏差达最大值(约30%).

Comparison of COSMIC retrieved temperature and humidity profiles with model objective analysis fields

The COSMIC retrieved temperature and relative humidity profiles are compared with the collocated spatially and temporally ECMWF(European Centre for Medium-Range Weather Forecasts) and NCEP(National Centers for Environmental Prediction) model objective analysis fields as well as radiosonde observations on global scale in different seasons in 2009.The primary research results show that the distributions of the deviations and the standard deviations from these data sources are similar in summer and winter,independent of seasons.The vertical and horizontal temperature distributions of these data sources are very close.Either temperature or relative humidity profiles from ECMWF are more close to COSMIC retrievals than NCEP fields.The humidity profiles of model objective analysis are all higher than radiosonde observations in nearly whole troposphere and wetter than COSMIC retrievals in middle-upper troposphere over most ocean area.The COSMIC retrieved relative humidity profiles are higher than the radisonde measurements,having obvious positive deviations with maximum(about 30%) at 300 hPa.