COSMIC掩星反演大气温湿资料的质量特征分析

Analyzing the quality of data for temperature and humidity using COSMIC radio occultation observations

摘要:

针对COSMIC（Constellation Observation System of Meteorology Ionosphere and Climate）掩星反演的大气温度和水汽压二级资料，利用常规探空观测和NCEP（National Centers for Environmental Prediction）分析资料分别进行质量检验分析，以揭示反演资料质量的海陆差异、随纬度和高度变化等三维空间特征。结果显示：我国区域反演资料的温度略低于探空观测与NCEP分析资料，温度与水汽压相对于检验资料的均方根误差较小；全球范围内，反演大气温湿资料的质量随高度和纬度的不同而存在明显差异，而且海洋和陆地上质量的水平和垂直分布特征也存在显著不同。总体上看，COSMIC反演大气温湿资料具有良好的可靠性与精确度，可作为我国数值预报资料同化的新资料，反演温湿资料的质量特征也可为COSMIC资料同化的质量控制和垂直稀疏化方案的设计提供科学依据。

Abstract:

The Global Positioning System (GPS) demonstrates a novel and practical approach which is well-known globally,representing high-precision,high-vertical-resolution,and long-time sustain ability in different weather conditions proposed in early 1990s.The Constellation Observation System of Meteorology Ionosphere and Climate (COSMIC) program has been designed to provide advances in climatology,and space weather by using GPS satellites.The gathered data provides notable advances on the probing of neutral atmosphere and ionosphere.In addition,it is regarded as a robust solution for numerical weather prediction and the monitoring the climate changes.Before acquiring the atmospheric temperature and vapor pressure data by the COSMIC program,it seems to be necessary to control the quality of the spatial distribution characteristics.In this paper,to identify the existing differences in the quality of observations for between the land and ocean areas,the evolution characteristics including latitude and altitude coordinates as well as the quality of the atmospheric temperature and vapor pressure data obtained from COSMIC program are analyzed and assessed with the help of conventional radiosonde observations provided by National Centers for Environmental Prediction(NCEP) throughout the world,respectively.The results show that the temperature data retrieved by the COSMIC program is slightly lower than the NCEP observations over China.Moreover,the values of Root Mean Square Error(RMSE)for the temperature and vapor pressure data is negligible.In the global scale,there is a significant difference between the quality of the temperature and vapor pressure data retrieved from the COSMIC atmospheric data with the given latitudes and altitudes.Moreover,the quality differences in the horizontal and vertical distribution for the retrieved data from COSMIC atmospheric retrieved data are significant over land and ocean area.In general,the atmospheric temperature and vapor pressure data retrieved from COSMIC program demonstrates to be reliable and accurate,in which can be used for numerical weather prediction.On the other hand,the special distribution characteristics of quality of atmospheric temperature and vapor pressure using COSMIC atmospheric retrieved data can be regarded as a base for the quality control of observations as well.