大气红外探测器(AIRS)温、湿度反演产品的有效性检验及在数值模式中的应用研究

VALIDATION OF AIRS RETRIEVAL TEMPERATURE AND MOISTURE PRODUCTS AND THEIR APPLICATION IN NUMERICAL MODELS

中文关键词:  AIRS，卫星资料，数值模拟，降雪

英文关键词:AIRS, Satellite data, Numerical simulation, Snowfall

中文摘要:

      利用中国540个地面气象观测站点资料，对1和7月大气红外探测器(AIRS)的反演中国区域地面气温精 度做了详细评估，分析了产生误差的原因。同时把AIRS的反演温、湿度廓线产品与T213数值预报产品进行比较，分析了它们之间的差异。为进一步考察AIRS温、湿度产品的有效性，我们把经过订正的AIRS地面气温以及温、湿度廓线产品分析同化到中尺度模式MM5中，用于华北降雪天气过程的对比模拟试验，分析AIRS反演产品对降雪量、水汽场、垂直速度场、散度场以及云物理过程等的影响。

英文摘要:

      To estimate the accuracy of AIRS retrieval products in the region of China, the surface air temperature derived from AIRS are compared with those obtained from 540 meteorological stations in the period of July 2004 and January 2005. The atmospheric temperature and humidity profiles derived from AIRS are also compared with T213 numerical forecasting products. Then the errors in AIRS atmospheric pro ducts are analyzed. Furthermore, the surface air temperature and atmospheric tem perature and humidity profiles derived from AIRS are assimilated into the MM5 nu merical model by analysis nudging, to investigate their effects on snowfall, and water vapor, vertical velocity and divergence fields as well as microphysical processes. The preliminary results are as following: (1) The errors in the surface air temperature retrieved from AIRS are systematic errors. The influence of terrain altitude can cause a negative deviation of 10 K. Also, the effects of land surface are significant, for the snow cover in winter can bring about a positive deviation of 5 K. (2) By comparing the atmospheric profiles derived from AIRS with those from T213 numerical products, it is found that the difference in temperature can reach 2 K, and the difference in relative humidity can reach 25%. (3) The numerical experiment results show that the use of AIRS atmospheric produ cts in the initial assimilation is able to improve the initial moisture field an d thus the snowfall prediction to some extent.