FY-2C云迹风资料时空分布特征分析

利用统计方法分析我国FY-2C静止卫星红外、水汽通道云迹风资料的数量和误差分布特征,通过分别统计昼夜、不同区域、冬夏季和不同年份的资料分布情况,得到以下主要结论:(1)云迹风资料在白天和黑夜80%以上的可用点资料都集中在200~300 hPa,但白天的资料总个数多于黑夜;误差统计结果表明在资料比较集中层次,昼夜的平均误差、标准误差和均方根误差变化趋势相近。(2)不同区域云迹风资料可用点的数量垂直分布差异不明显,而不可用点的数量分布差异很大;同时发现两个区域的3种误差表现出一定的区域性特征,高原地区的误差整体小于低海拔地区的。(3)冬夏季的统计结果表明云迹风资料在冬、夏季资料总个数及垂直分布变化不同,夏季资料个数多,且主要分布在200~300hPa,而冬季主要分布在100hPa和400hPa;误差统计结果表明夏季误差小、冬季误差大。(4)不同年份的数量统计表明:2005年和2008年的资料个数变化不大,但是IR1资料的数量垂直分布差异很大,而IR3的差异不明显;误差统计结果表明2008年云迹风资料的均方根误差整体比2005年的小。(5)在误差分析中发现,无论IR1资料还是IR3资料都存在一定的平均误差,但标准误差,即随机误差仍是产生均方根误差的主要原因。

Spatial-Temporal Characteristics of FY-2C Cloud Drift Wind

The aim of this paper is to analyse the number and error distributions of the FY-2C cloud drift wind (CDW) data using statistical methods.By comparing the CDW data in day and night, respectively, different regions, summer and winter, different years, the main conclusions as following:(1) More than 80% available points of the CDW data are concentrated in the 200~300hPa, but the total number during the day is more than the night;error statistical results of day and night show that the trend of the average error, standard error and RMS error is similar. (2) The vertical distribution of the available points' number of the CDW data in different regions have no significant difference, but the not-available points have contrary changes;At the same time, the errors in different regions have some regional characteristics, and in the plateau region are smaller than low altitude region. (3) The statistical results of two seasons show that the CDW data in summer and winner have different changes of total number and its vertical distribution.The number of summer data is more than the winner's, and the errors of summer are smaller than winner. (4) The results of different years show that there are little changes of the total number of the CDW data between in 2005 and 2008, but the vertical distribution of the IR1 CDW data has apparent change.The data errors in 2008 are smaller than 2005. (5) During the error analysis, it is found that the average error of the CDW data is certain, but the standard error is still the main reason that produces the RMS error.