两种再分析资料与RS92探空资料的比较分析

摘要

An intercomparison by interpolation is made between two types of reanalysis data (NCEP/NCAR and ERA-Interim) and seven months (May 2008 to December 2008) measurements of high vertical resolution GPS radiosonde (RS92) at Shouxian station (32. 56°N, 116. 78°E), China. The correlation coefficient (R), bias (Bins), and mean absolute deviation (Msd) of temperature (T), zonal wind (U), meridional wind (V), and relative humidity (RH) are presented at the standard pressure levels of two reanalysis data sets from 1000 hPa to 20 hPa. The results indicate better correlation of RS92 observations with the ERA-lnterim data than that with the NCEP/NCAR data. T, U, and V have higher correlation coefficients than RH at all levels. R of T is close to 1.0 from 1000 hPa to 250 hPa and decreases gradually above 250 hPa. The absolute values of bias for T is mostly less than 0. 3 ℃ between ERA-lnterim and RS92, but about two times between NCEP and RS92 at all levels. R of U is larger in middle and upper troposphere than in lower troposphere and lower stratosphere. R of V increases with height in the troposphere and decreases dramatically in lower stratosphere. R of RH decreases with height. It is shown that Bins ,of RH ranges from 10% to 20% through 400 hPa to 100 hPa and becomes smaller than 10% in the upper layers, which is in part attributed to the limitation of measurement precision.%利用2008年5～12月在安徽寿县获得的逐6小时RS92探空资料,与同期的NCEP/NCAR和ERAInterim两种再分析资料(6h)进行比较分析,计算分析了标准气压层上探空与再分析资料的温度、纬向风、经向风和相对湿度的相关系数、偏差和平均绝对差.结果表明:在所有标准层高度,ERA-Interim再分析资料与探空资料的相关优于NCEP再分析资料的与探空资料的相关,温度和风速再分析资料与探空资料的相关优于相对湿度的相关；温度再分析资料与探空资料的相关系数在1000～250hPa接近1,在250hPa以上随高度减小,ERA-Interim与探空资料的偏差的绝对值基本小于0.3℃,而NCEP与探空资料的偏差绝对值在1000hPa上要大一倍；纬向风再分析资料与探空资料的相关系数在对流层中高层大于对流层低层和平流层低层,经向风的相关在对流层随高度增加,在平流层低层迅速减小；风速再分析资料与探空资料的偏差绝对值小于1m·s-1；相对湿度再分析资料与探空资料的相关随高度减小,偏差在400～100hPa层较大,达10％～20％,在更高层小于10％.