本文利用2004—2008年6—8月中国673个气象站逐6小时降水资料检验同期TRMM测雨产品3B42的精度。经检验得出:卫星资料日平均降水和降水频率空间分布与台站资料非常类似,相关系数分别能达到0.79和0.84,降水频率与台站资料相比偏大;从日降水相关空间分布看,卫星资料在东部地区相关性较高,日降水相关系数都在0.6~0.9之间;从日降水和逐6小时降水平均绝对误差空间分布看,卫星资料在华南地区误差最大,长江流域次之;从中国8个区域逐6小时降水总量日变化看,卫星资料与台站资料有很好的一致性,但在华南地区20时降水量偏小;按不同雨量等级对比,发现卫星资料绝对误差相对百分率空间分布有如下特点:小雨全国普遍数值偏高,中雨东部部分地区偏大,大雨和暴雨整体上数值小于1;全国平均漏演率和空演率分别为10%和14%。
The 6-hourly precipitation data from 673 rain gauge records are used to verify the accuracy of Tropical Rainfall Measuring Mission(TRMM) 3B42 products from June to August(JJA) during 2004—2008 in China.The results show that the satellite products are similar to rain gauge data in revealing the spatial patterns of JJA mean precipitation amount and precipitation frequency during 2004—2008.The pattern correlation coefficients of daily rainfall amount and rainfall frequency are 0.79 and 0.84,respectively. The satellite product overestimates rainfall frequency.Based on the spatial distributions of correlation coefficients of daily rainfall amount,the correlation coefficients between TRMM products and rain gauge data range from 0.6 to 0.9 in eastern China.According to the spatial patterns of mean absolute error(MAE) of daily and 6-hourly precipitation amount,the MAE in South China is the largest,followed by the Yangtze River Basin.From diurnal cycle of the 6-hourly total precipitation amount over eight subregions,the TRMM product has a good resemblance with rain gauge observations except the big difference in the after- noon(1400—2000 LST) in South China.Based on the spatial patterns of mean relative error(MRE) of different rainfall amount,the TRMM product behaves as follows;light rains is overestimated nearly in whole country;moderate rain is larger in some regions of eastern China;the MREs of heavy rain and torrential rain are less than 1 in most areas of China.Mean rates of the missing retrieval and the vacancy retrieval are 10%and 14%respectively in China.