基于地面站点观测降水资料的中国区域日降水融合产品精度评价

论文对中国国家气象信息中心研制的逐日融合降水资料（1998—2010年）和全国633个气象站点观测降水资料进行了对比,分析了融合降水资料误差的空间分布和时间变化特征,研究了海拔高度及地形起伏度对融合降水资料精度的影响,同时就日降水融合产品不同降水强度进行了误差分析。结果表明：日降水融合产品与台站资料的年平均降水量空间分布具有很强的一致性;全国大部分地区日降水融合产品与台站资料的累计年降水量相关系数大于0.8,东部地区则普遍在0.9以上;日降水融合产品的误差特征值及其空间分布均较为合理,年际变化不大;海拔高度对日降水融合产品平均偏差和平均相对偏差的影响比地形起伏度大,且海拔高度的影响在高海拔区域比低海拔区域更显著。

Evaluation of the High-Resolution Daily Merged Precipitation Product over China Based on in situ Observations

We compared the daily merged precipitation product (DMPP) produced by the National Meteorological Information Center (NMIC) with the observed precipitation data (OPD) from 633 base stations over China during 1998-2010. We analyzed: 1) the temporal and spatial distributions of the error of DMPP, and the inter annual variation of DMPP; 2) the influence of terrain factor on the accuracy of DMPP; and 3) the error of the DMPP with different precipitation intensities. The results showed that the spatial distribution of the average annual precipitation of DMPP agreed well with the observed pattern, and the correlation coefficients of annual precipitation between DMPP and OPD in most areas were greater than 0.8. Specifically, the correlation coefficients in eastern China were generally greater than 0.9. The error characteristics and spatial distributions of DMPP were reasonable, with little interannual variation. The error and variability of DMPP correlated with the terrain features, i.e., the altitude. The altitude has more effect on annual average relative deviation of DMPP than the relief amplitude, and the impact of altitude in the high-altitude regions is greater than in the the low-altitude regions.