First evaluation of the climatological calibration algorithm in the real‐time TMPA precipitation estimates over two basins at high and low latitudes
First evaluation of the climatological calibration algorithm in the real‐time TMPA precipitation estimates over two basins at high and low latitudes
复制标题
DOI：
10.1002/wrcr.20246
复制
发表时间：
2013-05
影响因子：
5.4
通讯作者：
B. Yong;L. Ren;Y. Hong;J. Gourley;Yudong Tian;G. Huffman;X. Chen;Weiguang Wang;Y. Wen
中科院分区：
文献类型：
--
作者：
B. Yong;L. Ren;Y. Hong;J. Gourley;Yudong Tian;G. Huffman;X. Chen;Weiguang Wang;Y. Wen
TRMM多卫星降水分析（TMPA）系统于2009年初进行了关键升级，在其实时产品3B42RT中加入了气候校准算法（CCA），并且该算法将继续应用于未来全球降水测量时代的星座降水产品中。在本研究中，工作重点是在应用气候校准之前和之后对第 6 版 3B42RT 估计值进行比较和验证。该评估是利用位于中国高纬度老哈河盆地和低纬度密水盆地的独立雨量计网络完成的。分析表明CCA可以有效减少低纬度密水盆地的系统误差，但错误地反映了中高雨率的强度分布格局。这种行为可能会对 TMPA 的水文应用产生不利影响，特别是对于极端事件（例如洪水和山体滑坡）。结果还表明，CCA 的表现往往稍差，特别是在夏季和冬季，在高纬度老哈河流域。这可能是由于 CCA 中简化的校准处理方案直接将 40° 纬度内开发的气候校准器应用于 40°N–50°N 的纬度带。因此，在高纬度地区使用校准后的 3B42RT 进行与强降雨相关的洪水预报（或山体滑坡预警）时应谨慎，因为在 CCA 偏差校正中使用平滑填充方案可能会使不同的暴雨特征均匀化。最后，本研究强调，高纬度地区积雪的准确探测和估算对于卫星降水反演的未来发展仍然是一项具有挑战性的任务。
The TRMM Multi‐satellite Precipitation Analysis (TMPA) system underwent a crucial upgrade in early 2009 to include a climatological calibration algorithm (CCA) to its real‐time product 3B42RT, and this algorithm will continue to be applied in the future Global Precipitation Measurement era constellation precipitation products. In this study, efforts are focused on the comparison and validation of the Version 6 3B42RT estimates before and after the climatological calibration is applied. The evaluation is accomplished using independent rain gauge networks located within the high‐latitude Laohahe basin and the low‐latitude Mishui basin, both in China. The analyses indicate the CCA can effectively reduce the systematic errors over the low‐latitude Mishui basin but misrepresent the intensity distribution pattern of medium‐high rain rates. This behavior could adversely affect TMPA's hydrological applications, especially for extreme events (e.g., floods and landslides). Results also show that the CCA tends to perform slightly worse, in particular, during summer and winter, over the high‐latitude Laohahe basin. This is possibly due to the simplified calibration‐processing scheme in the CCA that directly applies the climatological calibrators developed within 40° latitude to the latitude belts of 40°N–50°N. Caution should therefore be exercised when using the calibrated 3B42RT for heavy rainfall‐related flood forecasting (or landslide warning) over high‐latitude regions, as the employment of the smooth‐fill scheme in the CCA bias correction could homogenize the varying rainstorm characteristics. Finally, this study highlights that accurate detection and estimation of snow at high latitudes is still a challenging task for the future development of satellite precipitation retrievals.