| 概率密度匹配法对中国区域卫星降水资料的改进 |
| |
| 引用本文： | 宇婧婧,沈艳,潘旸,赵平,周自江.概率密度匹配法对中国区域卫星降水资料的改进[J].应用气象学报,2013,24(5):544-553. |
| |
| 作者姓名： | 宇婧婧 沈艳 潘旸 赵平 周自江 |
| |
| 作者单位： | 1.国家气象信息中心，北京 100081 |
| |
| 基金项目： | 资助项目：国家重点基础研究发展计划项目（2010CB951602），公益性行业（气象）科研专项（GYHY201006042） |
| |
| 摘 要： | 为考察概率密度匹配法 (PDF方法) 对中国区域卫星反演降水产品系统误差订正的适用性，基于逐日和逐时我国地面观测降水量资料，引入PDF方法，分别对逐日0.25°×0.25°水平分辨率和逐时0.1°×0.1°水平分辨率的CMORPH (Climate Prediction Center Morphing Technique) 卫星降水产品的系统误差进行订正。在分析CMORPH卫星降水产品误差特征的基础上，根据两种资料不同的时空分辨率和误差特点，调整概率密度匹配时选取样本的时间和空间范围，设计相应的订正方案。评估结果表明: PDF方法订正后, 两种分辨率卫星降水资料在中国区域系统误差均显著减小，达到了理想的订正效果。在我国站点稀疏的西部地区，订正后的CMORPH卫星降水产品仍保持卫星观测的降水空间分布，降水量也明显接近于地面观测降水量。可见，PDF方法是中国区域卫星反演降水产品系统误差订正的一种有效方法。
|
| 关 键 词： | 卫星反演降水 地面观测降水 系统误差 概率密度匹配法 |
| 收稿时间： | 2012-10-15 |
| 修稿时间： | 4/3/2013 12:00:00 AM |
Improvement of Satellite based Precipitation Estimates over China Based on Probability Density Function Matching Method |
| |
| Yu Jingjing,Shen Yan,Pan Yang,Zhao Ping and Zhou Zijiang.Improvement of Satellite based Precipitation Estimates over China Based on Probability Density Function Matching Method[J].Quarterly Journal of Applied Meteorology,2013,24(5):544-553. |
| |
| Authors: | Yu Jingjing Shen Yan Pan Yang Zhao Ping and Zhou Zijiang |
| |
| Affiliation: | 1.National Meteorological Information Center, Beijing 1000812.State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081 |
| |
| Abstract: | In the evaluation and adjustment of satellite-based precipitation estimates, the gauge-based precipitation data is usually taken as the objective criteria. Assuming gauge-based analysis at grid boxes with station reports as the true value, the satellite precipitation data are corrected after adjusting probability density function (PDF), which makes the PDF distribution of the corrected measurements the same as that of the station observation. One advantage of the PDF method is that it can remove the range dependent bias effectively, which is also the main cause for its recent popularity in correcting the error of satellite-based precipitation estimations.Aiming to investigate the applicability of the PDF method, and then to adjust the systematic bias of the high resolution satellite-based precipitation estimations over China, the daily satellite precipitation data with the resolution of 0.25° by 0.25° and hourly data of 0.1° by 0.1°from CMORPH (Climate Prediction Center Morphing Technique) are adjusted, based on grid precipitation data interpolating stations collected and quality controlled by NMIC (National Meteorological Information Center) of China Meteorological Administration. Although CMORPH data has good performance on the space structure of rainfall over China in summer time, it has obvious systematic errors. CMORPH data underestimate large precipitation values while overrate small ones.After analyzing the bias characteristic of CMORPH precipitation data, different matching schemes are designed by adjusting PDF matching samples of spatial and temporal scale separately. The generalized cross-validation (GCV) statistical tests are used in evaluating the quality of correcting data. The evaluation results suggest that the PDF distribution and precipitation values of corrected precipitation products are close to those of the gauge-based precipitation. Both adjusted daily and hourly satellite precipitation data over China get a less systematic bias than the original ones. Even in the area of sparse observations, such as the Western China, the improvement is also remarkable. The adjusted rainfall data over the Western China not only maintain the basic spatial construction of original satellite products, but also improves their quantity value through closing them to the gauge observations. So the research demonstrates that the PDF method is an effective way in correcting systematic bias of satellite-based precipitation estimates over China. |
| |
| Keywords: | satellite based precipitation estimates gauge based precipitation systematic bias probability density function matching method |
|
| 点击此处可从《应用气象学报》浏览原始摘要信息 |
|
点击此处可从《应用气象学报》下载全文 |
|
