[关键词]
[摘要]
高时空分辨率的全球降水测量计划(Global Precipitation Measurement,GPM)是继热带降水观测计划(Tropical Rainfall Measuring Mission,TRMM)之后新一代的全球卫星降水产品,为全球气候变化、洪旱监测等研究工作提供了有力的数据支持。基于黄淮海平原2015年3月-2016年2月59个气象站点逐日降水数据,采用相关系数(CC)、相对误差(BIAS)、均方根误差(RMSE)3个指标在多时空尺度评估了GPM IMERG卫星降水产品在研究区的适用性。结果表明:日尺度上,GPM IMERG数据与站点数据拟合效果较好(CC=0.95),但GPM IMERG对降水高估1790%。月尺度上,6月-8月均方根误差最高,9个月份的相关系数均大于0.80;季节尺度上,除秋季的相关系数小于090外,其余季节的相关性均较高,夏季均方根误差最大。此外,GPM IMERG 还能较好地反映黄淮海平原由南到北降水量逐渐减少的空间分布格局。通过对比两种数据日降水时间序列,发现GPM IMERG降水产品与气象站点降水变化趋势较为一致。总体而言,GPM IMERG卫星降水产品与气象站点数据表现出较好的相关性,虽然存在轻微的高估现象,但能够以较高的精度和较小的误差估测降水。
[Key word]
[Abstract]
The Global Precipitation Measurement (GPM) with high spatial and temporal resolution,the new generation of global satellite precipitation products after Tropical Rainfall Measuring Mission (TRMM),provides strong data support for global climate change studies, and flood and drought monitoring.The applicability of GPM IMERG product was evaluated in this study using statistical metrics including correlation coefficient (CC),relative error (BIAS) and root mean square error (RMSE),based on the daily precipitation from 59 meteorological stations in the Huang-Huai-Hai Plain for the period of March 2015 to February [JP]2016.The results showed that:(1) GPM IMERG precipitation agreed well with observations at daily scale (CC=0.95).However it overestimated precipitation by 17.90%;(2) At monthly scale,RMSE was the highest from June to August and CC for nine months was greater than 0.80;(3)At seasonal scale,CC was less than 0.90 in autumn and RMSE was the largest in summer:(4) GPM IMERG can simulate the spatial pattern of precipitation decreasing from south to north in the Huang-Huai-Hai Plain;(5) It was also found that the trends from GPM IMERG and observations were consistent.In summary,GPM IMERG satellite precipitation presented a good correlation with the observations at meteorological stations, although there is an overestimation.
[中图分类号]
[基金项目]
国家自然科学基金(41807170);山东省自然科学基金(ZR2017BD021);山东科技大学科研创新团队支持计划项目(2014TDJH101);山东省基础地理信息与数字化技术重点实验室开放课题基金