欧洲中期天气预报中心第五代全球再分析土壤湿度资料在内蒙古的适用性评估

土壤湿度是研究陆-气耦合和陆面水循环过程中的重要参量,对大气环流、气候变化和干旱研究起着关键作用。由于土壤湿度观测资料较为缺乏,再分析土壤湿度资料在业务和研究扮演着重要角色。利用内蒙古自治区2018年5—10月37个气象台站逐日0～10 cm观测土壤湿度资料,对再分析[欧洲中期天气预报中心第五代再分析资料(ERA5)、欧洲中期天气预报中心第四代再分析资料(ERA-Interim)、美国全球陆面数据同化系统(GLDAS2.1-NOAH)和基于多卫星反演融合的土壤湿度业务产品系统(SMOPS)]土壤湿度资料验证评估。结果表明:4种土壤湿度资料均可以模拟出内蒙古区域土壤湿度的空间分布,但在数值上普遍高估了土壤湿度;从内蒙古3个研究分区土壤湿度时间序列统计特征来看,ERA5和GLDAS2.1-NOAH优于ERA-Interim和SMOPS资料,但ERA5高估较多;相对于ERA-Interim土壤湿度资料,ERA5模拟的土壤湿度空间分布更为合理,时间相关系数最高,但均方根误差较大。由此可见,ERA5模拟能力优于ERA-Interim,且再分析土壤湿度资料普遍好于卫星融合土壤湿度SMOPS资料。

Evaluation of ERA5 Reanalysis Soil Moisture over Inner Mongolia

Soil moisture is an important parameter in the process of land-atmosphere interactions research. It plays a significant role in atmospheric circulation, climate change and drought research. Lacking of soil moisture observation, reanalysis of soil moisture data plays an important role in operation and research. Evaluation and comparison of soil moisture (0-10cm) from May to October in 2018 over Inner Mongolia by using the Soil Moisture Operational Products System data, Global Land Data Assimilation System version2.1 data (NOAH) , European Centre for Medium-Range Weather Forecasts Reanalysis Interim data and European Centre for Medium-Range Weather Forecasts fifth Reanalysis data was made. After the analysis of temporal and spatial variation of soil moisture, results show that: SMOPS, GLDAS2.1, ERA-Interim and ERA5 soil moisture could be used to reproduce the spatial and temporal distribution with over estimation. The ERA5 and GLDAS2.1 are better than ERA-Interim and SMOPS with over estimation in 3 areas over Inner Mongolia. ERA5 has the highest correlation coefficient with higher Root Mean Square Errors. And reanalysis soil moisture is better than soil moisture retrievals from satellites/sensors.