天气雷达反射率资料订正前后在ARPS模式中的同化试验对比

摘要

以TRMM/PR反射率资料作参照,对常州、南京天气雷达反射率资料进行一致性订正,再利用中尺度模式ARPS及其数据同化系统ADAS对订正前、后的天气雷达反射率因子进行同化,模拟2013年6月25日和2010年8月24日江苏地区两次暴雨过程.两次暴雨过程均包括3组试验:控制试验和雷达资料订正前、后的同化试验.结果表明:(1)雷达反射率因子的同化很好地改进了模式初始湿度场,使降水预报在分布和强度上更接近实况;(2)雷达资料的订正进一步改进了反射率因子同化试验,并且通过调整初始湿度场和上升运动场(调整作用主要体现在前2～3h内)改善了对降水的模拟预报,其结果证明雷达反射率因子的订正改善了雷达资料的质量.%Taking advantage of reflectivity from the Precipitation Radar(PR) onboard the Tropical Rainfall Measuring Mission (TRMM) to calibrate weather radar at Changzhou and Nanjing.Reflectivity are added directly to the mesoscale model Advanced Regional Prediction System(ARPS) by its data processing system ARPS Data Analysis System (ADAS) of simulating two rainstorm process around Jiangsu Province.Each process includes three experiments:the control experiment,original and corrected reflectivity separately assimilated experiment.Results show that:(1) Reflectivity data assimilation improved the initial moisture field,and the rainfall prediction (rainfall area and precipitation) was more close to observation data.(2)Corrected reflectivity assimilation adjusted initial moisture field and ascending motion (The adjustment effect is mainly reflected in the first 2 to 3 hours),and improved the rainfall prediction than original reflectivity assimilation.The correction of radar reflectivity data has improved quality of the radar data.