摘要
针对2011年7月3日四川地区一次强降雨过程,以NECP/NCAR 1°×1°再分析资料为背景场,采用中尺度数值天气预报模式WRF及其三维变分同化系统3DVAR,同时对多普勒天气雷达的径向速度和反射率因子进行了三维变分同化对暴雨模拟效果影响的研究。结果表明:同化了雷达资料后的初始场能够更加精细的刻画初始风场和水汽通量场的分布与数值,能展现出风场的辐合辐散区域,对水汽通量的中心位置有较大影响,大风速区域和水汽通量高值中心有较好的对应关系;同化了多普勒雷达资料后能较为明显的改变降雨落区及强度的预报精度,前6h有明显的改善作用,随着时间的增加改善作用逐渐减小,前9小时改进作用仍很明显,对比24小时实况降雨仍存在一定的改善作用;经过质量控制后的雷达资料对暴雨预报的改善作用要优于未进行质量控制的雷达资料以及每隔一小时加入一次雷达资料要优于每隔半小时加入雷达资料对于暴雨预报的改善作用。
In order to study the influence of Doppler radar radial velocity and reflectivity factor in the numerical simu- lation of heavy rainfall event, usingNECP reanalysis data as background field, a investigation by WRF and WRF- 3DVAR. is conducted on a heavy rainfall event occurred in sichuan province on July 3, 2011. The results show that: The initial field assimilated the radar data can be describe the initial wind and water vapor flux distribution in more detail and show a wind field convergence and then, has great influence on to the center of the vapor flux. The big wind speed area and the vapor flux high value center has good corresponding relation; Assimilated Doppler radar data can obviously change the forecast accuracy of the drop zone and strength of the rainfall. There is obvious improvement in the first 6 hours and the improvement is reduced gradually. 9 hours forecast still has improvement, compared re- suits showed that 24 hours of live rainfall forecast still has some improvement; The assimilation experiment result with the quality control of the radar data is better than the result without quality control and a one hour assimilation interval is better than those with half an hour interval.
出处
《成都信息工程学院学报》
2013年第1期17-23,共7页
Journal of Chengdu University of Information Technology
基金
中国气象局西南区域气象中心区域重大科研业务资助项目(西域20101-1)
关键词
气象学
资料同化
暴雨
三维变分同化
径向速度
反射率因子
质量控制
meteorology
data assimilation
heavy rainfall
three-dimensional variational assimilation
radial velocity
reflectivity factor
quality control