摘要
利用华南一次强降水过程,通过雷达回波反演的云雨水及模式背景场的水汽和根据雨水修订的水汽场对GRAPES模式初始场通过Nuding技术进行调整,试图改善模式的临近预报。模拟结果对比发现,模式初始场通过Nudging技术只订正云水、雨水及水汽场2种情形,对模式雷达回波的临近预报效果都有一定的改善,其中前者对0～3h的临近预报效果改善明显,而后者对0～6h的预报效果都有所改善,且后者前3h的改善效果优于前者。对比模式初始场通过Nuding技术订正修订前后的水汽场的预报效果发现,修订后的水汽场的临近预报效果优于修订前的,尤其4～6h的差异较明显。分析原因发现,模式初始场中水汽场的修订,尤其是饱和水汽的修订,对模式预报的水汽场有明显影响,从而影响到了环流场,改善了模式的雷达回波和降水的预报。
In this study, we attempted to improve the nowcasting of GRAPES model by adjusting the model initial field through modifying the cloud water, rain water and vapor as well as revising vapor following rain water. The results show that the model nowcasting is improved when only the cloud water and rain water are modified or all of the cloud water, rain water and vapor are modified in the initial field. The forecasting of the former （latter） approach during 0 to 3 （0 to 6） hours is significantly improved. Furthermore, for the forecast for 0 to 3 hours, the latter approach is better than the former. Compared with the forecasting results for which the vapor of the model initial field is modified by the background vapor with those by the revised vapor, the nowcasting of the revised vapor is much better than that of background vapor. The reasons indicate when the vapor is adjusted in the model initial field, especially when the saturated vapor is considered, the forecasting of the vapor field is significantly affected. The changed vapor fields influence the circulation, which in turn improves the model forecasting of radar reflectivity and rainfall.
出处
《热带气象学报》
CSCD
北大核心
2012年第6期785-796,共12页
Journal of Tropical Meteorology
基金
国家自然科学基金项目资助(41075083)
"短时0-6小时定量降水(雪)预报技术研究"(GYHY201006001)资助
