基于WRF(Weather Research and Forecasting)模式及其3DVAR(3-Dimentional Variational)资料同化系统,采用36 km、12 km、4 km三层嵌套网格进行逐3 h资料同化和快速更新循环预报,对2011年5月8日鲁中一次局地大暴雨过程进行了资料同化敏...基于WRF(Weather Research and Forecasting)模式及其3DVAR(3-Dimentional Variational)资料同化系统,采用36 km、12 km、4 km三层嵌套网格进行逐3 h资料同化和快速更新循环预报,对2011年5月8日鲁中一次局地大暴雨过程进行了资料同化敏感性试验。试验结果表明,地面观测资料同化和快速更新循环对本次降水的预报起到了关键性作用。在快速更新循环预报时不同化地面观测资料,或同化全部观测资料进行冷启动预报,模式均不能预报出山东的降水。同化地面观测资料后,显著改进了模式降水落区预报。地面观测资料同化可以影响到700 hPa高度以上温压湿风要素的变化,从而改变了大气初始场的温湿结构,导致模式预报的700 h Pa附近高空大气湿度和热力不稳定增强,700 hPa以下低层风场更强,850 h Pa鲁中以南风速较无观测资料同化的偏强2～4 m·s-1,低层风场的动力作用触发高空的不稳定大气,降水出现在山东。展开更多
To improve the weather forecasting over the Beijing area for the 2008 Olympic Games,a triple-nested(27/9/3km) WRFVar/WRF system with 3-h update cycle was established.Experiments have been done for a convective event t...To improve the weather forecasting over the Beijing area for the 2008 Olympic Games,a triple-nested(27/9/3km) WRFVar/WRF system with 3-h update cycle was established.Experiments have been done for a convective event that occurred on August 1,2006.The results showed that the high-resolution rapid update cycle gave a good precipitation forecast;the tunings of background error statistics(BES) and observation-error statistics in WRFVar improved the skill of the precipitation forecast;the BES for the fine domain(3 km) obtained by interpolation from its parent domain(9 km) can be used in 3 km WRFVar as a reasonable approximation.The user can now save a great deal of work related to the derivation of the fine mesh BES from the forecast over a period of time;the rapid update cycle with 3-h frequency has satisfied the forecast,and the update cycle with 1-h frequency was not necessary.展开更多
文摘基于WRF(Weather Research and Forecasting)模式及其3DVAR(3-Dimentional Variational)资料同化系统,采用36 km、12 km、4 km三层嵌套网格进行逐3 h资料同化和快速更新循环预报,对2011年5月8日鲁中一次局地大暴雨过程进行了资料同化敏感性试验。试验结果表明,地面观测资料同化和快速更新循环对本次降水的预报起到了关键性作用。在快速更新循环预报时不同化地面观测资料,或同化全部观测资料进行冷启动预报,模式均不能预报出山东的降水。同化地面观测资料后,显著改进了模式降水落区预报。地面观测资料同化可以影响到700 hPa高度以上温压湿风要素的变化,从而改变了大气初始场的温湿结构,导致模式预报的700 h Pa附近高空大气湿度和热力不稳定增强,700 hPa以下低层风场更强,850 h Pa鲁中以南风速较无观测资料同化的偏强2～4 m·s-1,低层风场的动力作用触发高空的不稳定大气,降水出现在山东。
文摘To improve the weather forecasting over the Beijing area for the 2008 Olympic Games,a triple-nested(27/9/3km) WRFVar/WRF system with 3-h update cycle was established.Experiments have been done for a convective event that occurred on August 1,2006.The results showed that the high-resolution rapid update cycle gave a good precipitation forecast;the tunings of background error statistics(BES) and observation-error statistics in WRFVar improved the skill of the precipitation forecast;the BES for the fine domain(3 km) obtained by interpolation from its parent domain(9 km) can be used in 3 km WRFVar as a reasonable approximation.The user can now save a great deal of work related to the derivation of the fine mesh BES from the forecast over a period of time;the rapid update cycle with 3-h frequency has satisfied the forecast,and the update cycle with 1-h frequency was not necessary.
