摘要
针对2008年6月12日广西特大暴雨个例,利用华南野外试验获得的高时空分辨率资料,采用Barnes滤波方法,分离了其中的中尺度系统。对比雷达观测资料和模式模拟结果,发现在不同的降水阶段,造成暴雨的中尺度系统类型不同。暖湿气流中的中尺度涡旋造成了对流降水,冷暖空气交汇带上的中尺度涡旋增强了层积混合降水。通过滤波前后包含不同尺度信息的初值进行模式积分,发现基流稳定的暖湿气流中的弱扰动,不能通过模式积分过程产生,基流变化较大的冷暖空气交汇带上的中尺度扰动,可以通过模式积分产生,AREM模式对不同类型的中尺度系统具有不同的预报能力。
Using Barnes band pass filter, the mesoscale disturbances are separated from the high resolution data observed in a heavy rainfall event on 12 June 2008. In contrast with the radar figures and model simulation results, it is found that different kinds of mesoscale disturbance contribute to different types of precipitation in two precipitation periods. A mesoscale vortex in warm and moist south-west flows contributes to convective precipitation, and another mesoscale vortex in the convergence of warm and cold air makes the stratocumulus precipitation much stronger. By examining the predictability of these two mesoscale vortexes in the numerical model, we found that the weak disturbance in the warm and stable basic flow cannot be reproduced in the integration when only large-scale information is included in the model initial data, while strong disturbance in the convergence and unstable belt can be reproduced by the same model initialization. It suggests that the AREM model has different abilities in forecasting different mesoscale disturbances.
出处
《热带气象学报》
CSCD
北大核心
2013年第1期161-168,共8页
Journal of Tropical Meteorology
基金
国家重点基础研究专项(2010CB951904)
国家自然科学基金(41075034)共同资助
关键词
中尺度气象学
暴雨
数值模拟
中尺度涡
模式预报能力
mesoscale meteorology
heavy rainfall
numerical simulation
mesoscale vortex
modelpredictability
