雷达资料同化与提高模式水平分辨率对短时预报影响的数值对比试验  

COMPARATIVE EXPERIMENTS BETWEEN EFFECTS OF DOPPLER RADAR DATA ASSIMILATION AND INCEASING HORIZONTAL RESOLUTION ON SHORT-RANGE PREDICTION

作　　者：盛春岩[1] 薛德强[2] 雷霆[1] 高守亭[1] 

机构地区：[1]中国科学院大气物理研究所云降水物理与强风暴实验室,北京100029 [2]山东省气象台,济南250031

出　　处：《气象学报》2006年第3期293-307,i0001,共16页Acta Meteorologica Sinica

基　　金：国家自然科学基金重点项目(40433007);山东省气象局2005年一期重点项目(2005sdqxzl9);中国科学院海外杰出学者基金(2004-2-7)

摘　　要：为对比雷达资料同化与提高模式水平分辨率对短时数值预报的影响,利用美国Oklahoma大学风暴分析和预测中心开发的ARPS(The Advanced Regional Prediction System)模式及其资料分析系统ADAS(ARPS Data AnalysisSystem),对一次华北暴雨过程进行了18,15,9,6,3 km 5种不同水平分辨率的数值对比试验,并对比了使用雷达资料进行云分析时5种分辨率的模拟结果,结果表明,仅使用常规观测资料的情况下,通过提高模式水平分辨率,可以改进6 h内的短时预报,模拟的锋面结构更为细致,降水尤其是强降水预报评分提高了。而使用雷达资料改进模式初始场后,能明显改进模式6 h内的预报尤其是降水强度和落区预报,使得18 km上使用雷达资料同化的预报结果好于3 km不使用雷达资料同化的结果,表明雷达资料同化比单纯提高模式水平分辨率更为有效。不同分辨率上使用雷达资料同化的对比发现,对于40 mm以下的一般性降水,从18—3 km的模拟结果差别不大,而对于强降水,仍然需要提高模式的水平分辨率。但无论初始场是否使用雷达资料同化,但当分辨率由6 km提高到3 km时,模拟结果无明显改进,因此,提高模式分辨率有一定的限度,而在适当提高模式分辨率的同时使用雷达资料同化改进模式初始场,则是提高模式短时预报的一个非常有效的途径。To examine effects of radar data assimilation and increasing horizontal resolution on the short-range numerical weather prediction of precipitation, comparative numerical experiments are conducted for a Huabei torrential rainfall event using the Advanced Regional Prediction System （ARPS） and its Data Analysis System （ADAS）. The experiments differ in five different horizontal grid-spacings of 18, 15, 9, 6 and 3 km and two initial fields with/without initial radar data assimilation. Results show that, when the radar data are not used in the initial fields （i. e., using the conventional observation data only）, increasing horizontal resolution can improve the short-range prediction within six hours with better representation of the frontal structure and higher scores of rainfall prediction, especially heavy rain prediction. The initial radar data assimilation is able to significantly improve the precipitation location and intensity prediction within the first six hours such that the 6 h precipitation prediction of the ARPS at 18 km resolution with initial radar data assimilation is better than that of the APRS at 3 km resolution without initial radar data assimilation. This suggests that the radar data assimilation is more effective in improving the short-range precipitation prediction than increasing the horizontal resolution alone. Under the condition of initial radar data assimilation, experimental results of different resolutions show that differences of prediction results among among different resolution schemes are not evident for ordinary precipitation （≤40 mm/（6 h） ）, but prediction of higher resolution experiment scheme for extraordinary precipitation （〉40 mm/（6 h）） is better than other schemes. However, when the resolution increases from 6 km to 3 km, there is no evident improvement in precipitation prediction whether the initial radar data assimilation is performed or not. Therefore, the effect of increasing resolution is limited, and combining an adequate higher resolution

关 键 词：雷达资料同化 提高模式分辨率 对比试验 短时预报 

分 类 号：P457.6[天文地球—大气科学及气象学] TN948.41[电子电信—信号与信息处理]