2008年9月吉林省一次强对流天气过程分析     

苏丽欣  李尚峰  陈长胜 《吉林气象》2010,(2):8-10,38

利用MM5V3和T213数值预报产品,对2008年9月吉林省一次强对流天气过程的环流形势预报场及实况场进行一些浅显地分析,结果表明：在这次强对流降水过程中,高、低层天气系统有着良好的配合和变化,有利于引导气流配合形势,吉林省中部地区受气压梯度较大的锋区控制,产生量级较大的降水。在良好的水汽条件和层结不稳定条件下,0se和K指数值的变化为降水提供了有利的热力不稳定条件;而辐合上升运动和正涡度为出现暴雨提供了良好的动力条件,这也是产生此次降水的重要条件。  相似文献   

Dynamic-analogue correction of the decadal change of East Asian summer precipitation in the late 1990s     

龚志强  李尚峰  胡泊  沈栢竹  封国林 《Acta Meteorologica Sinica》2016,30(3):341-355

This paper systematically evaluates the deviations that appear in the hindcasts of the East Asian summer precipitation (EASP) decadal change in the late 1990s in two global coupled models (BCC_CGCM and BCC_CSM). The possible causes for the deviations between the model hindcasts and observations are analyzed. The results show that the hindcasts of EASP by BCC_CGCM and BCC_CSM deviate from observations, with the anomaly correlation coefficient (ACC) being -0.01 and -0.09 for the two models, respectively. The SST anomalies in North and West Pacific and the SST index values predicted by the two models also deviate from the observations, indicating that inconsistent SST fields may be the key factor leading to the deviation in the prediction of the EASP decadal shift. Thus, a dynamic-analogue scheme is proposed to correct the precipitation hindcasts by using SSTs, where SST and EASP are highly correlated, to select historical analogue cases. Cross validations show that the average ACC of the temporal-latitude distribution of the EASP between the corrected hindcasts and observations is 0.18 for BCC_CGCM and 0.02 for BCC_CSM; both are much higher than the uncorrected hindcasts. Applying the dynamic-analogue correction scheme in both models successfully improves prediction of the EASP decadal change in the late 1990s.  相似文献