【摘要】 结合"海棠"台风在2005年7月19日08:00~20日08:00再次登陆福建省24 h期间所造成的降水过程,在WRF模式成功地模拟了此次降水过程的基础上,利用模式模拟输出结果,通过计算900~600 hPaQ矢量散度的气柱平均值、Q矢量散度强迫产生的降水场,定量比较分析了非地转干Q矢量、非地转湿Q矢量及改进的湿Q矢量的诊断能力差异,结果表明:(1)非地转干Q矢量、非地转湿Q矢量及改进的湿Q矢量散度辐合场,对同期模拟雨区都具有一定指示作用,同时,非地转湿Q矢量和改进的湿Q矢量的散度辐合强度都较非地转干Q矢量散度辐合强度强,且改进的湿Q矢量散度辐合强度强于非地转湿Q矢量散度辐合强度,尤其是在主雨区表现的更为明显。相对来讲,改进的湿Q矢量散度辐合场对雨区的反映能力最强。(2)非地转湿Q矢量散度与改进的湿Q矢量散度强迫产生的降水范围几乎相同,且明显较非地转干Q矢量散度强迫产生的雨区范围大,相对来讲,与同期模拟降水场的雨区更接近。改进的湿Q矢量散度强迫产生的降水强度最强,非地转湿Q矢量散度强迫次之,非地转干Q矢量散度强迫产生的降水强度最弱。三种Q矢量散度强迫产生的降水强度都明显弱于同期模式模拟的降水强度,相对来讲,改进的湿Q矢量散度强迫产生的降水强度更接近于模拟的降水强度。(3)三种Q矢量散度场以及强迫产生的降水场之间的差异,充分表明此次台风降水过程中伴有大量的大尺度稳定水汽凝结潜热和对流水汽凝结潜热释放,考虑了水汽凝结潜热加热作用的非地转湿Q矢量与改进的湿Q矢量,对降水反映能力均较非地转干Q矢量有所改进,尤其是后者。更多还原

【Abstract】 There is an obvious precipitation event associated with the typhoon Haitang landfalling Fujian Province during 19~20 July 2005,which is simulated successfullyby WRF model.By means of output data of the WRF model simulation,the volume averaged(900~600 hPa) field of Qvector divergence and precipitation caused by the forcing of Qvector divergence are calculated,whereby the differences of diagnostic ability among ageostrophic-dry-,ageostrophic-wet-and revised-wet-Qvectors are quantitatively examined.The results are as follows:(1) The convergence fields of ageostrophic-dry-,ageostrophic-wet-and revised-wet-Qvector divergences all have reflecting ability to synchronous simulated rainfall area on somedegree,meanwhile,the convergence intensities of ageostrophic-wet-and revised-wet-Qvector divergences are both stronger than the counterpart of ageostrophic-dry-Qvector divergence,in particular,which is more obvious in primary rain area.Relatively,the reflecting ability of theconvergence field of the revised-wet-Qvector divergences to precipitation area is the best.(2) The ranges of rainfall forced by ageostrophic-wet-and revised-wet-Qvector divergence respectively are almostthe same,which both are evidently larger than the counterpart forced by ageostrophic-dry-Qvector divergence,relatively speaking,the two formers are more close to synchronous simulated rainfall range.Based on the intensities of the rain forced by the three types of Qvector divergence respectively,the revised-wet-Qvector is the strongest,the ageostrophic-wet-Qvector is the secondary,and the ageostrophic-dry-Qvector is the weakest,however,they are all significantly weaker as against to the counterpart of the synchronous simulated precipitation,and the intensity of the rainfall caused by the revised-wet-Qvector divergence is more close relatively to the counterpart of simulated precipitation.(3) The differences among the three forced precipitation fields as well as among the three kinds of Qvector divergence fields sufficiently suggest that there are a lot of synoptic scale stable vapor condensational potential heating and convective vapor condensational potential heating release,what′s more,the ageostrophic-wet-and revised-wet-Qvectors considering vapor condensational potential are advanced in comparison to the ageostrophic-dry-Qvector in the context of the reflecting ability to precipitation,especially,the counterpart of the revised-wet-Qvector is more marked.更多还原