Abstract: Based on the dataset of the hourly FY-2C infrared TBB, the radar reflectivity from 6 radar sites, and the cloud-to-ground (CG) lightning from Hong Kong, the distribution and spatio-temporal variations of deep convection over Guangdong and adjacent areas from May to June of 2008 are analyzed. The relationship between mesoscale convective systems and heavy precipitation, the differences of TBB, radar reflectivity and CG lightning data, are emphatically compared. The results show that the characteristics of deep convection over Guangdong and adjacent areas during this period are as follows: 1) The activity of deep convection denoted by TBB, radar reflectivity and CG lightning, respectively, obviously correspond to the persisting heavy rain events, and the statistical characteristics of these three data types reveal that the third period of precipitation is the severest, but the distribution of CG lightning density is remarkably different from that of TBB and radar reflectivity. 2) The peaks of deep convection denoted by these three data types in one day are almost consistent with the precipitation peak. 3) The diurnal variations of deep convection show that the convection over land differed from that over sea, which developed earlier than the former. However, the convection over coastal areas is the most frequent. 4) The CG lightning distribution can largely reveal the convection with smaller scale and shorter lifetime, radar reflectivity and TBB distribution can, to a great extent, reflect the convection with larger scale and longer lifetime.

Key words: radar reflectivity, CG lightning density, contrast analysis , TBB

摘要： 综合利用逐时FY-2C 卫星红外亮温(TBB) 资料、广东6 部雷达资料和香港提供的地闪资料, 对2008 年5?6月广东及周边海域深对流活动的时空分布及演变特征进行分析, 以考察对流系统的活动和强降水的关系, 并对比分析了TBB、雷达资料和闪电三者所表征对流系统特征的差异。分析结果表明2008 年前汛期我国广东及周边海域对流活动具有如下特征:1) TBB、雷达回波和地闪资料所表征的对流活动都与 4 个强降水阶段有明显的对应关系, 并有明显的持续性, 3种资料都反映出第3阶段(6月12?14日)强对流活动和降水最强, 但地闪密度分布与TBB、雷达回波有显著的差异; 2)对流活动的日际和日变化都表明TBB≤-52℃频率、雷达回波所追踪的对流风暴次数、地闪密度和降水的峰值对应基本一致; 3)对流活动的日变化特征表明山地和海洋的对流活动在性质上存在差异; 海上的对流活动早于陆地, 海岸线附近是对流活动的过渡带, 对流活动最频繁, 夜间也有较多的对流活动;4) 地闪资料更多地反映尺度较小生命史较短的对流活动, 雷达回波和 TBB 资料则更能反映尺度较大生命史较长的对流活动。

关键词: 雷达回波, 地闪密度, 对比分析, TBB