利用全球闪电定位网 (WWLLN) 获取的闪电定位资料和中国气象局 (CMA) 提供的台风定位资料, 分析了2007年第9号超强台风圣帕的闪电时空演变特征。分析结果表明: 在热带低压至强热带风暴时期, 台风中心闪电活动频繁, 外围闪电少; 台风成熟时期, 呈现明显的三圈结构; 减弱消散时期, 中心闪电骤减, 几乎为零, 外围闪电密度远远超过中心闪电密度。眼壁闪电和台风总闪电存在阶段性变化。在台风中心最大风速急剧增大的阶段, 眼壁上的闪电两次爆发, 而在第二次眼壁闪电爆发后的两个小时, 中心风速达到最大值, 表明闪电活动有可能对台风增强有指示意义。台风眼壁置换是台风强度发生变化的一个转折点, 也是台风闪电活动发生变化的一个转折点, 从台风眼壁置换开始, 眼壁上闪电数接近于零。闪电次数跟云顶亮温存在显著性相关。结合热带测雨计划任务卫星 (TRMM) 上装载的闪电成像仪 (LIS) 和微波辐射计 (TMI) 资料, 进一步对比分析了台风闪电与强对流区域的关系, 发现闪电易发生在修正极化亮温低于225 K的深对流系统中, 但并不是所有的深对流中都能探测到闪电的发生。WWLLN和LIS探测到闪电发生区域基本一致。
The spatial and temporal distribution of lightning activity was examined in super typhoon Sepat in 2007, by using the data from the World Wide Lightning Location Network (WWLLN) and China Meteorological Administration (CMA). The results indicated that during the initial stage of typhoon, lightning near the centre was more active than that in outer rainbands. There were three lightning flash regions in the mature stage. During the dissipate stage, the lightning at the centre sharply decreased, and the lightning density in the outer rainband was much more than that at the centre. The evolution of eyewall lightning and total lightning tended to be episodic. Two eyewall lightning outbreaks occurred during the intensification of typhoon Sepat, and the second outbreak happened two hours prior to its maximum intensity, indicating that lightning activity might be used as a proxy of intensification of super typhoon. Eyewall replacement is indicative of typhoon intensity change and eyewall lightning change. Since the eyewall replacement, the flashes happening in the eyewall region was nearly zero. The flashes number was significantly correlated with the cloud top bright temperature. By combining the data of lightning imaging sensor (LIS) and TRMM Microwave Imager (TMI) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite, it is found that lightning was most likely to occur in the deep convective systems with the polarized brightness temperature lower than 225 K. Lightning areas indicated by the WWLLN were similar to that by the TRMM-LIS.