摘要
基于1995～2011的卫星闪电格点资料和NCEP／NCAR再分析资料，研究了全球热带副热带地区春、冬季节闪电活动对ENSO的响应特征及相应的环境场变化特征。结果表明，全球热带副热带闪电活动对ENSO的响应存在明显的区域差异：（1）厄尔尼诺时期闪电增多、拉尼娜时期闪电减少的地区主要位于墨西哥湾、乌拉圭、孟加拉、中国东南沿海和苏门答腊；（2）厄尔尼诺时期闪电减少、拉尼娜时期闪电增多的地区主要位于厄瓜多尔、刚果、莫桑比克和马达加斯加；（3）ENSO时期闪电始终增加的地区为百慕大群岛、巴西东部、撒哈拉以南的非洲西部和澳大利亚西北部；（4）ENSO时期闪电始终减少的地区为墨西哥湾沿岸、撒哈拉南侧、喜马拉雅山西南麓、中南半岛以及澳大利亚中部和东海岸。厄尔尼诺时期闪电密度与ENSO强度的相关性好于拉尼娜时期，并且显著相关区域的范围更大。厄尔尼诺时期闪电密度与海洋Nifio指数（Oceanic Nifio Index，ONI）显著正相关的地区主要位于赤道和南半球大洋及其沿岸，拉尼娜时期显著负相关的地区多位于南半球陆地。闪电密度距平与近地面气压距平的分布有较好的对应，这与气压变化同大气环流及局地对流活动的紧密关系有关。厄尔尼诺时期升温区（拉尼娜时期降温区）中闪电密度与ONI的相关性更好，表明这些地区闪电活动对近地面温度变化具有更敏感的响应。ENSO期间，大部分地区的闪电和降水并不同步变化，但在太平洋及其沿岸（厄尔尼诺时期）和北印度洋沿岸（拉尼娜时期）的闪电和降水呈一致的变化。
The spring and winter variabilities of lightning activity and meteorological factors over tropical and subtropical regions on ENSO time scales were investigated based on the satellite flash data and the NCEP/NCAR reanalysis data during 1995 -2011. There was an obvious regional difference about the response of lightning to ENSO over tropic and subtropics. Firstly, the regions with lightning increase during E1 Nino period and decrease during La Nifia period were in the Gulf of Mexico, Uruguay, Bengal, southeast China and Sumatra. Secondly, the regions with lightning decrease during E1 Nifio period and increase during La Nifia period were in Ecuador, Congo, Mozambique and Madagascar. Thirdly, lightning always increased on ENSO time scales over the Bermuda Islands, east Brazil, west of sub - Saharan Africa and northwest of Australia. Last, lightning always decreased on ENSO time scales over Gulf Coast, south of Saharan, the southwestern foot of the Himalayas Mountain, Indo - China Peninsula, the middle and east of Australia. During E1 Nifio period, holistic correlation between lightning density and ENSO intensity was better than that during La Nifia period, and significantly related regions were larger. The obviously positive correlated regions between lightning density and Oceanic Nifio Index （ONI） were in the equator and the Southern Hemisphere oceans and coasts during E1 Nifio period, and the negative correlated regions were mostly in the Southern Hemisphere lands during La Nifia period. The good correspondence of lightning density anomaly and surface pressure anomaly was a result of close relationship between pressure, atmospheric circulation and local convection activity. Lightning activity had a significant response to surface temperature, and the warming area during E1 Nifio period （the cooling area during La Nifia period） had better correlation between lightning density and ONI. Most regions of tropic and subtropics did not have a synchronous lightning and precipitation variation on ENSO time scales,
出处
《干旱气象》
2015年第3期395-404,共10页
Journal of Arid Meteorology
基金
973计划项目"雷电重大灾害天气系统的动力-微物理-电过程和成灾机理"(2014CB441406)
国家杰出青年科学基金项目"大气化学与气候的相互作用以及平流层对流层物质交换"(41225018)共同资助
