闪电活动的气候学特征研究进展

综述了闪电活动与气候和气候变化相关研究的一系列最新进展。这些研究表明全球闪电活动可以通过卫星光学方法、地面的单站舒曼共振法以及低频多站时差法进行观测,其结果指出全球闪电密度高值区主要分布在海岸地区、山地地区、中尺度气旋多发地区以及热带辐合带的辐合区内,大陆、海岛、沿海地区所发生的闪电占全球的88%,全球3个闪电密度极大值依次出现在赤道地区的非洲刚果、南美洲大陆和东南亚。大量的研究结果表明全球闪电活动是与气候和气候变化相关的,在日、5d、季、半年、年、ENSO、10a多个时间尺度上,闪电活动对温度做出了一定的正响应,但在更长时间尺度上这种敏感性似乎是减弱的。闪电活动因易于被持续监测而可以作为监测气候一些重要参数变化的有利工具。闪电活动是氮氧化物(NOx)的重要产生源,这与臭氧等温室气体以及地球辐射之间存在密切关系。在短时间尺度上,对流层上层水汽和全球闪电活动之间存在非常好的相关性。气溶胶对雷暴以及闪电活动的影响还不明确。气候变化与雷暴和闪电活动之间的相互耦合机制还有待于更多的观测和深入的研究。

Review on climate characteristic of lightning activity

Latest research results indicate that lightning can be measured by using satellite optical sensor,Schumann resonances and the time-of-arrival(TOA)techniques at very low frequency.It is observed that high lightning density areas mainly lie in seaboards,mountains,high frequency mesoscale cyclone areas and convergent regions of the tropical convergence zone.88% of global lightning discharges occur in continent,island and seaboard areas.The three regions hit most frequently by lightning are Congo in equatorial Africa,South America,and South and Southeast Asia.A lot of studies reveal that the global lightning activity is directly linked to the Earth's climate and climate change.The global lightning activity responds positively to temperature changes on many time scales,such as diurnal,pentad,intraseasonal,semiannual,annual,ENSO,and decadal time scales.However,the sensitivity of lightning to temperature appears to diminish at longer time scales.Since lightning can be monitored easily and continuously,it may become a useful tool for monitoring changes in important climate parameters.The lightning discharge is a significant producing source of nitrogen oxides(NOx)in the atmosphere,which is closely associated with ozone production and the Earth's radiation balance.There appears to be a robust positive correlation between lightning activity and upper tropospheric water vapor on short time scales.The effect of aerosol on thunderstorm and lightning is uncertain.More observations and investigations are needed to identify the coupling mechanism between lightning and climate change.