Global Lightning Phenomena and Time Series Model of Lightning Flash Radiance

Abstract

Lightning is a fundamental atmospheric phenomenon that significantly affects the Earth's climatology. Recently, Bangladesh has hosted a sensor station of the World-Wide Lightning Location Network (WWLLN). This is the first study of the data obtained from this sensor station that reveals some interesting features and shows a high connection with the flashes detected by the International Space Station (ISS) Lightning Imaging Sensor (LIS). We present global maps depicting the lightning distribution of WWLLN in relation to ISS-LIS across landmasses and oceanic regions. It confirms that global distribution has no resemblance to the usual three lightning chimneys. Our analysis reveals that about 60% of the total lightning of the globe occurs in the oceans and the rest 40% in the landmass, which is further distributed according to continent and ocean. Our study also reveals that the number of lightning strokes/km2 over Bangladesh's landmass and over the Bay of Bengal is significantly high. During Summer, the lightning maxima lie along 30°N and during Winter, the lightning maxima shifts towards the low latitude region by around 45°N. This analysis also reveals that lightning strokes occur most frequently in the morning and afternoon and least frequently at night. In an effort to switch data analysis from descriptive to predictive, ISS-LIS lightning flash radiance (J/m2/steradian/s) is modeled using time series analysis. After a detailed diagnostic test, ARIMA (2,1,2)x(0,1,1)12 is found to be the best-fitted model.