Cloud-to-Ground Lightning Response to Aerosol over Air-Polluted Urban Areas in China

Haichao Wang,Luying Li,Xiaotong Lin,Yongbo Tan,Xuejuan Wang,Zheng Shi,Honglei Wang

doi:10.3390/rs13132600

Abstract

The effect of aerosols on lightning has been noted in many studies, but much less is known about the long-term impacts in air-polluted urban areas of China. In this paper, 9-year data sets of cloud-to-ground (CG) lightning, aerosol optical depth (AOD), convective available potential energy (CAPE), and surface relative humidity (SRH) from ground-based observation and model reanalysis are analyzed over three air-polluted urban areas of China. Decreasing trends are found in the interannual variations of CG lightning density (unit: flashes km−2day−1) and total AOD over the three study regions during the study period. An apparent enhancement in CG lightning density is found under conditions with high AOD on the seasonal cycles over the three study regions. The joint effects of total AOD and thermodynamic factors (CAPE and SRH) on CG lightning density and the percentage of positive CG flashes (+CG flashes/total CG flashes × 100; PPCG; unit: %) are further analyzed. Results show that CG lighting density is higher under conditions with high total AOD, while PPCG is lower under conditions with low total AOD. CG lightning density is more sensitive to CAPE under conditions with high total AOD.

Highlights

Lightning is one of the deadliest meteorological phenomena and causes severe damage to infrastructure or causes forest fires [1,2,3]
An apparent enhancement in CG lightning density is found under high aerosol optical depth (AOD) conditions on seasonal cycles during the study period
Decreasing trends are both found in the interannual variations of CG lightning density and total AOD over the three study regions during the study period; 2

Summary

Introduction

Lightning is one of the deadliest meteorological phenomena and causes severe damage to infrastructure or causes forest fires [1,2,3]. Cloud-to-ground (CG) lightning, accounting for about 25% of total lightning (including CG lightning and intracloud lightning), is one of the major causes of nature-related fatalities throughout the world. During 1997–2009, CG lightning caused 5022 deaths and 4670 injuries in China [4]. It is important to study and understand the activity of CG lightning to protect and mitigate against the harmful impacts of it. Since Westcott [5] first linked lightning enhancement with urban aerosols, many studies have demonstrated the aerosol effects on lightning activity. Altaratz et al [6]

Methods

Results

Conclusion