{"title":"Thermodynamic control of lightning activity in premonsoon and monsoon season over the Indian region","authors":"B. Abida Choudhury, M.I.R. Tinmaker","doi":"10.1016/j.jastp.2024.106410","DOIUrl":null,"url":null,"abstract":"<div><div>Understanding the relationship between lightning activity and atmospheric thermodynamics is important for improving thunderstorm forecasting and mitigating lightning-related hazards. The study investigates the linkage between lightning activity and thermodynamic indices over the Indian subcontinent during pre-monsoon and monsoon seasons across 17 years (1998–2014). The flash count data was obtained from the Tropical Rainfall Measuring Mission's (TRMM) Lightning Imaging Sensor (LIS); the upper air sounding data for thermodynamic indices was archived from the University of Wyoming. Additionally, air temperature and relative humidity data at various pressure levels were retrieved from the National Oceanic and Atmospheric Administration (NOAA) during the same period over the Indian region. In the present study, the results indicate that the flash counts, surface maximum temperature, and Deep Convective Index (DCI) show a high peak in the month of May, before the onset of monsoon season. The higher peak of surface maximum temperature and DCI value is associated with strong convection which plays a crucial role in the occurrence of high lightning activity. The Bowen ratio (BR), planetary boundary layer (PBL), and Vertical Total Index (VTI) show a high peak in May. These are because of increased sensible heat flux and a strong vertical lapse rate. The PBL and high Cross Total Index (CTI) values contribute to more lightning strikes during the pre-monsoon season. The decrease in flash count and thermodynamic indices after the onset of monsoon season is due to the transport of more moisture from the ocean into the free atmosphere, large cloud coverage, shallow convection, slow charging mechanism, low cloud electrification and hence low lightning activity. The present study underscores the importance of evaluating threshold values of thermodynamic indices during seasonal transitions (premonsoon to monsoon season), which is useful for predicting the severity of thunderstorm formation and lightning intensity over the Indian region.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"268 ","pages":"Article 106410"},"PeriodicalIF":1.8000,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Atmospheric and Solar-Terrestrial Physics","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1364682624002384","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Understanding the relationship between lightning activity and atmospheric thermodynamics is important for improving thunderstorm forecasting and mitigating lightning-related hazards. The study investigates the linkage between lightning activity and thermodynamic indices over the Indian subcontinent during pre-monsoon and monsoon seasons across 17 years (1998–2014). The flash count data was obtained from the Tropical Rainfall Measuring Mission's (TRMM) Lightning Imaging Sensor (LIS); the upper air sounding data for thermodynamic indices was archived from the University of Wyoming. Additionally, air temperature and relative humidity data at various pressure levels were retrieved from the National Oceanic and Atmospheric Administration (NOAA) during the same period over the Indian region. In the present study, the results indicate that the flash counts, surface maximum temperature, and Deep Convective Index (DCI) show a high peak in the month of May, before the onset of monsoon season. The higher peak of surface maximum temperature and DCI value is associated with strong convection which plays a crucial role in the occurrence of high lightning activity. The Bowen ratio (BR), planetary boundary layer (PBL), and Vertical Total Index (VTI) show a high peak in May. These are because of increased sensible heat flux and a strong vertical lapse rate. The PBL and high Cross Total Index (CTI) values contribute to more lightning strikes during the pre-monsoon season. The decrease in flash count and thermodynamic indices after the onset of monsoon season is due to the transport of more moisture from the ocean into the free atmosphere, large cloud coverage, shallow convection, slow charging mechanism, low cloud electrification and hence low lightning activity. The present study underscores the importance of evaluating threshold values of thermodynamic indices during seasonal transitions (premonsoon to monsoon season), which is useful for predicting the severity of thunderstorm formation and lightning intensity over the Indian region.
期刊介绍:
The Journal of Atmospheric and Solar-Terrestrial Physics (JASTP) is an international journal concerned with the inter-disciplinary science of the Earth''s atmospheric and space environment, especially the highly varied and highly variable physical phenomena that occur in this natural laboratory and the processes that couple them.
The journal covers the physical processes operating in the troposphere, stratosphere, mesosphere, thermosphere, ionosphere, magnetosphere, the Sun, interplanetary medium, and heliosphere. Phenomena occurring in other "spheres", solar influences on climate, and supporting laboratory measurements are also considered. The journal deals especially with the coupling between the different regions.
Solar flares, coronal mass ejections, and other energetic events on the Sun create interesting and important perturbations in the near-Earth space environment. The physics of such "space weather" is central to the Journal of Atmospheric and Solar-Terrestrial Physics and the journal welcomes papers that lead in the direction of a predictive understanding of the coupled system. Regarding the upper atmosphere, the subjects of aeronomy, geomagnetism and geoelectricity, auroral phenomena, radio wave propagation, and plasma instabilities, are examples within the broad field of solar-terrestrial physics which emphasise the energy exchange between the solar wind, the magnetospheric and ionospheric plasmas, and the neutral gas. In the lower atmosphere, topics covered range from mesoscale to global scale dynamics, to atmospheric electricity, lightning and its effects, and to anthropogenic changes.