Spatio-Temporal Climatology and Trends of Convective Available Potential Energy (CAPE) over Bangladesh, including three lightning hotspots during 40 years (1982-2021)

Abstract

This study investigates the climatology of Convective Available Potential Energy (CAPE) over Bangladesh and its eight administrative divisions, along with three lightning hotspots (Sherpur, Shahjadpur, and Bajitpur), using monthly, seasonal, and annual data for 40 years (1982–2021). The monthly CAPE data at 0000 UTC and 1200 UTC has been collected from the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis data (ERA5) at 0.25° resolution. The study reveals that the increasing CAPE trend over Bangladesh may be responsible for the increased frequency of extreme events. Significant CAPE values were observed in Bangladesh’s south-west and southern parts from March to May. In April, there was a notable increasing trend in CAPE values, particularly in the north-western region. The average CAPE values for Bangladesh’s three lightning hotspot regions (Sherpur, Shahjadpur, and Bajitpur) is higher than 1500 J/kg during the pre-monsoon at 0000 UTC, directly correlating with the lightning and thunderstorm. The Mann-Kendall test has been employed to follow yearly and seasonal trends. Overall, this study provides valuable insights into the spatial distribution of CAPE and its association with thunderstorms in Bangladesh, which can inform the development of effective strategies to manage weather-related hazards in the country.