Investigating the Spatio-Temporal Distribution of Gravity Wave Potential Energy over the Equatorial Region Using the ERA5 Reanalysis Data

Abstract

Atmospheric gravity waves play a crucial role in affecting atmospheric circulation, energy transportation, thermal structure, and chemical composition. Using ERA5 temperature data, the present study investigates the tropospheric to the lower mesospheric gravity wave potential energy (EP) over the equatorial region to understand the vertical coupling of the atmosphere. EP is mainly controlled by two factors. The first is zonal wind through wave–mean flow interactions, and thus EP has periodic variations that are correlated to the zonal wind oscillations and enhances around the altitudes of zero-wind shears where the zonal wind reverses. The second is the convections caused by atmospheric circulations and warm oceans, resulting in longitudinal variability in EP. The lower stratospheric and the lower mesospheric EP are negatively correlated. However, warm oceanic conditions can break this wave energy coupling and further enhance the lower mesospheric EP.