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

• Main Authors: Shih-Sian Yang, Chen-Jeih Pan, Uma Das
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Atmosphere
• Subjects: atmospheric gravity waves; potential energy; ERA5; wave–mean flow interactions; El Niño and La Niña; the 2015–2016 anomalous QBO
• Online Access: https://www.mdpi.com/2073-4433/12/3/311

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 (E_P) over the equatorial region to understand the vertical coupling of the atmosphere. E_P is mainly controlled by two factors. The first is zonal wind through wave–mean flow interactions, and thus E_P 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 E_P. The lower stratospheric and the lower mesospheric E_P are negatively correlated. However, warm oceanic conditions can break this wave energy coupling and further enhance the lower mesospheric E_P.