Comparison of gravity waves from multi-instrument measurements in the African and American midlatitude sectors during quiet geomagnetic conditions

Numerous past studies have been dedicated to characterizing atmospheric gravity waves and the various processes through which they are generated [e.g. Ford et al., 2008, Ding et al., 2008, 2011; Hernandez-Parajes et al., 2011; Habarulema at al., 2016; Katamzi-Joseph et al. 2019]. This renewed focus on the wave structures is mainly due to the appreciation of their ability to transport energy and momentum from one region or layer of the atmosphere to the another and thereby coupling different layers/regions dynamically [e.g. Vadas and Fritts, 2006; Plougonven et al., 2013; Liu, et al., 2013]. The other aspect of the interest in gravity waves is understanding their effects, particularly on the thermosphere-ionosphere, which include triggering plasma instabilities such as equatorial plasma bubbles and equatorial and midlatitude spread F [e.g. Fritts et al., 2008; Abdu et al., 2009; Earle et al., 2010; Wu et al., 2015].

This study uses airglow intensity, neutral winds and total electron content measurements from multi-wavelengths all-sky camera, 630 nm Fabry-Perot interferometer and global navigation satellites systems over midlatitudes in the American and African sectors to determine the characteristics (i.e. period, wavelength and propagation) of gravity waves in the thermosphere-ionosphere. We look at how these characteristics change with season and time of day based on multi-instrumental approach and in different longitudinal sectors. This is used to investigate the possible mechanisms that are responsible for their generation.