Exploring the Venusian clouds: Atmospheric Gravity Waves with Akatsuki UVI instrument

Abstract

Atmospheric gravity waves are oscilatory disturbances that occur on a specific layer of the atmosphere and whose restoration force is buoyancy [2]. Because of this, these waves can only exist in a continuously stably stratified atmosphere. These waves play an essential role in the global circulation of a planets atmosphere. They are responsible for very important dynamic phenomena such as, for example, the vertical transfer of energy, momentum and chemical species (atmospheric gravity waves transport energy and momentum from the troposphere and deposit it in the thermosphere and mesosphere) since they can form on one region of the atmosphere and travel through it, sometimes over great distances [1]. As such, the study of the properties of atmospheric gravity waves is an essential tool to answer some of the fundamental questions regarding the Venusian atmosphere dynamics, in particular, the fascinating mechanism of superrotation of the atmosphere. With this work we present observations of wave-like structures on the dayside of Venuss atmosphere using the ultraviolet wavelength of 365nm from Akatsuki’s UVI instrument. The main goal is to evaluate the population of atmospheric waves in Akatsuki’s public database by measuring their physical properties(crest number, horizontal wavelength, packet length, width and orientation ), dynamical properties and distribution in order to establish possible links with previous studies of waves. This work follows a previous study performed by Peralta et al. (2008)[1] and by Silva et al. (2021) [3]. [1] Peralta et al., Characterization of mesoscale gravity waves in the upper and lower clouds of venus from vex-virtis images. Journal of Geophysical Research: Planets, 113(E5), 2008.[2] Piccialli et al., High latitude gravity waves at the venus cloud tops as observed by the venus monitoring camera on board venus express. Icarus, 227:94 111, 01 2014.[3] Silva et al., Characterising atmospheric gravity waves on the nightside lower clouds of Venus: a systematic analysis, AA 649 A34, 2021.