2023 Workshop: Gravity waves in the upper atmosphere and ionosphere

Contributions to the upper atmospheric dynamics and the ionospheric irregularities by the ubiquitous gravity waves’ modulations with various scales have been recognized and studied intensively over the past decades. The associated dynamical features, such as Kelvin-Helmholtz Instability (KHI), can further induce considerable variations in this region. Their horizontal scales have been found to vary from around a few tens of km to several thousand kilometers. The impacts of small-scale features, frequently observed in the mesosphere and lower thermosphere, are believed to be as significant as those of larger scale waves in the thermosphere and ionosphere, because of their fast phase speeds and the high momentum density they are carrying. The dynamical behaviors under atmospheric instability conditions, changing the laminar flow to turbulence flow, are especially important and enticing, when the energy and momentum transfer between them and the mean flow occurs, altering larger-scale dynamic features and potentially triggering some of the most significant ionospheric irregularities.
Various state-of-art ground-based, airborne and space borne experimental investigations have been dedicated to the investigations on this topic in the past decade, facilitated by many advanced regional and global numerical models. While considerable progress in understanding their contributions to the energy and momentum budget in the thermosphere ionosphere have been achieved, more and more unknown physics and dynamic processes have also been revealed in these observations. In addition, the lack of global coverage, and the limited observed gravity wave spectrum further limit the community’s progress in the understanding of the Ionosphere-Thermosphere (IT) gravity wave coupling.
In this workshop, we will discuss the gaps, challenging problems and coordinated approaches of addressing the role of gravity waves in the mesosphere, thermosphere and ionosphere coupling.