Modeling of Secondary Gravity Waves in the Mesosphere and Lower Thermosphere
Atmospheric gravity waves (GWs) play a vital role in transporting energy and momentum, effectively coupling different layers of the atmosphere from the surface to the thermosphere. Among these, secondary gravity waves (SGWs)—which are generated in situ, primarily through the dissipation and breaking of primary waves—have gained increasing attention for their significant contributions, especially within the mesosphere, lower thermosphere (MLT), and thermosphere-ionosphere system. In this talk, we present a synthesis of current knowledge on SGWs, with a particular focus on insights gained from high-resolution numerical modeling. Key generation mechanisms are explored, including: 1) Linear responses to transient body forces resulting from primary wave momentum deposition, 2) Wave packet self-acceleration dynamics, 3) Nonlinear dynamics arising from wave breaking, and 4) Instabilities such as Kelvin-Helmholtz and convective instabilities. We will also highlight our recent progress in applying artificial intelligence (AI) to the simulation of GWs and global-scale atmospheric dynamics, and discuss both the potential and challenges of incorporating AI-based approaches into GW parameterizations for global climate and weather models.
Wenjun Dong is a research scientist at the Center for Space and Atmospheric Research at Embry-Riddle Aeronautical University (Florida), with a primary workplace in Boulder, Colorado. He also serves as an adjunct scientist at Global Atmospheric Technologies and Sciences, Inc. (GATS, Boulder). His research centers on gravity wave modeling, including their generation, propagation, breaking, and interactions with background atmospheric conditions. He works extensively with both high-resolution regional and global circulation models, and collaborates closely with modeling teams at ERAU and GATS. Dr. Dong is also advancing the use of artificial intelligence in atmospheric science, developing machine learning models for simulating gravity waves and global dynamics, and exploring AI-driven approaches to gravity wave parameterization in global models.