CEDAR: Characterization of Upper Atmospheric Effects of Hurricanes

Hurricanes are among the most powerful recurring weather events and play a crucial role in redistributing atmospheric energy. This project will study hurricane-induced changes in the upper atmosphere, tens of kilometers above the Earth’s surface. Satellite observations as well as mathematical models will be used to characterize the impact of hurricanes on the atmosphere by quantifying changes in winds, temperature, and atmospheric waves in unprecedented detail. Gaining a better understanding of atmospheric changes caused by hurricanes has important benefits for both the scientific community and the general public. This research can contribute to space-born hurricane prediction and inform efforts to mitigate the potential impacts of these disastrous events on human activities and technological systems. The activities will benefit Science Technology Engineering and Math (STEM) education within and beyond George Mason University. This project will support a graduate student and provide summer internships to several undergraduate students. The research material produced in this project will be integrated into various courses taught by the PI and will be shared on a website with the broader community. The PI and the graduate student plan on visiting a local community college to promote science. This project is an observational and modeling study of hurricane-induced changes in the upper atmosphere. A suite of satellite observations from COSMIC-2, ICON, GOLD, and TIMED will be used to characterize variations in neutral temperature, horizontal winds, O/N2, and electron density in the thermosphere-ionosphere during hurricanes, and to quantify the associated Gravity Wave (GW) activity. To aid the interpretation of the observed behavior of the large-scale atmosphere GW activity during hurricanes, the team will perform general circulation model simulations from the tropopause to the thermosphere, driven by MERRA-2 lower boundary forcing and incorporating subgrid-scale gravity waves. Overall, this work aims to offer meaningful insight into hurricane-induced vertical coupling between the lower and upper atmosphere. Topics under study include (1) the influence of hurricanes on the mean structure and variability of the thermosphere, (2) the characterization of gravity wave activity during hurricanes, and (3) propagation, dissipation of gravity waves and the resulting dynamical and thermal effects in the thermosphere during hurricanes. The observational work could be useful in helping refine the procedure of retrieving GW signatures as a proxy for hurricane intensity evolution in the upper atmosphere. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.