Jacksonville Simulations

This page describes a numerical simulation of gravity waves generated by an idealized thunderstorm over Jacksonville, Florida. The thunderstorm parameters are modifications to those used by Heale et al. (2020) for their study of wave filtering and ultimate breaking for various climatological conditions. In particular, in Heale's work, the thunderstom has a radially-symmetric Gaussian distribution in the horizontal plane with standard deviation 8 km and cosine distribution in the vertical with wavelength 11.25 km. It also has a cosine variation in time (one cycle) with period 20 minutes. Here we used the same thunderstorm dimensions but increased its amplitude by a factor of 4 and increased its duration to 30 minutes.

Computational Domain

The mesh is clustered in both horizontal directions in order to achieve 500 x 500 meter spacing over the center 60 x 60 km region. Very weak stretching is used so that the resolution is still ~500 x 500 m over the entire grid. The domain extends to an altitude of 64 km and uses uniform vertical spacing of 250 m. A total of 340 x 340 x 256 mesh points are used. Sponge layers are used on all external boundaries in order to absorb outgoing waves.

Wind and Thermodynamic Profiles

The mean winds and temperature profile are taken from radiosonde data, on June 15 2018, from a launch site in Jacksonville, Florida. The data reach an altitude of slightly more than 30 km. The profiles were then extended to higher altitudes using polynomial curve fits. Three scenerios are considered, one having increasing easterly winds aloft (Case A), a second having nearly constant weak easterly winds aloft (Case B), and a third having increasing westerly winds aloft (Case C). The meridional winds were set to zero above 30 km and the temperature was taken from climatology. Plots of various profiles for the three cases are shown below. Note that each profile is resampled on the 250m mesh spacing.

winds