Simulation of the propagation and effects of gravity waves generated by Tonga volcano eruption in the thermosphere and ionosphere using nested-grid TIEGCM

The simulation results indicate that the critical parameter to simulate GW propagation is horizontal resolution. Inside the high-resolution nested region, GWs with horizontal wavelengths of similar to 400 km and periods of 10-30 min can propagate outward and upward and produce significant ionospheric disturbances close to observations. Outside the nested region, only long-wavelength, low-frequency waves survive.

Another test indicates that GWs can be better resolved when geopotential height is nudged at TIEGCM lower boundaries. With the capability of simultaneously simulating local, small to mesoscale I-T processes, TIEGCM-NG is superior to global high-resolution simulations due to its largely reduced computation cost and may find its application in the study of I-T system regional dynamics.