We investigate gravity-wave-induced variations in exothermic heating in the OH nightglow region at a latitude of 18° in the Northern and Southern Hemispheres during March. An OH nightglow chemistry model with gravity wavefields from a spectral full-wave model is used for the investigation. Our simulation results show that the wave packet induces a large secular increase in the number densities of the minor species involved in the OH chemistry, a 50% increase in O3, 42% in O, and 29% in OH (v = 8), and the ultimate driver for these increases is the wave-driven downward transport of O. We find that the total exothermic heating rates have increased by ∼44.2% for 18°S and ∼30.9% for 18°N by the end of the simulation time. Also, the peak values of the mean wave-induced total exothermic heating rates are significant, ∼2.0 K d-1 at the peak altitude of 88 km and ∼2.2 K d-1 at 89 km for 18S and 18N, respectively. The major reactions contributing to exothermic heating rates are the three-body recombination O + O + M and the H + O3 reaction. The hemispheric asymmetry in the heating rates is mainly due to the different atmospheric conditions at 18N and 18S since the same wavefields are used in the numerical simulations.
All Science Journal Classification (ASJC) codes
- Space and Planetary Science