A method for estimating global subgrid-scale orographic gravity-wave temperature perturbations in chemistry-climate models

Gravity-wave-induced temperature perturbations have been shown to affect atmospheric chemistry, but accounting for this process in chemistry-climate models has been a challenge because many gravity waves have scales smaller than the typical model resolution. Here, we present a method to account for subgrid-scale orographic gravity-wave-induced temperature perturbations on the global scale for the Whole Atmosphere Community Climate Model.

Temperature perturbation amplitudes (T)over cap> consistent with the model's subgrid-scale gravity wave parameterization are derived and then used as a sinusoidal temperature perturbation in the model's chemistry solver. Because of limitations in the parameterization, we explore scaling of (T)over cap> between 0.6 and 1 based on comparisons to altitude-dependent (T) over cap distributions of satellite and reanalysis data, where we discuss uncertainties.