Gravity Wave Effects on Short-Term Tidal Variability in WACCM and eCMAM

Abstract:

Gravity waves and atmospheric tides have strong interactions in the mesopause region and is a major contributor to short term variabilities of the tides in this region. Here, the local time short term variability of the diurnal tide due to gravity waves is investigated in the extended Canadian Middle Atmosphere Model (eCMAM), the Specified Dynamics Whole Atmosphere Community Climate Model (SD-WACCM) and the free run WACCM. The run parameters of each model are set to be similar as possible to minimize the influences from model differences. The contributions of these variabilities from the parameterized GW forcings is analyzed and compared in each GCM by investigating the overall momentum balance of the horizontal winds.