The migrating terdiurnal tide (TW3) effect on the thermosphere-ionosphere as simulated by TIEGCM-ICON

The ICON mission measured wind and temperature between 10S to 40N at 90-105km during the day and nighttime. Using the Hough Mode Extension method (HME) measurements, the global diurnal and semidiurnal tidal components were derived and used as the lower boundary of the Thermosphere-Ionosphere-Electrodynamics General Circulation Method (TIEGCM) to study the effect of upward propagating tides on the thermosphere and ionosphere system. The migrating terdiurnal tide gets less attention than the diurnal and semidiurnal counterparts since its amplitude is smaller. In this study, we focus on the terdiurnal migrating component, which in the ICON data can reach approximately 25% of the semidiurnal tide around 100km and can be locally even larger. To evaluate the importance of the terdiurnal tide on the thermosphere and ionosphere and quantify the effect, we compare TIEGCM simulations with and without the terdiurnal tide based on ICON observations. We discuss the contribution of the terdiurnal tide to the day and nighttime thermosphere and ionosphere.