Tropospheric tides from 80 to 400 km: Propagation, interannual variability, and solar cycle effects

We thus stand at an exciting research frontier: understanding how persistent, large-scale tropospheric weather systems affect the geospace environment. Science challenge questions include: (1) How much of the tropospheric influence is due to tidal propagation directly into the upper thermosphere?

(2) How large is the interannual and the solar cycle variability of the tides and what causes them? These questions are addressed using solar maximum to solar minimum tidal wind and temperature analyses from the Thermosphere Ionosphere Mesosphere Electrodynamics and Dynamics (TIMED) satellite in the mesosphere/lower thermosphere (MLT), and from the Challenging Minisatellite Payload (CHAMP) satellite at ˜400 km. A physics-based empirical fit model is used to connect the TIMED with the CHAMP tides, i.e., to close the "thermospheric gap" of current spaceborne observations.