Evaluating the Impact of GOLD Data Assimilation on Atmospheric Tidal Modes

The upper atmosphere is strongly driven by atmospheric tidal waves. Although climatological tidal variability is relatively well represented in current models, it is challenging to accurately capture their day-to-day changes. On the other hand, observations of thermospheric dynamical variables are limited in their spatiotemporal coverage to enable daily diagnostics of tides solely from observational data. This poster presents comparative ensemble square-root filter cycling experiments to evaluate the impact of assimilating GOLD far ultraviolet disk emission measurements into the NOAA Whole Atmosphere Model (WAM) on its representation of tidal modes. Characterizations of tidal modes in WAM simulations with and without data assimilation are compared to each other as well as to tidal diagnostics obtained independently from ICON and GOLD data products. This study demonstrates the potential of GOLD data assimilation to enhance the capability of current whole-atmosphere models in better representing day-to-day variability of the upper atmosphere dynamics.