Improving the Thermosphere Ionosphere in a Whole Atmosphere Model by
Assimilating GOLD Disk Temperatures
Fazlul I Laskar
Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
Corresponding Author:[email protected]
Author ProfileAbstract
Global-scale Observations of Limb and Disk (GOLD) disk measurements of
far ultraviolet molecular nitrogen band emissions are used to retrieve
column integrated disk temperatures (Tdisk), which are representative of
the lower-and-middle thermosphere. The present work develops a new
approach to assimilate the Tdisk in the Whole Atmosphere Community
Climate Model with thermosphereĆ¢\euro?ionosphere eXtension (WACCMX)
using the Data Assimilation Research Testbed (DART) ensemble adjustment
Kalman filter. Nine days of data,1 to 9 November 2018, are assimilated.
Analysis state variables such as thermospheric effective temperature
(Teff, airglow layer integrated temperature), ratio of atomic oxygen to
molecular nitrogen column densities (O/N2), and column electron content
are compared with a control simulation that is only constrained up to
~50 km. It is observed that assimilation of the GOLD
Tdisk improves the analysis states when compared with the control
simulation. The analysis and model states, particularly, Teff, O/N2, and
Electron Column Density (ECD) are also compared with their measurement
counterparts for a validation of the assimilation. Teff and O/N2 are
compared with GOLD Tdisk and O/N2. While, the ECD is compared with
ground based Total Electron Content (TEC) measurements from Global
Navigational Satellite System (GNSS) receivers. Root Mean Square Error
(RMSE) improvements in Teff and O/N2 are about 10.8% and 22.6%,
respectively. The RMSE improvement in analyses ECD is about 10%
compared to control simulation.