HAO Colloquium - Fazlul Laskar, CU/LASP

Improving Thermosphere-Ionosphere in WACCMX by Assimilating GOLD Disk Temperature
Understanding of the temperature and number density variability of the thermosphere-ionosphere (TI) system is essential for satellite drag forecasting and for reliable space-based communication and navigation. The TI system is influenced by waves from the lower atmosphere and solar and geomagnetic forcing from above. Accurate characterization of the system depends on realistic whole atmosphere-ionosphere parameters. The availability of unprecedented thermospheric data from Global-scale Observations of the Limb and Disk (GOLD) has dramatically increased the number of observations in the upper atmosphere. Also, there are lower atmosphere observations from meteorological data and middle atmosphere temperatures from Thermosphere Ionosphere Mesosphere Energetics and Dynamics - Sounding of the Atmosphere using Broadband Emission Radiometry (TIMED-SABER) and Aura-Microwave Limb Sounder (Aura-MLS). The present investigation assimilates lower, middle, and upper atmosphere data in the Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (WACCMX) using the Data Assimilation Research Testbed (DART) framework. These whole atmosphere data are assimilated in WACCMX+DART to assess the improvement in the TI system parameters. From a set of Observing System Simulation Experiments it is observed that specification of the amplitudes of global DW1 and the local diurnal tide in the analyses are improved by about 7% and about 17%, respectively, when GOLD temperatures are assimilated. Furthermore, experiments in WACCMX+DART demonstrate improvements in the TI when assimilating real GOLD temperature observations. By comparing the analysis states with independent TI measurements, which were not included in the data assimilation, we find that both the thermosphere and ionosphere are improved significantly. In particular, the root mean square error in GOLD equivalent temperature, O/N2, and electron column density shows improvement of about 12.8%, 13.2%, and 8.2%, respectively when compared with respect to a control simulation.
Date and time: 
Wednesday, October 6, 2021 - 2:00pm to 3:00pm