Speaker
Description
Accurate estimation of thermospheric neutral density is vital for atmospheric drag compensation. Actual measurements of thermospheric neutral density are rare, and often limited to specific altitude ranges. Numerical models are often used as a substitute, sometimes in conjunction with data assimilation schemes. During geomagnetic storms, having an accurate representation of the thermosphere-ionosphere (TI) is vital, since climatological models cannot accurately model the system response. Recently, the physics-based Coupled Thermosphere Ionosphere Plasmasphere electrodynamics (CTIPe) model has been shown to provide accurate global estimates of neutral density when used in conjunction with the Thermosphere Ionosphere Data Assimilation scheme (TIDA). This approach adds the model inputs to the state vector and better accounts for the strongly forced nature of the TI. In this study, we expand on previous work by demonstrating the use of TIDA-CTIPe for neutral density estimation over a much broader time interval, covering multiple geomagnetic events. We demonstrate the capability to improve global estimates of neutral density by assimilating measurements in a narrow altitude range, from the CHAMP mission. Additionally, multiple data assimilation configurations are tested to highlight the complexity of accurately modelling the TI response to external forcings. Finally, we discuss the need for near-real-time data for potential forecasting applications.
