Reproducing storm-time densities with Kp, Hpo and TIMED/SABER CO2 cooling power

A major application of semi-empirical thermosphere specification models is in the computation of the atmospheric drag force in the orbit determination and prediction of spacecraft as well as debris. The models provide low spatial and temporal resolution average (climatological) predictions of temperature, total and partial densities of the main constituents as a function of location (altitude, latitude, longitude, local solar time), solar and geomagnetic activity, and season.

 

The research DTM2020 thermosphere model uses a new driver for geomagnetic activity, the hourly Hp60 index (https://doi.org/10.5880/Hpo.0001) instead of the three-hourly Kp. However, thermosphere cooling due to enhanced C02 and NO production in particular during storms is not explicitly taken into account in the semi-empirical models. In this study, we will use density observations of CHAMP, GOCE, GRACE, and Swarm, the Kp and Hpo indices, and the TIMED/SABER measured CO2 and NO cooling power per profile and per day, for selected geomagnetic storms. We will investigate the benefits of Hpo vs Kp, and if it is possible to reproduce storm density more precisely in semi-empirical thermosphere models by adding observed cooling power as model driver.