Model data comparison with an improved data set of thermosphere density and crosswind observation

Abstract

Within the TOLEOS project improved processing standards are used to process GRACE, GRACE-FO and CHAMP accelerometer data resulting in a new unique thermosphere density and crosswind observations data set. The improvements in the processing focus on the radiation pressure modelling, which is expected to have a significant effect on the density observations at altitudes above 450 km during solar minimum conditions and crosswind observations in general. Because these observations will complement ESA’s Swarm and GOCE data bases and achieve a full coverage of all accelerometer missions, they are subject to substantial validation. The validation of the densities is performed by comparing models with observations from multiple missions as well as via models. This validation study will involve density observations of CHAMP, GOCE, GRACE, GRACE/GFO and Swarm. The involved models will be the empirical model DTM2020 and the physics-based models CTIPe and TIE-GCM. The comparisons with model predictions aims at determining a scale difference between the model and observations. In addition, we are comparing with other thermosphere density data, too, e.g. comparing CHAMP-GRACE and GRACE-Swarm, as well as with HASDM density data for example. For the validation of the wind observations, the available wind data and wind models are much less and less accurate. Thus, the level of accuracy and confidence of the wind product validation is lower than for the density products. This presentation will summarize the validation results of the improved thermosphere density and crosswind observations generated in the TOLEOS project.