DTM

The Drag Temperature Model (DTM) is a semi-empirical model describing the temperature, density, and composition of the Earth's thermosphere in the altitude range [120 - 1,500] km. DTM2013 was developed in the framework of the Advanced Thermosphere Modelling and Orbit Prediction project (ATMOP). The DTM2020 model is fitted to the high-resolution and high-precision accelerometer-inferred densities from the CHAMP and GRACE missions, but also to 2.5 years of GOCE data at 270 km. The low-resolution densities derived from orbit perturbation analysis as well as spectrometer data from Atmosphere Explorer and Dynamics Explorer have also been used, i.e., the same density data sets that were used in the construction of DTM2009 and DTM2012. This model is constructed using the 30 cm radio flux as solar proxy, and the 3-hour am index as geomagnetic proxy.

The model inputs of the DTM2020 operational model are F10.7 and the geomagnetic index Kp, whereas the more accurate DTM2020 research model uses a more representative but possibly less robust solar proxy, F30, and the new hourly geomagnetic index Hp60.

The model predicts total and partial densities (atomic hydrogen, helium, atomic oxygen, molecular nitrogen, and molecular oxygen in g/cm^3), as well as temperature, exospheric temperature and density uncertainty, as a function of the user-provided values of date, location, solar flux and geomagnetic activity.