Using MFACE as input in the UAM to specify the MIT dynamics

Abstract

The magnetosphere‐ionosphere‐thermosphere (MIT) dynamic system significantly depends on the highly variable solar wind conditions, in particular, on changes of the strength and orientation of the interplanetary magnetic field (IMF). The solar wind and IMF interactions with the magnetosphere drive the MIT system via the magnetospheric field‐aligned currents (FACs). The global modeling helps us to understand the physical background of this complex system. With the present study, we test the recently developed high‐resolution empirical model of field‐aligned currents MFACE (a high‐resolution Model of Field‐Aligned Currents through Empirical orthogonal functions analysis). These FAC distributions were used as input of the time‐dependent, fully self‐consistent global Upper Atmosphere Model (UAM) for different seasons and various solar wind and IMF conditions. The modeling results for neutral mass density and thermospheric wind are directly compared with the CHAMP satellite measurements. In addition, we perform comparisons with the global empirical models: the thermospheric wind model (HWM07) and the atmosphere density model (Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Extended 2000). The theoretical model shows a good agreement with the satellite observations and an improved behavior compared with the empirical models at high latitudes. Using the MFACE model as input parameter of the UAM model, we obtain a realistic distribution of the upper atmosphere parameters for the Northern and Southern Hemispheres during stable IMF orientation as well as during dynamic situations. This variant of the UAM can therefore be used for modeling the MIT system and space weather predictions. The MIT dynamic system is modeled using the MFACE as input for the UAM The modeling results show good agreement with CHAMP data at high latitudes The UAM model better reproduces mesoscale structures than empirical models