Exploration of the divergent effects of CMEs on low Earth orbiting satellites – current status of the project ESPRIT

With a view to the rising solar cycle 25 (maximum expected to be 2025/26) the solar activity level will steadily increase, which implies that the Earth’s atmosphere is expanding, and higher drag forces are acting on near-Earth satellites. To avoid earlier re-entries of satellite missions it is mandatory to monitor and at best accurately forecast extreme space weather conditions. We investigated different kinds of coronal mass ejections (CMEs) which had divergent effects on the trajectories of low Earth orbiting satellites. A special focus is given to the interaction of sequentially occurring CME events (e.g., 2021/11/03). So called multiple events lead to multiple field compressions and a capable to increase the severity of the impact on the near-Earth environment. 

Furthermore, we investigated the predominant chemical composition of Earth atmosphere based on satellite observation from the TIMED satellite (SEE, SABER). Additionally, we explored identified diverging behavior of various CMEs by simulating the events with the Kompot code, a 1D first-principles hydrodynamic upper atmosphere model. We found that for some of the selected events the atmospheric exobase and density profile shows some significant expansion mainly based on the increased XUV flux from the Sun. However, we also found that the sole effect of the incident XUV flux might only partially explain NO production, and the structure of the upper atmosphere.