FWF - ESPIRE - Earth and Space Weather: Interdisciplinary research

Wider research context: Solar cycle 25, characterized by its recent surge in activity and the occurrence of extreme solar storms like the "Mother's Day Storm" of May 2024, provides a unique opportunity to advance our understanding of Sun-Earth interactions. This project addresses critical gaps in modeling the response of the Earth's upper atmosphere to complex solar events, focusing on the interplay of successive coronal mass ejections (CMEs), solar flares, and their preconditioning effects and the limitations of current solar proxies. Objectives: This project aims to address: (1) What are the preconditioning effects on neutral density and atmospheric chemistry resulting from successive CMEs and simultaneous flare-CME impacts? (2) How reliable are current solar proxies for atmospheric models during periods of high solar activity? (3) What is the role of CME-related energetic electron precipitation in shaping upper atmospheric dynamics? Objectives include refinement of gas-surface interaction modelling, evaluation of solar proxies, and adaptation of THP-MoCaCo to simulate electron precipitation. Approach: Our analysis will be both data-driven, based on observations from a variety of low Earth orbiting satellites, and theoretical, using analytical orbital modelling. A novel approach will use gravity field data to improve the modelling of gas-surface interactions. The THP-MoCaCo will be extended to include CME related energetic auroral electron deposition. Finally, comparative analyses of solar proxies will be performed to assess their effectiveness in representing storm-induced variations. Innovation: The project will uniquely investigate the influence of supra-thermal atoms and energetic electron precipitation, resulting from flares and successive CMEs with the upper atmosphere. Recognizing the strong influence of solar activity on the thermosphere, the project will also consider satellite positions (relative to the Sun) as a parameter to understand the dynamics behind CME induced perturbations of the neutral atmosphere. In addition, a novel approach will be developed to model the gas-surface interaction using the Earth's gravity field as an external validation parameter. Thus, the project will provide a more comprehensive and accurate understanding of upper atmospheric dynamics and density variations during solar storms. Primary researchers involved: To address the complex challenges of space weather research, we have established a cross-disciplinary scientific project consortium. This involves the space-geodetic community represented by the Institute of Geodesy (Graz University of Technology), the solar and heliospheric physics community represented by the Institute of Physics (University Graz), and the Space Research Institute (Austrian Academy of Sciences). Additionally, the consortium benefits from expertise of three cooperation partners: the University of Rome Tor Vergata, the University of Vienna and the Austrian Space Weather Office.