Göttingen 2025 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 9: Exoplanets and Astrobiology
EP 9.6: Vortrag
Mittwoch, 2. April 2025, 17:45–18:00, ZHG005
The Influence of Stellar Energetic Particles (SEPs) on the Atmosphere of Rocky Explanets — •Andreas Bartenschlager1, M. Sinnhuber1, J. L. Grenfell2, N. Iro2, B. Taysum2, and K. Herbst2 — 1KIT, Karlsruhe — 2DLR, Berlin
New instruments (JWST) open up the possibility of studying the composition of exoplanetary atmospheres in habitable zones. On explanets around active and quite M-stars like TRAPPIST-1 and LHS1140, the impact of SEPs and GCRs on the atmosphere plays an important role and is investigated with the ion chemistry model ExoTIC (Herbst et al. 2022). We perform model experiments with different N2- or CO2-dominated atmospheres, depending on the initial CO2 partial pressure, as well as humid and dry conditions (Wunderlich et al. 2020). A further specification is the distinction between dead and alive atmospheres, whose composition is characterized by initial lower/higher O2 fractions. New modules give the possibility to simulate the ion chemistry’s impact on the atmospheric composition of multiple ionization events with different strengths and frequencies, based on the observed flaring frequency of TRAPPIST-1 and the permanent GCR impact on LHS1140b. Preliminary results show a significant impact of SEP events on the chemical composition of the atmospheres, including biosignatures such as O3 and N2O, especially in the recovery of the ozone layer after multiple SEP events. These changes have an impact on the observed transmission spectra. The strength and structure of these impacts depend on the initial composition, in particular on the availability of O2, N2 and H2O.