The Solar Wind-Ionosphere-Thermosphere Coupling at Mars: Combined Data Analysis of Mars Express and MAVEN Observations.

• Applicants: Privatdozent Dr. Martin Pätzold; Dr. Silvia Tellmann
• Subject Area: Astrophysics and Astronomy
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433762250

• Final Report Year: 2025

Final Report Abstract

The variability in the Sun’s electromagnetic and energetic particle output has a significant impact on the state of the Martian thermosphere. Solar radiation is the primary driver of thermospheric photo-chemistry. UV and IR solar flux components (< 800 nm) are responsible for thermospheric heating, while EUV (5–95 nm) and soft solar X-rays (0.1–5 nm) provide energy for ionosphere formation through ionization and electron impact. The lack of a global magnetic field on Mars results in direct interaction between the solar wind and the planetary ionosphere/neutral atmosphere, creating a strong coupling between these regions. Planetary waves, tides, and gravity waves, which propagate upward from the lower atmosphere to the upper atmosphere, serve as another powerful source of momentum deposition in the upper mesosphere and thermosphere. A combination of Mars Express and MAVEN observations of the Sun-Mars interaction offers a unique opportunity to investigate the temporal and spatial response/regulation patterns of the coupled ionosphere-thermosphere system. The simultaneous measurement of solar variability (e.g., solar X-ray/EUV flux, solar wind conditions, and solar energetic particle flux) at Mars, coupled with detailed observations of atmospheric and ionospheric characteristics, provides a valuable opportunity to gain deep insights into the flow of solar energy throughout the strongly interconnected Martian atmospheric system. The structure of the ionosphere is strongly influenced by dust in the upper neutral atmosphere. Observations by MaRS reveal that the peak altitude of the main ionospheric layer (M2) rises by several kilometers due to the expansion of the neutral atmosphere at ionospheric altitudes caused by dust heating.

Publications

• Crustal magnetic fields at Mars and ion escape. Copernicus GmbH.
  Dubinin, Eduard; Fraenz, Markus; Pätzold, Marin; Woch, Joachim; Fan, Kai; Wei, Yong; McFadden, Jim; Tsareva, Olga & Zelenyi, Lev
  
• Bursty Ion Escape Fluxes at Mars. Journal of Geophysical Research: Space Physics, 126(4).
  Dubinin, E.; Fraenz, M.; Pätzold, M.; Tellmann, S.; Woch, J.; McFadden, J. & Zelenyi, L.
  
• Induced Magnetic Fields and Plasma Motions in the Inner Part of the Martian Magnetosphere. Journal of Geophysical Research: Space Physics, 126(12).
  Dubinin, E.; Fraenz, M.; Modolo, R.; Pätzold, M.; Tellmann, S.; Vaisberg, O.; Shuvalov, S.; Zelenyi, L.; Chai, L.; Wei, Y.; McFadden, J.; DiBraccio, G. & Espley, J.
  
• Do we understand well how the Martian magnetosphere is organized?. Copernicus GmbH.
  Dubinin, Eduard; Fraenz, Markus & Paetzold, Martin
  
• Hybrid magnetosphere of Mars. Magnetic fields and Plasma motions. 44th COSPAR Scientific Assembly. Held 16-24 July 44, 959.
  Dubinin, Eduard; Fraenz, Markus; Paetzold, Martin; Tellmann, Silvia; Dibraccio, Gina; McFadden, James; Vaisberg, Oleg; Zelenyi, Lev & Grigorenko, Elena
  
• The variability of the topside ionospheres of Venus and Mars in light of radio science observations. Copernicus GmbH.
  Peter, Kerstin; Pätzold, Martin; Chu, Feng; Ramstad, Robin; Thiemann, Ed; Fränz, Markus; Girazian, Zachary; Kopf, Andy; Tellmann, Silvia; Häusler, Bernd; Futaana, Yoshifumi & Holmström, Mats
  
• Magnetic Fields and Plasma Motions in a Hybrid Martian Magnetosphere. Journal of Geophysical Research: Space Physics, 128(1).
  Dubinin, E.; Fraenz, M.; Pätzold, M.; Tellmann, S.; Modolo, R.; DiBraccio, G.; McFadden, J. & Espley, J.
  
• The effects of atmospheric dust and solar radiation on the dayside ionosphere of Mars derived from 17 years of Mars Express radio science observations. Icarus, 400, 115565.
  Peter, Kerstin; Pätzold, M.; Montabone, L.; Thiemann, E.; González-Galindo, F.; Witasse, O.; Tellmann, S. & Bird, M.K.
  
• The Mini Induced Magnetospheres at Mars. Geophysical Research Letters, 50(3).
  Dubinin, E.; Fraenz, M.; Pätzold, M.; Tellmann, S.; DiBraccio, G. & McFadden, J.
  
• The mini induced magnetospheres at Mars.. Copernicus GmbH.
  Dubinin, Eduard; Fraenz, Markus; Paetzold, Martin; Tellmann, Silvia; DiBraccio, Ginna & McFadden, James
  
• The variability of the topside ionospheres of Venus and Mars. AAS/Division for Planetary Sciences Meeting Abstracts #55
  Peter, Kerstin et al.
  
• The effect of atmospheric dust on the Mars dayside ionosphere derived from 17 years of Mars Express Radio Science observations. Copernicus GmbH.
  Peter, Kerstin; Pätzold, Martin; Montabone, Luca; Thiemann, Ed; Witasse, Olivier; Tellmann, Silvia & Bird, Michael K.
  
• The variability of the ionospheres of Mars and Venus derived from Mars Express and Venus Express radio science observations. Copernicus GmbH.
  Peter, Kerstin; Pätzold, Martin; Chu, Feng; Fränz, Markus; Thiemann, Ed; Witasse, Oliver; Girazian, Zachary; Kopf, Andrew; Tellmann, Silvia; Häusler, Bernd & Bird, Michael K.