Mars ionospheric response to solar wind variability

• Published in: Journal of geophysical research. Space physics Vol. 118; no. 10; pp. 6558 - 6587
• Main Authors: Opgenoorth, H. J., Andrews, D. J., Fränz, M., Lester, M., Edberg, N. J. T., Morgan, D., Duru, F., Witasse, O., Williams, A. O.
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 01-10-2013; Wiley
• Subjects: Astronomy; Atmosphere; Earth; Earth, ocean, space; Exact sciences and technology; External geophysics; Interplanetary space; Ionosphere; Magnetic fields; magnetosphere; Mars; Physics of the ionosphere; Physics of the magnetosphere; Solar physics; Solar system; solar wind; Space exploration; Spacecraft; Upper atmosphere; Interplanetary magnetic field; Plasma; magnetic field; Coronal mass ejection; Orbit; Perturbation; Ionospheric sounder; variability; solar wind; ESA; magnetosphere; Planetary ionospheres; Upper atmosphere; Corotating interaction region; NEAR space probe; Dynamic pressure; STEREO satellite
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1002/jgra.50537

At planets with induced magnetospheres, the coupling between the ionosphere, the weak draped magnetosphere, and the solar wind is very direct in comparison to Earth. The weak induced magnetosphere itself is created by the prevailing Solar wind conditions and therefore in its shape and strength dynamically depending on it. In early 2010, Mars was located behind Earth in the Solar wind; thus, we can use coordinated data from multiple near‐Earth spacecraft (Stereo, Wind) to evaluate what kind of Solar wind disturbances have passed by Earth and might consecutively hit Mars, and when. We employ plasma data from the ESA Mars‐Express mission, the ASPERA‐3 particle instrument, and the MARSIS Active Ionospheric Sounder (AIS) to investigate, for a number of isolated events in March and April 2010, how the ionosphere and the induced magnetosphere at Mars develop and decay in response to Solar wind variability in the magnetic field, density, and velocity. In a dedicated campaign mode, we use frequent long‐duration MARSIS AIS operations for several consecutive orbits, to monitor for the first time the long‐term development of the Martian plasma environment during solar wind disturbances. We find that the magnetosphere and ionosphere of Mars can become considerably compressed by solar wind dynamic pressure variations, which usually are also associated with changes in the magnetic draping of the interplanetary magnetic field around the planet. These are typically associated with corotating interaction regions and coronal mass ejections, and can last for several days. During such episodes of compression, we see signatures of increased plasma transport over the terminator and enhanced ion outflow from the upper atmosphere.
Key Points
Mars ionosphere and induced magnetosphere response to solar wind variability
Ionospheric compressions and plasma transport from day to night‐side of Mars
Magnetospheric reconfigurations and ion outflow from Mars upper atmosphere