Event Details

Space and Planetary Physics webinar

The ionosphere of Mars is an integral part of the atmosphere that links the lower atmosphere with the solar wind, and it is a natural sink for both internal and external energy inputs into the Martian system. As a reactive medium, the ionosphere is very sensitive to the neutral atmosphere variability, such as surface and lower atmospheric phenomena that propagate upwards in the atmosphere (e.g. dust storms, gravity waves, or atmospheric cycles). As an ionized medium, the ionosphere is strongly dependent on solar wind variability and electromagnetic fields. Since Mars does not have a global intrinsic magnetic field, the ionosphere is the main obstacle that the solar wind encounters at Mars, and a number of phenomena depends on this interaction, such as atmospheric escape and auroral processes. Moreover, it favours/inhibits the propagation of radio frequencies, and so, it has important consequences for robotic and eventually human exploration.

In this seminar, I will present an overview of the Martian ionosphere, and how the coupling of its different layers are affected by a number of internal and external processes. Examples of internal processes include dust storms (both globally and locally), and lower atmosphere cycles such as the seasonal CO2 cycle that have an influence on the upper atmosphere, especially notable at spring when the polar caps sublimate. As example of external processes, the effect of electron precipitation from large solar storms in the Martian atmosphere will be presented. This precipitation produces lower-ionospheric radio absorption layers at ~60-80 km, a region not well characterised so far. This work is based on observations from Mars Express, Mars Reconnaissance Orbiter, Mars Odyssey, and the Mars Atmosphere and Volatile EvolutioN (MAVEN) missions, as well as on ionospheric modelling

If someone from outside of the SPP group would like to join the webinar, please send a request to w.gould@lancaster.ac.uk