EGU22-13045, updated on 28 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

A Model Analysis of the Northern Ionospheric Structure Observed with the MAVEN/ROSE at Mars

Tariq Majeed1,2, Hessa AlSuwaidi1, Stephen W. Bougher2, and Achim Morschhauser3
Tariq Majeed et al.
  • 1American University of Sharjah, UAE (
  • 2University of Michigan, Ann Arbor, USA (
  • 3GFZ German Research Centre for Geosciences ( D-14473 Potsdam, Germany

The northern hemispheric electron density (Ne) data acquired by the Radio Occultation Science Experiments (ROSE) onboard the Mars Atmosphere and Volatile Evolution (MAVEN) have indicated more complicated ionospheric structure of Mars than previously thought.  Large variations in the topside Ne scale heights are observed presumably in response to the outward flow of the ionospheric plasma or changes in plasma temperatures.   We use our 1-D chemical diffusive model coupled with the Mars - Global Ionosphere Thermosphere Model (M-GITM) to interpret the northern upper ionospheric structure at Mars.  The primary source of ionization in the model is due to solar EUV radiation. Our model is a coupled finite difference primitive equation model which solves for plasma densities and vertical ion fluxes.  The photochemical equilibrium for each ion is assumed at the lower boundary of the model, while the flux boundary condition is assumed at the upper boundary to simulate plasma loss from the Martian ionosphere.  The crustal magnetic field at the measured Ne locations is weak and mainly horizontal and does not allow plasma to move vertically.   Thus, the primary plasma loss from the topside ionosphere at these locations is most likely caused by diverging horizontal fluxes of ions, indicating that the plasma flow in the upper ionosphere of Mars is controlled by the solar wind dynamic pressure.  We find that the variation in the topside Ne scale heights is sensitive to magnitudes of upward ion fluxes derived from ion velocities that we impose at the upper boundary to explain the topside ionospheric structure.  The model requires upward velocities ranging from 50 ms-1 to 90 ms-1 for all ions to ensure an agreement with the measured Ne profiles. The corresponding outward fluxes in the range 1.1 x 10– 5.8 x 106 cm-2 s-1 are calculated for O2+ compared to those for O+ in the range 3.8 x 105 – 6.7 x 105 cm-2 s-1.  The model results for the northern Ne profiles will be presented in comparison with the measured Ne profiles.  

How to cite: Majeed, T., AlSuwaidi, H., Bougher, S. W., and Morschhauser, A.: A Model Analysis of the Northern Ionospheric Structure Observed with the MAVEN/ROSE at Mars, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13045,, 2022.


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