A one-dimensional multispecies magnetohydrodynamic model of the dayside ionosphere of Mars

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA06p06506· OSTI ID:6050984

Shinagawa, H; Cravens, T E ^[1]

---

1. Univ. of Michigan, Ann Arbor (USA)

The existence of a small intrinsic magnetic field at Mars is still being debated. The ion densities, measured in the Martian ionosphere above 300 km by the retarding potential analyzers on the Viking landers, are very low. The ionospheric thermal pressure above 300 km is insufficient by itself to withstand the solar wind dynamic pressure, suggesting the presence of a magnetic field in the ionosphere of Mars. However, two types of ionospheric magnetic field are possible: (1) a weak intrinsic magnetic field, or (2) an induced magnetic field driven by the solar wind interaction with Mars. The latter situation is analogous to the Venus ionosphere during conditions of high solar wind dynamic pressure. It has been pointed out that the measured plasma scale heights and temperatures for the Martian ionosphere are very similar to those observed in the Venus ionosphere during conditions of large solar wind dynamic pressure. The authors present a one-dimensional, multispecies, magnetohydrodynamic model of the Martian ionosphere. Scenarios with and without a small intrinsic field are modeled for Viking conditions (solar minimum). They find that the calculated ion density profiles are not in better agreement with the measured ones if an intrinsic magnetic field is included in the model. The results also indicate that large horizontal plasma motions must be present at high altitudes, which implies that the dynamics of the upper ionosphere of Mars is controlled by the solar wind.

• OSTI ID: 6050984
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A6; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FLUID MECHANICS
HYDRODYNAMICS
INTERACTIONS
ION DENSITY
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MARS PLANET
MATHEMATICAL MODELS
MECHANICS
ONE-DIMENSIONAL CALCULATIONS
PLANETARY IONOSPHERES
PLANETS
PRESSURE EFFECTS
SOLAR ACTIVITY
SOLAR WIND