Does Mars have a Magnetosphere?

Wallis, M. K.

doi:10.1111/j.1365-246x.1975.tb01620.x

Cited by 22 publications

(10 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Mariner 4 and 5 fly-by missions to Mars and Venus, respectively, provided the first detailed examination of their ionospheres by means of radio occultation experiments [Kliore et al, 1965; Mars to support the solar wind pressure were' also raised by Gringauz et al [1974], Whitten and Colin [1974], Wallis [1975], Gringauz [1976], Breus and Gringauz [1980], and Gringauz [1980]. However, only Gringauz, Wallis, and Breus have used the lack of ionopause signatures and weaknesses of the ionosphere as evidence for the existence of a significant intrinsic magnetic field.…”

Section: Balancing Solar Wind Dynamic Pressurementioning

confidence: 99%

The solar wind interaction with Mars revisited

Slavin¹,

Holzer²

1982

J. Geophys. Res.

View full text Add to dashboard Cite

Owing to a paucity of observational data, no clear consensus has been reached concerning the general nature of the solar wind interaction with Mars. In particular, the previous analyses are still at odds regarding the existence of a small intrinsic field magnetosphere at Mars as opposed to a Venus‐type ionospheric interaction (e.g., Russell, 1978a,b; Dolginov, 1978b,c). This study contributes to the resolution of this question in three ways. First, an improved determination of effective obstacle altitude and shape is obtained from the Mars 2,3, and 5 bow shock encounters through the use of a recently published catalog of gasdynamic flow solutions (Spreiter and Stahara, 1980a,b). Second, building upon the Pioneer Venus findings at a field‐free planet (Brace et al., 1980; Elphic et al., 1980), it is shown that the Martian ionosphere cannot support a Venus‐type ionopause at the obstacle altitudes inferred through our modeling of the bow wave observations even when maximal induced ionospheric magnetic fields and solar maximum EUV levels are assumed. These results allow an effective Mars magnetic dipole moment of 1.4 (±0.6) × 1022 G‐cm3 to be determined that stands off the solar wind over the dayside hemisphere at altitudes ranging from∼500 km at the subsolar point to ∼1000 km near the terminator with no direct aid from the ionosphere under average solar wind/magnetospheric conditions. Third, a search of published Mars and Mariner radio occultation measurements produced no evidence for the existence of an ionopause at Mars in agreement with the Viking study of Lindal et al. (1979). Rather, the electron density altitude profiles appear qualitatively consistent with the Martian ionosphere terminating in a chemopause associated with the effects of magnetospheric convection as first proposed by Bauer and Hartle (1973). After a review of the various arguments in the literature, as supplemented by the results of this study, we conclude that Mars most probably possesses a small intrinsic field magnetosphere.

show abstract

Section: Balancing Solar Wind Dynamic Pressurementioning

confidence: 99%

The solar wind interaction with Mars revisited

Slavin¹,

Holzer²

1982

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…Several authors have analyzed these data to describe the interaction of solar wind with the atmosphere of Mars (Gringauz et al 1974, Whitten and Colin 1974, Wallis 1975, Breus and Gringauz 1980, Slavin and Holzer 1982, Luhmann et al 1987, Hanson and Mantas 1988, Dubinin et al 1991, Schwingenschuh et al 1992, Shinagawa and Cravens 1992, Fox 1997. The MGS spacecraft has obtained magnetic field and plasma observations throughout the Mars environment from beyond the influence of Mars to just above the surface at an altitude of ∼100 km.…”

Section: Introductionmentioning

confidence: 97%

Solar EUV and Electron-Proton-Hydrogen Atom-Produced Ionosphere on Mars: Comparative Studies of Particle Fluxes and Ion Production Rates Due to Different Processes

Haider

Seth

Kallio

et al. 2002

Icarus

View full text Add to dashboard Cite

“…The calculated electric current distribution was similar to that of wind dynamic pressure [Gringauz et al, 1974;Whitten and Colin, Venus. Recently, Luhmann et al [1987] also suggested that the 1974; Wallis, 1975;Gringauz, 1976;Breus and Gringauz, 1980; intrinsic magnetic field is negligible, and that the solar wind-Mars lntriligator and Smith, 1979; Slavin and Holzer, 1982;Luhmann et al, 1987;Hanson and Mantas, 1988]. In fact, the ionospheric thermal pressure near 300 km is exceeded by the typical solar wind dynamic pressure 85% of the time [cf.…”

mentioning

confidence: 99%

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

1989

View full text Add to dashboard Cite

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 (Hanson et al., 1977). 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 (Hanson and Mantas, 1988). 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 (Luhmann et al., 1987). We 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). We 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.

show abstract

Does Mars have a Magnetosphere?

Cited by 22 publications

References 16 publications

The solar wind interaction with Mars revisited

The solar wind interaction with Mars revisited

Solar EUV and Electron-Proton-Hydrogen Atom-Produced Ionosphere on Mars: Comparative Studies of Particle Fluxes and Ion Production Rates Due to Different Processes

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

Contact Info

Product

Resources

About