A two-dimensional kinematic dynamo model of the ionospheric magnetic field at Venus

Journal Article · Thu Nov 01 00:00:00 EST 1990 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/GL017i012p02261· OSTI ID:5502868

Cravens, T E; Wu, D ^[1]; Shinagawa, H ^[2]

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1. Univ. of Kansas, Lawrence (USA)
2. Marshall Space Flight Center, Huntsville, AL (USA)

The ionosphere of Venus was observed by the magnetometer on the Pioneer Venus Orbiter (PVO) to be permeated by a large-scale magnetic field for conditions of high solar wind dynamic pressure. The ionospheric conductivity is very high above 170 km and magnetic flux is carried by the plasma flow both vertically downward and in an antisunward direction. Ohmic dissipation of the electric current allows the magnetic field to diffuse for altitudes below 150-170 km. A number of one-dimensional kinematic dynamo and MHD models have been developed to explain the observed vertical magnetic field profiles, but did not include the effects of horizontal transport. The authors have constructed a two-dimensional kinematic dynamo model of the dayside ionospheric magnetic field at Venus in which the 2-D magnetic induction equation (i.e., magnetic diffusion-convection equation) is numerically solved using specified plasma velocities. The vertical velocity profile is taken from the one-dimensional MHD model of Shinagawa and Cravens (1988) and the horizontal velocities are adapted from published PVO retarding potential analyzer results (Knudsen et al., 1982). They demonstrate that the basic features of the vertical magnetic field profile, such as the presence of a magnetic layer at 170 km, remain unaltered by horizontal flow effects. However, they also show that horizontal plasma flow can strongly affect the magnetic field for altitudes above 300 km.

• OSTI ID: 5502868
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 17:12; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
PLANETARY IONOSPHERES
MATHEMATICAL MODELS
VENUS PLANET
ELECTRIC CONDUCTIVITY
ENERGY LOSSES
MAGNETIC FIELDS
MAGNETIC FLUX
NUMERICAL SOLUTION
PLASMA DRIFT
SOLAR WIND
ELECTRICAL PROPERTIES
LOSSES
PHYSICAL PROPERTIES
PLANETS
SOLAR ACTIVITY
640107* - Astrophysics & Cosmology- Planetary Phenomena