Electron temperatures and densities in the venus ionosphere: Pioneer Venus orbiter electron temperature probe results

Journal Article · Fri Feb 23 04:00:00 EST 1979 · Science; (United States)

DOI:https://doi.org/10.1126/science.203.4382.763· OSTI ID:5605360

Brace, L H; Theis, R F; Krehbiel, J P

Altitude profiles of electron temperature and density in the ionosphere of Venus have been obtained by the Pioneer Venus orbiter electron temperature probe. Elevated temperatures observed at times of low solar wind flux exhibit height profiles that are consistent with a model in which less than 5% of the solar wind energy is deposited at the ionopause and is conducted downward through an unmagnetized ionosphere to the region below 200 kilometers where electron cooling to the neutral atmosphere proceeds rapidly. When solar wind fluxes are higher, the electron temperatures and densities are highly structured and the ionopause moves to lower altitudes. The ionopause height in the late afternoon sector observed thus far varies so widely from day to day that any height variation with solar zenith angle is not apparent in the observations. In the neighborhood of the ionopause, measurements of plasma temperatures and densities and magnetic field strength indicate that an induced magnetic barrier plays an important role in the pressure transfer between the solar wind and the ionosphere. The bow shock is marked by a distinct increase in electron current collected by the instrument, a feature that provides a convenient identification of the bow shock location.

• Research Organization: NASA, Goddard Space Flight Center, Greenbelt, MD
• OSTI ID: 5605360
• Journal Information: Science; (United States), Journal Name: Science; (United States) Vol. 203; ISSN SCIEA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ELECTRON DENSITY
ELECTRON TEMPERATURE
MAGNETIC FIELDS
PIONEER SPACE PROBES
PLANETARY ATMOSPHERES
PLANETARY IONOSPHERES
PLANETS
SHOCK WAVES
SPACE VEHICLES
VENUS PLANET