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Modulation of dayside on and neutral distributions at Venus Evidence of direct and indirect solar energy inputsThe details of solar variability and its coupled effects on the Venusian dayside are examined for evidence of short-term perturbations and associated energy inputs. Ion and neutral measurements obtained from the Orbiter Ion Mass Spectrometer and Orbital Neutral mass Spectrometer are used to show that the dayside concentrations of CO2(+) and the neutral gas temperature are smoothly modulated with a 28-day cycle reasonably matching that of the solar F(10.7) and EUV fluxes. Earlier measurements show less pronounced and more irregular modulations and more conspicuous short-term day-to-day fluctuations in the ions and neutrals, as well as relatively large enhancements in the solar wind, which appear consistent with differences in solar coronal behavior during the two periods. It is suggested that the solar wind variations cause fluctuations in joule heating, producing the observed short-term ion and neutral variations.
Document ID
19830054139
Document Type
Reprint (Version printed in journal)
Authors
Taylor, H. A., Jr. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mayr, H. G. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Grebowsky, J. M. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Niemann, H. B. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Hartle, R. E. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Cloutier, P. A. (Rice University Houston, TX, United States)
Barnes, A. (NASA Ames Research Center Moffett Field, CA, United States)
Daniell, R. E., Jr. (Beers Associates, Inc. Reston, VA, United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1982
Publication Information
ISSN: 0273-1177
Subject Category
LUNAR AND PLANETARY EXPLORATION
Distribution Limits
Public
Copyright
Other