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Pioneer and Voyager observations of solar cycle variations in the outer heliosphere
Author(s) -
Gazis P. R.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl01428
Subject(s) - heliosphere , solar cycle , solar cycle 22 , solar wind , solar minimum , latitude , physics , equator , atmospheric sciences , solar maximum , coronal mass ejection , energetic neutral atom , astronomy , environmental science , plasma , quantum mechanics
Solar wind measurements from the Pioneer 10, Pioneer 11, and Voyager 2 spacecraft are now available through mid‐1993. These measurements extend our knowledge of the outer heliosphere to heliographic latitudes that range between −10° and 17.5°, and provide insight into the variation with solar cycle of the structure of the distant solar wind. The average temperature, mass flux density, dynamic pressure, and kinetic and thermal energy flux densities varied strongly with solar cycle at the latitude of Pioneer 11 (10° to 17° N), but were almost constant in the vicinity of the solar equator. These parameters may have increased with latitude between the solar equator and 17° N. There was also a short‐term variation in average solar wind parameters near the time of the 1986 solar minimum, when the inclination of the heliospheric current sheet dropped below the latitude of Pioneer 11.