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Radial evolution of the solar wind from IMP 8 to Voyager 2
Author(s) -
Richardson John D.,
Paularena Karolen I.,
Lazarus Alan J.,
Belcher John W.
Publication year - 1995
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 - 10.1029/94gl03273
Subject(s) - heliosphere , physics , solar wind , solar rotation , solar minimum , astrophysics , solar physics , maxima , solar cycle , adiabatic process , astronomy , atmospheric sciences , plasma , art , quantum mechanics , performance art , art history , thermodynamics
Voyager 2 and IMP 8 data from 1977 through 1994 are presented and compared. Radial velocity and temperature structures remain intact over the distance from 1 to 43 AU, but density structures do not. Temperature and velocity changes are correlated and nearly in phase at 1 AU, but in the outer heliosphere temperature changes lead velocity changes by tens of days. Solar cycle variations are detected by both spacecraft, with minima in flux density and dynamic pressure near solar maxima. Differences between Voyager 2 and IMP 8 observations near the solar minimum in 1986–1987 are attributed to latitudinal gradients in solar wind properties. Solar rotation variations are often present even at 40 AU. The Voyager 2 temperature profile is best fit with a R −0.49±0.01 decrease, much less steep than an adiabatic profile.