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On the Origins of the Intercorrelations Between Solar Wind Variables
Author(s) -
Borovsky Joseph E.
Publication year - 2018
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2017ja024650
Subject(s) - solar wind , polar wind , atmospheric sciences , coronal mass ejection , magnetopause , solar irradiance , thermosphere , physics , solar rotation , ionosphere , environmental science , meteorology , astronomy , plasma , solar physics , quantum mechanics
Abstract It is well known that the time variations of the diverse solar wind variables at 1 AU (e.g., solar wind speed, density, proton temperature, electron temperature, magnetic field strength, specific entropy, heavy‐ion charge‐state densities, and electron strahl intensity) are highly intercorrelated with each other. In correlation studies of the driving of the Earth's magnetosphere‐ionosphere‐thermosphere system by the solar wind, these solar wind intercorrelations make determining cause and effect very difficult. In this report analyses of solar wind spacecraft measurements and compressible‐fluid computer simulations are used to study the origins of the solar wind intercorrelations. Two causes are found: (1) synchronized changes in the values of the solar wind variables as the plasma types of the solar wind are switched by solar rotation and (2) dynamic interactions (compressions and rarefactions) in the solar wind between the Sun and the Earth. These findings provide an incremental increase in the understanding of how the Sun‐Earth system operates.