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The three‐dimensional solar wind around solar maximum
Author(s) -
McComas D. J.,
Elliott H. A.,
Schwadron N. A.,
Gosling J. T.,
Skoug R. M.,
Goldstein B. E.
Publication year - 2003
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 - 10.1029/2003gl017136
Subject(s) - coronal hole , solar cycle 22 , solar minimum , solar maximum , coronal mass ejection , solar cycle 23 , solar wind , physics , solar cycle , atmospheric sciences , heliosphere , northern hemisphere , southern hemisphere , astronomy , environmental science , plasma , quantum mechanics
Ulysses is now completing its second solar polar orbit, dropping back down in latitude as the Sun passes through its post‐maximum phase of the solar cycle. A mid‐sized circumpolar coronal hole that formed around solar maximum in the northern hemisphere has persisted and produced a highly inclined CIR, which was observed from ∼70°N down to ∼30°N. We find that the speed maxima in the high‐speed streams follow the same slow drop in speed with decreasing latitude observed in the large polar coronal holes around solar minimum. These results suggest a solar wind acceleration effect that is related to heliolatitude or solar rotation. We also find that the solar wind dynamic pressure is significantly lower in the post‐maximum phase of this solar cycle than during the previous one, indicating that while the heliosphere is larger than near solar minimum, it should be smaller than during or after the previous maximum.