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Composition measurements above the Southern Solar Polar Region around the solar activity maximum by the Ulysses COSPIN/LET instrument
Author(s) -
Hofer M. Y.,
Marsden R. G.,
Sanderson T. R.,
Tranquille C.
Publication year - 2002
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 - 10.1029/2002gl014944
Subject(s) - physics , polar , latitude , coronal mass ejection , heliosphere , solar energetic particles , range (aeronautics) , solar minimum , coronal hole , solar maximum , atmospheric sciences , solar cycle , astrophysics , corona (planetary geology) , astronomy , solar wind , astrobiology , plasma , materials science , venus , composite material , quantum mechanics
In November 2000, during the second southern polar passage (SPP), the Ulysses spacecraft reached its highest heliographic latitude (80.2°) at a solar radial distance of ∼2.27 AU. The first SPP in 1994 took place as the level of solar activity was approaching the minimum between the cycles 22 and 23. The recent high‐latitude observations during the second SPP in 2000/2001 correspond to near‐maximum activity conditions with a large number of transient phenomena. These heliospheric conditions are reflected in the energetic particle composition data covering the energy range 4–20 MeV/n recorded by the COSPIN/‐LET instrument. Most of the particles observed at high heliographic latitudes had their origin in solar energetic particle events. Furthermore, the results suggest coronal mass ejection‐driven shock acceleration of coronal material as the source.