Premium
Ulysses high‐latitude observations of ions accelerated by co‐rotating interaction regions
Author(s) -
Sanderson T. R.,
Marsden R. G.,
Wenzel K.P.,
Balogh A.,
Forsyth R. J.,
Goldstein B. E.
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 - 10.1029/94gl01062
Subject(s) - ecliptic , heliosphere , physics , solar wind , proton , latitude , coronal hole , ion , astrophysics , spacecraft , plasma , astronomy , coronal mass ejection , nuclear physics , quantum mechanics
We present observations of energetic ions (E∼1 MeV) from the Ulysses spacecraft during its first pass from the ecliptic plane to the southern high‐latitude regions of the heliosphere. At latitudes less than ∼13°S Ulysses was completely immersed in the heliomagnetic streamer belt, and observed a ∼1 MeV proton intensity which showed little evidence of a periodic structure. Between ∼13°S and ∼29°S Ulysses observed one dominant recurrent co‐rotating interaction region, its reverse shocks being mainly responsible for accelerating the ∼1 MeV protons. At ∼29°S the spacecraft left this region and entered the solar wind flow from the polar coronal hole. From ∼29° up to ∼45°S, reverse shocks from this and other interaction regions were still being observed. Accelerated energetic ions, with proton‐to‐alpha ratio signatures consistent with having been accelerated by the reverse shocks of these co‐rotating interacting regions, were still being observed up to latitudes of ∼50°S.