Premium
Differences between the 0.35–1.0 MeV/nucleon H/He ratio in solar and Co‐rotating events at high heliolatitude
Author(s) -
Simnett G. M.,
Sayle K. A.,
Roelof E. C.
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 - 10.1029/95gl02780
Subject(s) - physics , astrophysics , transient (computer programming) , spacecraft , solar energetic particles , nucleon , intensity (physics) , coronal mass ejection , solar wind , astronomy , plasma , nuclear physics , optics , computer science , operating system
We discuss measurements from the Ulysses spacecraft of the 0.35–1.0 MeV/nucleon H/He intensity ratio at high heliolatitudes. In early 1994 two transient solar events were detected in the gaps between particle intensity increases associated with the passage at low latitude of a co‐rotating interaction region. The H/He ratio was ≳ one order‐of‐magnitude lower in the co‐rotating events than in the transient solar events. Several similar instances, but not so cleanly separated, were observed from mid‐1992 to the end of 1993. We interpret the lower H/He ratio in recurrent events as the result of efficient acceleration of interstellar pickup He + at corotating reverse shocks to which Ulysses remains connected even at high heliolatitudes.