Properties of high heliolatitude solar energetic particle events and constraints on models of acceleration and propagation
- 18 September 2003
- journal article
- research article
- Published by American Geophysical Union (AGU) in Geophysical Research Letters
- Vol. 30 (19)
- https://doi.org/10.1029/2003gl017139
Abstract
We analyse 9 large solar energetic particle (SEP) events detected by the Ulysses spacecraft at high heliolatitudes during the recent solar maximum polar passes. Properties of time intensity profiles from the Ulysses/COSPIN instrument are compared with those measured by SOHO/COSTEP and Wind/3DP near Earth. We find that onset times and times to maximum at high latitude are delayed compared to in‐ecliptic values. We show that the parameter which best orders these characteristics of time profiles is the difference in latitude between the associated flare and the spacecraft. We find that the presence of a shock is not necessary for the establishing of near equal intensities at Ulysses and in the ecliptic during the decay phase. The model of SEP acceleration by coronal mass ejection driven shocks does not appear to account for our observations, which would more easily be explained by particle diffusion across the interplanetary magnetic field.This publication has 10 references indexed in Scilit:
- Propagation of energetic particles in the high‐latitude high‐speed solar windGeophysical Research Letters, 2003
- Ulysses COSPIN observations of cosmic rays and solar energetic particles from the South Pole to the North Pole of the Sun during solar maximumAnnales Geophysicae, 2003
- Delay in solar energetic particle onsets at high heliographic latitudesAnnales Geophysicae, 2003
- Energetic particle propagation in the inner heliosphere as deduced from low‐frequency (<100 kHz) observations of type III radio burstsJournal of Geophysical Research, 2003
- Ulysses observations of solar energetic particles from the 14 July 2000 event at high heliographic latitudesJournal of Geophysical Research, 2003
- 3–20 MeV Electrons in the Inner Three‐dimensional Heliosphere at Solar Maximum:UlyssesCOSPIN/KET ObservationsThe Astrophysical Journal, 2002
- Particle acceleration at the Sun and in the heliosphereSpace Science Reviews, 1999
- Spatial and Temporal Invariance in the Spectra of Energetic Particles in Gradual Solar EventsThe Astrophysical Journal, 1997
- Perpendicular Transport of Low-Energy Corotating Interaction Region–associated NucleiThe Astrophysical Journal, 1997
- The role of interplanetary shocks in the longitude distribution of solar energetic particlesJournal of Geophysical Research, 1988