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Full-Text Articles in Physical Sciences and Mathematics
Delay In Solar Energetic Particle Onsets At High Heliographic Latitudes, Silvia C. Dalla, Ming Zhang
Delay In Solar Energetic Particle Onsets At High Heliographic Latitudes, Silvia C. Dalla, Ming Zhang
Aerospace, Physics, and Space Science Faculty Publications
Ulysses observations have shown that solar energetic particles (SEPs) can easily reach high heliographic latitudes. To obtain information on the release and propagation of SEPs prior to their arrival at Ulysses, we analyse the onsets of nine large high-latitude particle events. We measure the onset times in several energy channels, and plot them versus inverse particle speed. This allows us to derive an experimental path length and time of release from the solar atmosphere. We repeat the procedure for near-Earth observations by Wind and SOHO. We find that the derived path lengths at Ulysses are 1.06 to 2.45 times the …
Ulysses Cospin Observations Of Cosmic Rays And Solar Energetic Particles From The South Pole To The North Pole Of The Sun During Solar Maximum, Robert Bruce Mckibben, Ming Zhang
Ulysses Cospin Observations Of Cosmic Rays And Solar Energetic Particles From The South Pole To The North Pole Of The Sun During Solar Maximum, Robert Bruce Mckibben, Ming Zhang
Aerospace, Physics, and Space Science Faculty Publications
In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum. Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ∼10 MeV and extending up to …