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Full-Text Articles in Physical Sciences and Mathematics
The Role Of Interplanetary Scattering In Western Hemisphere Large Solar Energetic Particle Events, Glenn M. Mason, Mihir I. Desai, Christina M.S. Cohen, Richard A. Mewaldt, Edward C. Stone, Joseph R. Dwyer
The Role Of Interplanetary Scattering In Western Hemisphere Large Solar Energetic Particle Events, Glenn M. Mason, Mihir I. Desai, Christina M.S. Cohen, Richard A. Mewaldt, Edward C. Stone, Joseph R. Dwyer
Aerospace, Physics, and Space Science Faculty Publications
Using high-sensitivity instruments on the ACE spacecraft, we have examined the intensities of O and Fe in 14 large solar energetic particleevents whose parent activity was in the solar western hemisphere. Sampling the intensities at low (∼273 keV nucleonˉ¹) and high (∼12 MeV nucleonˉ¹) energies, we find that at the same kinetic energy per nucleon, the Fe/O ratio decreases with time, as has been reported previously. This behavior is seen in more than 70% of the cases during the rise to maximum intensity and continues in most cases into the decay phase. We find that for most events if we …
Solar Cycle Variations In The Composition Of The Suprathermal Heavy-Ion Population Near 1 Au, Mihir I. Desai, Glenn M. Mason, Joseph E. Mazur, Joseph R. Dwyer
Solar Cycle Variations In The Composition Of The Suprathermal Heavy-Ion Population Near 1 Au, Mihir I. Desai, Glenn M. Mason, Joseph E. Mazur, Joseph R. Dwyer
Aerospace, Physics, and Space Science Faculty Publications
We have measured the annual variation in the quiet-time composition of interplanetary suprathermal ions between 0.04 and 1 MeV nucleon-1 from 1994 November 20 through 2006 January 1. Our results show the following: (1) The C/O and Fe/O ratios are similar to the corresponding values measured in the solar wind and corotating interaction regions (CIRs) during solar minimum conditions of 1994-1997 and 2005. (2) During periods of increased solar activity between 1998 and 2002, the C/O ratio is similar to that measured in solar energetic particle (SEP) events, while the Fe/O ratio lies between the values measured in coronal mass …