Physical Sciences and Mathematics Commons^™

Spectral Properties Of Heavy Ions Associated With The Passage Of Interplanetary Shocks At 1 Au, Mihir I. Desai, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

We have surveyed the energy spectra of ∼0.1-100 MeV nucleonˉ¹ C, O, and Fe nuclei associated with the passage of 72 interplanetary (IP) shocks observed on board the ACE spacecraft during the period 1997 October-2002 October. Our main results are as follows: (1) The spectral fit parameters are independent of the local shock properties. (2) About 7% of the events exhibit increasing Fe/O ratios with energy; the remaining events have Fe/O ratios that either remain constant or decrease with energy. (3) The Fe/O ratio in the shock-associated particles is typically ∼30% lower than in the ambient population. (4) The fractionation …