12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Inner magnetosphere heavy ion composition durin...
View graph of relations

« Back

Inner magnetosphere heavy ion composition during high-speed stream-driven storms

Research output: Contribution to journalJournal article

Published

Journal publication date07/2013
JournalJournal of Geophysical Research
Journal number7
Volume118
Number of pages14
Pages4066-4079
Original languageEnglish

Abstract

Ion composition data, taken by the Combined Release and Radiation Effects Satellite Magnetospheric Ion Composition Spectrometer instrument, are investigated across eight high-speed solar wind-stream-driven storms (HSSs) during 1991. The HSSs are identified using solar wind data from OMNI alongside geomagnetic indices, and the behavior of ions in the energy range 31.2–426.0 keV is investigated. A case study of the single HSS event that occurred on 30 July 1991 is performed, and superposed epoch analyses of five events are conducted. The data show evidence of a local minimum (dropout) in the flux and partial number density of ionic species H+, He+, He++, and O+ close to the onset of magnetospheric convection. The flux and number density rapidly fall and then recover over a period of hours. The initial rapid recovery in number density is observed to consist primarily of lower-energy ions. As the number density reaches its maximum, the ions show evidence of energization. Heavy ion-to-proton ratios are observed to decrease substantially during these HSS events.

Bibliographic note

©2013. American Geophysical Union. All Rights Reserved.