Journal article
Ion composition in interchange injection events in Saturn's magnetosphere
Journal of geophysical research. Space physics, Vol.119(12), pp.9761-9772
12/2014
DOI: 10.1002/2014JA020489
Abstract
Interchange injection events are commonly observed by the Cassini spacecraft in the region between about 6 and 12 R-s (1 R-s = 60,268 km) and even frequently beyond. In this study, 13 examples of interchange injection events are identified in Cassini/Cassini Plasma Spectrometer data under special conditions such that time-of-flight (TOF) mass spectra could be obtained from entirely within the events. Using the TOF data to separate the main ion species H+, H-2(+), and W+, approximate densities of each species are calculated under the assumption that all distributions were isotropic. The light-ion density ratios, H-2(+)/H+, in the injection events are not discernibly different from those ratios in control intervals from the ambient plasma. However, the water-group ratio, W+/H+, is significantly lower than ambient. The comparison of the measured density ratios with the range of values observed throughout Saturn's magnetosphere indicates that the values of W+/H+ that are as low as those observed within the injection events are found primarily beyond L similar to 14 (where L is the equatorial crossing distance, in Saturn radius, of a dipole field line), indicating that the injection events are delivering plasma from the outer magnetosphere at times traveling at least 6 R-s.
Details
- Title: Subtitle
- Ion composition in interchange injection events in Saturn's magnetosphere
- Creators
- M. F. Thomsen - Planetary Science InstituteD. B. Reisenfeld - University of MontanaR. J. Wilson - Laboratory for Atmospheric and Space PhysicsM. Andriopoulou - Austrian Academy of SciencesF. J. Crary - Laboratory for Atmospheric and Space PhysicsG. B. Hospodarsky - University of IowaC. M. Jackman - University of SouthamptonX. Jia - University of Michigan–Ann ArborK. K. Khurana - Planetary Science InstituteC. Paranicas - Johns Hopkins University Applied Physics LaboratoryE. Roussos - Max Planck Institute for Solar System ResearchN. Sergis - Academy of AthensR. L. Tokar - Planetary Science Institute
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.119(12), pp.9761-9772
- Publisher
- Amer Geophysical Union
- DOI
- 10.1002/2014JA020489
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Number of pages
- 12
- Grant note
- ST/L004399/1 / STFC; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC) 1243218 / NASA Cassini program through JPL ST/L004399/1 / Science and Technology Facilities Council; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC) Southwest Research Institute
- Language
- English
- Date published
- 12/2014
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455269702771
Metrics
4 Record Views