Equatorial distributions of energetic ion moments in Saturn's magnetosphere using Cassini/MIMI measurements
Abstract
We use kappa distribution fits to combined Charge Energy Mass Spectrometer (CHEMS, 3 to 236 keV/e), Low Energy Magnetosphere Measurements System (LEMMS, 0.024 < E < 18 MeV), and Ion Neutral Camera (INCA, 5.2 to >220 keV for H+) proton and singly ionized energetic ion spectra to calculate the >20 keV energetic ion moments inside Saturn's magnetosphere. Using a realistic magnetic field model (Khurana et al. 2007) and data from the entire Cassini mission to date (2004-2016), we map the ion measurements to the equatorial plane and via the modeled kappa distribution spectra we produce the equatorial distributions of all ion integral moments, focusing on partial density, integral intensity, partial pressure, integral energy intensity; as well as the characteristic energy (EC=IE/In), Temperature and κ-index of these ions as a function of Local Time (00:00 to 24:00 hrs) and L-Shell (5-20). A modified version of the semi-empirical Roelof and Skinner [2000] model is then utilized to retrieve the equatorial H+ and O+ pressure, density and temperature in Saturn's magnetosphere in both local time and L-shell. We find that a) although the H+ and O+ partial pressures and densities are nearly comparable, the >20 keV protons have higher number and energy intensities at all radial distances (L>5) and local times; b) the 12
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSM51F2559D
- Keywords:
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- 2723 Magnetic reconnection;
- MAGNETOSPHERIC PHYSICSDE: 2756 Planetary magnetospheres;
- MAGNETOSPHERIC PHYSICSDE: 2772 Plasma waves and instabilities;
- MAGNETOSPHERIC PHYSICSDE: 2784 Solar wind/magnetosphere interactions;
- MAGNETOSPHERIC PHYSICS