Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR) as tracers of solar wind conditions near Saturn: Event lists and applications

Roussos, E.; Jackman, C. M.; Thomsen, M. F.; Kurth, W. S.; Paranicas, C.; Kollmann, P.; Krupp, N.; Bučík, R.; Mitchell, D. G.; Krimigis, S. M.; Hamilton, D. C.; Radioti, Aikaterini

doi:10.1016/j.icarus.2017.08.040

Cited by 33 publications

(70 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 2-week periodicity identified in the prenoon sector's L b values (Figure 2b) hints that the strength of convection is modulated by the interaction of Saturn's magnetosphere with the solar wind. A similar periodicity has been observed in the intensity and extent of the electron radiation belts in 2008 and was attributed to Saturn's magnetosphere interaction with two CIRs every solar rotation (Roussos, Jackman, et al, 2018). Evidence that Saturn was almost continuously exposed to CIRs during the proximal orbits is provided in .…”

Section: The Origin Of the Inner Electron Radiation Belt Boundarysupporting

confidence: 69%

Sources, Sinks, and Transport of Energetic Electrons Near Saturn's Main Rings

Roussos

Kollmann

Krupp

et al. 2019

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

The inner boundary of Saturn's electron radiation belts, near the planet's A ring (∼2.27 Rs), is studied using Cassini's proximal orbit measurements. We find that variable convective flows transport energetic electrons to the A ring, which absorbs them instantaneously, forming the inner belt boundary. These flows are also responsible for a variable and longitudinally asymmetric boundary configuration. Prenoon, the boundary oscillates toward and away from the A ring with a 2‐week period. Postnoon, it maps persistently near the F ring (∼2.32 Rs) and coexists with localized MeV electron intensity enhancements (microbelts). We propose that the microbelts contain electrons in drift resonance with corotation, trapped in local time‐confined trajectories, which result from the aforementioned convective flows. The microbelts' collocation with the F ring implies either a local, secondary electron production due to galactic cosmic ray collisions with F ring dust or an enhanced resonant electron trapping due to an electrodynamic interaction between the F ring and Saturn's magnetosphere.

show abstract

Section: The Origin Of the Inner Electron Radiation Belt Boundarysupporting

confidence: 69%

Sources, Sinks, and Transport of Energetic Electrons Near Saturn's Main Rings

Roussos

Kollmann

Krupp

et al. 2019

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…As it was reported by Roussos, Jackman, et al (2018) the background GCR noise in the various channels of the Cassini MIMI/LEMMS instrument decreased notably during the close approach to the planet. In Figure 8d we compared the LEMMS E7 count rates from Saturn Orbit Insertion normalized to integral flux at 12R S , with the integrated above 300-MeV modeled flux profile for preequinox.…”

Section: Gcr Spectra and Integral Fluxsupporting

confidence: 67%

Galactic Cosmic Rays Access to the Magnetosphere of Saturn

et al. 2019

Self Cite

View full text Add to dashboard Cite

The megaelectron volt proton radiation belts of Saturn are isolated from the middle and outer magnetosphere, and the source of these high‐energy protons is thought to be linked to the access of galactic cosmic rays (GCRs) in the system. To validate this hypothesis, it is first of all necessary to determine the realistic spectrum of GCRs at Saturn. Previously, only analytical attempts were performed in order to calculate the GCR spectra. In this letter we provide for the first time the numerical solution for the determination of the GCR access to the upper atmosphere and rings of Saturn. The proposed method is based on the charged particle tracing technique. As a result the GCRs access energies to the atmosphere and to the equatorial plane of the magnetosphere as a function of radial distance to the planet were obtained and the GCRs spectra were reconstructed. Dependencies of the spectral parameters such as the time or the incidence direction were also obtained offering all necessary information for simulating the interaction of GCRs with the Saturnian system during different phases of the Cassini mission.

show abstract

“…This similarity of profiles is not surprising, since these ions actually carry much of the ring current Sergis et al, 2009). Third, the ring current strength peaks near 10 (Roussos et al, 2018). The vertical dot-dash line indicates the peak of the SEP event.…”

Section: Discussionmentioning

confidence: 97%

A New Ring Current Model for Saturn

Carbary

2019

JGR Space Physics

View full text Add to dashboard Cite

The ring current of Saturn is obtained by taking the curl of the observed magnetic field. An analytical model of this ring current can then be obtained by fitting it to a lognormal in ρ and a Gaussian in z. Local time dependence is included as a harmonic expansion in ϕ for coefficients of the lognormal; radial dependence is included as a quadratic expansion in ρ of the width of the Gaussian. In this model, the ring current peaks at ~0.25 MA/RS2 at ~10 RS on the nightside near ~1 hr. The ring current strength minimizes at ~0.17 MA/RS2 on the dayside near ~16 hr. The cross‐sectional shape of the ring current is a teardrop extending from ~5 to ~20 RS or more.

show abstract

Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR) as tracers of solar wind conditions near Saturn: Event lists and applications

Cited by 33 publications

References 65 publications

Sources, Sinks, and Transport of Energetic Electrons Near Saturn's Main Rings

Sources, Sinks, and Transport of Energetic Electrons Near Saturn's Main Rings

Galactic Cosmic Rays Access to the Magnetosphere of Saturn

A New Ring Current Model for Saturn

Contact Info

Product

Resources

About