Cassini INMS measurements of Enceladus plume density

Perry, M. E.; Teolis, B. D.; Crider, D. H.; Magee, B.; Waite, J. H.; Brockwell, T.; Perryman, R.; McNutt, R. L.

doi:10.1016/j.icarus.2015.04.037

Cited by 26 publications

(43 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…So far, these discontinuities have been observed by Cassini during 11 crossings of the Enceladus flux tube . Several studies [e.g., Smith et al, 2010;Kriegel et al, 2014;Perry et al, 2015] showed that the diameter of the Enceladus plume clearly exceeds the extension of the Enceladus flux tube. We would like to emphasize that this does not cancel the hemisphere coupling effect and the associated magnetic discontinuities, since the height-integrated Pedersen and Hall conductivities along field lines threading Enceladus are still much larger than the conductances outside the Enceladus flux tube .…”

Section: The Hemisphere Coupling Effectmentioning

confidence: 99%

“…In the real scenario, the complex interplay between dust, neutral, and charged particles within the plume certainly produces a much more complex dependency of these currents on Enceladean longitude. On the other hand, the neutral gas emerging from the Enceladus plume extends to way beyond the boundary of the Enceladus flux tube at r = R E [e.g., Perry et al, 2015]. An extended gas population outside of the Enceladus flux tube will weaken the hemisphere coupling effect and "symmetrize" the obstacle, since its outer regions can directly connect to Saturn's northern polar ionosphere through wing-aligned currents.…”

Section: Impact Of the Anti-hall Effectmentioning

confidence: 99%

See 1 more Smart Citation

An analytical model of sub‐Alfvénic moon‐plasma interactions with application to the hemisphere coupling effect

Simon

2015

JGR Space Physics

View full text Add to dashboard Cite

We develop a new analytical model of the Alfvén wing that is generated by the interaction between a planetary moon's ionosphere and its magnetospheric environment. While preceding analytical approaches assumed the obstacle's height‐integrated ionospheric conductivities to be spatially constant, the model presented here can take into account a continuous conductance profile that follows a power law. The electric potential in the interaction region, determining the electromagnetic fields of the Alfvén wing, can then be calculated from an Euler‐type differential equation. In this way, the model allows to include a realistic representation of the “suspension bridge”‐like conductance profile expected for the moon's ionosphere. The major drawback of this approach is its restriction to interaction scenarios where the ionospheric Pedersen conductance is large compared to the Hall conductance, and thus, the Alfvénic perturbations are approximately symmetric between the planet‐facing and the planet‐averted hemispheres of the moon. The model is applied to the hemisphere coupling effect observed at Enceladus, i.e., to the surface currents and the associated magnetic discontinuities that arise from a north‐south asymmetry of the obstacle to the plasma flow. We show that the occurrence of this effect is very robust against changes in the conductance profile of Enceladus' plume, and we derive upper limits for the strength of the magnetic field jumps generated by the hemisphere coupling effect. During all 11 reported detections of the hemisphere coupling currents at Enceladus, the observed magnetic field jumps were clearly weaker than the proposed limits. Our findings are also relevant for future in situ studies of putative plumes at the Jovian moon Europa.

show abstract

Section: The Hemisphere Coupling Effectmentioning

confidence: 99%

Section: Impact Of the Anti-hall Effectmentioning

confidence: 99%

An analytical model of sub‐Alfvénic moon‐plasma interactions with application to the hemisphere coupling effect

Simon

2015

JGR Space Physics

View full text Add to dashboard Cite

show abstract

“…Ich reflektancja rejestrowana przez sensor zmienia się w czasie i jest zależna od kąta widzenia spektrometrów [6,9]. Na podstawie pomiarów przeprowadzonych w ciągu sześciu przelotów w latach 2008-2013 potwierdzono również zmienną gęstość strumienia cząsteczek [14]. Zmienność parametrów chemicznych i fizycznych pióropuszy oraz możliwość wnioskowania na ich podstawie o naturze aktywności kriowulkanicznej i biotycznych przyczynach obecności biomarkerów są ważnymi Table 1.…”

Section: Wprowadzenieunclassified

Detection of Biomarkers in Gas Plumes Using a Multi-Spectral Camera in the Proposed Enceladus Orbiter Mission (NASA)

Zalewska

Kotlarz

Kacprzak

et al. 2017

PAR

View full text Add to dashboard Cite

“…In Figure , we map the INMS data [ Perry et al , ] from these four flybys radially downward to the ground track to show the location relative to surface features. Figure (top) displays the scaled INMS data for 28 u while Figure (bottom) contains scaled INMS data for 44 u.…”

Section: Data Comparisonmentioning

confidence: 99%

“…Figure (top) displays the scaled INMS data for 28 u while Figure (bottom) contains scaled INMS data for 44 u. Each point corresponds to a data point from Perry et al []. In this view, the relationship between observed high‐density regions and proximity to physical features can be viewed.…”

Section: Data Comparisonmentioning

confidence: 99%

Modeling insights into the locations of density enhancements from the Enceladus water vapor jets

Crider

Perry

Waite

2015

J. Geophys. Res. Planets

View full text Add to dashboard Cite

Monte Carlo modeling of the vapor erupting from Enceladus' south polar region is presented to demonstrate the influence of physical characteristics of the emitted vapor on the distribution of particles at altitude. The modeled sources include localized jets and eruptions distributed along the surface features labeled “tiger stripes.” The modeling reveals that density enhancements are displaced from the source location caused not only by the angle of emission but also by superposition of material from nearby sources. The altitude of the superposition is mass dependent and contributes to differences observed in the mass 28 and mass 44 channels of the Cassini Ion and Neutral Mass Spectrometer (INMS) during Enceladus encounters. INMS data are well modeled using only the tiger stripe sources; however, certain regions require additional sources to reproduce some features of the data. In particular, an excess source is required for 44 unified atomic mass unit (u) on the Saturn‐facing hemisphere of Baghdad Sulcus. It is apparent in three parallel Cassini flybys. A relative decrease in the source rate is observed for mass 28 u for E14. The more diffuse nature of the 28 u INMS observations compared to the more collimated structure of the 44 u INMS observations is consistent with increased thermal spreading for low‐mass constituents of the plume.

show abstract

Cassini INMS measurements of Enceladus plume density

Cited by 26 publications

References 30 publications

An analytical model of sub‐Alfvénic moon‐plasma interactions with application to the hemisphere coupling effect

An analytical model of sub‐Alfvénic moon‐plasma interactions with application to the hemisphere coupling effect

Detection of Biomarkers in Gas Plumes Using a Multi-Spectral Camera in the Proposed Enceladus Orbiter Mission (NASA)

Modeling insights into the locations of density enhancements from the Enceladus water vapor jets

Contact Info

Product

Resources

About