Magnetic Induction Responses of Jupiter's Ocean Moons Including Effects from Adiabatic Convection

Vance, S.; Bills, B. G.; Cochrane, Corey J.; Soderlund, K. M.; Pérez, Nelly Diego; Styczinski, Marshall J.; Paty, C. S.

doi:10.1002/essoar.10502420.2

Cited by 10 publications

(26 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These include the uniform icy shell thickness due to the efficient meridional heat transport of Europa’s ocean predicted in our simulations. The small meridionally variations of salinity predicted here may similarly be observable in future missions as well through its magnetic signal 49 although this may be challenging. In addition to these observable predictions, the eddy diffusivity and viscosity coefficients—estimated here from an eddy-resolving simulation of Europa’s ocean—should help in estimating ocean heat generation due to tides 41 .…”

Section: Discussionmentioning

confidence: 75%

Dynamic Europa ocean shows transient Taylor columns and convection driven by ice melting and salinity

Ashkenazy

Tziperman

2021

Nat Commun

View full text Add to dashboard Cite

The deep (~100 km) ocean of Europa, Jupiter’s moon, covered by a thick icy shell, is one of the most probable places in the solar system to find extraterrestrial life. Yet, its ocean dynamics and its interaction with the ice cover have received little attention. Previous studies suggested that Europa’s ocean is turbulent using a global model and taking into account non-hydrostatic effects and the full Coriolis force. Here we add critical elements, including consistent top and bottom heating boundary conditions and the effects of icy shell melting and freezing on ocean salinity. We find weak stratification that is dominated by salinity variations. The ocean exhibits strong transient convection, eddies, and zonal jets. Transient motions organize in Taylor columns parallel to Europa’s axis of rotation, are static inside of the tangent cylinder and propagate equatorward outside the cylinder. The meridional oceanic heat transport is intense enough to result in a nearly uniform ice thickness, that is expected to be observable in future missions.

show abstract

Section: Discussionmentioning

confidence: 75%

Dynamic Europa ocean shows transient Taylor columns and convection driven by ice melting and salinity

Ashkenazy

Tziperman

2021

Nat Commun

View full text Add to dashboard Cite

show abstract

“…For additional background, we refer the reader to the Supporting Information of Vance et al. (2021), where it is shown that the complex response function

A_{k} e^{- i ϕ_{k}}

is a special case of the complex amplitude

A_{n}^{e}

when

n = 1

, representing the dipolar response to a uniform excitation field. Here, we negate the exponent of the complex response function, to match the definitions of past work by Zimmer et al.…”

Section: Induction Models Of Miranda Ariel and Umbrielmentioning

confidence: 99%

“…This conservative upper limit to ionospheric conductance serves as a stress test for the detection of possible oceans within the moons. For simplicity, we set a fixed height of the ionosphere as also done in previous studies (Hartkorn & Saur, 2017; Vance et al., 2021). Our modeled thickness of the ionosphere is 300 km for Ariel and Umbriel.…”

Section: Induction Models Of Miranda Ariel and Umbrielmentioning

confidence: 99%

In Search of Subsurface Oceans Within the Uranian Moons

et al. 2021

Self Cite

View full text Add to dashboard Cite

The Galileo mission to Jupiter discovered magnetic signatures associated with hidden subsurface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate from electrically conductive layers within the moons and are driven by Jupiter's strong time‐varying magnetic field. The ice giants and their moons are also ideal laboratories for magnetic induction studies. Both Uranus and Neptune have a strongly tilted magnetic axis with respect to their spin axis, creating a dynamic and strongly variable magnetic field environment at the orbits of their major moons. Although Voyager 2 visited the ice giants in the 1980s, it did not pass close enough to any of the moons to detect magnetic induction signatures. However, Voyager 2 revealed that some of these moons exhibit surface features that hint at recent geologically activity, possibly associated with subsurface oceans. Future missions to the ice giants may therefore be capable of discovering subsurface oceans, thereby adding to the family of known “ocean worlds” in our Solar System. Here, we assess magnetic induction as a technique for investigating subsurface oceans within the major moons of Uranus. Furthermore, we establish the ability to distinguish induction responses created by different interior characteristics that tie into the induction response: ocean thickness, conductivity and depth, and ionospheric conductance. The results reported here demonstrate the possibility of single‐pass ocean detection and constrained characterization within the moons of Miranda, Ariel, and Umbriel, and provide guidance for magnetometer selection and trajectory design for future missions to Uranus.

show abstract

“…Similar to the hypothesized Triton ocean, the icy Galilean moons possess subsurface oceans with conductances on the order of

1 0^{4}

S, sustained by thermal contributions from accretional and radiogenic sources in addition to tidal heating—except for Callisto, which receives negligible tidal heat (see, e.g., Schilling et al., 2007; Seufert et al., 2011; Saur et al., 2015; Vance et al., 2021). Each of these moons displays strong inductive responses to the changing magnetic field of their ambient magnetospheric environments (e.g., Kivelson, 2000; Saur et al., 2010) which, outside of their conducting layers, are well‐represented using a magnetic moment located at the center of each moon (e.g., Zimmer et al., 2000).…”

Section: Methodology: the Aikef Hybrid Modelmentioning

confidence: 99%

Triton’s Variable Interaction With Neptune’s Magnetospheric Plasma

et al. 2021

Self Cite

View full text Add to dashboard Cite

Neptune's largest moon Triton (radius 𝐴𝐴 𝐴𝐴𝑇𝑇 = 1, 353 km) is thought to be an erstwhile Kuiper belt object that was captured by the ice giant (Agnor & Hamilton, 2006). Orbiting at a radial distance of 𝐴𝐴 14.4𝑅𝑅𝑁𝑁 (radius of Neptune 𝐴𝐴 𝐴𝐴𝑁𝑁 = 24, 622 km), Triton is always located within Neptune's magnetosphere (Curtis & Ness, 1986;Mejnertsen et al., 2016;Ness et al., 1989;Richardson, 1993). The moon's highly inclined orbit-tilted nearly 𝐴𝐴 157 • with respect to its parent planet's rotational equator-results in a retrograde orbital motion around Neptune. Triton possesses the second-most dense moon atmosphere in the solar system after Titan (Broadfoot et al., 1989;Strobel et al., 1990;Strobel & Zhu, 2017). Mainly comprised of neutral 𝐴𝐴 N2 , its maximum surface number density is on the order of 𝐴𝐴 10 15 cm −3 , with a scale height between 10 and 70 km (Broadfoot et al., 1989). Additionally, trace gases including methane are present, with surface densities below 𝐴𝐴 10 11 cm −3 (e.g., Summers & Strobel, 1991;Trafton, 1984;Krasnopolsky et al., 1992). This neutral envelope is predominantly ionized by a combination of magnetospheric electron impacts and photoionization, resulting in an ionospheric Pedersen conductance that may exceed 𝐴𝐴 10 4 S (Strobel et al., 1990). In addition to this global atmosphere, observations during the Voyager 2 encounter of Neptune in 1989 indicated localized, geyser-like vapor plumes emanating from the surface to an altitude of ∼10 km (Smith et al., 1989). Since the moon's interior is likely differentiated in a hydrosphere and rocky mantle, it is possible that these plumes originate from a global, deep ocean sustained via radiogenic heating and/or tidal forcing (Nimmo & Spencer, 2015).

show abstract

Magnetic Induction Responses of Jupiter's Ocean Moons Including Effects from Adiabatic Convection

Cited by 10 publications

References 39 publications

Dynamic Europa ocean shows transient Taylor columns and convection driven by ice melting and salinity

Dynamic Europa ocean shows transient Taylor columns and convection driven by ice melting and salinity

In Search of Subsurface Oceans Within the Uranian Moons

Triton’s Variable Interaction With Neptune’s Magnetospheric Plasma

Contact Info

Product

Resources

About