References of "Baines, K. H"
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See detailDynamic auroral storms on Saturn as observed by the Hubble Space Telescope
Nichols, J. D.; Badman, S. V.; Baines, K. H. et al

in Geophysical Research Letters (2014), 41

We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission ... [more ▼]

We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ˜330% rigid corotation from near ˜01 h LT toward ˜08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current. [less ▲]

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See detailAuroral counterpart of magnetic field dipolarizations in Saturn's tail
Jackman, C. M.; Achilleos, N.; Bunce, E. J. et al

in American Geophysical Union, Fall Meeting 2011, abstract #SM14A-07 (2011, December 01)

Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations ... [more ▼]

Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations can be initially identified from the magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially stretched configuration to a more dipolar field topology. The highly stretched geometry of the kronian magnetotail lobes gives rise to a tail current which flows eastward (dusk to dawn) in the near equatorial plane across the centre of the tail. During reconnection and associated dipolarization of the field, the inner edge of this tail current can be diverted through the ionosphere, in a situation analogous to the substorm current wedge picture at Earth [McPherron et al. 1973]. We present a picture of the current circuit arising from this tail reconfiguration, and outline the equations which govern the field-current relationship. We show a number of examples of dipolarizations as identified in the Cassini magnetometer data and use this formalism to calculate limits for the ionospheric current density that would arise for these examples. In addition to the magnetometer data, we also present data from the Cassini VIMS and UVIS instruments which have observed small 'spots' of auroral emission lying near the main oval - features thought to be associated with dipolarizations in the tail. We compare the auroral intensities as predicted from our calculation with the observed spot sizes and intensities. [less ▲]

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See detailSaturn's aurora as viewed by Cassini VIMS
Melin, H.; Stallard, T.; Badman, S. V. et al

Conference (2011, December 01)

The stunning views of the kronian aurora captured by the Visual and Infrared Imaging Spectrograph (VIMS) onboard the Cassini spacecraft continues to provide crucial observations of the fervent interaction ... [more ▼]

The stunning views of the kronian aurora captured by the Visual and Infrared Imaging Spectrograph (VIMS) onboard the Cassini spacecraft continues to provide crucial observations of the fervent interaction between the upper atmosphere and the magnetosphere of Saturn. Here, we present recent findings of VIMS auroral research, which includes both statistical studies and case studies of auroral events and morphology. In addition to stand-alone observations, there is a small subset of VIMS observations during which UVIS was also acquiring data. These observations enable the comparison between observations of H, H2 in the ultraviolet and H3+ in the infrared that are both spatially overlapping and temporally simultaneous. Whilst emission tends to coincide for these three species on the main oval, there are significant differences both pole-ward and equator-ward, such that observations of H and H2 is generally a poor proxy for emissions of H3+. VIMS is sensitive to infrared thermal emission from the H3+ molecule, which is formed very efficiently via the ionisation of H2. Therefore, the morphology of H3+ emission becomes a tracer of energy injected into the upper atmosphere - the most striking of which is auroral particle precipitation. [less ▲]

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See detailSimultaneous Cassini VIMS and UVIS observations of Saturn's southern aurora
Melin, H.; Stallard, T.; Miller, S. et al

in EPSC-DPS Joint Meeting 2011 (2011, October 01)

Here, temporally simultaneous and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. The pointing is fixed at a constant local time of 04:55, covering ... [more ▼]

Here, temporally simultaneous and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. The pointing is fixed at a constant local time of 04:55, covering latitudes between 64°S and 82°S and longitudes between 127° and 186°. The spatial resolution is high, with 1 mrad covering ˜300 km, such that only a small part of the pre-dawn aurora is observed. Ultraviolet auroral H and H2 emissions from UVIS are compared to infrared H+3 emission from VIMS. The auroral emission is structured into three arcs - H, H2 and H+3 are morphologically identical in the bright main auroral oval (˜73°S), but there is an equatorward arc that is seen predominantly in H (˜70°S), and a poleward arc (˜74°S) that is seen mainly in H2 and H+3 . These observations indicate that, for the main auroral oval, the UV emission is a good proxy for the infrared H+3 morphology (and vice versa), but for emission either poleward or equatorward this is no longer true. Hence, given the highly dynamic nature of the aurora of Saturn, simultaneous UV/IR observations are crucial for completing the picture of how the atmosphere interacts with the magnetosphere. [less ▲]

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See detailSimultaneous Cassini VIMS and UVIS observations of Saturn's southern aurora: Comparing emissions from H, H2 and H3+ at a high spatial resolution
Melin, H.; Stallard, T.; Miller, S. et al

in Geophysical Research Letters (2011), 38

Here, for the first time, temporally coincident and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. Ultraviolet auroral H and H[SUB]2[/SUB] emissions ... [more ▼]

Here, for the first time, temporally coincident and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. Ultraviolet auroral H and H[SUB]2[/SUB] emissions from UVIS are compared to infrared H[SUB]3[/SUB][SUP]+[/SUP] emission from VIMS. The auroral emission is structured into three arcs - H, H[SUB]2[/SUB] and H[SUB]3[/SUB][SUP]+[/SUP] are morphologically identical in the bright main auroral oval (˜73°S), but there is an equatorward arc that is seen predominantly in H (˜70°S), and a poleward arc (˜74°S) that is seen mainly in H[SUB]2[/SUB] and H[SUB]3[/SUB][SUP]+[/SUP]. These observations indicate that, for the main auroral oval, UV emission is a good proxy for the infrared H[SUB]3[/SUB][SUP]+[/SUP] morphology (and vice versa), but for emission either poleward or equatorward this is no longer true. Hence, simultaneous UV/IR observations are crucial for completing the picture of how the atmosphere interacts with the magnetosphere. [less ▲]

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