BibTex format
@article{Meredith:2014:10.1002/2013JA019598,
author = {Meredith, CJ and Alexeev, II and Badman, SV and Belenkaya, ES and Cowley, SWH and Dougherty, MK and Kalegaev, VV and Lewis, GR and Nichols, JD},
doi = {10.1002/2013JA019598},
journal = {Journal of Geophysical Research: Space Physics},
pages = {1994--2008},
title = {Saturn's dayside ultraviolet auroras: Evidence for morphological dependence on the direction of the upstream interplanetary magnetic field},
url = {http://dx.doi.org/10.1002/2013JA019598},
volume = {119},
year = {2014}
}
RIS format (EndNote, RefMan)
TY - JOUR
AB - We examine a unique data set from seven Hubble Space Telescope (HST) “visits” that imagedSaturn’s northern dayside ultraviolet emissions exhibiting usual circumpolar “auroral oval” morphologies,during which Cassini measured the interplanetary magnetic field (IMF) upstream of Saturn’s bow shock overintervals of several hours. The auroras generally consist of a dawn arc extending toward noon centered near~15° colatitude, together with intermittent patchy forms at ~10° colatitude and poleward thereof, locatedbetween noon and dusk. The dawn arc is a persistent feature, but exhibits variations in position, width, andintensity, which have no clear relationship with the concurrent IMF. However, the patchy postnoon aurorasare found to relate to the (suitably lagged and averaged) IMF Bz, being present during all four visits withpositive Bz and absent during all three visits with negative Bz. The most continuous such forms occur in thecase of strongest positive Bz. These results suggest that the postnoon forms are associated with reconnectionand open flux production at Saturn’s magnetopause, related to the similarly interpreted bifurcated auroral arcstructures previously observed in this local time sector in Cassini Ultraviolet Imaging Spectrograph data,whose details remain unresolved in these HST images. One of the intervals with negative IMF Bz howeverexhibits a prenoon patch of very high latitude emission extending poleward of the dawn arc to the magnetic/spin pole, suggestive of the occurrence of lobe reconnection. Overall, these data provide evidence ofsignificant IMF dependence in the morphology of Saturn’s dayside auroras.
AU - Meredith,CJ
AU - Alexeev,II
AU - Badman,SV
AU - Belenkaya,ES
AU - Cowley,SWH
AU - Dougherty,MK
AU - Kalegaev,VV
AU - Lewis,GR
AU - Nichols,JD
DO - 10.1002/2013JA019598
EP - 2008
PY - 2014///
SN - 2169-9402
SP - 1994
TI - Saturn's dayside ultraviolet auroras: Evidence for morphological dependence on the direction of the upstream interplanetary magnetic field
T2 - Journal of Geophysical Research: Space Physics
UR - http://dx.doi.org/10.1002/2013JA019598
UR - http://hdl.handle.net/10044/1/27484
VL - 119
ER -