Statistical characteristics of field-aligned currents in Saturn's nightside magnetosphere
Talboys, D. and Bunce, E.J. and Cowley, S.W.H. and Arridge, Chris S. and Coates, Andrew J. and Dougherty, M.K. (2011) Statistical characteristics of field-aligned currents in Saturn's nightside magnetosphere. Journal of Geophysical Research: Space Physics 116 , ISSN 0148-0227.
During 2008, the Cassini spacecraft traversed Saturn's high-latitude field-aligned current systems on sequential north-south periapsis passes in the nightside magnetosphere. Two types of current systems have previously been identified, associated with antisymmetric azimuthal field signatures in the northern and southern hemispheres. The first exhibits exclusively "lagging" field morphology, while the second also includes an equatorward interval of "leading" field. Here we report the statistical characteristics of these currents, their strength, ionospheric location, and relationship to plasma boundaries. From high to low latitude, the first type comprises a downward current followed by an upward current, whose strengths are similar to 0.5-3.5 MA per radian of azimuth. The downward current maps to ionospheric colatitudes of similar to 13.5 degrees and similar to 16 degrees in the north and south, respectively, usually centered in the outer magnetosphere, while the upward current maps to similar to 16.5 degrees and similar to 19 degrees in the north and south, located within the ring current region. The second type comprises a distributed downward current of similar to 1-2 MA rad(-1) flowing in the open field and outer magnetosphere regions, followed by an upward current of similar to 2.5-5 MA rad(-1) mapping to similar to 15.5 degrees and similar to 18 degrees in the north and south, corresponding to the outer magnetosphere and outer ring current, and a further downward current of similar to 1-2.5 MA rad(-1) mapping to similar to 17.5 degrees and similar to 20 degrees in the north and south, corresponding to the inner ring current.
|School:||Birkbeck Schools and Departments > School of Science > Earth and Planetary Sciences > UCL/Birkbeck Centre for Planetary Sciences|
|Date Deposited:||20 Jun 2011 07:35|
|Last Modified:||17 Apr 2013 12:20|
Additional statistics are available via IRStats2.