Extraordinary field-aligned current signatures in Saturn's high-latitude magnetosphere: Analysis of Cassini data during Revolution 89 - Bunce,EJ; Cowley,SWH; Talboys,DL; Dougherty,MK; Lamy,L; Kurth,WS; Schippers,P; Cecconi,B; Zarka,P; Arridge,CS; Coates,AJ (JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2010)