John Coxon¹, Robert Michael Shore², Mervyn P Freeman², Robert C Fear³, Stephen Daniel Browett³, Andrew W Smith⁴, Daniel K Whiter¹ and Brian J Anderson⁵, (1)University of Southampton, Southampton, United Kingdom, (2)British Antarctic Survey, Cambridge, United Kingdom, (3)University of Southampton, Southampton, SO14, United Kingdom, (4)Mullard Space Science Laboratory, Dorking, United Kingdom, (5)Johns Hopkins Univ, Laurel, MD, United States