Authors: O R Cooper; D D Parrish; A Stohl; M Trainer; P Nédélec; V Thouret; J P Cammas; S J Oltmans; B J Johnson; D Tarasick; T Leblanc; I S McDermid; D Jaffe; R Gao; J Stith; T Ryerson; K Aikin; T Campos; A Weinheimer; M A Avery Journal: Nature Date: 2010-01-21 Impact factor: 49.962