Liu Y., C. X. Liu, H. P. Wang, X. X. Tie, S. T. Gao, D. Kinnison, and G. Brasseur, 2009: Atmospheric tracers during the 2003–2004 stratospheric warming event and impact of ozone intrusions in the troposphere. Atmos. Chem. Phys., 9, 2157–2170.