Monitoring atmospheric phenomena on Titan M. Hirtzig, A. Coustenis, E. Gendron, P. Drossart, A. Negrão, M. Combes, O. Lai, P. Rannou, S. Lebonnois and D. Luz A&A, 456 2 (2006) 761-774 Published online: 31 August 2006 DOI: 10.1051/0004-6361:20053381