An atmospheric radiation model for Cerro Paranal - I. The optical spectral range S. Noll, W. Kausch, M. Barden, A. M. Jones, C. Szyszka, S. Kimeswenger and J. Vinther A&A, 543 (2012) A92 Published online: 03 July 2012 DOI: 10.1051/0004-6361/201219040