Chlorine activation and ozone loss as observed by ground-based FTIR measurements at Kiruna since winter 1993/94 and as calculated with model simulations - Blumenstock, T.; Barthlott, S.; Gisi, M.; Hase, F.; Kirner, O.; Kohlhepp, R.; Raffalski, U.; Reddmann, Th.; Rex, M.; Ruhnke, R.; Sinnhuber, B. M. (2012)