Ozone loss rates in the Arctic stratosphere in the winter 1994/1995: Modelsimulations underestimate results of the Match analysis

We present box model simulations of ozone loss rates in the Arctic lower st ratosphere for the winter 1994/1995, The ozone loss was simulated along eac h of the trajectories of the Match data set for 1994/1995 to conduct a quan titative comparison with the Match results, The simulated ozone loss rates reach their maximum value of approximate to 4 ppb per sunlit hour at the en d of January, For this period and for potential temperatures below 475 K th e model results are in good agreement with the Match results, but for poten tial temperatures above 475 K the model underestimates the ozone loss rate by up to a factor of 2. This difference cannot be explained by known uncert ainties of the model. Enhanced ozone loss has also been observed in March 1 995 for potential temperatures below 475 K. These loss rates are also subst antially underestimated by the model, but are within the range of the model uncertainties, In particular, the ozone loss rates simulated for March 199 5 strongly depend on the extent of denitrification.