Early unusual ozone loss during the Arctic winter 2002/2003 compared to other winters
[摘要] Ozone loss during the winter 2002/2003 has been evaluated from comparisonsbetween total ozone reported by the SAOZ network and simulated in passivemode by both REPROBUS and SLIMCAT. Despite the fact that the two models havea different approach to calculate the descent inside vortex, bothevaluations provide similar results 18±4% using REPROBUSand 20±4% using SLIMCAT and show that the loss startedaround mid-December, at least ten to twenty days earlier than during any ofthe previous eleven winters, except 1993/1994. This unusual behaviour isconsistent with the low temperatures reported in the stratosphere as well tothe signature of early chlorine activation indicated by ground-based,balloon and satellite observations.
A significant ozone loss is also simulated by the current versions of twomodels, but of lesser amplitude compared to SAOZ, 13±2%for REPROBUS and 16±2% for SLIMCAT, the underestimationbeing already observed by mid-January. The early ozone depletion captured byboth model show that chemical depletion did indeed take place in December,predominantly at the illuminated edge of the distorted vortex, but thereason for the underestimation compared to the observations and thedifferences among the models have still to be investigated.
