HR: 11:35h
AN: A32C-05    [Abstracts]
TI: Arctic Ozone Loss and Climate Change - Large Ozone Loss in Arctic Winter 2004/2005
AU: * Rex, M
EM: mrex@awi-potsdam.de
AF: Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, Potsdam, 14473 Germany
AB: Based on measurements of the Arctic ozonesonde network we have quantified the degree of chemical ozone loss in the Arctic polar vortex for most winters since the early 1990ies. Based on this data and meteorological analyses we show a close quantitative relation between the average volume of air below the temperature threshold for PSC formation (Vpsc) and the overall loss of ozone during winter. With this we have quantified the potential impact of changes in stratospheric climate on Arctic ozone loss. We find that ~15 DU additional ozone loss can be expected per Kelvin cooling of the Arctic lower stratosphere. The ability of current 3d models of the Arctic stratosphere to reproduce the climate sensitivity of Artic ozone loss is discussed. We show that over the past 40 years the maximum potential for formation of polar stratospheric clouds increased steadily by more than a factor of three. This change in climate conditions largely contributed to the occurrence of severe Arctic ozone loss during the past decade. Unusually cold meteorological conditions occurred during Arctic winter 2004/2005. The value of Vpsc exceeded the previous record from winter 1999/2000 by 30%. We show that chemical ozone losses were unusually large and the total column loss reached record values. It will be discussed how the winter relates to the long term trend towards colder Arctic winters noted above, and the empirical relation between ozone loss and Vpsc.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere: composition and chemistry
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3349 Polar meteorology
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005