Chemical ozone loss in Arctic and Antarctic polar winter/spring season derived from SCIAMACHY limb measurements 2002–2009

Abstract

Abstract. Stratospheric ozone profiles are retrieved for the period 2002–2009 from SCIAMACHY measurements of limb-scattered solar radiation in the Hartley and Chappuis absorption bands of ozone. This data set is used to determine the chemical ozone loss in both the Arctic and Antarctic polar vortices using the vortex average method. The chemical ozone loss at isentropic levels between 450 K and 600 K is derived from the difference between observed ozone abundances and the ozone modelled considering diabatic cooling, but no chemical ozone loss. The results show chemical ozone losses of up to 20–40% between the beginning of January and the end of March inside the Arctic polar vortex. Strong inter-annual variability of the Arctic ozone loss is observed, with the cold winters 2004/2005 and 2006/2007 showing the largest chemical ozone losses. The ozone mass loss inside the polar vortex is also estimated. In the coldest Arctic winter 2004/2005 the total ozone mass loss is about 30 million tons inside the polar vortex between the 450 K and 600 K isentropic levels from the beginning of January until the end of March. The Antarctic vortex averaged ozone loss as well as the size of the polar vortex do not vary much from year to year. At the 475 K isentropic level ozone losses of 70–80% between mid-August and mid-November are observed every year inside the vortex, also in the anomalous year 2002. The total ozone mass loss inside the Antarctic polar vortex between the 450 K and 600 K isentropic levels is about 55–75 million tons for the period between mid-August and mid-November. Comparisons of the vertical variation of ozone loss derived from SCIAMACHY observations with several independent techniques for the Arctic winter 2004/2005 show very good agreement.