GOME ozone columns at polar sunrise

Abstract

GOME ozone columns near the poles can be derived only half of the year, since measurements of the backscattered Sun light are only possible when the Sun is illuminating the Earth. The sunrise at the poles in spring induces photochemical reactions, which, in combination with low temperatures, lead to destruction of ozone. The strong polar vortex at the South Pole prevents mixing of ozone, leading to the formtaion of an `ozone hole'. The North Pole shows similar processes, but much weaker due to the less persistent North polar vortex. Observing ozone during polar sunrise, is of great importance for the study of these processes. However, the derivation of GOME ozone values at polar sunrise, which is based on theoretical knowledge about radiation transport in the atmosphere, is difficult, because of the very long light paths involved. This paper studies some aspects of the validity of GOME ozone columns at polar sunrise, using the multi-wavelength information embedded in GOME Earth-shine spectra.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry