<title>Detection of minor trace species in the atmosphere</title>

Abstract

The Global Ozone Monitoring Experiment (GOME) is an atmospheric chemistry instrument on-board the ERS-2 satellite which is able to measure a range of important atmospheric trace constituents on a global scale. Atmospheric UV/visible backscatter spectra obtained by the GOME spectrometer were used to retrieve column amounts of key trace species associated with biomass burning events and ozone hole chemistry. In particular, the column distributions of ozone (O<SUB>3</SUB>), nitrogen dioxide (NO<SUB>2</SUB>), formaldehyde (CH<SUB>2</SUB>O), and bromine-monoxide (BrO) were retrieved on an operational basis. The differential optical absorption spectroscopy technique (DOAS) is applied to backscatter spectra and yields slant column distributions of the aforementioned species. Additionally, the vertical columns of O<SUB>3</SUB> and NO<SUB>2</SUB> are provided. A strong enhancement of both the NO<SUB>2</SUB> and CH<SUB>2</SUB>O contents were detected during the severe biomass burning event in September 1997 in SE Asia. A higher NO<SUB>2</SUB> content is apparent over a large area within the smoke clouds, where formaldehyde is detected only in areas closest to combustion sources. BrO has been detected on a global scale and under Antarctic winter (ozone hole) conditions. The knowledge about the spatial distribution and the amount of BrO is of high relevance because BrO is a key species for the depletion of stratospheric ozone.