Determining Tropospheric Concentrations of Trace Gases from Space

Background The new observations of the tropospheric distributions of trace gases such as NO2 (nitrogen dioxide), SO2 (sulphur dioxide), HCHO (formaldehyde), BrO (bromine monoxide) and O3 (ozone), retrieved from GOME (Global Ozone Monitoring Experiment) measurements, herald the opening of a new era for tropospheric production, as a result of agricultural activities, and above all by vehicles such as cars and aircraft. Many of these primary pollutants are transformed in the atmosphere to secondary pollutants, such as ozone or formaldehyde, via sequences involving literally hundreds of compounds and thousands of reactions. These pollutants are transported within the atmosphere to regions that can be far from the sources, and there give rise to profound ecological damage and change. Many of the pollutants are damaging to human health and natural ecosystems.