During the last decades it has become increasingly apparent that the chemical composition of the atmosphere is changing on a global scale, and that human activity is partly responsible for this change.
Ozone plays a central role in the atmospheric chemistry.
In order to understand the processes which determine the physical and the photochemical behavior of the atmosphere, detailed global measurements of the amount, and of the horizontal and vertical distribution of ozone and of the other gases is necessary. A comparison of ozone trend measurements with simulation models still shows large discrepancies. Consequently, there is a clear need to increase our understanding of the central processes involved in atmospheric chemistry, and it is vitally important to monitor and investigate global budgets of ozone and other chemically important gases. In order to fulfill this need, accurate altitude-resolved data are necessary. The primary measurement objective of GOME is the measurement of total column amounts and profiles of ozone and of other gases involved in ozone photo chemistry.