Abstract

The changes in the composition of the atmosphere are predicted to be very fast compared to the usual geological time scales but they are still subtle and slow from the point of view of monitoring. Only long-term monitoring can be hoped to reveal the trends of anthropogenic origin from the natural variations. Moreover, the change may be small in the total amount of a trace gas but can still be seen clearly in the vertical distribution. The case of ozone is a good example. The stratospheric depletion of ozone due to CFC gases is largest at about 40 km altitude whereas the tropospheric ozone is predicted even to increase. It is therefore evident that in the monitoring of the atmosphere we need instruments which have global coverage, stable operation and ability to vertical resolution.

© 1990 Optical Society of America