STRATOSPHERIC FTS

Fourier-transform spectroscopy has played a prominent role over the pa st quarter century in Furthering our understanding of the properties o f the upper atmosphere and, in particular, in elucidating the processe s that control the chemical and dynamical stability of the stratospher e. The first detections of HCl and HF in the early 1970s led to the di scovery of the discrimination between anthropogenic and natural emissi ons of halogens which the changing ratio of these two trace compounds provided. More recently, the comparison, against model predictions of refined and revised measurements of the altitude-dependent budgets of the source and reservoir components of the chlorine, fluorine and nitr ogen families of trace molecular species, has formed the basis of well -constrained rests against which the effectiveness of international pr otocols to control the release of industrial chemicals can be assessed . The contribution of the FTS methods to these and other global atmosp heric environmental problems has been invaluable. Experimentalists hav e responded to the challenge of adapting Fourier-transform techniques to the often difficult environments of spacecraft, balloon, aircraft o r remote ground-based sites in order to exploit the advantages afforde d by making observations from these platforms. These developments and the current status of the results obtained from them are described.