Stratospheric trace gases
Event K085

NIWA
Private Bag 50061
Omakau
Central Otago
Dr Stephen Wood
Telephone (03) 447 3411
Facsimile (03 447 3348
email: [email protected]

The relative stability of the southern polar vortex creates conditions for enhanced chemical changes in the stratosphere that are quite remarkable. The depletion of ozone that these conditions cause in the spring has direct effects on the Antarctic environment but its potential feedback to the radiative forcing that drives atmospheric circulation are important in understanding atmospheric change for the whole Southern Hemisphere. This programme aims to improve the combination of ground based trace gas measurements available from Arrival Heights and Scott Base, with collaboration from other research groups. Combined measurements of closely related chemically active gases, and of less reactive gases that act as tracers, can identify transport and chemical processes in the atmosphere. A comparison of data with modelling calculations enables physical insight into these processes. In particular the work is directed towards understanding the reasons for, and the significance of, the changes with time in stratospheric nitrogen, chlorine and bromine compounds that are active in ozone chemistry.