PATTERNS OF TROPOSPHERIC OZONE IN THE PRE-ALPINE REGION

In view of a reassessment of air quality standards for ozone, frequently exceeded in the pre-Alpine region, concentrations have been measured at different sites and altitudes during 30 months. Data analysis allows the identification of the different mechanisms influencing ozone distribution. In addition to photochemical processes on a local and regional scale, exchange processes of thermal or dynamic origin (e.g. foehn) between the lower layers and the free troposphere play an important role in this region. Episodic instrusions from the stratosphere are also described. © 1990.