Owen Cooper launches an ozonesonde. Data from Sable Island were combined with O3 data collected at other sites as part of an international study of O3 profiles (see Cooper et al. 2001). The NARE 97 program revealed how airstreams within mid-latitude cyclones draw trace gases from the polluted continental boundary layer, mid-troposphere and stratosphere of North America and export them to the troposphere of the North Atlantic Ocean. These data also established that strong stratospheric intrusions occur over Sable Island.