OZONE MEASUREMENTS IN A TROPOPAUSE FOLD ASSOCIATED WITH A CUTOFF LOW SYSTEM

The two-dimensional structure of a tropopause fold that formed on the western flank of a cut-off cyclone over the western United States is e xamined through time series of vertical ozone profiles made using the NOAA Aeronomy Laboratory's Differential Absorption Lidar (DIAL) system at Fritz Peak Observatory (39.9 degrees N, 105.3 degrees W, 2.68 km a bove sea level). The observations are compared to calculated potential vorticity fields, and the net influx of ozone to the troposphere is e stimated to be similar to 5.5 x 10(32) molecules assuming that the fol d is irreversibly mixed into the troposphere below 8.5 km.