Aircraft Ozone and Carbon Monoxide Measurements During ACE-1

R. D. Schillawski, A. S. H Prevot, and G. L. Kok (Research Aviation Facility, National Center for Atmospheric Research*, P. O. Box 3000, Boulder CO 80307-3000).

Boundary layer ozone concentrations were typically 15-25 ppbv and those of carbon monoxide typically 60-75 ppbv during the flights out of Tasmania during the ACE-1 project (November and December 1995). At highter altitudes, typical ozone concentrations increased to 30-55 ppbv, while typical carbon monoxide concentrations increased only slightly, if at all. The lowest ozone concentrations, down to 10 ppbv, were found in the tropical boundary layer during the transect flights before and after the Tasmanian portion of the project. Carbon monoxide concentrations during these transects were typically in the 40-80 ppbv range in the southern hemisphere, but increased with latitude north of the equator to 80-140 ppbv at the northern-most extent of both transects. During the two Lagrangian experiments, concentrations of both ozone and carbon monoxide in the boundary layer varied only slightly.

Factors affecting instrument performance and measurement accuracy, and some comparison of these measurements with others will be discussed.

* The National Center for Atmospheric Research is sponsored by the National Science Foundation.