NORTH-ATLANTIC AIR-TRAFFIC WITHIN THE LOWER STRATOSPHERE - CRUISING TIMES AND CORRESPONDING EMISSIONS

This study estimates cruising times and related pollutant emissions (N O(x), CO, HC) and H2O Of today's aircraft fleet within the troposphere and stratosphere performed for the North Atlantic region in between 4 5-degrees-N, 65-degrees-N, 10-degrees-W, and 50-degrees-W for the year s 1989, 1990, and 1991. The tropopause surface distribution is determi ned through analysis of assimilated data. Both conventional lapse rate and potential vorticity criteria are employed to determine the locati on of the tropopause surface. These data combined with air traffic sta tistics are used to evaluate cruising times within the troposphere and stratosphere separately. The study shows an average of about 44% of t he cruising time of the aircraft above the North Atlantic flown within the stratosphere. Based on emission indices of aircraft engines, the emission rates of NO(x) (in mass units of NO2) into the stratosphere a nd troposphere in the given region result in 0.26 and 0.33 x 10(-12) k g M-2 s-1, respectively.