Ozone destructing spicies in relation to air traffic - concerns in connection to the governmental directives regarding ozone

The Swedish Defence Research Agency, FOI, and IVL, Swedish Environmental Research Institute have been commissioned by the Swedish Civil Aviation Administration, CAA, to perform a literature review aimed at clarifying the knowledge of today of the changes in ozone concentration in the trophopause region and at altitudes where a possible high speed supersonic aircraft fleet would operate. In addition, effects of aircraft pollutant emissions in this context are discussed. Since the atmosphere´s composition varies with altitude, the effects of aircraft pollutant emissions vary depending on the discharge altitude. Besides, the latitude and the season are of importance. One conclusion is that the NOx emissions from air traffic will increase or decrease the ozone formation rate depending on the surrounding NOx concentration. An assessment of a future high-speed supersonic aircraft fleet´s effects on the atmospheric ozone concentration is reported in the IPCC-report of 1999. The largest effect is observed at 45°N, where the change of the ozone column in July is estimated to -0.4%. If only the emissions of the high-speed fleet is considered the result is -1.3%, while the conventional aviation provide a change of +0.9%. The general conclusion from the IPCC report is that the ozone formation increase in the trophopause region due to NOx emissions of conventional aviation. Concerning the effect of a future fleet of civil high-speed supersonic aircraft on the total ozone column of a future fleet of civil high-speed supersonic aircraft, two studies point out differences compared to the IPCC report. Both suggest that the emissions would increase the ozone column.