CONCENTRATIONS AND DISTRIBUTIONS OF ATMOSPHERIC TRACE GASES

The tropospheric concentrations of most reactive trace gases have been found to vary in space and time. Many show systematic secular trends and seasonal variations, as well as consistent large scale patterns in their global concentration distributions, in particular when projected on the latitude by altitude plane. The measured trends and seasonal variations of the most important trace gases are presented and their origins briefly discussed. - Special emphasis will be given to the latitude by altitude distributions of CH4, C2H6, CO, O3 and NO measured during the STRATOZ III mission. All of these distributions show a latitudinal gradient with higher concentrations in the Northern Hemisphere due to anthropogenic emissions. Their vertical gradient is indicative of fast vertical convective transport during summer. - The short lived trace gases also show strong variations in the longitude by altitude plane. These will be demonstrated using the model calculated distribution of NO.