In the troposphere, ozone concentrations are regulated, among others, by essentially photochemical mechanisms that explain the ozone concentrations during summer; yet opinions differ as to the processes that control the maximum records in Spring, partly because of the difficulty in separating the contributions to processes of global and local/regional scale, including dynamic competitive processes to photochemical processes, as phenomena associated with stratosphere-troposphere exchange (STE) and to vertical tropospheric dynamic mechanisms (e.g. cut-off lows).

The main objectives of this project are to identify and characterize:
– the no photochemical origin of some ozone events;
– and the contribution of changes in atmospheric circulation for the decrease of the total ozone column at mid-latitudes.

Thus it is intended that the project results help the Portuguese authorities to justify, science-based, ozone events in which the control of emissions of its precursors in the boundary layer is inefficient, and thus to meet what is required by the European Directive 2008/50/EC and by the Law-Decree 102/2010, of 23rd of September of the Portuguese Republic, on several air pollutants, including tropospheric ozone.

UFP participant:
– Prof. Dr. Nelson Barros

Submitting entity:
– Universidade Nova de Lisboa

Project supported by:
– Fundação para a Ciência e a Tecnologia