20 July 2001

Partners Scientific goals Workshop
Background Documents Data Directory

Background of the project

Tropospheric ozone has a dual role with respect to climatic changes. Ozone is itself a greenhouse gas and it also plays a key role in the production of the hydroxyl radical (OH), which controls the lifetime of many climatically important tropospheric gases. Tropospheric ozone and OH are produced as a result of photochemical processes, through reactions involving ozone precursors. The proposed project is defined in order to answer three main questions : first, can the surface emissions of ozone precursors, and their variability be accurately quantified? Second, how should the current observations of chemical species be optimally coupled with chemistry-transport models (CTMs) to quantify the global budgets of ozone precursors and ozone ? Third, how do future changes in surface emissions and proposed future scenarios influence the lifetime of greenhouse gases and ozone distribution ? The project will provide a quantitative basis for emissions, distributions and evolution of chemical tropospheric species for discussions related to policies aimed at improving the quality of air or at reduction of greenhouse species anthropogenic emissions