Tropospheric Chemistry Modelling at BIRA-IASB

Tropospheric chemistry studies at BIRA-IASB are mainly concerned with the emissions, chemistry and role of chemical compounds involved in the global budget of oxidants (ozone, OH) and on the formation of organic aerosols in the troposphere.

Tropospheric ozone is an important greenhouse gas and a major pollutant causing respiratory deficiencies and decreased agricultural yields. Ozone photochemistry is closely related to the radicals HOx and NOx, as well to the cycle of reactive carbon in the troposphere. Ozone precursors include:

• the nitrogen oxides (NOx),
• carbon monoxide (CO) and
• the volatile organic compounds (VOC).

Their emissions are partly natural (vegetation, lightning, etc.), partly anthropogenic (use of fossil fuels, industries, fertilizers, vegetation fires, etc.).

Access to state-of-the-art emission inventories is provided at the recently developed GEIA/ACCENT emission portal.

An important class of organic compounds is represented by the Biogenic Volatile Organic Compounds (BVOC). On a global scale huge amounts of BVOCs are emitted by terrestrial vegetation (ca. 1150 Tg C per year). The BVOCs are a focus of our research at BIRA-IASB. Models are being developed and used in order to estimate their emissions as well as their role in the atmosphere.

The global budget and distribution of the major ozone precursors has also been the subject of several modeling studies at BIRA-IASB, in part in the framework of an international effort aiming to determine the possible future changes in the composition of the troposphere.

The inverse modeling of emissions of reactive gases is another important topic of research at BIRA-IASB.