Modelling Chemistry-Aerosols-Climate interactions

An important topic in our group is studying the interactions between atmospheric constituents and other components of the earth system. We study greenhouse gas abundances and lifetimes, and feedbacks between air pollution and climate. An important compound in the atmosphere is the hydroxyl radical OH, the 'detergent' of the atmosphere, which reacts with many compounds such as CO and CH₄ and controls their atmospheric lifetimes.

We also study aerosols, tiny particles that originate from natural processes (wind-blown desert dust and sea salt, volcanic eruptions, emissions from vegetation and plankton) and from human activities (fossil fuel burning, agriculture, traffic). Aerosols are an important factor in the Earth's radiation budget. Depending on their chemical composition, aerosols may reflect (e.g. sulfate) or absorb (e.g. black carbon) solar radiation. This is called the 'direct aerosol effect'. Another effect of aerosols is related to the fact that cloud drops grow on aerosol. The amount of aerosol influences the reflectivity and the potential for rain formation of a cloud, and is therefore indirectly affecting the climate system.

We use the TM5 global transport and chemistry model to simulate greenhouse gas and aerosol concentrations and atmospheric chemistry. TM5 is also imbedded in the EC-Earth climate model, which is used to investigate the interactions between climate and the composition of the atmosphere.

For more information check out this poster about modelling activities within APCG.