Understanding the implications of changes in atmospheric chemistry for air quality and for climate.
The chemistry of the atmosphere determines the concentrations and distributions of the reactive greenhouse gases (methane, nitrous oxide, ozone) and stratospheric ozone. In the stratosphere, ozone is an important driver of the dynamics and absorbs harmful ultraviolet radiation. At the Earth's surface, some of these reactive gases, such as ozone, are damaging to human and plant health.
In Climate Chemistry and Ecosystems, our focus is on the evolution of atmospheric chemistry associated with changes in climate; changes in emissions of tropospheric ozone precursors, and stratospheric ozone depleting substances. In particular, we examine atmospheric chemistry on a decadal-to-centennial timescale. Within the Met Office Hadley Centre, atmospheric chemistry is included in the Met Office Unified Model using the United Kingdom Chemistry and Aerosols (UKCA) model. Currently, tropospheric and stratospheric chemistry are treated separately, although our aim is to combine these into a 'whole-atmosphere' chemistry and dynamical model, in collaboration with Cambridge University. There are a variety of tropospheric chemistry schemes within '. The simplest chemistry scheme, named 'Standard', treats up to C3 non-methane hydrocarbons and is the default configuration of HadGEM2. The most comprehensive treatment of tropospheric chemistry, called 'Extended', includes isoprene, terpene, and aromatic chemistry.
A major research interest within Climate Chemistry and Ecosystems is the interactions between the atmospheric chemistry and the biosphere; through natural emissions of methane and volatile organic compounds, and through impacts of ozone and reactive nitrogen on plant growth and the carbon cycle.
The gas-phase chemistry described here is intimately connected with the research on aerosols through generation of secondary organic and inorganic aerosols.
Research on short-term forecasts of air quality is carried out in the Dispersion group.