Multiphase Chemical Kinetics

Multiphase Chemical Kinetics

Trace gases that are emitted in the atmosphere contain elements in relatively low oxidation states. Their oxidation in the O₂-rich atmosphere is crucial in determining their impact on atmospheric composition. This is brought about by chemical reactions across the gas phase, deliquescent aerosols, and cloud droplets. Chemical kinetics in and across these different media is our key to advance the understanding and prediction of oxidants and aerosol precursors in the troposphere.

Tropospheric oxidants

• Volatile organic compounds and tropospheric ozone
• Influence of transition metal ions on radical cycling
• Heterogeneous formation of nitrous acid

Aerosol precursors

• Pathways to formation of organic acids
• Formation of polyols and oligomers
• Highly oxygenated molecules from auto-oxidation of organics
• Formation of carbonyl sulfide from biogenic organic sulfur
• Sulfur and nitrogen chemistry leading to extreme haze
• Formation and ageing of aromatics contributing to brown carbon

Activities

1. Oxidation mechanisms development with the open community box model CAABA/MECCA.
2. Development of a 0D-base model within MESSy comprising multiphase chemical kinetics, aerosol microphysics, photolysis etc.
3. ECHAM5/MESSy for atmospheric chemistry (EMAC), the only global model explicitly simulating multiphase chemical kinetics
4. Design and interpretation of SAPHIR experiments.
5. Mechanism evaluation against chamber experiments.
6. Collect experimental kinetic data and compare simulation results to field campaign measurements.