Atmospheric Chemistry

Abstract

This is a self-study course targeted at Master students who did not follow the bachelor course "atmospheric chemistry" or equivalent, providing a general introduction into atmospheric chemistry. It introduces the relevant fundamental concepts, which are explored in the context of key environmental issues, such as air pollution, stratospheric ozone depletion, and connections to climate change.

Objective

At the end of this course, students are able to: 1. describe the structure of the atmosphere and list atmospheric components and their main properties 2. define and describe the chemical and physical processes in the stratosphere and troposphere, follow reaction mechanisms, and apply rate laws 3. describe the physical and chemical principles of air pollution and summarize the most important legislative measures 4. discuss the local, regional, and global aspects of interactions between air quality, ecosystem health, and climate

Content

- Origin and properties of the atmosphere: composition (gases and aerosols), atmospheric structure, UV radiation, transport timescales - Kinetics of gas phase reactions: rate laws, mechanisms of bimolecular and termolecular reactions. - Stratospheric chemistry: Chapman cycle, catalytic ozone destruction cycles, polar ozone hole, Montreal protocol - Tropospheric chemistry: oxidizing capacity of the troposphere and the role of OH, oxidation and global budgets of CO and CH4, role of NOx, and the global tropospheric O3 budget - Surface ozone chemistry: HOx-NOx cycle, role of VOCs, O3 isopleth, ozone production efficiency - Aerosols: primary and secondary sources, composition, quantities and measures, connections to climate - Multiphase chemistry: solubility of gases, Raoult’s Law and hygroscopicity, kinetics of gas to particle transfer, N2O5 chemistry, aqueous phase sulfur chemistry, secondary organic aerosol formation - Air quality: role of planetary boundary layer, deposition processes, summer- versus winter-smog, environmental problems, legislation, long-term trends - Global aspects: air quality - climate interactions

Resources