Aerosol Chemistry
The primary goals of aerosol chemical measurements at GAW stations are: (i) to determine long-term trends locally and, taken collectively, in global distribution (ii) assess the impact of aerosols on regional and global climate and (iii) monitor regional air quality. In addition, long-term measurements of aerosol chemical size distribution can be used to evaluate and improve aerosol chemical transport models used in air quality forecast and climate models.
Due to the complexity of aerosols, a successful network programme must address numerous issues in chemical measurement. Several guiding principles are recommended for chemical sampling and analysis in the GAW aerosol network:
1) Simplicity and ruggedness of the measurement system
2) Use of a standardized aerosol filter medium
3) Minimize hardware and training costs
GAW aerosol chemical measurements draw upon the activities of several contributing regional networks, e.g. EMEP, as well as the University of Miami networks. Establishing the comparability of the measurements across these networks is an important task for GAW.