The aerosol observing system (AOS) is the primary platform for in situ aerosol measurements at Earth’s surface. Each AOS has a different complement of instruments, which are selected to ensure the best measurements at each deployment site.
The AOS measures aerosol optical properties to better understand how particles interact with solar radiation and influence the Earth’s radiation balance. These measurements are useful for calculating parameters used in radiative forcing calculations, such as the aerosol single scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. Measurements made with the AOS form a long-term record at the ARM fixed sites. Shorter measurement records are available from mobile deployments in a wide variety of geographical regions. These measurements are valuable for:
- identifying long-term changes in aerosol properties
- identifying atmospheric processes controlling aerosol life cycle and their influence on clouds
- providing experimental data for developing and testing atmospheric climate models.