GAW-PFR AOD Network


GAW-PFR Measurements		Classic extinction measurements at the recommended 4 WMO wavelengths 368, 415, 500 and 862 nm using Precision Filter Radiometers (PFRs). PFRs are manufactured by PMOD/WRC, and have optical filters from the same batch. Continuous sampling at a 1- minute frequency by automated systems. Data are transferred on a monthly basis to WORCC which acts as a central processing hub for data evaluation. Quality control flags cover solar pointing, housing temperature, and cloud screening. Continuous in-situ and/or (annual) centralized calibration based on high altitude references, and linear interpolation in time. Data products: AOD and the Angström coefficients alpha and beta (no inversions). Hourly mean AOD archived at the World Data Center for Aerosols (WDCA), Ispra. Data with a 1-minute resolution are available from WORCC upon request.

GAW-PFR Network		GAW-PFR and Associate stations around the world currently in operation. (Click on station for station homepage)
Current Activities		WORCC has developed a central facility with a web-based user interface for unified processing, archiving and presentation of PFR measurements within GAW-PFR. In addition, WORCC is participating in EUSAAR (European Supersites for Atmospheric Aerosol Research), which is part of the EU I3 Programme (Integrated Infrastructures Initiatives). The objective of EUSAAR is the integration of measurements of atmospheric aerosol properties performed in a distributed network of 20 high quality European ground-based stations. This integration contributes to a sustainable reliable operational service in support of policy issues on air quality, long-range transport of pollutants and climate change.

Contact		Christoph Wehrli, Senior Scientist Stephan Nyeki, Scientist