Welcome to the Quality Assurance/Science Activity Centre – Americas (QA/SAC-Americas), one of four QA/SACs operating to ensure data quality and support science activities in the World Meteorological Organization Global Atmospheric Watch (GAW).

The QA/SAC-Americas seeks to document and help improve the quality of precipitation chemistry measurements from around the world. It conducts semi-annual laboratory intercomparison studies. Guidance on all aspects of collecting precipitation for chemical analysis is provided in the Manual for the GAW Precipitation Chemistry Programme (WMO-GAW Report No. 160).