GAW logo vert 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 Atmosphere 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 inter-laboratory comparison studies. Graphical and tabular results of past studies are available by accessing Study Results.

 Guidance on all aspects of collecting precipitation for chemical analysis is provided in the GAW Guidelines for Precipitation Chemistry and Deposition Measurements.

Visit the World Data Centre for Precipitation Chemistry Web site for information about the new Global Assessment of Precipitation Chemistry and Deposition.