Compinents of the WMO/GAW programme
The Global Atmosphere Watch Programme (GAW) of the World Meteorological Organization (WMO) has a unique long-term international framework that provides the technical basis for integrated observations, analysis and assessment of atmospheric chemical composition. The missions of the GAW, as described in the “WMO Global Atmosphere Watch (GAW) Strategic Plan: 2016 - 2021” (GAW Report No. 172), are to implement “maintaining and applying global, long-term observations of the chemical composition and selected physical characteristics of the atmosphere; emphasizing quality assurance and quality control; and delivering integrated products and services of relevance to users."
The WMO/GAW quality assurance system includes five types of central facilities dedicated to six groups of measurement variables, which are operated by WMO Members. Its key role is played in the quality assurance system by World Calibration Centres (WCCs), which assists WMO Members in assuring the quality of observations and in particular in establishing observations traceable to the WMO/GAW Reference Scale.