What is a CCL?

A World Meteorological Organization (WMO) Central Calibration Laboratory (CCL) is responsible for maintaining and distributing the WMO Mole Fraction scale for a specified gas in air. NOAA GML is the WMO, Global Atmosphere Watch (GAW) CCL for CO2, CH4, N2O, SF6, and CO. In support of GAW, GML offers calibration services for these gases for a fee.

According to recommendations by the WMO/IAEA group of experts on carbon dioxide and related tracer measurement techniques (WMO 2020), a CCL will:

GML Quality Manuals for Measurement Services in support of WMO/GAW