Ensuring compatibility and data quality in the atmospheric greenhouse gas observations network: The role of a central laboratory of National Institute of Meteorological Sciences

Accurate and traceable greenhouse gas (GHG) observations are critical for understanding climate change and supporting global mitigation policies. Data compatibility across observation networks requires robust calibration protocols and sustained quality assurance. This study assesses the calibration infrastructure of the Central Laboratory of the National Institute of Meteorological Sciences (NIMS), which disseminates World Meteorological Organization (WMO) reference scales across Korea’s GHG observation network under the Global Atmosphere Watch (GAW) framework. Calibration performance was validated through audits by the WMO World Calibration Centre (WCC), WMO/IAEA and JMA round-robin intercomparisons, and domestic comparison campaigns. The NIMS calibration standards and our calibration strategies consistently met WMO compatibility goal (±0.1 mmol mol^-1 for CO₂ and ±2 nmol mol-1 for CH₄), demonstrating robust traceability and analytical accuracy. The NIMS system includes traceable standard gas production, interlaboratory comparisons, and uncertainty verification, providing a scalable model for national-level calibration infrastructure. This enhances the integrity of domestic observations while strengthening regional QA/QC capacity under WMO/GAW.