| The NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) in Boulder, Colorado, USA has been designated by WMO as the Central CO2 Calibration Laboratory responsible for maintaining the GAW Reference Standard for CO2. In its role as the World Calibration Centre (WCC) for CO2, CMDL maintains a high-precision manometric system for absolute calibration of CO2 reference gases to prepare and/or calibrate the CO2 standards gases used for GAW measurements worldwide [Zhao et al., 1997]. It is recommended that the standards of GAW measurement laboratories be calibrated on a regular basis (such as every two years) at the CCL. In 1995, CMDL took over the role of CCL from the Scripps Institution of Oceanography (SIO) in San Diego, California, USA. |
| Under the WMO calibration system, several calibration scales exist for CO2 data, e.g. X74, X85, X87, X93 and the WMO Mole Fraction Scale. The WMO Xyy Scales were traceable to the primary standards of the former CCL at SIO, while the WMO Mole Fraction Scale was traceable to those at CMDL. CMDL showed no significant offset between the WMO Mole Fraction Scale and the Xyy Scales through repeated intercalibration with the primary standards of SIO [GLOBALVIEW-CO2, 2001]. |
| To assess differences in standard scales among CO2 measuring laboratories, CMDL organizes intercomparison or round-robin experiments endorsed by WMO every few years. Many laboratories participated in the experiments organized in 1991-1992, 1995-1997 and 1999-2000. In addition, many laboratories compare their standards bilaterally or multilaterally among themselves. |
| The table below lists laboratories contributing CO2 measurement data to WDCGG or other laboratories involved in CO2 measurement with standard scales of reported data and participation history in WMO intercomparison experiments. |
| Laboratory | Sites
(WDCGG Site Index) | Reported Standard Scale | Most Recent Calibration | WMO Round Robin |
|---|
| CSIRO | CGR540S0, CSIRO Flask Network** | WMO | 2001-11 at CMDL | 91/92, 95/97, 99/00 |
| NIWA | BAR541S0 | SIO 1995 | 1995-11 at SIO | 91/92, 95/97, 99/00 |
| CAMS | WLG236N0 | X93 | 1994-01 at SIO | 95/97, 99/00 |
| METRI/SNU | KSN233N0 | X97 | SIO | 95/97 |
| JMA | NMN224N0, RYO239N0, YON224N0, ALG99990, EOM99990, RYF99990 | WMO | 1999-03 at CMDL | 91/92, 95/97, 99/00 |
| MRI | TKB236N0, INS9999A, HKH99990, KIY99990, NTU99990, RFM99990, WLT99990 | MRI 1997 | | 91/92, 95/97, 99/00 |
| NIES | COI243N0, HAT224N0 | NIES 95 | | 95/97, 99/00 |
| Tohoku | SYO769S0 | Tohoku | | 91/92, 95/97, 99/00 |
| Shizuoka | HMM234N0 | | Nippon Sanso | |
| Aichi | MKW234N0 | WMO | JMA | |
| Saitama | DDR236N0, URW235N0 | WMO | JMA | |
| CMDL | BRW471N0, MLO519N0, SPO789S0, SMO514S0, CMDL flask network* | WMO | 2001-01 at CMDL | 91/92, 95/97, 99/00 |
| NIST | | NIST | | 91/92, 95/97, 99/00 |
| SIO | | SIO | | 91/92, 95/97, 99/00 |
| MSC | ALT482N0, CSJ451N0, SBL443N0 | SIO 1991 | 2000-03 at CMDL | 91/92, 95/97, 99/00 |
| IGP | HUA312S0 | X81 | | |
| MGO | BER255N0, KOT276N0, KYZ240N0, STC652N0, TER669N0 | X97 | 1991 at SIO | |
| KSNU | ISK242N0 | | MGO | |
| INM | IZA128N0 | X87, X93 | 1997-01 at CMDL | 91/92, 95/97, 99/00 |
| LSCE | AMS137S0, MCH653N0 | X93 | 1998-08 at CMDL | 91/92, 95/97, 99/00 |
| IMS | CMN644N0 | X93 | 1998-10 at CMDL | 91/92, 95/97 |
| ENEA | LMP635N0 | X93 | 2000-08 at CMDL | 91/92, 95/97, 99/00 |
| CNR | JBN762S0 | WMO | ENEA | |
| CESI | PLR645N00 | X85 | 1997-07 at CMDL | 99/00 |
| UBA | BRT648N0, DEU649N0, NGL653N0, SSL647N0, LGB652N0, WST654N0, ZGT654N0, ZGP647N0 | WMO | 1998-10 at CMDL | 91/92, 95/97, 99/00 |
| Heidelberg | | WMO | 1998-10 at CMDL | 95/97, 99/00 |
| IFU | WNK647N0, ZSP647N00 | SIO 1974 | | 99/00 |
| ZAMG | SNB647N00 | WMO | UBA | |
| RIVM | KMW653N0 | NIST | | |
| MISU/NILU | ZEP678N0 | X93 | 1996-07 at CMDL | 95/97, 99/00 |
| HMS | KPS646N0 | WMO 1985 | 2000-03 at CMDL | 91/92, 95/97, 99/00 |
| NIMH | FDT645N20 | | SIAD SpA, Italy | |
| SAWS | CPO134S0 | WMO | 1997-06 at CMDL | 99/00 |
| * CMDL flask network: ALT482N10, AMS137S10, ASC107S10, ASK123N10, BAL655N10, BRW471N10, SGI354S10, BSC644N10, NMB123S10, CGO540S10, KUM519N10, CHR501N10, CBA455N10, CRZ146S10, GOZ636N10, EIC329S10, ITN435N10, GMI513N10, HBA775S10, HUN646N10, ICE663N10, KEY425N10, MHD653N10, SEY104S10, MLO519N10, MBC476N10, WLG236N10, NWR440N10, ZEP678N10, STC654N10, STM666N10, POC9XXX10, PSA764S10, LEF445N10, RPB413N10, MID528N10, WIS631N10, SHM452N10, SCS9XXX10, SPO789S10, BMW432N10, AVI417N10, BME432N10, SYO769S10, TAP236N10, AZR638N10, TDF354S10, SMO514S10, UUM244N10, UTA439N10 |
| ** CSIRO flask network: AIA999930, ALT482N30, CFA519S30, CGR540S30, EPC449N30, MQA554S30, MLO519N30, MAA767N30, SIS660N30, SPO789S30 |
| Aichi: | Aichi Prefecture, Japan |
| CAMS: | Chinese Academy of Meteorological Sciences, China Meteorological Administration |
| CESI: | Italian Electrical Experimental Center |
| CNR: | Istituto di Fisica dell'Atmosfera, Consiglio Nazionale delle Ricerche, Italy |
| CMDL: | Climate Monitoring and Diagnostics Laboratory, NOAA, USA |
| CSIRO: | Commonwealth Scientific and Industrial Research Organisation, Australia |
| ENEA: | Italian National Agency for New Technology, Energy and the Environment |
| HMS: | Hungarian Meteorological Service |
| IFU: | Fraunhofer-Institut fur Atmospharische Umweltforschung, Germany |
| IGP: | Instituto Geofisico del Peru |
| INM: | Instituto Nacional de Meteorologia, Spain |
| IMS: | Centro Aeronautico di Montagna, Italian Air Force Meteorological Service |
| JMA: | Atmospheric Environment Division, Japan Meteorological Agency |
| KSNU: | Kyrgyz State National University |
| LSCE: | Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS, France |
| METRI: | Meteorological Research Institute, Korea Meteorological Administration |
| MGO: | Main Geophysical Observatory, Russian Federation |
| MISU: | Department of Meteorology, Stockholm University, Sweden |
| MRI: | Meteorological Research Institute, Japan Meteorological Agency |
| MSC: | Meteorological Service of Canada |
| NIES: | National Institute for Environmental Studies, Japan |
| NILU: | Norwegian Institute for Air Research |
| NIMH: | Institutul National de Meteorologie, Hidrologie si Gospodarirea Apelor, Romania |
| NIST: | National Institute of Standards and Technology, USA |
| NIWA: | National Institute of Water and Atmospheric Research, New Zealand |
| RIVM: | National Institute for Health and Environment, Netherlands |
| Saitama: | Saitama Prefecture, Japan |
| SAWS: | South African Weather Service |
| Shizuoka: | Shizuoka University, Japan |
| SIO: | Scripps Institution of Oceanography, USA |
| SNU: | Seoul National University, Republic of Korea |
| Tohoku: | Tohoku University, Japan |
| UBA: | Umweltbundesamt, Germany |
| UHEI-IUP: | Institut fur Umweltphysik, Universitat Heidelberg, Germany |
| ZAMG: | Central Institute of Meteorology and Geodynamics, Austria |
