World Calibration Centre (WCC-Empa) for Surface Ozone, Carbon Monoxide, Methane and Carbon Dioxide

WCC-Empa was established in 1996, assuming worldwide responsibility for surface ozone, carbon monoxide and methane inter-comparisons at global GAW stations. In 2010, WCC-Empa was also assigned to extend its activities towards carbon dioxide.
/documents/56101/250799/Audits230510/eb5188fb-07c9-437c-a7d7-c5f30399d9e4?t=1683723425360
Cumulative number (left) and scope (right) of WCC-Empa audits since 1996

The goals of the WCC-Empa are

  • To ensure that measurements are fully traceable to the designated GAW reference
  • To assist stations with regards to instrument and/or measurement problems
  • To improve technical know-how at stations through on-site training

through

  • Regular system and performance audits at global GAW stations including inter-comparison measurements with traveling standards.
  • Maintaining laboratory and traveling standards for surface ozone, carbon monoxide, methane and carbon dioxide.
  • Ensuring traceability of the WCC-Empa laboratory standards trough regular inter-comparisons with the corresponding GAW Central Calibration Laboratories.
/documents/56101/250799/traceability/5be36b4c-8ae8-435a-ad9a-1d2c324293c9?t=1544181691680
General traceability chain from the primary standards to atmospheric observations (measurements) at sites of a global network. b) Independent verification of traceability by system and performance audit carried out by the World Calibration Centres. Arrows indicate regular comparisons.

WCC-Empa measurements are traceable to

/documents/56101/250799/WCC-Empa_audits_1996-2023/6eb90d6d-1e73-459c-a9cd-184725e9940c?t=1690274584340
GAW stations audited by WCC-Empa (red triangles)

Achievements

Benefits of WCC-Empa audits include

  • Improved data quality
  • Increased data availability
  • Improved technical know-how of station operators
  • Increased awareness and acceptance of the GAW programme

WCC-Empa Audits

Further Information
Please direct questions and/or comments about Empa’s GAW activities to  (WCC-Empa),  Martin Steinbacher (QA/SAC Switzerland) or Lukas Emmenegger (Head of Laboratory).

more about...

Global Atmosphere Watch: Introduction

WCC-Empa (World Calibration Centre for Surface Ozone, Carbon Monoxide, Methane and Carbon Dioxide)

QA/SAC Switzerland (Quality Assurance/Scientific Activity Centre)

GAW Station Support

CATCOS webpage @ Empa

Publications



downloads

Questionnaire: Audit Gases

SOP: Audit Gases

WMO Report No. 1215: An Update on Low-cost Sensors for the Measurement of Atmospheric Composition, December 2020

WMO Report No. 1215: Low-cost sensors for the measurement of atmospheric composition: overview of topic and future applications (2018)

GAW Report No. 255: 20th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Measurement Techniques (GGMT-2019)

GAW Report No. 242: 19th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Measurement Techniques (GGMT-2017)

GAW Report No. 229: 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Measurement Techniques (GGMT-2015)

GAW Report No. 213: 17th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques (GGMT-2013)

GAW Report No. 209: Guidelines for Continuous Measurements of Ozone in the Troposphere

GAW Report No. 192: Guidelines for the Measurement of Atmospheric Carbon Monoxide


presentations
material from selected presentations can be found here

WCC-Empa activity reports