The aim of the AtmoChemECV project is to provide SI-traceable references with the required uncertainty to detect spacial gradients, shifts and/or long-term trends. Target substances are reactive compounds, in particular those for which reference gas mixtures are not stable in cylinders or at least not at ambient molar fractions. The project focuses on
• water vapour at upper tropospheric level ,
• fluorinated gases (currently HFC-125, HFC-1234yf, SF6) and
• volatile organic compounds (currently α-pinene, butanone or MEK, butenone or MVK, limonene, acetone, ethanol),
and complements the European projects HIGHGAS and KEY-VOCs.
METAS has more than 10 years’ experience in dynamic generation methods, i.e. standards being produced constantly over time, for regulated air pollutants. The project aims at extending these capabilities to very low amount of substance fractions of atmospheric chemical ECVs, which, due to their reactivity cannot be provided in gas cylinders. In order to reduce uncertainties, adsorption/desorption phenomena of reactive compounds on surfaces are minimised.
This project supports and encourages the implementation of such low uncertainty, SI-traceable references in the Global Climate Observing System (GCOS) monitoring network. Thus METAS resp. Switzerland supports the work of the UNFCCC ("United Nations Framework Convention on Climate Change") and the IPCC ("Intergovernmental Panel on Climate Change) and contributes to long-term stable and comparable climate data.
Methods to provide gas standards in situ and/or canisters will be developed in close collaboration with the project partners:
• Oeschger Centre for Climate Change Research, University of Bern
• Swiss Federal Laboratories for Material Science Technology Empa
• Federal Office of Meteorology and Climatology MeteoSwiss
News and Events
SF6 Inter-Comparison Experiment (SICE)
METAS participated in the SF6 Inter-Comparison Experiment (SICE) organised by KMA, Korea Meteorological Administration, World Calibration Centre for SF6 for the GAW (Global Atmosphere Watch) network. This intercomparison exercise took place from April 2016 to February 2017. Results are expected soon.
EGU 2017 conference in Vienna, Austria
Results of the AtmoChemECV project will be presented at the EGU conference in Session AS3.27: "Climate and atmospherically important trace gases: metrology, quality control and measurement comparability".
- SI-traceable and dynamic reference gas mixtures for water vapour at polar and high troposphere atmospheric levels
- SI-traceable standards for atmospheric monitoring of halogenated gases
- New SI-traceable reference gas mixtures for sulfur hexafluoride (SF6) at the pmol/mol level using static and dynamic preparation methods and comparison to existing scales
- Gas adsorption and desorption effects on high pressure small volume cylinders and their relevance to atmospheric trace gas analysis
GAS 2017 conference in Rotterdam
Results will be presented in Session B – Health, safety and the environment.
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