Traceability of Measurements within the Global Atmosphere Watch - PowerPoint PPT Presentation

Federal Office of Meteorology Federal Office of Meteorology and Climatology MeteoSwiss and Climatology MeteoSwiss Traceability of Measurements within the Global Atmosphere Watch Programme: Results from the World Calibration Centre WCC-Empa Christoph Zellweger 1 , Martin Steinbacher 1 , Lukas Emmenegger 1 , Brigitte Buchmann 2 1 Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, Switzerland 2 Empa, Department Mobility, Energy and Environment, Dübendorf, Switzerland NOAA ESRL Global Monitoring Annual Conference 2016

International GAW Activities of Switzerland WCC-Empa (O 3 , CO, CH 4 , CO 2 ) Audits by WCC-Empa from 1996 - 2016 NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Audits: Travelling Standards vs. Parallel Measurements WCC-Empa Traveling Standard  Only instrument comparison  Assessment of the whole system  Snapshot in time  Special care might influence results  Longer time period  Covers wider mole fraction range  Less influence by operator  Repeatability conditions  Limited to ambient mole fraction range NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Explanation for the following figures… Station analyser / (ppb) 1500 500 WCC-Empa TS 0 0 500 1500 TS / (ppb) 12-04-18 07:04 to 12-04-18 14:01 Picarro G2401 CFKADS-2018 6 6 Bias at 1900 ppb / (ppb) 4 4 [CH4 - <NOAA04>] (ppb) 2 2 Compatibility goal 0 0 -2 -2 Extended compatibility goal -4 -4 DQOs for range 1700-2100 ppb Range in unpolluted troposphere -6 -6 0.97 0.99 1.01 1.03 1700 1800 1900 2000 2100 <NOAA04> (ppb) Slope / (-)  Intercept = 12.4 ppb  Slope = 0.993  Bias @ 1900 ppb = -1.03 ppb NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Explanation for the following figures… Station analyser / (ppb) 1500 500 WCC-Empa TS 0 0 500 1500 TS / (ppb) 12-04-18 07:04 to 12-04-18 14:01 Picarro G2401 CFKADS-2018 6 6 Bias at 1900 ppb / (ppb) 4 4 [CH4 - <NOAA04>] (ppb) 2 2 Compatibility goal 0 0 -2 -2 Extended compatibility goal -4 -4 DQOs for range 1700-2100 ppb Range in unpolluted troposphere -6 -6 0.97 0.99 1.01 1.03 1700 1800 1900 2000 2100 <NOAA04> (ppb) Slope / (-)  Intercept = 12.4 ppb  Slope = 0.993  Bias @ 1900 ppb = -1.03 ppb NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Explanation for the following figures… Station analyser / (ppb) 1500 500 WCC-Empa TS 0 0 500 1500 TS / (ppb) 12-04-18 07:04 to 12-04-18 14:01 Picarro G2401 CFKADS-2018 6 6 Bias at 1900 ppb / (ppb) 4 4 [CH4 - <NOAA04>] (ppb) 2 2 Compatibility goal 0 0 -2 -2 Extended compatibility goal -4 -4 DQOs for range 1700-2100 ppb Range in unpolluted troposphere -6 -6 0.97 0.99 1.01 1.03 1700 1800 1900 2000 2100 <NOAA04> (ppb) Slope / (-)  Intercept = 12.4 ppb  Slope = 0.993  Bias @ 1900 ppb = -1.03 ppb NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

GHG: Relationship performance – analytical technique CH 4 CO 2  Results for GHGs were recently published: C. Zellweger et al., Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations, Atmos. Meas. Tech. Discuss., 2016, 1-30, 2016. NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

RG: Relationship performance – analytical technique O 3 CO  Ozone: >50 % of the comparisons were within 1 ppb  CO remains challenging, although significant improvement is over the range 0-100 ppb. observed when newer techniques are used  Almost all measurements are done using UV absorption technique.  Cases with lager deviations usually either due to inappropriate calibration or instrument faults. NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Parallel Measurements for CO at Ushuaia  Station instrument: HORIBA APMA-360  Travelling instrument: Picarro G2401 without sample air drying  From 2016-02-05 to 2016-05-10  Travelling instrument used independent inlet lines to same sampling location 9 NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Ushuaia – HORIBA APMA-360  Reason for bias? 16-02-05 03:56 to 16-02-05 15:26 HORIBA APMA-360 SN 712020  Difference in calibration scale? – not confirmed by performance audit results 40  Remaining bias due to water vapor correction of the [CO - <WMO-X2014>] (ppb) Picarro G2401 instrument? 20  Instrumental issues of the HORIBA APMA-360 instrument, e.g. pressure dependence leading to inappropriate zero 0 correction. -20 -40 0 200 400 600 800 <WMO-X2014> (ppb) NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Ushuaia – HORIBA APMA-360  Reason for bias?  Difference in calibration scale? – not confirmed by performance audit results  Remaining bias due to water vapor correction of the Picarro G2401 instrument?  Instrumental issues of the HORIBA APMA-360 instrument, e.g. pressure dependence leading to inappropriate zero correction. NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Ushuaia – HORIBA APMA-360  Reason for bias?  Difference in calibration scale? – not confirmed by performance audit results  Remaining bias due to water vapor correction of the Picarro G2401 instrument?  Instrumental issues of the HORIBA APMA-360 instrument, e.g. pressure dependence leading to inappropriate zero correction. NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Cape Point: Picarro G2302  Station instrument: Picarro G2302  Travelling instrument: Picarro G2401 without sample air drying  From 2015-10-22 to 2016-02-24  Travelling instrument used independent inlet lines to same sampling location and occasionally sampled from CPT inlet after drier 13 NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Cape Point – Picarro G2302 15-11-03 00:00 to 15-11-28 16:00 Picarro G2302 #835-CKADS2026  Very good agreement for the first two months of the 10 comparison, in agreement to performance audit results.  However, a difference between the two inlets was [CO - <WMO-X2014>] (ppb) 5 observed. The travelling instrument Picarro G2401 was recording higher mole fractions when sampling dry air from the Cape Point inlet. 0  This is in line with a potential influence of water vapor on CO that was observed for this particular instrument. -5 -10 100 150 200 250 <WMO-X2014> (ppb) NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Cape Point – Picarro G2302  Very good agreement for the first two months of the comparison, in agreement to performance audit results.  However, a difference between the two inlets was observed. The travelling instrument Picarro G2401 was recording higher mole fractions when sampling dry air from the Cape Point inlet.  This is in line with a potential influence of water vapor on CO that was observed for this particular instrument. NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Cape Point – Picarro G2302  Very good agreement for the first two months of the comparison, in agreement to performance audit results.  However, a difference between the two inlets was observed. The travelling instrument Picarro G2401 was recording higher mole fractions when sampling dry air from the Cape Point inlet.  This is in line with a potential influence of water vapor on CO that was observed for this particular instrument. NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Jungfraujoch: Los Gatos LGR-23r  Station instruments: Los Gatos LGR-23r (and Picarro G2401)  Travelling instrument: Picarro G2401 without sample air drying  From 2015-03-19 to 2015-05-29  Travelling instrument used independent inlet lines to same sampling location plus additional inlet at a different location 17 NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Jungfraujoch – LGR-23r 15-03-17 23:37 to 15-03-18 02:56 LGR-23r #12-0066  Good agreement over the entire comparison period, in agreement to performance audit results. 5 [CO - <WMO-X2014>] (ppb) 0 -5 0 50 100 150 200 250 300 <WMO-X2014> (ppb) NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Jungfraujoch – LGR-23r NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Advantage of Parallel Measurements GAW/NABEL inlet AGAGE inlet  A significant influence of the tourists and/or other emissions can be occasionally observed during calm days. Both instruments sample from Both instruments sample from station inlet on top of the station inlet on top of the building building WCC instruments samples from the AGAGE inlet below the tourist platform 1-min data 20 NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016

Advantage of Parallel Measurements GAW/NABEL inlet AGAGE inlet  A significant influence of the tourists and/or other emissions can be occasionally observed during calm days. Both instruments sample from Both instruments sample from station inlet on top of the station inlet on top of the building building WCC instruments samples from the AGAGE inlet below the tourist platform 1-min data 21 NOAA ESRL Global Monitoring Annual Conference 2016, May 17-18, 2016