Compatibility of atmospheric greenhouse gas measurements in Europe as assessed by the Cucumbers intercomparison programme

Transcription

1 Compatibility of atmospheric greenhouse gas measurements in Europe as assessed by the Cucumbers intercomparison programme Andrew Manning Armin Jordan, Martina Schmidt, Ingeborg Levin and Slide 1of 31

2 66 authors, from 34 institutions! A. C. Manning 1, A. Jordan 2, M. Schmidt 3,4*, I. Levin 4, R. E. M. Neubert 5, S. Hammer 4, M. Delmotte 3, M. Hewitt 1, A. Etchells 1, P. A. Pickers 1, M. Alemanno 6, F. Apadula 7, J. Arduini 8, Z. Barcza 9, A. Båth 10, W. A. Brand 2, H. Chen 11,5*, A. Di Diodato 6, M. Ernst 12, G. L. Forster 1, B. D. Hall 13, H. C. Hansson 14, L. Haszpra 15, J. Hatakka 16, O. Hermansen 17, R. Howard 18, K. Katsumata 19, V. Kazan 3, P. Keronen 20, D. Kitzis 13, R. L. Langenfelds 21, M. Lanoisellé 22, J. V. Lavric 2, M. C. Leuenberger 23, M. Lopez 3, D. Lowry 22, T. Machida 19, M. Maione 8, G. Manca 24, F. Meinhardt 25, M. Mölder 10, J. Moncrieff 18, C. L. Myhre 17, J. Necki 26, B. Noone 14, P. Novelli 13, S. O Doherty 27, S. Piacentino 28, M. E. Popa 2,29*, J. Richter 2, L. Ries 25, M. Rothe 2, H. A. Scheeren 24,5*, M. F. Schibig 23, T. G. Spain 30, L. P. Steele 21, M. Steinbacher 31, I. Szilagyi 32, W. C. M. van den Bulk 33, S. van der Laan 5,23,1*, I. T. van der Laan Luijkx 5,23, 34*, A. T. Vermeulen 33,10*, B. Wastine 3, P. A. Wilson 1, D. E. Worthy 12, C. Yver Kwok 3 Slide 2of 31

3 Objective, aims and limitations Overarching objective: to assess and quantify offsets in calibration scales, and consequently in ambient air measurements, between different field stations and labs. Main aims: determine measurement compatibility so that field stations and labs become more aware of where problems lie; thus able to address analytical procedures with expectation of reducing calibration scale offsets; contribute to quantifiable estimation of uncertainties in field station and lab data sets; achieve improved scientific interpretation of data sets by taking into account** quantified calibration scale offsets. ** But not correcting data sets. Limitations: air sampled from Cucumbers does not pass through inlet tubing, sample pumps and drying systems at the field station BUT THERE S NO REASON WHY NOT! stations receive Cucumbers ~once a year. Not frequent enough to rely solely on Cucumbers programme to highlight quality control issues. definition of zero compatibility offset in interpretation of results. Slide 3of 31

4 History of the programme Nov 2004: Conceptualised at end of EU TACOS programme. Early 2005: Initiated in EU CHIOTTO tall towers project, as Travelling Secondary Standards. End 2005: Initiated in EU CarboEurope project as Cucumbers programme. Mid 2006: Shutdown over concerns of using and transporting US made cylinders. Jan 2008: Restarted with UK made cylinders : Continued in EU IMECC project : Continued in EU InGOS project; likely to end at end of this year. Slide 4of 31

5 Scale of the Cucumbers programme 66 authors. 23 in situ atmospheric field stations in Europe. 11 measurement laboratories. 34 organisations. 16 countries. 9 atmospheric species compatibility assessed. 10+ years of intercomparison measurements. 21 high pressure cylinders (Cucumbers) in 7 loops of 3 Cucumbers each. 440 graphs on the website. Slide 5of 31

6 7 loops of circulating Cucumbers (3 in each loop) NOR ZEP EURO-1 TTA HYY PAL NIES CMAR NOAA ZUG CMN EURO-5 CBW PRS EURO-4 ISP SCH MPI-BGC LMP LUT OXK UHEI INTER-1 INTER-2 CIO-RUG EURO-3 BIK UBERN EGH WAO MHD JFJ LSCE EnCan HUN EURO-2 TRN KAS PUY Slide 6of 31

7 Dedicated website: Slide 7of 31

8 Excel logsheets for submitting data Slide 8of 31

9 CSV file format for submitting data Allows automated generation of files for submission by participants. Results in much, much less errors and mistakes!! And big reduction in manpower requirements (both for UEA and participants). Slide 9of 31

10 Results interpretation of following field station plots Top plot = Average offsets Zero is defined as initial measurements made by central lab in given loop of all 3 Cucumbers. Each point is average offset from initial central lab measurements of all 3 Cucumbers. Sometimes only 1 or 2, if species deemed to be outside measurement range. WMO compatibility goals shown as dashed horizontal lines. Y axis scale always symmetrical about zero. Sometimes zero needs to be reset, when a Cucumber is replaced in a loop. Bottom plot = Standard deviations Standard deviations of average offset of 3 Cucumbers. Y axis scale always half of scale on average offset plot. All red symbols/lines are central labs. Common symbol used for a given loop. Slide 10 of 31

11 CO2

12 CH4

13 N 2 O

14 SF6

15 CO Cylinders clearly drifting. Perhaps work around via redefining zero for every lab measurement?

16 H 2 Also drifting, but less of a problem relative to WMO compatibility goal (and much better than WMO RR results, strangely)

17 O2/N2

18 Also plots of individual lab/station showing each Cucumber These plots can show possible concentration dependent offset, shown here for UHEI N 2 O. All such plots on website: red/yellow = high conc; green = medium conc; blue = low conc. N.B. Most people s N 2 O precision is much too poor to be able to show concentration dependence seen here! Slide 18 of 31

19 To compare field stations, need inter lab comparisons Inter 1 and Inter 2 loops: Establish lab offsets; include non European international partners. Results used to compare field stations that have different central labs. CO 2 (ppm) MPI-BGC UHEI-IUP LSCE CIO-RUG NOAA EnCan CMAR NIES UBERN Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 19 of 31

20 Central labs: CH 4 CH 4 (ppb) MPI-BGC UHEI-IUP LSCE CIO-RUG NOAA EnCan CMAR NIES (-5 ppb) Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 20 of 31

21 Central labs: N 2 O 1.0 N 2 O (ppb) MPI-BGC UHEI-IUP LSCE NOAA EnCan CMAR NIES Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 21 of 31

22 Central labs: SF MPI-BGC UHEI-IUP LSCE NOAA EnCan NIES SF 6 (ppt) 0.00 Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 22 of 31

23 Central labs: CO (UK cylinders drift but US stable?!) CO (ppb) MPI-BGC UHEI-IUP LSCE CIO-RUG NOAA EnCan CMAR NIES Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 23 of 31

24 Central labs: H MPI-BGC UHEI-IUP LSCE NOAA CMAR NIES H 2 (ppb) 0 Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 24 of 31

25 Central labs: δ 13 C CO 2 13 CO 2 (per mil) MPI-BGC UHEI-IUP EnCan NOAA CMAR NIES RHUL Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 25 of 31

26 Central labs: δ 18 O CO 2 18 O-CO 2 (per mil) MPI-BGC UHEI-IUP EnCan NOAA CMAR NIES Inter-1 Inter Jan06 Jan07 Jan08 Jan09 Jan10 Jan11 Jan12 Jan13 Jan14 Jan15 Slide 26 of 31

27 Quantified field station offsets from central labs Station: TTA NOR PAL ZEP NILU ZEP SU HYY TRN PUY KAS HUN LUT OXK BIK JFJ EMPA Blue indicates improvement over period compared to ; red indicates worsening results; black indicates no measurements in one time period. Disappointing results! No overall clear improvement in compatibility over time. JFJ UBERN MHD LSCE MHD AGAGE MHD EPA PRS CMN LMP ISP SCH ZUG CBW WAO EGH CO 2 avg. offset ±0.1 std. dev no. analyses CH 4 avg. offset ±2 std. dev no. analyses N 2O avg. offset ±0.1 std. dev no. analyses SF 6 avg. offset ±0.02 std. dev no. analyses CO avg. offset ±2 std. dev no. analyses H 2 avg. offset ±2 std. dev no. analyses O 2/N 2 avg. offset ±2 std. dev no. analyses Central lab: UHEI UHEI UHEI UHEI UHEI UHEI LSCE LSCE LSCE LSCE MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI Slide 27 of 31

28 Central lab offsets from initial MPI BGC values Laboratory: UHEI LSCE CIO RuG EnCan NOAA CMAR NIES UBERN RHUL SU MPI BGC CO 2 avg. offset ±0.1 std. dev no. analyses CH 4 avg. offset ±2 std. dev no. analyses N 2 O avg. offset ±0.1 std. dev no. analyses SF 6 avg. offset ±0.02 std. dev no. analyses CO avg. offset ±2 std. dev no. analyses H 2 avg. offset ±2 std. dev no. analyses O 2 /N 2 avg. offset ±2 std. dev no. analyses δ 13 CO 2 avg. offset ±0.01 std. dev no. analyses δ 18 O avg. offset ±0.05 std. dev no. analyses Slide 28 of 31

29 Quantified field station offsets from MPI BGC Station: TTA NOR PAL ZEP NILU ZEP SU HYY TRN PUY KAS HUN LUT OXK BIK JFJ EMPA JFJ UBERN MHD LSCE MHD AGAGE MHD EPA PRS CMN LMP ISP SCH ZUG CBW WAO EGH CO 2 avg. offset ±0.1 std. dev no. analyses CH 4 avg. offset ±2 std. dev no. analyses N 2O avg. offset ±0.1 std. dev no. analyses SF 6 avg. offset ±0.02 std. dev no. analyses CO avg. offset ±2 std. dev no. analyses H 2 avg. offset ±2 std. dev no. analyses O 2/N 2 avg. offset ±2 std. dev no. analyses Central lab: UHEI UHEI UHEI UHEI UHEI UHEI LSCE LSCE LSCE LSCE MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI MPI Blue indicates data with valid reported offsets; red indicates data not representative of field station (because of central lab or cylinder issues). Slide 29 of 31

30 Field stations meeting WMO compatibility goals Subjective how to determine this criteria, so we use several measures: 1) Based on average offsets (from central lab initial measurements). 2) Based on standard deviations of average offsets. Table 1 is table in 3 slides previously station offsets from their central lab. Table 3 is from previous slide every station referenced to MPI BGC, after taking into account average central lab offsets from MPI BGC. Average offset (AVstn) Standard deviation (SDstn) Species Based on Table 1 Based on Table 3 Based on Table 1 Based on Table 3 CO2 17/26 (65%) 17/26 (65%) 9/26 (35%) 8/26 (31%) CH4 20/23 (87%) 22/23 (96%) 18/23 (78%) 18/23 (78%) N2O 2/17 (12%) 2/13 b (15%) 0/17 (0%) 0/13 b (0%) SF6 6/15 (40%) 5/15 (33%) 3/15 (20%) 3/15 (20%) CO a a a a H2 5/9 (56%) 4/7 c (57%) 7/9 (78%) 5/7 c (71%) O2/N2 0/4 (0%) d 0/4 (0%) d Slide 30 of 31

31 Species specific field station conclusions from the results (Overall: disappointing, but at least have quantified offsets!) CO 2 compatibility is very poor. Avg offsets not bad (2/3rd stations within WMO goal); but std dev very poor (only 1/3rd stations within WMO goal). Surprising (many decades of experience) and worrying (most important GHG). CH 4 compatibility generally excellent! N 2 O compatibility is very poor. Limitation is analytical measurements methods. Need to prioritise shift to new instrumentation (Los Gatos; Ecotech). SF 6 compatibility is disappointing. About one third stations meeting WMO goal. No known new analytical techniques, so need to persist with (and improve) GC/ECD. CO compatibility: no conclusion. Cucumbers programme not fit for purpose owing to CO mole fraction drift in cylinders H 2 compatibility is good. Some evidence of H 2 mole fraction drift in cylinders, but not as clear as CO. Despite this, good results relative to WMO goal. Slide 31 of 31