| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
UTC |
| Sampling |
| Sampling height |
: |
38 |
| Description |
: |
flask |
| Sampling and analysis frequency |
: |
Several times a month |
| Sampling environment |
: |
|
| Description for sampling analysis |
: |
SAMPLING:
The listed data have been obtained from flask air samples returned to GASLAB for analysis. The flasks are of 6 types, 4 of which are the property of CSIRO (items a-d below) and 2 of which are the property of the Meteorological Service of Canada for air sampling at the Canadian sites, Alert, Estevan Point and Fraserdale (items e and f): (a) glass 0.5 litre, sealed with two stopcocks fitted with PTFE, PFA or Viton O-rings (flask identifier prefix “G050”), (b) glass 5.0 litre, sealed with two stopcocks fitted with PTFE O-rings (“G500”), (c) glass 0.8 litre, sealed with two stopcocks fitted with PTFE or PFA O-rings (“G080”), (d) electropolished stainless steel 1.6 litre “Sirocans” fitted with two stainless steel valves manufactured by either Nupro or Hoke (“S160”), (e) glass 2.0 litre sealed with a single stopcock fitted with a Viton O-ring (“F”, “FF”, “FA”, “FE”, “EP”, ALT”) or (f) glass 2.0 litre sealed with two stopcocks fitted with Viton O-rings (“M1”, “S”, “P2”, “TEMP”). Experiments carried out to test for changes in sample CO mixing ratio during storage have shown significant drifts in some flask types over test periods of several months to years (Cooper et al., 1999). Corrections derived from the test results are applied to network, glass flask data according to flask type. Data from the “S160” flasks have been rejected due to large and variable drift. Typical sample storage times range from days to weeks for some sites (e.g. Cape Grim, Aircraft) to as much as 1 year for Macquarie Island and the Antarctic sites.
ANALYSIS:
Samples were analysed by gas chromatography with a mercuric oxide reduction gas detector. CO reduces HgO to Hg vapour which is detected by UV absorption. One Trace Analytical gas chromatograph, labelled “RGA3-1” (R1) was used over the length of the record. Further details are provided elsewhere of CSIRO’s global sampling network, sampling and analytical techniques (Francey et al., 1996), and measurement uncertainty (Francey et al., 2003). |
| Instrument and Analysis |
| Measurement method |
: |
Gas Chromatography (RGD) |
| Current status and history of instrument |
: |
Gas Chromatography with a mercuric oxide reduction gas detector |
| Description of instrument |
: |
Trace Analytical, MD, USA
RGA3 |
| Calibration |
| Current scale employed in the measurement |
: |
CSIRO Scale (derived from the scale maintained by NOAA/CMDL in 1991) |
| Measurement calibration |
: |
Data are linked to the gravimetrically-derived scale of NOAA (Novelli et al., 1991) using a single high-pressure cylinder standard with CO mole fraction of 196 ppb. This standard is one of five synthetic mixtures of CO2, CH4 and CO in zero natural air, in the range 30–196 ppb of CO, that were calibrated at NOAA between 1992 and 1994. Stability of the CSIRO scale and variations in instrument response are monitored with ~20 high-pressure cylinder standards, with lifetimes of 10-16+ years, spanning a CO range of 20–400 ppb. A number of observed systematic influences complicate the international calibration of CO measurements. Further details are provided elsewhere [Masarie et al., 2001; Francey et al., 2003]. |
| Scale and calibration(treasability) |
: |
Observer's standard - CSIRO
NOAA (2008) |
| Data Processing |
| Measurement unit |
: |
ppb |
| Data processing |
: |
Flask data are assigned flags to indicate whether they are classified as retained or rejected. Cause of rejection falls into three broad categories: (i) the sample is considered to be not representative of the atmosphere at the time and place of sampling due to identified or inferred sampling or analytical problems (eg. sample contamination, poor analysis), (ii) the sample is considered to be “non-baseline” as indicated by the meteorological conditions at the time of sampling and (iii) any remaining outliers are flagged on the basis of a 3-sigma filter (geographically fixed sites only). For completeness, all data are included here, regardless of whether they are retained or rejected. Please note that for routine “baseline” applications, any rejected data must be actively excluded from the provided data sets, while for “non-baseline” applications data flagged under categories (ii) and (iii) above may carry biogeochemical information (see DATA FORMAT section below). Also, further data selection may be desirable for those data sets that cannot be screened by the 3-sigma filter (e.g. AIA; aircraft). |
| Processing for averaging |
: |
Processing for Monthly Data:
For the geographically fixed sites, data are also provided in the form of monthly means, which are calculated as the mean of daily values from a smooth curve fit to the data using the curve-fitting routines described by Thoning et al. (1989). |
| Data flag |
: |
flags: “...” indicates no flags, sample retained. Any entry other than “.” in the first flag column indicates the sample is not representative of the time and place of sampling:
A = no sample taken
B = sample lost before analysis
C = identified sampling error
D = suspected sampling problem (eg. 2 or more species give anomalous values)
E = mixed samples (time/place not unique)
N = unacceptable analysis
* = no analysis data available
H = species-specific manually applied rejection flag
I = species-specific sample collection problem
J = irretrievable sample storage effect
. = not subject to any of the above flags
Any entry other than “.” in the second flag column indicates the sample is non-baseline, rejected only on grounds of being an outlier or is excluded from this data set because of a non-standard sampling technique.
F = non-baseline meteorological conditions
G = marginal-baseline meteorological conditions
K = species-specific non-baseline meteorological conditions
L = species-specific marginal-baseline meteorological conditions
M = 3 sigma filter rejected
O = non-standard sampling technique
. = not subject to any of the above flags |
| Data remarks |
: |
REM is the flask ID code |
| Other Information |
| Scientific aim |
: |
To provide high quality measurements of atmospheric composition (the major long-lived greenhouse gases, and some related species) that can be used in studies of global biogeochemical cycles, particularly the global carbon cycle. To make it possible to seamlessly merge these measurements with those made by other organisations for purposes of modelling and interpretation. |
| Reference |
: |
Bhattacharya, S.K., D.V. Borole, R.J. Francey, C.E. Allison, L.P. Steele, P. Krummel, R. Langenfelds, K.A. Masarie, Y.K. Tiwari and P.K. Patra, Trace gases and CO2 isotope records from Cabo de Rama, India, Current Science, 97, 9, 2009.
Bousquet, P., C. Yver, I. Pison, Y.S. Li, A. Fortems, D. Hauglustaine, S. Szopa, P.J. Rayner, P. Novelli, R. Langenfelds, P. Steele, M. Ramonet, M. Schmidt, P. Foster, C. Morfopoulus & P. Ciais, A three-dimensional synthesis inversion of the molecular hydrogen cycle: Sources and sinks budget and implications for the soil uptake, J. Geophys. Res., 116, D01302, doi:10.1029/2010JD014599, 2011.
Cooper, L.N., L.P. Steele, R.L. Langenfelds, D.A. Spencer and M.P. Lucarelli. Atmospheric methane, carbon dioxide, hydrogen, carbon monoxide and nitrous oxide from Cape Grim flask air samples analysed by gas chromatography. Baseline Atmospheric Program (Australia) 1996, edited by J.L. Gras, N. Derek, N.W. Tindale and A.L. Dick, pp 98 - 102, Bureau of Meteorology and CSIRO Atmospheric Research, Melbourne, Australia, 1999.
Francey, R.J., L.P. Steele, R.L. Langenfelds, M.P. Lucarelli, C.E. Allison, D.J. Beardsmore, S.A. Coram, N. Derek, F.R. de Silva, D.M. Etheridge, P.J. Fraser, R.J. Henry, B. Turner, E.D. Welch, D.A. Spencer and L.N. Cooper. Global Atmospheric Sampling Laboratory (GASLAB): supporting and extending the Cape Grim trace gas programs. Baseline Atmospheric Program (Australia) 1993, edited by R.J.
Francey, A.L. Dick and N. Derek, pp 8 - 29, Bureau of Meteorology and CSIRO Division of Atmospheric Research, Melbourne, Australia, 1996.
Francey, R.J., L.P. Steele, R.L. Langenfelds, C.E. Allison, L.N.
Cooper. B.L. Dunse, B.G. Bell, T.D. Murray, H.S. Tait, L. Thompson and K.A. Masarie. Atmospheric carbon dioxide and its isotopes, methane, carbon monoxide, nitrous oxide and hydrogen from Shetland. Atmos. Environ., 32, 3331-3338, 1998.
Francey, R.J., L.P. Steele, R.L. Langenfelds and B.C. Pak, High precision long-term monitoring of radiatively-active trace gases at surface sites and from ships and aircraft in the Southern Hemisphere atmosphere. J. Atmos. Science, 56, 279-285, 1999.
Francey, R.J., L.P. Steele, D.A. Spencer, R.L. Langenfelds, R.M. Law, P.B. Krummel, P.J. Fraser, D.M. Etheridge, N. Derek, S.A. Coram, L.N. Cooper, C.E. Allison, L. Porter and S. Baly, The CSIRO (Australia) measurement of greenhouse gases in the global atmosphere, report of the 11th WMO/IAEA Meeting of Experts on Carbon Dioxide Concentration and Related Tracer Measurement Techniques, Tokyo, Japan, September 2001, S.Toru and S. Kazuto (editors), World Meteorological Organization Global Atmosphere Watch, 97-111, 2003.
Jordan, A. and B. Steinberg (2011), Calibration of atmospheric hydrogen measurements, Atmos. Meas. Tech., 4, 509–521, doi:10.5194/amt-4-509-2011.
Langenfelds, R.L., R.J. Francey, L.P. Steele, P.J. Fraser, S.A. Coram, M.R. Hayes, D.J. Beardsmore, M.P. Lucarelli, and F.R. de Silva, Improved vertical sampling of the trace gas composition of the troposphere above Cape Grim since 1991, in Baseline Atmospheric Program (Australia) 1993, edited by R.J. Francey, A.L. Dick and N. Derek, pp 45-56, Bureau of Meteorology and CSIRO Division of Atmospheric Research, Melbourne, Australia, 1996.
Langenfelds, R.L., L.N. Cooper, L.P. Steele, D.A. Spencer, P.B. Krummel and P.J. Fraser. Atmospheric methane, carbon dioxide, hydrogen, carbon monoxide and nitrous oxide from Cape Grim flask air samples analysed by gas chromatography. Baseline Atmospheric Program (Australia) 1997-98, edited by N.W. Tindale, N. Derek, and R.J. Francey, pp 69 - 74, Bureau of Meteorology and CSIRO Atmospheric Research, Melbourne, Australia, 2001a.
Langenfelds, R.L., R.J. Francey, L.P. Steele, D.A. Spencer and B.L. Dunse, Flask sampling from Cape Grim overflights, in Baseline Atmospheric Program (Australia) 1997-98, edited by N.W. Tindale, N. Derek and R.J. Francey, pp 74 - 84, Bureau of Meteorology and CSIRO Atmospheric Research, Melbourne, Australia, 2001b.
Langenfelds, R.L., R.J. Francey, B.C. Pak, L.P. Steele, J. Lloyd, C.M. Trudinger and C.E. Allison, Interannual growth rate variations of atmospheric CO2 and its 13C, H2, CH4 and CO between 1992 and 1999 linked to biomass burning, Glob. Biogeochem. Cycles, 16(3), 1048, doi:10.1029/2001GB001466, 2002a.
Langenfelds, R.L., Studies of the global carbon cycle using atmospheric oxygen and associated tracers, PhD thesis, University of Tasmania, Hobart, Australia, 320 pp., 2002b.
Langenfelds, R.L., P.B. Krummel, C.E. Allison, R.J. Francey, L.P. Steele, L.N. Cooper, D.E.J. Worthy, L. Huang, M. Ernst and A. Chivulescu, Intercomparison of MSC and CSIRO trace gas data from Alert and Estevan Point, Canadian Baseline Program Summary of Progress to 2002, Meteorological Service of Canada, 67-76, 2003a.
Langenfelds, R.L., R.J. Francey, L.P. Steele, B.L. Dunse, T.M. Butler, D.A. Spencer, L.M. Kivlighon and C.P. Meyer, Flask sampling from Cape Grim overflights, in Baseline Atmospheric Program (Australia) 1999-2000, edited by N.W. Tindale, N. Derek and P.J. Fraser, pp 73 - 75, Bureau of Meteorology and CSIRO Atmospheric Research, Melbourne, Australia, 2003b.
Langenfelds, R.L., M.V. van der Schoot, L.P. Steele, L.N. Cooper, D.A.Spencer and P.B. Krummel, Atmospheric methane, carbon dioxide, hydrogen, carbon monoxide and nitrous oxide from Cape Grim flask air samples analysed by gas chromatography. Baseline Atmospheric Program (Australia) 2001-2002, edited by J. Cainey, N. Derek, and P.B. Krummel, pp 46 - 47, Bureau of Meteorology and CSIRO Atmospheric Research, Melbourne, Australia, 2004.
Masarie, K.A., R.L. Langenfelds, C.E. Allison, T.J. Conway, E.J. Dlugokencky, R.J. Francey, P.C. Novelli, L.P. Steele, P.P. Tans, B. Vaughn and J.W.C. White, NOAA/CSIRO Flask Air Intercomparison Experiment: A strategy for directly assessing consistency among atmospheric measurements made by independent laboratories, J. Geophys. Res., 106, 20445-20464, 2001.
Pak, B.C., R.L. Langenfelds, R.J. Francey, L.P. Steele and I. Simmonds, A climatology of trace gases from the Cape Grim overflights, 1992 - 1995, in Baseline Atmospheric Program (Australia) 1994-5, edited by R.J. Francey, A.L. Dick and N. Derek, pp 41 - 52, Bureau of Meteorology and CSIRO Division of Atmospheric Research, Melbourne, Australia, 1996.
Pak, B.C., Vertical structure of atmospheric trace gases over Southeast Australia, PhD Thesis, University of Melbourne, Australia, 273 pp. (available at the University of Melbourne ePrints Repository via http://www.lib.unimelb.edu.au/eprints/), 2000.
Pak, B. C., R.L. Langenfelds, S.A. Young, R.J. Francey, C.P. Meyer, L.M. Kivlighon, L.N. Cooper, B.L. Dunse, C.E. Allison, L.P. Steele, I.E. Galbally and I.A. Weeks, Measurements of biomass burning influences in the troposphere over southeast Australia during the SAFARI 2000 dry season campaign, J. Geophys. Res., 108(D13), 8480, doi:10.1029/2002JD002343, 2003.
Pieterse, G., M.C. Krol, A.M. Batenburg, L. P. Steele, P.B. Krummel, R. Langenfelds and T. Rockmann, Global modelling of H2 mixing ratios and isotopic compositions with the TM5 model, Atmos. Chem. Phys., 11, doi:10.5194/acp-11-7001-2011, 2011.
Pieterse, G., M.C. Krol, A.M. Batenburg, C.A.M. Brenninkmeijer, M.E. Popa, S. O’Doherty, A. Grant, L. P. Steele, P.B. Krummel, R. Langenfelds, H.J. Wang, A.T. Vermuelen, M. Schmidt, C. Yver, A. Jordan, A. Engel, R.E. Fisher, D. Lowry, E.G. Nisbet, S. Reimann, M.K. Vollmer, M. Steinbacher, S. Hammer, G. Forster, W.T. Sturges and T. Rockmann, Reassessing the variability in atmospheric H2 using the two-way nested TM5 model, J. Geophys. Res. Atmos., 118, 3764-3780, doi:10.1002/jgrd.50204, 2013.
Steele, L.P., R.L. Langenfelds, M.P. Lucarelli, P.J. Fraser, L.N. Cooper, D.A. Spencer, S. Chea and K. Broadhurst. Atmospheric methane, carbon dioxide, carbon monoxide, hydrogen and nitrous oxide from Cape Grim flask air samples analysed by gas chromatography. Baseline Atmospheric Program (Australia) 1994-95, edited by R.J. Francey, A.L. Dick and N. Derek, pp 107 - 110, Bureau of Meteorology and CSIRO Division of Atmospheric Research, Melbourne, Australia, 1996.
Sturm, P., M. Leuenberger, C. Sirignano, R. E. M. Neubert, H. A. J. Meijer, R. Langenfelds, W. A. Brand and Y. Tohjima, Permeation of atmospheric gases through polymer O-rings used in flasks for air sampling, J. Geophys. Res., 109, D04309, doi:10.1029.2003JD004073, 2004.
Thoning, K.W., P.P. Tans and W.D. Komhyr, Atmospheric carbon dioxide at Mauna Loa Observatory, 2, Analysis of the NOAA/GMCC data, 1974 - 1985, J. Geophys. Res., 94, 8549-8565, 1989.
Xiao, X., R. Prinn, P. Simmonds, L.P. Steele, P. Novelli, J. Huang, R.L. Langenfelds, S. O’Doherty, P.B. Krummel, P.J. Fraser, L.W. Porter, R.F. Weiss, P. Salameh and R.H.J. Wang, Optimal estimation of the soil uptake rate of molecular hydrogen from the Advanced Global Atmospheric Gases Experiment and other measurements, J. Geophys. Res., 112, D07303, doi:10.1029/2006JD007241, 2007. |
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