------------------------------------------------------------------------------- Readme file to accompany CSIRO gaslab flask data: CH4 v20030429, CO v20030429, CO2 v20030429, H2 v20030429, 13CO2 v20030508 ------------------------------------------------------------------------------- TERMS AND CONDITIONS (Adapted from NOAA and NACP data policy) ------------------------------------------------------------- Use of these data in any part implies an agreement on the part of the user that individuals and/or institutions responsible for contributing to data sets used must be specifically cited in addition to a general citation of the NACP greenhouse gas database. All gases can be cited as: Steele, L.P., Krummel, P.R., and Langenfelds, R. L., CSIRO GASLAB Network: Individual Flask Measurements of Atmospheric Trace Gases (April 2003), DOI: 10.3334/CDIAC/atg.db1021 http://cdiac.ornl.gov/epubs/db/db1021/db1021.html. NACP investigators will include an acknowledgement in each publication or presentation arising from participation in NACP. The wording shall be similar to the following: "This study was part of the North American Carbon Program." Data providers and funding agencies may request additional acknowledgements. Upon publication of results, investigators should send the NACP Office an electronic copy of the publication. USE OF DATA These data are made freely available to the public and the scientific community in the belief that their wide dissemination will lead to a greater understanding and new scientific insights. The availability of these data does not constitute publication of the data. We rely on the ethics and integrity of the user to assure that the source(s) receive fair credit for their work. If the data are obtained for potential use in a publication or presentation, the source(s) should be informed at the outset of the nature of this work. If the source's data are essential to the work, or if an important result or conclusion depends on their data, co-authorship may be appropriate. This should be discussed at an early stage in the work. Manuscripts using the source's data should be sent to the source(s) for review before they are submitted for publication so we can ensure that the quality and limitations of the data are accurately represented. RECIPROCITY AGREEMENT Use of these data implies an agreement to reciprocate. Laboratories making similar measurements agree to make their own data available to the general public and to the scientific community in an equally complete and easily accessible form. Modelers are encouraged to make available to the community, upon request, their own tools used in the interpretation of the source data, namely well documented model code, transport fields, and additional information necessary for other scientists to repeat the work and to run modified versions. Model availability includes collaborative support for new users of the models. CSIRO FLASK DATA PROJECT PURPOSE & DESCRIPTION ---------------------------------------------- The PIs for the project are: Paul Krummel, Commonwealth Scientific and Industrial Research Organisation (CSIRO) Atmospheric Research, paul.krummel@csiro.au Ray Langenfelds, CSIRO Atmospheric Research, ray.langenfelds@csiro.au Paul Steele, CSIRO Atmospheric Research, paul.steele@csiro.au Colin Allison, CSIRO Atmospheric Research, colin.allison@csiro.au Roger Francey, CSIRO Atmospheric Research, roger.francey@csiro.au I. Introduction The CSIRO flask study presents data from 1984 to 2001, based at 9 stationary surface sites and one moving platform. These stations span the globe, but there are three sites of interest for North America: Alert, Canada (82.45, -62.51, 6 masl); Mauna Loa, HI (19.54, -155.58, 3397 masl); and Estevan Point, Canada (49.58, -126.37, 39 masl), denoted by the station codes ALT, MLO, and ESP. The study traces four crucial gases, CH4, CO2, CO, and H2, with a number of daily flask samples each week. These four gases have been chosen due to their impact on climate change. CO2 and CH4 are the two most effective anthropogenic greenhouse gases; CO and H2 influence concentrations of the hydroxyl radical (OH), thereby affecting the main sink for atmospheric CH4. H2 is produced in a sequence of reactions following the reaction of OH with CH4. Additional reactions involving these compounds and their importance for atmospheric chemistry are discussed by Langenfelds et al., Global Biogeochemical Cycles 16(3), 2002. The 13C isotope data are useful in identifying sources of atmospheric CO2. The flasks are of 5 types: (i) glass 0.5 litre, sealed with two stopcocks fitted with PTFE, PFA or Viton O-rings (flask identifier prefix "G050"), (ii) glass 5.0 litre, sealed with two stopcocks fitted with PTFE O-rings ("G500"), (iii) glass 0.8 litre, sealed with two stopcocks fitted with PTFE or PFA O-rings ("G080"), (iv) electropolished stainless steel 1.6 litre "Sirocans" fitted with two stainless steel valves manufactured by either Nupro or Hoke ("S160"), (v) glass 2.0 litre sealed with a single stopcock fitted with a Viton O-ring ("F", "FF", "FA", "FE", "EP", ALT") and provided by the Meteorological Service of Canada for air sampling at the Canadian sites, ALT, ESP and Fraserdale. Flasks are analyzed at GASLAB, where gas chromatography with various detection methods is used for mixing ratios, while mass spectrometry (MS) determines isotopic composition. For more information and data updates, visit: http://cdiac.ornl.gov/epubs/db/db1021/db1021.html II. Methods parameter method PI a. CO Gas Chromatography (GC) P. Steele, P. Krummel, R. with mercuric oxide Langenfelds, CSIRO reduction. CO reduces HgO to Hg vapor which is detected by UV absorption. RGA3-1 (R1) Trace Analytical gas chromatograph was used over the length of the record. b. CH4 GC with flame ionization detection (FID). Three Carle GC's were used: Carle-1, Carle-2, and Carle-3 (C1, C2, C3) c. CO2 GC/FID d. H2 GC/HgO e. 13CO2 dual inlet stable P. Krummel, C. Allison, isotope ratio mass R. Francey, CSIRO spectrometry (M1, Finnigan MAT252), after CO2 was captured with automated cryogenic trapping system. VARIABLE NAMES -------------- YYYYMMDD : Year, month, and day of sampling doy : Absolute day of year UTC : Universal Coordinated Time, in seconds from midnight flask.ID : Canister identification number sample.method : method of sample collection. See below for sample collection code instrument : analytical instrument code. R1, M1, or C1, C2, C3 (see above) station : Three-letter NOAA station code latitude : Latitude, in degrees longitude : Longitude, in degrees altitude : altitude, in meters above sea level CH4_CSIRO : CH4 mixing ratio via GC/FID, in ppbv CH4_CSIRO.flag : 3-column data flags, see below for flag code CO_CSIRO : CO mixing ratio via GC/HgO, in ppbv CO_CSIRO.flag : 3-column data flags, see below for flag code CO2_CSIRO : CO2 mixing ratio via GC/FID, in ppmv CO2_CSIRO.flag : 3-column data flags, see below for flag code CO2C13_CSIRO : 13CO2 isotopic composition against VPDB-CO2 (standard) via mass spectrometry, in per mil CO2C13_CSIRO.flag: 3-column data flags, see below for flag code H2_CSIRO : H2 mixing ratio via GC/HgO, in ppbv H2_CSIRO.flag : 3-column data flags, see below for flag code MISSING VALUES -------------- For files in .RData format, missing values are represented by "NA" For files in .csv format, missing values are represented by "NaN" ------------------------------------------------------------------------------ sample collection method code for the retained data: A = GASLAB flask pump unit (FPU) with anhydrous Mg(ClO4)2 drying, D = metal bellows pump with anhydrous Mg(ClO4)2 drying, C = manual aircraft sampling unit with anhydrous Mg(ClO4)2 drying, H = automated aircraft sampling unit with anhydrous Mg(ClO4)2 drying, 6 = method not directly recorded SUMMARY OF SELECTION AND COMMENT 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