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Title: CSIRO GASLAB Network: Individual Flask Measurements of Atmospheric Trace Gases (April 2003)

Data are available for four atmospheric trace gases at nine stationary sites and one moving platform (aircraft over Cape Grim, Tasmania, and Bass Strait, between the Australian continent and Tasmania). The trace gases are carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and hydrogen (H2). Measurements of δ13C from CO2 are also included in this database. The nine stationary sites are, from north to south: Alert, Canada; Shetland Islands, Scotland; Estevan Point, Canada; Mauna Loa, Hawaii; Cape Ferguson, Australia; Cape Grim, Australia (Tasmania); Macquarie Island, Australia; Mawson, Antarctica; and the South Pole station, Antarctica.
Authors:
 [1] ;  [1] ;  [1]
  1. Commonwealth Scientific and Industrial Research Organisation (CSIRO), Aspendale, Victoria, Australia
Publication Date:
Report Number(s):
DB-1021
Product Type:
Dataset
Research Org(s):
Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (USA)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Subject:
54 ENVIRONMENTAL SCIENCES
OSTI Identifier:
1389381
No associated Projects found.
No associated Collections found.
  1. This data set presents globally averaged atmospheric concentrations of chlorofluorocarbon 11, known also as CFC-11 or F-11 (chemical name: trichlorofluoromethane; formula: CCl3F). The monthly global average data are derived from flask air samples collected at eight sites in six locations over the period August 1980-Julymore » 1992. The sites are Barrow (Alaska), Cape Meares (Oregon), Cape Kumukahi and Mauna Loa (Hawaii), Cape Matatula (American Samoa), Cape Grim (Tasmania), Palmer Station, and the South Pole (Antarctica). At each collection site, monthly averages were obtained from three flask samples collected every week. In addition to the monthly global averages available for 1980-992, this data set also contains annual global average data for 1975-1985. These annual global averages were derived from January measurements at the South Pole and in the Pacific Northwest of the United States (specifically, Washington state and the Oregon coast). « less
  2. This data set provides monthly average concentrations of atmospheric methyl chloride taken from seven locations distributed among the polar, middle, and tropical latitudes of both hemispheres. The seven primary sites include Pt. Barrow, Alaska; Cape Kumukahi and Mauna Loa, Hawaii; Cape Matatula, Samoa; Cape Grim,more » Tasmania; and the South Pole and Palmer Station, Antarctica. Concentration measurements from these seven sites cover a period of 16 years, extending from 1981-1997. Monthly data taken between 1987-1989 from 20 short-term sites and vertical distribution measured at various latitudes are also provided. Air samples were collected from various sites in stainless steel flasks and methyl chloride concentrations were measured using an Electron Capture Gas Chromatograph. Concentrations are reported as mixing ratios in dry air. The concentrations are determined by using a set of calibration standards that are referenced against a primary standard which is also used to establish the absolute concentration. The primary standards were prepared by the investigators in the absence of an available standard from a centralized location. The data are useful in global methyl chloride budget analyses and for determining the atmospheric distribution and trends of methyl chloride and estimating the total emissions at various latitudes. « less
  3. The Antarctic CH4 records presented here are derived from three ice cores obtained at Law Dome, East Antarctica (66°44'S, 112°50'E, 1390 meters above mean sea level). Law Dome has many qualities of an ideal ice core site for the reconstruction of past concentrations of atmosphericmore » gases; these qualities include: negligible melting of the ice sheet surface, low concentrations of impurities, regular stratigraphic layering undisturbed by wind stress at the surface or differential ice flow at depth, and a high snow accumulation rate. Further details on the site, drilling, and cores are provided by Etheridge et al. (1998), Etheridge et al. (1996), Etheridge and Wookey (1989), and Morgan et al. (1997). The two Greenland ice cores are from the Summit region (72°34' N, 37°37' W, 3200 meters above mean sea level). Lower snow accumulation rate there results in lower air-age resolution, and measurements presented here cover only the pre-industrial period (until 1885). More details about these measurements are presented in Etheridge et al. (1998). Additionally, this site contains firn data from Core DE08-2, and archived air samples from Cape Grim, Tasmania, for comparison. « less
  4. In the ALE/GAGE/AGAGE global network program, continuous high frequency gas chromatographic measurements of four biogenic/anthropogenic gases (methane, CH4; nitrous oxide, N2O; hydrogen, H; and carbon monoxide, CO) and several anthropogenic gases that contribute to stratospheric ozone destruction and/or to the greenhouse effect have been carriedmore » out at five globally distributed sites for several years. The program, which began in 1978, is divided into three parts associated with three changes in instrumentation: the Atmospheric Lifetime Experiment (ALE), which used Hewlett Packard HP5840 gas chromatographs; the Global Atmospheric Gases Experiment (GAGE), which used HP5880 gas chromatographs; and the present Advanced GAGE (AGAGE). AGAGE uses two types of instruments: a gas chromatograph with multiple detectors (GC-MD), and a gas chromatograph with mass spectrometric analysis (GC-MS). Beginning in January 2004, an improved cryogenic preconcentration system (Medusa) replaced the absorption-desorption module in the GC-MS systems at Mace Head and Cape Grim; this provided improved capability to measure a broader range of volatile perfluorocarbons with high global warming potentials. More information may be found at the AGAGE home page: http://agage.eas.gatech.edu/instruments-gcms-medusa.htm. « less
  5. Since 1982, a continuous program of sampling atmospheric CO2 to determine stable isotope ratios has been maintained at the Australian Baseline Air Pollution Station, Cape Grim, Tasmania (40°, 40'56"S, 144°, 41'18"E). The process of in situ extraction of CO2 from air, the preponderance of samplesmore » collected in conditions of strong wind from the marine boundary layer of the Southern Ocean, and the determination of all isotope ratios relative to a common high purity CO2 reference gas with isotopic δ13C close to atmospheric values, are a unique combination of factors with respect to obtaining a globally representative signal from a surface site. Air samples are collected during baseline condition episodes at a frequency of around one sample per week. Baseline conditions are characterized by wind direction in the sector 190°-280°, condensation nucleus concentration below 600 per cm-3, and steady continuous CO2 concentrations (variation ± 0.2 ppmv per hour). A vacuum pump draws air from either the 10 m or 70 m intakes and sampling alternates between the two intakes. The air from the intake is dried with a trap immersed in an alcohol bath at about -80°C. Mass spectrometer analyses for δ13C and δ18O are carried out by CSIRO's Division of Atmospheric Research in Aspendale, usually one to three weeks following collection. This record is possibly the most accurate representation of global atmospheric 13C behavior over the last decade and may be used to partition the uptake of fossil-fuel carbon emissions between ocean and terrestrial plant reservoirs. Using these data, Francey et al. (1995) observed a gradual decrease in δ13C from 1982 to 1993, but with a pronounced flattening from 1988 to 1990; a trend that appears to involve the terrestrial carbon cycle. « less