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

Data

Investigators

L.P. Steele, P.R. Krummel, and R.L. Langenfelds
Commonwealth Scientific and Industrial Research Organisation (CSIRO)

DOI

10.3334/CDIAC/atg.db1021

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.

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.

Details of the instruments and their calibration, analysis procedures, and reporting standards are given in separate readme files for each gas (e.g., readmeco2.txt, readmech4.txt, readmeco.txt, readmeh2.txt, readme13co2.txt). Additional discussion of calibration and error terms for all four gases and δ¹³C is provided in the file: (calib.txt).

Questionable or flawed data are left in this data base and flagged, and the user is cautioned accordingly. The "readme" files provide explanations of each data flag symbol. Interpretations of results obtained by analysis of this database should be examined to be sure they do not result from the use of data that are questionable or unacceptable for the particular analysis.

Data from aircraft flights over Bass Strait are particularly variable because a) more than one air mass may be sampled on any particular flight, b) samples are taken at varying altitudes, and c) the plume from the heavily populated Melbourne area is occasionally sampled. Such data points often represent valid samples and analyses, and they may be useful for certain investigations; therefore, they are not flagged. CDIAC recommends contacting the providers of these data before performing any detailed analyses.

^a The date given corresponds to the first data available for analysis, although flask sampling began 2 to 13 months earlier, depending on station.

^b Data are available from the last half of September, 1984; otherwise, the period of available data begins in February of 1985.

^c Data are available from June 1988 and August 1990, otherwise, the record of available data begins in late July of 1991.

May 2003