| Summary: | Progress Code: onGoing Maintenance and Update Frequency: continual Statement: Ion corrections applied to stable isotope measurements using CO2 and N2O measurements taken by gas chromatography with FID & ECD detectors. Results adjusted onto the VPDB-CO2 scale. Flask data are assigned flags to indicate whether they are classified as retained or rejected. Monthly means 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). Credit CSIRO - Marine and Atmospheric Research (CMAR), Australian Bureau of Meteorology (BoM), Australian Antarctic Division (AAD), Australian Institute of Marine Science (AIMS), National Oceanic and Atmospheric Administration (NOAA), Environment Canada (EC). Credit Colin Allison(CSIRO) Credit Paul Krummel (CSIRO) Credit Paul Steele (CSIRO). The CSIRO Global Atmospheric Sampling Laboratory (GASLAB) Flask Sampling Network archive for the oxygen 18 isotope (O18) of atmospheric trace gas carbon dioxide (CO2) concentrations. GASLAB principally analyzes air samples that have been captured at eleven fixed geographic sites and one moving (aircraft over bass strait and Cape Grim), but also includes other sites at various locations globally on a less regular or as needed basis. The CO2O18 measurements are made by concentrating the CO2 from the air sample utilising a 3 step automated cryogenic trapping system connected to a dual inlet stable isotope ratio mass spectrometer (Finnigan MAT252) for analysis. The CO2 and N2O gas chromatography concentrations data for the sample are used for ion corrections on the stable isotope measurements. Alternatively the Cape Grim in situ air sample (cia) which has already had the trapping process applied to it on site, uses the data from the Cape Grim in situ CO2 analyser, with the N2O concentration determined by interpolation from the CSIRO global flask network data. There are 6 differant types of flask that are used to store and transport air samples from site ...
|
|---|