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WDCGG Data Submission and Dissemination Guide (PDF 1.2Mbyte)

WDCGG leaflet (PDF 2.7MByte, July 2008)

Alert - CSIRO

Parameter Inventory Parameter Metadata Station Contributor
13CO2 *
flask
CH4 * *
flask
CO *
flask
CO2 * *
flask
H2 *
flask
N2O ** *
flask
Observation Processing/Calibration Contact Person Reference Data/Quick Plot
Category Air sampling observation
Sampling Type flask
Sampling Height/Depth
Sampling and Analysis Frequency
Sampling Environment
Measurement Method Mass Spectrometry
Current status and history of Instruments dual-inlet Finnigan MAT252 stable isotope ratio mass spectrometer (IRMS) following cryogenic extraction of CO2 from sample air using the Finnigan MAT252 MT-Box-C attachment
Description of Instruments
Time Zone UTC
Data Period 1990-01-01 - 2016-12-30
Data Type event, monthly
Parameter detail
Other Descriptions for Sampling and Analyses 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 Environment Canada for air sampling at the Canadian sites, Alert and Estevan Point (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 CO2 mixing ratio during storage have shown significant drifts in some flask types over test periods of several months to years (Cooper et al., 1999) and can be largely attributed to permeation through O-rings (Langenfelds, 2002; Sturm et al., 2004). Corrections are applied to network CO2 concentration data according to flask type, sample and ambient pressure, but no significant changes in stable isotopic composition were observed and no correction is applied to the d13c or d18o data from this source. 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 are measured using a dual-inlet Finnigan MAT252 stable isotope ratio mass spectrometer (IRMS) following cryogenic extraction of CO2 from sample air using the Finnigan MAT252 MT-Box-C attachment. The CO2 from sample air is assigned an isotopic composition relative to the mean isotopic composition in CO2 obtained from bracketing extractions and measurement of standard air in a high pressure cylinder. The measured d13C and d18O of CO2 in flask-air from the CSIRO GASLAB global network are reported on the international VPDB-CO2 scale, via a precisely-maintained internal scale designated CSIRO2005:CO2-in-air.
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
Supporting Contributor(s)
Last update 2017-08-07
Situation ongoing

Category Parameter Country/Territory Contributor
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in cooperation with the World Meteorological Organization
(Created : 2001/07/02    Updated : 2017/12/05)

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