 |
| Titel |
Jena Reference Air Set (JRAS): a multi-point scale anchor for isotope measurements of CO2 in air |
| VerfasserIn |
M. Wendeberg, J. M. Richter, M. Rothe, W. A. Brand |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 6, no. 3 ; Nr. 6, no. 3 (2013-03-26), S.817-822 |
| Datensatznummer |
250017850
|
| Publikation (Nr.) |
 copernicus.org/amt-6-817-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
The need for a unifying scale anchor for isotopes of CO2 in air was
brought to light at the 11th WMO/IAEA Meeting of Experts on Carbon Dioxide in
Tokyo 2001. During discussions about persistent discrepancies in isotope
measurements between the worlds leading laboratories, it was concluded that a
unifying scale anchor for Vienna Pee Dee Belemnite (VPDB) of CO2 in air was desperately needed.
Ten years later, at the 2011 Meeting of Experts on Carbon Dioxide in Wellington, it
was recommended that the Jena Reference Air Set (JRAS) become the official
scale anchor for isotope measurements of CO2 in air (Brailsford, 2012).
The source of CO2 used for JRAS is two calcites. After releasing
CO2 by reaction with phosphoric acid, the gases are mixed into
CO2-free air. This procedure ensures both isotopic stability and
longevity of the CO2. That the reference CO2 is generated from
calcites and supplied as an air mixture is unique to JRAS. This is made to
ensure that any measurement bias arising from the extraction procedure is
eliminated. As every laboratory has its own procedure for extracting the
CO2, this is of paramount importance if the local scales are to be
unified with a common anchor.
For a period of four years, JRAS has been evaluated through the
IMECC1 program, which made it possible to
distribute sets of JRAS gases to 13 laboratories worldwide. A summary of
data from the six laboratories that have reported the full set of results is
given here along with a description of the production and maintenance of the
JRAS scale anchors.
1 IMECC refers to the EU project "Infrastructure for
Measurements of the European Carbon Cycle"
(http://imecc.ipsl.jussieu.fr/). |
| |
|
| Teil von |
|
|
|
|
|
|
|
|