 |
| Titel |
Evaluating calibration strategies for isotope ratio infrared spectroscopy for atmospheric 13CO2 / 12CO2 measurement |
| VerfasserIn |
X.-F. Wen, Y. Meng, X.-Y. Zhang, X.-M. Sun, X. Lee |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 6, no. 6 ; Nr. 6, no. 6 (2013-06-05), S.1491-1501 |
| Datensatznummer |
250017907
|
| Publikation (Nr.) |
 copernicus.org/amt-6-1491-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Isotope ratio infrared spectroscopy (IRIS) provides an in situ technique for
measuring δ13C in atmospheric CO2. A number of methods
have been proposed for calibrating the IRIS measurements, but few studies
have systematically evaluated their accuracy for atmospheric applications.
In this study, we carried out laboratory and ambient measurements with two
commercial IRIS analyzers and compared the accuracy of four calibration
strategies. We found that calibration based on the 12C and 13C
mixing ratios (Bowling et al., 2003) and on linear interpolation
of the measured delta using the mixing ratio of the major isotopologue (Lee
et al., 2005) yielded accuracy better than 0.06‰. Over a
7-day atmospheric measurement in Beijing, the two analyzers agreed to within
−0.02 ± 0.18‰ after proper calibration.
However, even after calibration the difference between the two analyzers
showed a slight correlation with concentration, and this concentration
dependence propagated through the Keeling analysis, resulting in a much
larger difference of 2.44‰ for the Keeling intercept.
The high sensitivity of the Keeling analysis to the concentration dependence
underscores the challenge of IRIS for atmospheric research. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|