We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Intercomparison of in-situ NDIR and column FTIR measurements of CO<sub>2</sub> at Jungfraujoch.
- Authors
Schibig, Michael F.; Mahieu, Emmanuel; Henne, Stephan; Lejeune, Bernard; Leuenberger, Markus C.
- Abstract
We compare two CO2 time series measured at the High Alpine Research Station Jungfraujoch (3580 m a.s.l., Switzerland) in the period from 2005 to 2013 with an in-situ surface measurement system using a nondispersive infrared analyzer (NDIR) and a ground-based remote sensing system using solar absorption Fourier Transform Infrared spectrometry (FTIR). Although the two data sets show an absolute shift of about 13 ppm, the slopes of the annual CO2 increase are in good agreement within their uncertainties. They are 2.04 ± 0.07 ppm yr-1 and 1.97 ± 0.05 ppm yr-1 for the FTIR and the NDIR system, respectively. The seasonality of the FTIR and the NDIR system is 4.46 ± 1.11 ppm and 10.10 ± 0.73 ppm, respectively. The difference is caused by a dampening of the CO2 signal with increasing altitude due to mixing processes. While the minima of both data series occur in the middle of August, the maxima of the two datasets differ by about ten weeks, the maximum of the FTIR measurements is in middle of January, whereas the maximum of the NDIR measurements is found at the end of March. Sensitivity analyses revealed that the air masses measured by the NDIR system at the surface of Jungfraujoch are mainly influenced by central Europe, whereas the air masses measured by the FTIR system in the column above Jungfraujoch are influenced by regions as far west as the Caribbean and the United States. The correlation between the hourly averaged CO2 values of the NDIR system and the individual FTIR CO2 measurements is 0.820, which is very encouraging given the largely different sampling volumes. Further correlation analyses showed, that the correlation is mainly driven by the annual CO2 increase and to a lesser degree by the seasonality. Both systems are suitable to monitor the long-term CO2 increase, because this signal is represented in the whole atmosphere due to mixing.
- Subjects
FOURIER transform infrared spectroscopy; ATMOSPHERIC carbon dioxide; MIXING; AIR masses; ATMOSPHERIC models
- Publication
Atmospheric Chemistry & Physics Discussions, 2016, Vol 16, Issue 3, p1
- ISSN
1680-7367
- Publication type
Article
- DOI
10.5194/acp-2016-125