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dc.contributor.author
Schibig, Michael F.
dc.contributor.author
Steinbacher, Martin
dc.contributor.author
Buchmann, Brigitte
dc.contributor.author
Laan-Luijkx, Ingrid T. van der
dc.contributor.author
Laan, Sander Van Der
dc.contributor.author
Ranjan, Shyam
dc.contributor.author
Leuenberger, Markus C.
dc.date.accessioned
2019-08-26T17:16:54Z
dc.date.available
2017-06-11T16:48:02Z
dc.date.available
2019-08-26T17:16:54Z
dc.date.issued
2015
dc.identifier.issn
1867-1381
dc.identifier.issn
1867-8548
dc.identifier.other
10.5194/amt-8-57-2015
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/99636
dc.identifier.doi
10.3929/ethz-b-000099636
dc.description.abstract
Since 2004, atmospheric carbon dioxide (CO2) is being measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP) using a nondispersive infrared gas analyzer (NDIR) in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring-down spectroscopy (CRDS) as part of the Swiss National Air Pollution Monitoring Network were added by the Swiss Federal Laboratories for Materials Science and Technology (Empa). To ensure a smooth transition – a prerequisite when merging two data sets, e.g., for trend determinations – the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows the identification of potential offsets between the two data sets and the collection of information about the compatibility of the two systems on different time scales. A good agreement of the seasonality, short-term variations and, to a lesser extent mainly due to the short common period, trend calculations is observed. However, the comparison reveals some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It is possible to adapt an improved calibration strategy based on standard gas determinations, which leads to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS – NDIR) of the two systems is −0.03 ppm ± 0.25 ppm. Although the difference of the two data sets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO), the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min) for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additional time for signal stabilization after switching the sample, an effective data coverage of only one-sixth for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates may affect observed differences.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
Copernicus
en_US
dc.rights.uri
http://creativecommons.org/licenses/by/3.0/
dc.title
Comparison of continuous in situ CO2 observations at Jungfraujoch using two different measurement techniques
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution 3.0 Unported
dc.date.published
2015-01-06
ethz.journal.title
Atmospheric Measurement Techniques
ethz.journal.volume
8
en_US
ethz.journal.issue
1
en_US
ethz.journal.abbreviated
Atmos. meas. tech.
ethz.pages.start
57
en_US
ethz.pages.end
68
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.identifier.wos
ethz.identifier.nebis
010152804
ethz.publication.place
Göttingen
en_US
ethz.publication.status
published
en_US
ethz.date.deposited
2017-06-11T16:48:41Z
ethz.source
ECIT
ethz.identifier.importid
imp5936530f5e09213206
ethz.ecitpid
pub:155948
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2017-07-17T08:32:50Z
ethz.rosetta.lastUpdated
2019-08-26T17:17:09Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
ethz.COinS
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