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Ten years of eddy covariance measurements in Basel, Switzerland: Seasonal and interannual variabilities of urban CO2 mole fraction and flux

Schmutz, Michael and Vogt, R. and Feigenwinter, C. and Parlow, E.. (2016) Ten years of eddy covariance measurements in Basel, Switzerland: Seasonal and interannual variabilities of urban CO2 mole fraction and flux. Journal of Geophysical Research JGR / D - Atmospheres, 121 (14). pp. 8649-8667.

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Official URL: http://edoc.unibas.ch/44286/

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Abstract

Eddy covariance (EC) measurements of carbon dioxide (CO2) in urban environments are carried out widely since the late nineties. However, long-term time series are still rare and little is known about long-term tendencies, even though cities are major sources of CO2 globally. Here a full decade of EC measurements from Basel, Switzerland, is presented. An approach for the calculation of horizontal averages is presented. It improves the significance and comparability of measured fluxes from heterogeneous environments and emphasizes the need of adequate weighting by horizontal averaging in such heterogeneous urban environments, especially for the derivation of cumulative quantities like the annual net ecosystem exchange. The urban CO2 mole fraction (ρC) is compared with regional background measurements, and good agreement in terms of long-term trend and seasonal variability is found. Over the last decade an increase of 2 ppm y1 is observed, both locally and globally. CO2 flux (FC) data are analyzed for diurnal and seasonal cycles as well as interannual variabilities. FC shows a large interannual variability in times of high source activity (e.g., during the day and in winter). In contrast, a relatively constant background flux of 5 μmolm2 s1 is found during periods of low source activity. The long-term trend of FC is mostly superimposed by the large temporal variability and is found to be 5% over the last 10 years.
Faculties and Departments:05 Faculty of Science > Departement Umweltwissenschaften > Meteorologie, Klimatologie und Fernerkundung > Meteorologie (Parlow)
UniBasel Contributors:Feigenwinter, Christian and Vogt, Roland and Parlow, Eberhard and Schmutz, Michael
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Wiley
ISSN:2169-897X
e-ISSN:2169-8996
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:01 Dec 2017 13:16
Deposited On:30 Oct 2017 10:46

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