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.
from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2xxUtGl
via IFTTT
Εγγραφή σε:
Σχόλια ανάρτησης (Atom)
Δημοφιλείς αναρτήσεις
-
Publication date: Available online 4 January 2018 Source: European Journal of Radiology Author(s): Peiyao Zhang, Jing Wang, Qin Xu, Zhen...
-
Dtsch med Wochenschr DOI: 10.1055/s-0043-100054 Hintergrund und Fragestellung Ein etablierter Weg, die optimale Behandlung von Tumorpatien...
-
Publication date: March 2017 Source: Free Radical Biology and Medicine, Volume 104 from #AlexandrosSfakianakis via Alexandros G.Sfak...
-
Background Hyperthyroidism is associated with increased thrombotic risk. As contact system activation through formation of neutrophil extrac...
-
Antibodies, Vol. 9, Pages 21: Construction of Ant... In Vivo and In Vitro Evaluation of Bull Semen Pro... Vertebral artery fenestration mimi...
-
Deepak Thapa, Vanita Ahuja, Deepanshu Dhiman Indian Journal of Anaesthesia 2017 61(12):1012-1014 from #AlexandrosSfakianakis via Alexa...
-
Editors' Recognition for Reviewing in 2020 No abstract available Establishing Satellite Lung Cancer Screening Sites With Telehealth to A...
-
ecancer is supporting #BowelCancerAwarenessMonth https://t.co/opXxCAAxzE from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inore...
-
Abstract Silvicultural models are often developed and applied without due consideration of fire modelling. Yet, this information is import...
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου