Effects of urban density on carbon dioxide exchanges: Observations of dense urban, suburban and woodland areas of southern England. (March 2015)

• Record Type: Journal Article
• Authors: Ward, H.C.; Kotthaus, S.; Grimmond, C.S.B.; Bjorkegren, A.; Wilkinson, M.; Morrison, W.T.J.; Evans, J.G.; Morison, J.I.L.; Iamarino, M.
• Is Part Of: Environmental pollution. Volume 198(2015)
• Page Start: 186
• Page End: 200
• Publication Date: 2015-03
• Subjects: Carbon emissions -- Emissions inventory -- Human impact -- Land use change -- Net ecosystem exchange; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2014.12.031
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Anthropogenic and biogenic controls on the surface–atmosphere exchange of CO2 are explored for three different environments. Similarities are seen between suburban and woodland sites during summer, when photosynthesis and respiration determine the diurnal pattern of the CO2 flux. In winter, emissions from human activities dominate urban and suburban fluxes; building emissions increase during cold weather, while traffic is a major component of CO2 emissions all year round. Observed CO2 fluxes reflect diurnal traffic patterns (busy throughout the day (urban); rush-hour peaks (suburban)) and vary between working days and non-working days, except at the woodland site. Suburban vegetation offsets some anthropogenic emissions, but 24-h CO2 fluxes are usually positive even during summer. Observations are compared to estimated emissions from simple models and inventories. Annual CO2 exchanges are significantly different between sites, demonstrating the impacts of increasing urban density (and decreasing vegetation fraction) on the CO2 flux to the atmosphere. Highlights: Multi-seasonal comparison of contemporaneous CO2 fluxes over contrasting land cover. Signatures of anthropogenic and biogenic processes explored at various timescales. Observations reveal relative magnitude of anthropogenic emissions. CO2 fluxes related to surface controls, strongly dependent on land cover. Abstract : Direct measurements of CO2 fluxes reveal the impact of urbanisation and human behavioural patterns on the atmosphere at sub-daily to inter-annual time scales.