Helen C. Ward

Effects of urban density on carbon dioxide exchanges: Observations of dense urban, suburban and woodland areas of southern England

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.

Multi-Scale Sensible Heat Fluxes in the Suburban Environment from Large-Aperture Scintillometry and Eddy Covariance

Sensible heat fluxes (

Urban Multi-scale Environmental Predictor (UMEP): an integrated tool for city-based climate services

Q_{H}

Multi-season eddy covariance observations of energy, water and carbon fluxes over a suburban area in Swindon, UK

QH) are determined using scintillometry and eddy covariance over a suburban area. Two large-aperture scintillometers provide spatially integrated fluxes across path lengths of 2.8 and 5.5 km over Swindon, UK. The shorter scintillometer path spans newly built residential areas and has an approximate source area of 2–4

Surface Urban Energy and Water Balance Scheme (SUEWS):development and evaluation at two UK sites

\text {km}^{2}

Assessing the impact of changes in surface cover, human behaviour and climate on energy partitioning across Greater London

km2, whilst the long path extends from the rural outskirts to the town centre and has a source area of around 5–10