Display Settings:

Format

Send to:

Choose Destination
Environ Sci Technol. 2002 Jul 15;36(14):3139-46.

Micrometeorological measurements of the urban heat budget and CO2 emissions on a city scale.

Author information

  • 1Centre for Ecology and Hydrology, Edinburgh, Midlothian, Scotland. en@ceh.ac.uk

Abstract

Direct measurements of urban CO2 emissions and heat fluxes are presented, made using the eddy covariance technique. The measurements were made from the top of a tower, approximately 65 m above the street level of Edinburgh, Scotland, and the fluxes are representative of footprint source areas of several square kilometers. The application of a stationarity test and spectral analysis techniques shows that at this height, the stationarity criterion for eddy covariance is fulfilled for wind directions from the city center for 93% of the time, while for other wind directions this declines to 59%, demonstrating that pollutant fluxes from urban areas can be measured. The average CO2 emission from the city center was 26 micromol m(-2) s(-1) (10 kt of C km(-2) yr(-1)), with typical daytime peaks of 50-75 and nighttime values of 10 micromol m(-2) s(-1). The correlation between CO2 emission and traffic flow is highly significant, while residential and institutional heating with natural gas are estimated to contribute about 39% to the emissions during the day and 64% at night. An analysis of the energy budget shows that, during the autumn, fossil fuel combustion within the city contributed one-third of the daily anthropogenic energy input of 3.8 MJ m(-2) d(-1), with the remainder coming from other energy sources, dominated by electricity. Conversely, the total energy input in late spring (May/June) was found to be approximately half this value.

PMID:
12141496
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk