Micrometeorological Measurements of the Urban Heat Budget and CO2 Emissions on a City Scale
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- 作者：Eiko Nemitz ; Kenneth J. Hargreaves ; Alan G. McDonald ; James R. Dorsey ; and David Fowler
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：July 15, 2002
- 年：2002
- 卷：36
- 期：14
- 页码：3139 - 3146
- 全文大小：279K
- 年卷期：v.36,no.14(July 15, 2002)
- ISSN：1520-5851
文摘
Direct measurements of urban CO2 emissions and heatfluxes are presented, made using the eddy covariancetechnique. The measurements were made from the top ofa tower, approximately 65 m above the street level ofEdinburgh, Scotland, and the fluxes are representative offootprint source areas of several square kilometers.The application of a stationarity test and spectral analysistechniques shows that, at this height, the stationaritycriterion for eddy covariance is fulfilled for wind directionsfrom the city center for 93% of the time, while for otherwind directions this declines to 59%, demonstrating thatpollutant fluxes from urban areas can be measured. Theaverage CO2 emission from the city center was 26 
mol m-2s-1 (10 kt of C km-2 yr-1), with typical daytime peaks of 50-75 and nighttime values of 10 mol m-2 s-1. The correlationbetween CO2 emission and traffic flow is highly significant,while residential and institutional heating with naturalgas are estimated to contribute about 39% to the emissionsduring the day and 64% at night. An analysis of theenergy budget shows that, during the autumn, fossil fuelcombustion within the city contributed one-third of the dailyanthropogenic energy input of 3.8 MJ m-2 d-1, with theremainder coming from other energy sources, dominated byelectricity. Conversely, the total energy input in latespring (May/June) was found to be approximately halfthis value.
mol m-2s-1 (10 kt of C km-2 yr-1), with typical daytime peaks of 50-75 and nighttime values of 10 mol m-2 s-1. The correlationbetween CO2 emission and traffic flow is highly significant,while residential and institutional heating with naturalgas are estimated to contribute about 39% to the emissionsduring the day and 64% at night. An analysis of theenergy budget shows that, during the autumn, fossil fuelcombustion within the city contributed one-third of the dailyanthropogenic energy input of 3.8 MJ m-2 d-1, with theremainder coming from other energy sources, dominated byelectricity. Conversely, the total energy input in latespring (May/June) was found to be approximately halfthis value.