In part 1 of this series, techniques for generating quantitative information on fine airborne particulate‐size and chemically resolved mass concentration from an Aerodyne aerosol mass spectrometer were introduced. Presented here are the results generated using these techniques from sampling U.K. urban air with such an instrument in Edinburgh during October 2000 and in Manchester during July 2001 and January 2002. Data on the total mass concentrations and size‐resolved mass distributions of nitrate, sulfate, and organic compounds were obtained for all three campaigns and compared with data from other sources, including a micro‐orifice uniform deposit impactor, total particle numbers, CO and NOx concentrations, local wind speed and temperature, and back trajectory analysis. All three locations showed evidence for emissions from local transport, with a mass modal aerodynamic diameter of around 100–200nm. This mode was dominated by hydrocarbons showing little evidence of oxidization. The three sites also exhibited a larger mode consisting of inorganic chemicals and oxidized organics, which appeared to be governed by sources external to the cities and showed evidence of internal mixing. The mass modal aerodynamic diameter varied between approximately 200–500 nm during the winter and 500–800 nm during the summer. The summer also showed an increased mass loading without an increase in total particle number. Evidence of material building up and ageing in the atmospheric surface layer during periods of low wind speeds was also observed.

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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.

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