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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An atmospheric chemical transport model was adapted to simulate the concentration and deposition of heavy metals (arsenic, cadmium, chromium, copper, lead, nickel, selenium, vanadium, and zinc) in the United Kingdom. The model showed that wet deposition was the most important process for the transfer of metals from the atmosphere to the land surface. The model achieved a good correlation with annually averaged measurements of metal concentrations in air. The correlation with measurements of wet deposition was less strong due to the complexity of the atmospheric processes involved in the washout of particulate matter which were not fully captured by the model. The measured wet deposition and air concentration of heavy metals were significantly underestimated by the model for all metals (except vanadium) by factors between 2 and 10. These results suggest major missing sources of annual heavy metal emissions which are currently not included in the official inventory. Primary emissions were able to account for only 9%, 21%, 29%, 21%, 36%, 7% and 23% of the measured concentrations for As, Cd, Cr, Cu, Ni, Pb and Zn. A likely additional contribution to atmospheric heavy metal concentrations is the wind driven re-suspension of surface dust still present in the environment from the legacy of much higher historic emissions. Inclusion of two independent estimates of emissions from re-suspension in the model was found to give an improved agreement with measurements. However, an accurate estimate of the magnitude of re-suspended emissions is restricted by the lack of measurements of metal concentrations in the re-suspended surface dust layer.

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Simple bioenergetics models were used to derive annual nitrogen excretion rates of each seabird species occurring at colonies in the UK. These were combined with population distribution data and an estimated fraction of nitrogen volatilized to estimate the spatial distribution of NH 3 emissions from seabird colonies at a 1 km resolution. The effect of these emissions on atmospheric NH 3 concentrations and nitrogen deposition in the UK was assessed using the FRAME atmospheric chemistry and transport model. The total emission of NH 3 from the UK seabird colonies is estimated at 2.7 kt yr −1 . Emissions from seabirds are largely concentrated in remote parts of Britain, where agricultural and other anthropogenic emissions are minimal. Although seabirds account for less than 1% of total UK NH 3 emissions (∼370 kt yr −1 ), their occurrence in remote areas and frequently large colony sizes results in seabirds providing a major fraction of the atmospheric nitrogen deposition for many remote ecosystems.

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