1. University of Leicester CityZen Contributions
Erika von Schneidemesser, Paul Monks,
John Remedios, Vijay Kanawade

2. Current Work Completed London assessment HC emissions from megacities:
Evaluating VOC emission speciation on the basis of existing ambient VOC observations (Task 3.2)
Marylebone Road Data
Harwell Data
Developing a customized data analysis package/toolkit (in R) to assess trends in large VOC data sets across multiple years and locations

3. Greater London City of London and 32 London boroughs
~7.5 million people (2005 )
14 million (entire metro area)
1,570 sq km around the Thames River
Mobile sources are a significant factor in London emissions
Over the past decade decreasing trends of some atmospheric air pollutants have been observed
CO, SO2, NOx, VOCs
In addition to air quality guidelines, London has programs in place to address air pollution from motor vehicles
Low Emissions Zone (2003), Congestion Charging (2008)

4. VOC results/data
VOC measurements at Harwell and Marylebone Road in London show VOC emissions have been decreasing
Except some of the lighter alkanes
CO emissions have been similarly decreasing
In agreement with results from US cities, C5-C8 alkanes, alkenes, ethyne, and aromatics showed similar patterns when normalized to CO, indicating similar emissions sources (transportation)
Task 3.2

5. Individual VOC Trends
1,3bd – mainly petrol&diesel combustion, also some industrial processes; benzene motor vehicles, isoprene biogenic, toluene industrial solvents, ethane and propane – non motor vehicle fossil fuel use, off gas, coal mining and nat’l gas operations

6. VOC Trends Harwell London **note y-axes scales
Annual average means only for those with more than 50% of data present
**note y-axes scales

7. CO Trend

8. London VOC/CO Ratio Trends

9. VOC/CO ratios in US Cities
Baker, et al., 2008

10. London & US cities data

11. Next step to look at oxidative potential; how those change over time, biogenic emissions should be more present

12. Anthropogenic vs. Biogenic Isoprene
London Marylebone Road Data

13. Satellite Data Carbon Monoxide pollution from
megacities and urban centres
MOPITT CO Column
This shows comparison between the global L2V3 MOPITT CO total column distribution averaged over 7 years, EDGARv3.2FT 2000 anthropogenic emissions for CO, and population density for Asian region.
A very good correlation, especially for China and Indo-Gangetic basin, is observed between MOPITT CO total column and the population density, with the highest Co levels observed where the higher population density occurs.
In China and India, large use of coal as anthropogenic fuels contributes to elevated levels of CO.
EDGARv3.2FT CO
Task 1.2
CIESIN Population Density

14. Quantitative Analysis for CO flux
This plot compares pollution markers such as MOPITT/TERRA surface CO, SCIAMACHY/ENVISAT NO2 total column, MODIS/TERRA AOD and EDGARv3.2FT Anthropogenic CO emissions for China megacities. There is a good agreement between among these pollution indicator suggesting use of satellite data to quantity pollution from urban centres and megacities.
[Ratios of MOPITT 850 mb/350 mb give confidence in presence of lower tropospheric CO]
How do we get appropriate background CO concentrations for urban centres, which is largely driven by OH chemistry and uneven source distribution?
How do we calculated elevated CO flux over megacity and outflow from urban centres?

15. Second example of CO pollution from urban centres and comparison with other pollution markers for Japan.

16. Future Work
Assessment of the scale, magnitude, and variability of oxidant and particle production in the London metropolitan area (Task 1.4)
observations used to assess impact of a megacity on the regional atm, ozone, and oxidant budgets.
Comparison of ‘normal’ conditions to summer 2003 situation (as above) (Task 2.2)
role of in-situ chemistry -> SOA
role of biogenics
influence from forest fires?
Quantification of exports from megacities using satellite data (CO, CO2) (Task 1.2)