The%20aim%20of%20this%20work%20was%20to%20create%20background%20and%20roadside%20maps%20of%20pollutant%20concentrations%20for%20Scotland%20and%20to%20compare%20these%20with%20similar%20maps%20created%20for%20the%20whole%20of%20the%20UK.

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Introduction

• The aim of this work was to create background and
  roadside maps of pollutant concentrations for
  Scotland and to compare these with similar maps
  created for the whole of the UK.
• Work undertaken within Netcens Pollution Climate
  Mapping Team by Andrew Kent, supervised by John
  Stedman.
• Technical queries can be directed to
  andrew.kent_at_aeat.co.uk
• The technical aspects of this work will be
  available in a report soon.

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Why modelling and mapping?

• A good question given the extensive national
  monitoring campaigns undertaken by Defra and the
  DAs and by LAs
• Maps provide complete coverage over the modelled
  area, so filling in the gaps where no monitoring
  is present.
• Can help identify local and national scale
  hotspots where there is no monitoring i.e.
  selection of monitoring site location.
• At an advanced level, the maps can be used to
  illustrate the impact of policy scenarios e.g.
  the impact of changing emissions legislation
• Maps for future years can be made based on
  projected emissions e.g. to show whether an
  area is likely to meet future legislative
  objectives

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Examples
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The national maps what are they used for?

• These cover the whole of the UK.
• The map outputs are provided to the Commission
  each year, together with the UK monitoring data
  for the purposes of the Daughter Directives.
• Defra and the DAs use them for policy guidance
• Policy scenario impacts
• Identify future compliance with AQS Objectives
  and Daughter Directive Limit Values.
• Local Authorities use background concentrations
  published on the national Air Quality Archive as
  an important component of the Review and
  Assessment process to determine air quality on
  a local level and decide on AQMA declaration.

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The Scottish mapping exercise

• Follows on from a similar comparison performed in
  Wales between national maps and Welsh monitoring
  data.
• Useful to examine the performance of the model
  for specific regions
• Promotes confidence in use of mapped background
  concentrations for Review and Assessment.
• Highlights areas of model improvement for future.
• Scotlands different meteorological conditions,
  northerly position and more rural characteristics
  may be better represented in a Scotland-specific
  model

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The Scottish model

• Developed from the national model
• Changes included
• Calibration relationships defined using only
  Scottish monitoring data
• Dispersion based on Scottish meteorological data
  (Edinburgh Airport, 2004)

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About the data

• A model is only as good as what you feed it!
  These models are dependent on as much good
  quality monitoring data as possible.
• Monitoring data is used to calibrate the model
  and to verify the results.
• Fully ratified monitoring data from the national
  networks for 2004 was used 11 AURN monitoring
  sites available (9 background and 3 roadside) in
  2004.
• NAEI 2003 emissions data were also used in the
  models.
• Meteorological data national model uses data
  from Waddington the Scotland model uses met data
  from Edinburgh.
• A data capture threshold was set for the
  monitoring data so that sites with untrustworthy
  amounts of data were removed.

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Testing the model performance - verification

• Scatter plots of modelled concentrations vs.
  measured concentrations
• Shows position of modelled results about the 11
  line to illustrate the variation and any over or
  under prediction
• Tabulated results including averages of the
  modelled and monitored data, correlation
  coefficients
• Data Quality Objectives set a defined target
  range for modelled data in the 1st and 2nd
  Daughter Directives
• Additional lines included for illustrative
  purposes where no formal DQOs for these metrics
• The data used to calibrate was the same data used
  to verify the results

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CO annual mean results

• CO annual mean verification 2004, mg m-3

• CO annual mean map 2004, mg m-3

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NO2 annual mean results

• NO2 annual mean verification 2004, µg m-3

• NO2 annual mean map 2004, µg m-3

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PM10 (TEOM) annual mean results

• PM10 (TEOM) annual mean model 2004, µg m-3

• PM10 (TEOM) annual mean map 2004, µg m-3

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SO2 15-minute results

• SO2 p99.9 of 15-min mean verification 2004,
  µg m-3

• SO2 99.9ile of 15-min mean map 2004, µg m-3

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Conclusions

• Modelling and mapping can provide a useful source
  of information to supplement monitoring
  campaigns.
• The national models can be tailored to Scotland,
  producing more accurate results for most
  pollutants/metrics provided that adequate
  monitoring data are available to support the
  model.

• The improvement resulting from Scottish
  calibration may be offset by the additional
  uncertainties resulting from such a small number
  of sites used for calibration.
• For the year 2004, there are not really
  sufficient monitoring data available in Scotland
  a meaningful repeat of the exercise would
  require a greater number of monitoring sites.

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Thank you-any questions?