UK feedback on Delta V3.0

Presented by: John Stedman, Daniel Brookes, Keith Vincent, Emily Connolly10 April 2013

Outline

• Practical aspects• Other aspects covered in accompanying

presentation– Use of models for UK compliance assessments– Feedback provided last year– Using Delta V3.0– Conclusions and recommendations

• Views of the UK Competent Authorities

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Models for UK compliance assessments

– Pollution Climate Mapping (PCM) models as supplementary assessment methods for annual compliance assessment (Decision 2004/461/EC)

– SO2, NOx, NO2, PM10, Pb, C6H6, O3, PM2.5, As, Cd, Ni and B[a]P

– Annual mean– Pollutant specific metrics

• High percentiles for SO2 and AOT40 and days above threshold for O3

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Models for UK compliance assessments

– Pragmatic dispersion model• Large point sources – modelled using the air dispersion

model ADMS and emissions estimates from the UK National Atmospheric Emissions Inventory (NAEI)

• Small point sources – modelled using the small points model and NAEI emissions

• Distant sources – characterised by the rural background concentration. From measurements or results from other models

• Area sources – modelled using a dispersion kernel and emissions estimates from the NAEI.

• Roadside increment model for traffic locations

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Models for UK compliance assessments

– Assessment is based on a combination of measurement data and model results. The compliance status for each zone is based on the maximum of the measured and modelled concentrations

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Models for UK compliance assessments

– The models are designed to assess compliance at locations defined within the directives

• Urban (and Rural) Background locations: 1 km x 1 km grid squares representative of the exposure of the general population

• Traffic locations: ~9000 receptors 4 m from the kerb of major roads in urban areas (to be representative of more than 100m segment and more than 25m from junctions.

– The same models are used for• Extent of exceedance• Source apportionment• Projections for the development of air quality plans• Consistent with the assessment for the reference year

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Feedback from 2012

• Easier input of annual mean data • 75% data capture threshold

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Delta V3.0: PCM model results for NO2 in 2010

– Problems with file headers now resolved• Manual had • an additional “;”

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Delta V3.0: PCM model results for NO2 in 2010

– In previous version had to enter 8760 identical values• If you do this in V3.0 DQO for hourly are used in the plot

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Delta V3.0: PCM model results for NO2 in 2010

– Parameter values in V3.0 (left) are not consistent with the paper circulated on 5 March 2013 (right)

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Mod

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d (µ

g m

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Measured (µg m-3)

PCM NO2 2010, k= 2, urlv=0.12, alpha=0.02, Np=5.6, Nnp=11.2, LV=200,|BIAS|/2U for 90%ile station=1.502

PCM NO2 2010

y = x

y+2U

y-2U

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0 20 40 60 80 100 120

Mod

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d (µ

g m

-3)

Measured (µg m-3)

PCM NO2 2010, k= 2, urlv=0.12, alpha=0.02, Np=4.7, Nnp=6.7, LV=200,|BIAS|/2U for 90%ile station=1.329

PCM NO2 2010

y = x

y+2U

y-2U

Delta V3.0: NO2 in 2010 and 2011

– Model performance varies from year to year• Using parameters from 5 March 2013 paper

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0 20 40 60 80 100 120

Mod

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d (µ

g m

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Measured (µg m-3)

PCM NO2 2010, k= 2, urlv=0.12, alpha=0.02, Np=4.7, Nnp=6.7, LV=200,|BIAS|/2U for 90%ile station=1.329

PCM NO2 2010

y = x

y+2U

y-2U

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0 20 40 60 80 100 120

Mod

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d (µ

g m

-3)

Measured (µg m-3)

PCM NO2 2011, k= 2, urlv=0.12, alpha=0.02, Np=4.7, Nnp=6.7, LV=200,|BIAS|/2U for 90%ile station=0.86

PCM NO2 2011

y = x

y+2U

y-2U

Delta V3.0: NO2 2011

– With (left) and without 2 term (right)• Using parameters from 5 March 2013 paper

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0 20 40 60 80 100 120

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d (µ

g m

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Measured (µg m-3)

PCM NO2 2011, k= 2, urlv=0.12, alpha=0.02, Np=4.7, Nnp=6.7, LV=200,|BIAS|/2U for 90%ile station=0.86

PCM NO2 2011

y = x

y+2U

y-2U

0

20

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60

80

100

120

0 20 40 60 80 100 120

Mod

elle

d (µ

g m

-3)

Measured (µg m-3)

PCM NO2 2011, k= 2, urlv=0.12, alpha=0.02, Np=4.7, Nnp=6.7, LV=200,|BIAS|/2U for 90%ile station=0.931

PCM NO2 2011

y = x

y+2U

y-2U

Delta V3.0: PCM PM10 in 2010

– Reproduced in spreadsheet calculations

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Mod

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d (µ

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Measured (µg m-3)

PCM PM10 2010, k= 2, urlv=0.115, alpha=0.19, Np=40, Nnp=40, LV=50,|BIAS|/2U for 90%ile station=2.972

PCM PM10 2010

y = x

y+2U

y-2U

Delta V3.0: PCM PM10 in 2010

– Using parameter values from 5 March paper (left)– Using parameters for TEOM (FDMS) (right)

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0

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Mod

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d (µ

g m

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Measured (µg m-3)

PCM PM10 2010, k= 2, urlv=0.138, alpha=0.02, Np=40, Nnp=1, LV=50,|BIAS|/2U for 90%ile station=1.342

PCM PM10 2010

y = x

y+2U

y-2U

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0 10 20 30 40

Mod

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d (µ

g m

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Measured (µg m-3)

PCM PM10 2010, k= 2, urlv=0.169, alpha=0.023, Np=40, Nnp=1, LV=50,|BIAS|/2U for 90%ile station=1.027

PCM PM10 2010

y = x

y+2U

y-2U

Conclusions and recommendations

• Input of annual data much easier• Parameters in Delta V3.0 do are not consistent

with the circulated paper– Assessment of model performance is highly sensitive

to the selection of parameters

• Recommendations– Include parameter values in Delta plots for version

control – Allow users to choose non-default values to explore

sensitivities– Will need to address all the AQD and DD4 pollutants

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