T i t l e Michael Schulz (MetNo) Martijn Schaap (TNO)

T i t l e

Atmosphere Monitoring

CAMS-71 policy user workshop

22. January 2018, Copenhagen, EEA

Source-receptor calculations for main European City Areas: status of 2017 products and their validation

Michael Schulz (MetNo)Martijn Schaap (TNO)Alvaro Valdebenito, Augustin Mortier, MatthieuPommier, Hilde Fagerli, Richard Kranenburg

AtmosphereMonitoring

Service Overview: Regional contributions to pollution in EU cities

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How to get there on the CAMS website ?

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http://policy.atmosphere.copernicus.eu

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Daily Forecasts of Source Contribution Split

• Available for 34 European Cities

• 4 Day forecasts of PM10 and Ozone

• Source contribution split into

Local – National – EU – Other countries Natural

• Country source contribution split (experimental)

• Access to previous periods

• Consistent with CAMS 50 forecasts

• Results available in json file format

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Source Contribution Split // Example PM10 Copenhagen Today

(Others=Natural+Rest of World)

(Others=Rest of Europe+World)

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Episode analysis

• Features as for daily forecasts

• BUT

• With two models (EMEP + TNO) for PM10

EMEP model for Ozone

• Report available one month after episode

• Activation with more output

on demand (up to 5 times per year)

• Service evolution test

Daily simulation from April 2018 onwards

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We provide:• 4 Day forecasts of PM10 and Ozone• Available for 34 European Cities• Source contribution split into

– Local– National – EU– Other countries – Natural

We operate two models:• EMEP• LOTOS-EUROS

We use two source apportionment techniques:• Ensemble based (EMEP)• Labelling (LOTOS-EUROS)

Why?• Increases service reliability• Allows service development

S o u r c e a p p o r t i o n m e n t s e r v i c eB


Can we trust in these results?

Are results model dependent? (Are the models simulating the same?)

How much do results depend on city area (=local) choice?

Are there non-linearities affecting the result?

Can we validate with measurements?

In-Depth Investigation undertaken with several model experiments using harmonised EMEP and TNOfor December 2016 Episode


Are results model dependent?

Brussels4-7 Dec 2016

PM10ChemicalCompositionevolution hourly

for comparableComponents

TNO

EMEP

Composition split



BrusselsPM104-7 Dec 2016

TNO

EMEP

Source Country split



Brussels4-7 Dec 2016

ElementalCarbonSootCountrySourceContributionsTNO

EMEP

Source Country to Soot/Elemental Carbon split


How much do results depend on city area (=local) choice?

Gridded administrative areaof the city

1 model grid cellin the center

9 model grid cellon the center

Whats the best choice for the city area? => three experiments


Two different city examples and city definitions used in experiments

Berlinbig city

Zagrebsmall cityRather large Admin


Local/External Pollution split for PM10 for 3 city area definition experiments

4-7 Dec 16Berlin

Zagreb

ADMIN area 1 grid box area 9 grid box area


W h a t s h a l l w e u s e f o r c i t y a r e a s ?

Gridded GADM administrative

area of the city

1 model grid cellin the center

9 model grid cellon the center

Gridded OECDFunctional

Urban Areas

Admin and 9 grid results are mostly similar, small cities most sensitive to definition=> we are open for suggestions what to use!

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Are non-linearities affecting the results?

PM10 Hourly Contributions Dec 2017

Others gets negativeOthers = Total-(Local+EU)

Now and then, yes….

2 EMEP experimentsWith different perturbations5% and 50% emission reduction(Instead of 15% standard)


Are there non-linearities affecting the results?

4-7 Dec16Rome

EMEP model two experiments

50% emission perturbation experiment

5 % emission perturbation experimentOthers gets negative

Others = Total-(Local+EU)-

++-


Are non-linearities affecting the results?

PM10 Hourly Contributions Dec 2017Now and then, yes….

But is it a problem?

Better statistics will be Produced…


Can we validate with measurements?

Berlin

Example PM10, Berlin, 2.12.2016Size of dot = measured PM10 concentration

City sites

Background sites

The idea:Derive City concentrationand Background concentrationfrom NRT observations

Derive External concentrationFrom difference City-Background

Plot latest NRT observationsalong with Source contribution time series


PM 10 measurements in episode Dec 2016 near Berlin

Hourly PM10 at stations in outer circle around Berlin (20-70 km distance to center)

Hourly PM10 at stations in center of Berlin (0-20 km distance to center)

There is potential butalso further work needed


Example of two days of PM10 measurements

Berlin

Size of dot = measured PM10 concentration

Dec 2Dec 4

Dec 4 large external contributionDec 2 relatively large local contribution

AtmosphereMonitoring Reanalysis source allocation PM10

Model results for UBA station Neuglobsow

Evaluation using source tracers

Wood combustion through Levoglucosan

E v a l u a t i o n s o u r c e p r o f i l e s - U B A p r o j e c t

Levoglucosan measurements

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Summary

• Hourly local/external SR relationships are available for PM10 and Ozonefor 34 EU cities and in more depth for selected episodes in 2017

• Results are available as 4 day forecasts since winter 2016

• EMEP results are very similar to TNO model, despite different SR method

• SIMILAR if meteorology, city area, emissions are harmonised

• Major differences can be attributed to model differences in aerosolcomponent treatments (seasalt, road dust, water, SOA …)and boundary layer parameterizations

• Non-linearities seem to influence Local/External split by up to ca 20%

• With current model resolution (0.25x0.125 degrees)the city definition is more relevant for small cities for SR results


Outlook / Plans

• More cities will be included to fill gaps on map ( Milano, Frankfurt, Lyon, Lille )

• Publication of December 2016 episode study

• Inclusion of January 2017 episode in interim assessment report

• More episodes in 2018, flexible hindsight activation by all partners and users

• New choice of city area definition (“local”), ideally with user input

• Experimental daily forecast of country source attribution from April 2018 onward

(harmonized city area definition, new CAMS emissions, composition output, more cities, 2 models)

Visualization of uncertainty in graphs

• Inclusion of NRT observations in daily forecast charts (based on background and city stations)Cooperation with TFMM twin site study

THANKS for the attention

Documents

T i t l e Michael Schulz (MetNo) Martijn Schaap (TNO)