1. CONTRIBUTION OF NATURAL SOURCES AND SOURCE APPORTIONMENT (SG2)
4th FAIRMODE Plenary Meeting, June 2011
CONTRIBUTION OF NATURAL SOURCES AND SOURCE APPORTIONMENT (SG2)

2. Participants Olivier Favez (INERIS) Massimo D’Isidoro (ENEA)
Jana Krajcovicova (Slovak Hydrometeorological Institute)
Viane (VITO)
Martijn Schaap (TNO)
Maria Luisa Volta (Univ. Brescia)

3. Status and main output of the SG since last meeting
A questionnaire was prepared and circulated to experts and institutions in Member States.
A contribution to the NO2 Guidance Document with a section on source apportionment was made.
An abstract on “The use and evaluation of multi-pollutant source apportionment methodologies by EU authorities and research groups”, has been submitted and accepted to the 14th Harmonisation conference in Athens, 2-6 October 2011

4. The source apportionment of NO2
Review of the current SA methods for NO2
Certain objectives were identified and discussed
Quantification of the proportion of exceedances due to local emissions or background levels.
Determination of the extent to which different vehicles types and driving conditions contribute to traffic NO2 emissions.
In addition to dispersion and receptor model there are other specific methods e.g. SO2/NOx ratio
Regarding CTM use, identification of the need for multiscale approaches in areas close to strong emission sources with high background levels.

5. Review of responses from the source apportionment methodologies questionnaire
The questionnaire concerned the methodologies used by MS to perform SA.
Most common target pollutants are PM and NO2. Dispersion and Receptor Modelling are equally used. Among RM, PMF is the preferred methodology.
Almost 90% of the MS declared they validate the results, the most common methodology is comparison with targeted measurements and model intercomparison. MS consider there is a need for standardized methodology as the estimation of uncertainty and validation of results are considered the most critical issues.

6. Participants reports on new studies, recent applications and ongoing projects for SA
Massimo D’Isidoro presented the activity of ENEA on NO2 and Saharian dust episode identification technique.
Jana Krajcovicova illustrated source apportionment using a CTM in two Slovakian towns in order to identify the causes of PM10 exceedances connected to the request of postponement of attainment.
Olivier Favez presented a project on the extension a aethalometer model.
Maria Luisa Volta reported the model the developed for integrated assesment using an innovative approach based on artificial neural networks.

7. Synergy with other SGs
SG3 EIs are input data for CTM. Reduction in EI uncertainty would lead to reduction in CTM output uncertainty.
Receptor Models could be used as independent check for problematic sources like: biomass burning, natural sources (Saharan dust, biogenic sources, etc.), ship emission, etc.
SG3 contributions to SA activity: include in the questionnaire a request of information about source profiles useful for RM. Raise concern about the need for disaggregated NO2 emissions by vehicle type.
Contributions from SG2 to Emission Inventories: Recommend the validation of emission inventories of problematic sources by comparison with receptor model outputs as part of QA/QC protocols. Provide a list of most relevant sources for which source profiles are needed. Contribute to the SG3 background document.
SG4: test the implementation of model evaluation indices developed in SG4 for SA purposes.
SG1: contribute to the development of the methodology for the evaluation of site representativeness.

8. The outline of a recommendations document for source apportionment and natural contribution was presented and discussed.