TFMM PM Assessment Report workshop Q1: Are there significant differences in the PM climate across Europe? Q4: How important are natural PM sources Q5: To what extent do sources outside Europe contribute to European PM ? Faced difficulties answering these questions before having National Contributions in hands

Q1: Are there significant differences in the PM climate across Europe ? - PM mass concentrations: YES from PM national monitoring data when stratified according to site types (if not ≠ % of rural, urban background, kerbside sites may confuse the picture) also from remote sensing (AOD and lidar), which can be give information on PM mass at ground level factors controlling PM mass concentrations are: - pollutant dispersion (orography + meteorology) - emissions - transboundary transport

- PM2.5 / PM10 ratios at both rural and urban sites: YES yearly av. PM2.5 / PM10 ratios are significantly lower at sites where specific sources of coarse particles are significant yearly averages may hide large day-to-day and seasonal variability seasonal variability in PM2.5 / PM10 also related to variations in mineral dust concentrations PM2.5 / PM10 depends even more on siting and specific events (e.g. precipitation, sporadic transport)

- Issues related to PM mass concentrations how much can the observed differences be artifact – driven gravimetric vs. TEOM TEOM correction factor (FDMS advisable) water

- PM2.5 and PM10 av. chemical composition at rural sites: YES NO3 / SO4 decreases from W to E NO3 / SO4 decreases from N to S ! NO3 and SO4 may sit in different size fractions ! OM / 2-ndary inorganics ranges from 0.5 to 1.2 (Carbosol) OM / EC ranges from 5 to 11 (Carbosol), even 15 (ES) EC / PM is 1 to 5% OM / PM is 9 to 37 % mineral dust differences in PM2.5 vs differences PM10 composition PM2.5 and PM10 chemistry at rural sites during episodes: YES >> dust, NH4NO3, POM from wood burning domestic and forest fires

- PM2.5 and PM10 av. chemical composition at urban sites: YES because urban PM is affected by regional PM mineral dust in both PM10 and PM2.5 EC contribution ? No data to answer - PM2.5 and PM10 chemistry at rural sites during episodes: YES dust (re)suspension from winter and studded tires Saharan dust sea salt

Issues related to PM chemical speciation sampling OC /EC (charring and charring correction) OC to OM conversion factor dust calculation

Q4: How important are natural PM sources ? More for PM10 than for PM2.5 Mineral dust: up to 500 ug / m3 in the Mediterranean basin, leading to 30-35 exceedances a year up to 15 ug / m3 annual average in the Med. Basin about 1 ug / m3 in Northern Europe Sea spray up to 35 ug / m3 at coastal sites, can lead to exceedances up to 10-12 ug/m3 annual average in Canary Islands 7 ug/m3 at coastal sites < 1 ug/m3 at continental sites - bioPOM (primary and secondary) based on literature PSI and Carbosol studies - H2O (NaCl or secondary inorganics- linked ?)

Issues related to natural PM sources ? Mineral dust: quantify and distinguish between road dust and desert dust resuspended and wind blown - BioPOM - C14 + wood combustion tracer measurements needed H2O direct measurements are difficult Also consider the report ordered by EC DG ENV on this topic

Q5: To what extent do sources outside Europe contribute to European PM ? Few data available to answer this question. CLRTAP TF on hemispheric transport modeling is addressing this question. On average: About 1 ug/m3 from N. America reaching the NL < 1 ug/m3 reaching Izana and Mace Head (see literature) Ship emissions from outside the EMEP domain to be looked at Episodes: - Large scale fires in North America (see papers in literature) Large scale forest fires in Siberia affecting Scandinavia (Risto) Transport from India to the East of the domain (e.g. Cyprus)