Size-segregated characterization of PM10 with five stage BERNER-impactors at Melpitz (Germany) – a six year study G. Spindler, A. Grüner, K. Müller, Y. Iinuma, T. Gnauk, H. Herrmann Leibniz-Institut für Troposphärenforschung e.V., (IfT), Leipzig CONVENTION ON LONG-RANGE TRANSBOUNDARY AIR POLLUTION 11th annual Meeting - Task Force on Measurement and Modelling Larnaca (Cyprus), May 12th – 14th 2010 Leibniz-Institut für Troposphärenforschung e.V. Leipzig

The German EMEP-site Melpitz – PM10 evolution since 1993 Outline The German EMEP-site Melpitz – PM10 evolution since 1993 Size-segregated sampling of PM10 with a five stage BERNER-impactor Analytical methods and derived parameters for characterization of sampled PM-fractions Mean distribution of particle constituents in size fractions for air masses from East and West in summer and winter (selected daily samples 2004-2009) Summary

The German EMEP-site Melpitz – PM10 evolution since 1993 Outline The German EMEP-site Melpitz – PM10 evolution since 1993 Size-segregated sampling of PM10 with a five stage BERNER-impactor Analytical methods and derived parameters for characterization of sampled PM-fractions Mean distribution of particle constituents in size fractions for air masses from East and West in summer and winter (selected daily samples 2004-2009) Summary

Location of the IfT research and EMEP site Melpitz in Europe Melpitz site (12°56‘ E, 51°32‘ N, Altitude 86 m above see level) Berlin German Ultrafine Aerosol Network (GUAN) © 2008 google

Melpitz - PM10 concentration and content of main ions (yearly means) PM study for daily high volume samples Spindler, G., et al. (2010) Atmospheric Environment, 44, 164-173 PM study for selected daily impactor samples Sixteen year seasonal and spatial study for PM10 (in preparation) The error bars are the standard deviation of daily particcle mass concentration means

The German EMEP-site Melpitz – PM10 evolution since 1993 Outline The German EMEP-site Melpitz – PM10 evolution since 1993 Size-segregated sampling of PM10 with a five stage BERNER-impactor Analytical methods and derived parameters for characterization of sampled PM-fractions Mean distribution of particle constituents in size fractions for air masses from East and West in summer and winter (selected daily samples 2004-2009) Summary

Low pressure five-stage BERNER-impactor Air inlet aerodynamic particle diameter [µm] Sampling volume: 108 m³ in 24h Impaction of particles into aluminium foils Stage 3 To the vacuum pump

PM modes and the five impactor stages (simplified) Aitken mode Accumulation mode Coarse mode 1 2 3 4 5 stages derived from Finlayson-Pitts, Pitts, Atmospheric Chemistry, Wiley, New York, 1986 8

The German EMEP-site Melpitz – PM10 evolution since 1993 Outline The German EMEP-site Melpitz – PM10 evolution since 1993 Size-segregated sampling of PM10 with a five stage BERNER-impactor Analytical methods and derived parameters for characterization of sampled PM-fractions Mean distribution of particle constituents in size fractions for air masses from East and West in summer and winter (selected daily samples 2004-2009) Summary

Analysis of the five stage samples (Al-foils) Gravimetric mass 50% relative humidity and temperature (20+2) °C (conditioning time 48 hours). Weighing with micro-balance AT 261 Delta range (Mettler Toledo, Germany). Water soluble ions Water-soluble ions were determined by standard ionic chromatography with columns by Dionex and Metrohm OC/EC: Two-step-method (VDI 2465, page 2) step: N2-atmosphere 650 °C  organic carbon OC step: O2-atmosphere 650 °C  elemental carbon EC Detection as CO2 (IR) oxidation of C on a CuO-catalytic converter (850 °C) The estimation of OM from OC considers the content of hetero-atoms in „OM“. This content varies for particles from different stages because they have different sources or life-times in the troposphere. The following factors used 1.4 (stage 1), 1.7 (stage 2) and 2.0 (Stage 3-5). Compare: Turpin and Lim (2001) Aerosol Science and Technology 35, 602-610

Calculation of water content and Mass closure mH2O = mdry ((( pwet/pdry ) f ) - 1) mass closure: gravimetric mass - ( ΣIons + EC + OM + mH2O ) = rest with mH2O – water content (result) mdry – chemical determined mass concentration pwet – density of wet particle pdry – density of dry particle Dwet,dry – diameter of wet or dry particles f = (Dwet/Ddry)3 – eveluation factor for volume (spherical particles) mean ratio Dwet/Ddry ≈ 1.1, f results to 1.33 Neusüß et al., 2000, Tellus 52B, 169-184, Neusüß et al. 2002, J.Geophys.Res 107, D21, 8127-8139 calculation of pdry from the parts of components: Ions (NH4HSO4, NH4NO3, pdryi = 1.7), OM (Oxalat, pdryOM = 1.65), EC (Soot, pdrys = 1.8) and non identified mass (SiO2 = 2.2) calculation of pwet pwet = (1-(1/f)) pH2O + (1/f) pdry

Organic species (n-alkanes and PAH) Determination by Curiepoint pyrolysis GC-MS directly from the impactor Al-foils using a fast thermal desorption injector (He, 510°C). 24 n-Alkanes (with 20 – 34 C-Atoms) 20 PAH and marker compounds Fluorene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Retene, Benzo(b)naphtho(1,2-d)thiophene, Cyclopenta(cd)pyrene, Benz(a)anthracene, Chrysene + Triphenylene, 2,2-Binaphthyl, Benzo(b)fluoranthene, Benzo(a)fluoranthene, Benzo(e)pyrene, Benzo(a)pyrene, Indeno(1,2,3-cd)pyrene, Dibenzo(ah)anthracene, Benzo(ghi)perylene, Coronene 1 Marker for coniferous wood combustion Marker for brown coal (lignite) combustion

mass concentration [ng/m³] Example for n-alkane characteristics (stage 4, aerodynamic diameter 1.2-3.5 µm) CPI = Σcodd / Σceven = 6.5 CPI = Σcodd / Σceven = 1.4 19.06.2005, SUMMER caverage = 27.2 caverage = 26.1 Cwax = 62.8% Cptr = 37.2% Cwax = 12.9% Cptr = 87.1% mass concentration [ng/m³] 01.02.2009, WINTER

Characteristics of the n-alkane-distrubution (C20-C34) Average alkane chain length (average C-number): smaller for anthropogenic influences and higher for biogenic influences Carbon preference index (CPI): 1-2 for anthropogenic and > 3 for more biogenic influence Concentration of wax n-alkanes (biogenic) Cwax and petroleum n-alkanes Cptr: 33 Cwax = Σ n=21 Cn – (Cn – 1 + Cn+1) /2 negative values for (Cn – (Cn – 1 + Cn+1) /2) will be taken as zero. Cptr = Calk - Cwax Yue and Fraser (2004), Aerosol Science and Technology 38, 60-67

Selection of measurements for air mass origin and season Example WEST Example EAST 96-hour backward trajectories for two times(10 and 18 o‘clock MEZ), for 200, 500 und 1500 m over ground source: http://www.arl.noaa.gov/ready/hysplit4.htm All days 170 4 categories (138) WW WE 48 19 SW SE 42 29 season Winter: November – April Summer: May - October Spindler et al. (2010) Atmos. Env. 44, 164-173

Example for daily BERNER-impactor measurements Since 2007 also Flextra – air mass trajectories 10.12.2006 Winter West 18.12.2007 Winter East

The German EMEP-site Melpitz – PM10 evolution since 1993 Outline The German EMEP-site Melpitz – PM10 evolution since 1993 Size-segregated sampling of PM10 with a five stage BERNER-impactor Analytical methods and derived parameters for characterization of sampled PM-fractions Mean distribution of particle constituents in size fractions for air masses from East and West in summer and winter (selected daily samples 2004-2009) Summary

170 sampling days (2004 – 2009) for the five-stage BERNER-impactor, analysis and air mass origin summer winter EMEP campaign results available air mass origin sector: West East

Mean of all 170 days with BERNER-impactor measurements in Melpitz (mass, water soluble ions, OC/EC and water) absolute mass n

BERNER-impactor measurements in Melpitz for WW, WE, SW and SE (mass, water soluble ions, OC/EC and water) absolute mass WW WE SE SW

BERNER-impactor measurements in Melpitz for WW, WE, SW and SE (mass, water soluble ions, OC/EC and water) mass closure (relative) WW WE SE SW

BERNER-impactor measurements in Melpitz for WW, WE, SW and SE (Summ of PAH and Particle mass concentration in ng/m³ and µg/m³) WE SE

Mass concentration [ng/m³] BERNER-impactor measurements in Melpitz for WW, WE, SW and SE (mean distribution for two tracers within the five stages) WE SE ( S Mass concentration [ng/m³] WE SE

Mass concentration [ng/m³] and units CPI BERNER-impactor measurements in Melpitz for WW, WE, SW and SE (Biogenic and Petroleum n-Alkanes, CPI and average C-Number) WE SE CPI(20-33) Mass concentration [ng/m³] and units CPI Stage days Caverage(20-34)

BERNER-impactor measurements in Melpitz for all days with PAH (ratio: summ PAH/summ petroleum n-alkanes) 1:1

Summary (1) The particle mass concentration PM10 decreases since 1992 and remains constant in the last years from 2000. Particles were sampled on 170 days with five stage BERNER-impactors in the time frame 2004 to 2009 (including the last four EMEP campaigns). The sampling days was separated and averaged for days with air mass transport from West and East and for summer and winter. The highest mean mass concentration was found during winters and air mass transport from East for particles with the longest atmospheric live-time on stage 3 (0.42 to 1.20 µm aerodynamic diameter). The relative content of the main water soluble ions and carbon depends on season, source region of air masses and on aerodynamic diameter. The smallest particles on stage 1 contain the highest parts of sulphate in summer and higher parts of nitrate and carbon in winter.

Summary (2) Particles on stage 3 and 2 are typically for long range transport and contain the highest parts of sulphate and carbon for air mass transport from East, because there are source regions with lower efficiency of waste gas treatment. The highest part of nitrate was found in winter for air masses from West, reasons are NOx sources (mainly in Germany) and low temperatures. The particles on stages 4 and 5 are more locally effected and contain water soluble calcium and in winter during air mass transport from West the highest amounts of sea salt. Tracers for lignite and coniferous wood combustion identify regions in the East and the surroundings of Melpitz as typical sources. The carbon-preference-index (CPI) shows biogenic n-alkane-emissions in summer with highest values for air mass transport from East. The mass closure shows only three overestimations in the range of 2-6% and results in comparable amounts of relative water content.

Thank You for Your Attention ! We acknowledge the support from the Umweltbundesamt in Germany in different projects (351 01 022, 351 01 031 and 351 01 38), and for the support for EMEP level 3 measuring campaigns We would like to thank Jörn Hanß, Eveline Neumann, Annelie Thomas, René Rabe and Anett Dietze.

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Annual average PM10-concentrations at German EMEP sites since 1970. Source UBA (German contribution to EMEP-TFMM PM-Assesment Report) ca. 50 % decrease in particle concentration, in contrast primary emissions in Germany decrease even by about 85 %

IfT-Research station Melpitz Flow Inlet BERNER-Impactor View South-East View West 51°32' N and 12°54 ' East, 87 m above sea level

Location of the IfT research site in the state of Saxony (Germany) maritime air masses continental air masses 120 km Melpitz

Four year means for sectors East and West and winter and summer (DIGITEL HV-Sammler) Mean PM1, PM2.5 and PM10 mass concentrations, the concentrations of the main ions (nitrate, sulfate and ammonium) and organic and elemental carbon content (OC and EC) in winter and summer. Only days with air mass transport explicitly from West (blue frame) or from East (green frame) are considered. The error bars are the standard deviation for the particle mass concentration. “n” is the number of days. Averages of four winters (2004/05, 05/06, 06/07, 07/08) and summers (2005, 06, 07, 08) are shown. EMEP (2007b), Convention on Long-range Transboundary Air Pollution EMEP/CCC-Report 8/2007

Particle life-time in the troposphere and the five impactor stages 1 2 3 4 5 stages Particle life-time aerodynamic diameter derived from Jaenicke, R. (1978) Über die Dynamik atmosphärischer Aitkenteilchen. Ber. Bunsen. Phys.Chem. 82, 1198-1202.