Num be r [cm -3 ] 1. 3-1 nm (UFP) 1-2 nm 4-8 nm 1. 1. 1 1 Aug 2 Jan 3 Aug 3 Jan 4 Aug 4 Jan 5 Aug 5 Jan 6 Aug 6 Jan 7 Aug 7 Five years particles number concentrations measurements in Dresden Gunter Löschau, Birgit Wehner, Alfred Wiedensohler UFIPOLNET Conference - Ultrafine Particles in Urban Air 23-24-Oct 27, Dresden/Germany
Overview 1 Introduction Motivation Instrumentation Measuring site 2 Results Average Trend 3 Some effects on particles number Summer/winter differences Reduction on Sunday 4 Summary 2
LfUG - Monitoring and Assessment of Air-quality Network in Saxony (Operated by UBG) Measurements are based on lows (BImSchG) 31 Measuring stations locations: urban streets (13 x) urban residential area (12 x) rural, hills (6 x) Particles: 25 x PM 1 6 x PM 2.5 1 x Particles number Measurement is based on precaution 3
Number of Particles in Dresden-Nord Particles number concentrations and Particles size distribution Particle diameter from 3 to 8 nm TDMPS (Twin Differential Mobility Particle Sizer) 2 DMA und 2 Condensation counters (TSI 31 und 325) Made by IfT Leipzig Integration into the Air-quality Network of Saxony Reducing the measured data: 8 particles size classes ½-h-average values stored in database Particles size classes are verified and catalogued with all other pollutants Teamwork: UBG Radebeul (Operation) IfT Leipzig (repairs, quality assurance) LfUG Dresden (measuring concept, data interpretation) 4
Measuring Station Dresden-Nord (Schlesischer Platz) A 4 Sampling point, 5 m from busy crossing ~ 5. vehicles/d, ~ 5 % heavy traffic 5
Measuring Station Dresden-Nord Measuring station ~ 5 m from a road with little traffic ~6.5 vehicles/d ~6 % heavy traffic 6
Average values over 5 years (from August 22 to July 27) Gases Particle mass Particle number 37 µg/m³ NO, 46 µg/m³ NO 2, 53 ppb NO x 2,4 µg/m³ Benzol,,6 µg/m³ CO 33 µg/m³ PM 1, 44 Tage pro Jahr > 5 µg/m³ PM 1 21 µg/m³ PM 2.5 (64 % PM 1 ), Im PM 1 : 4,4 µg/m³ Ruß,,9 ng/m³ BaP 23 * 1³ P/cm³ for size class 3-8 nm 2 * 1³ P/cm³ for utrafine particles (3-1 nm) Local meteorology temperature 11 C, humidity 72 % wind speed 1,7 m/s, radiation W/m² 7
Vehicle Counting Point (from August 24 to July 27) Counting point A 4 Measuring station Trend: Decrease in number of vehicles Increase of vehicles with diesel engine (registration) Car 5. Number of vehicles per Day Lorry 2.5 4. 2. 3. 2. Car Lorry 1.5 1. 1. 5 1 2 3 4 5 8/2-7/3 8/3-7/4 8/4-7/5 8/5-7/6 8/6-7/7 8
Number concentration of Particles over 5 years Num be r [cm -3 ] 75. Daily averages Particle size 3 8 nm Data capture 8 % from 7.3 to 71. cm -3 ½-h-average values from 1.9 to 19. cm -3 5. 25. Aug 2 Jan 3 Aug 3 Jan 4 Aug 4 Jan 5 Aug 5 Jan 6 Aug 6 Jan 7 Aug 7 9
Daily Averages of 3 Particles size Classes Num ber [cm -3-3 ] 75. 1. 3-1 nm (UFP) 1-2 nm 4-8 nm 3-1 nm (UFP) 1-2 nm 4-8 nm 1. 5. 1. 25. 1 Aug 1 2 Jan 3 Aug 3 Jan 4 Aug 4 Jan 5 Aug 5 Jan 6 Aug 6 Jan 7 Aug 7 Aug 2 Jan 3 Aug 3 Jan 4 Aug 4 Jan 5 Aug 5 Jan 6 Aug 6 Jan 7 Aug 7 87 % of all particles are ultrafine particles (3-1 nm) 1
Num ber [cm -3 ] 3. 25. Trend over 5 years Particles number concentrations Decrease in number of vehicles Decrease in number of particles Not uniforml for all size classes 3-8 nm 1-2 nm Num be r [cm -3 ] 8. 7. 2-5 nm 1-2 nm -19 % 6. 2. -8 % 5. 15. 4. 1. 3. 5. -19 % 2. 1. -4 % 1 2 3 4 5 1 2 3 4 5 8/2-7/3 8/3-7/4 8/4-7/5 8/5-7/6 8/6-7/7 8/2-7/3 8/3-7/4 8/4-7/5 8/5-7/6 8/6-7/7 11
Relative Change over 5 years (Results from regression analysis) Gases Particles number Particles mass Diameter [nm] NO2 NOx CO NO BEN 1 1 1 1 PM1 PM2.5 soot % -1% -2% Amongst others primary diesel engine particles -3% -4% Change in level Changes of meteorology: e.g. temperature increase of +1,9 C 12
Change: warm months (t>2 C, n=7) cold months (t< C, n=9) Gases Particles number Particles mass Change in level 2% Heating effect for PN 4 8 nm 15% 1% Without effect for PN 5 2 nm 5% NO2 NOx NO CO BEN % Soot PM1 PM2.5-5% 1 1 Diameter [nm] 1 Causes a) increased heater emissions b) more inversions c) increase imported particles due to high-pressured weather with wind from the east 13
Average weekly Course over 5 years Reduction on Saturday due to reduction of anthropogenic emissions. Nature doesn t know a Sunday from a Monday! Num ber [cm -3 ] 8. 1-2 nm -44 % 6. um ber [cm -3 ] 3-8 nm 3. 25. -33 % 4. 2. 2. Mo Tu W e Th Fr Sa Su 15. 1. 4-8 nm Num ber [cm -3 ] 8 6-19 % 5. 4 Mo Tu We Th Fr Sa Su 2 Mo Tu We Th Fr Sa Su 14
Average Reduction on Sundays over 5 years in comparison to the average from Mondays to Fridays Gases Particles number Particles mass Vehicles* CO Benzol NO2 NOx NO % 1 1 1 1 D [nm] PM2.5 PM1 Soot Car Lorry -2% -4% -6% -8% Important for Air-quality improvement plans: Estimating the effects for short-term measure - such as shouting down traffic for a day * 8/24-7/27 15
Average weekly Course over 5 years with high Time Resolution Num ber [cm -3 ] Num ber [cm -3 ] 1.2 3.5 1. 3-5 nm 3. 1-2 nm 8 2.5 6 4 2. 1.5 1. 2 5 Num ber [cm -3 ] Num ber [cm -3 ] 12. 12 1. 2-5 nm 1 4-8 nm 8. 8 6. 6 4. 4 2. Mo Th We Tu Fr Sa Su 2 Different shape for every size class The same shape for a class from Monday to Friday, but a different one for the weekend 16
Standardized* average weekly course over 5 years dimensionless PN 5 PN - 1 5 - nm 1 nm Car Lorry Car Soot_Ae Lorry NOx 2,5 2, 1,5 1,,5, :3 6:3 12:3 18:3 :3 6:3 12:3 18:3 :3 6:3 12:3 18:3 :3 6:3 12:3 18:3 :3 6:3 12:3 18:3 :3 6:3 12:3 18:3 :3 6:3 12:3 18:3 Extensive evaluation is possible, for example analysing polluter statistics as well as air chemistry and physics * According to average values 17
Summary, Outlook Particles number measurements + The study is carried out independently for precautionary health principles. + 5 years of experience, data capture 8 % + Particles number concentration in 8 sizes from 3 to 8 nm + need for a mobile aerosol standard to further improve further QA/QC + Expensive evaluations: * analysing polluter according particle size * epidemiological studies should use the data Is there a health impact or not? 18
Foto: Cornelia Klör Thank you! Birgit Wehner, Alfred Wiedensohler Leibniz-Institut für Troposphärenforschung (ift) Leipzig Ulrich Langer, Ulrich Müller, Michael Lohberger, Stefan Sorkalle Umweltbetriebsgesellschaft (UBG) Radebeul Heinz Gräfe Sächsisches (LfUG), Dresden Hartmut Schwarze Sächsisches Staatsministerium für Umwelt und Landwirtschaft (SMUL), Dresden 19