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J. Hovorka*, M.Bra niš * , J.Schwarz **

DIURNAL VARIATION OF SUBMICRON PM SIZE DISTRIBUTIONS AND GASEOUS POLLUTANT CONCENTRATIONS, PRAGUE 2004, POLLUTION SOURCE ESTIMATION. hovorka@cesnet.cz, branis@natur.cuni.cz, schwarz@icpf.cas.cz. J. Hovorka*, M.Bra niš * , J.Schwarz **.

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J. Hovorka*, M.Bra niš * , J.Schwarz **

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  1. DIURNAL VARIATION OF SUBMICRON PM SIZE DISTRIBUTIONS AND GASEOUS POLLUTANT CONCENTRATIONS, PRAGUE 2004, POLLUTION SOURCE ESTIMATION hovorka@cesnet.cz, branis@natur.cuni.cz, schwarz@icpf.cas.cz J. Hovorka*, M.Braniš*, J.Schwarz** *Institute for Environmental Studies,Charles Universityin Prague, Benátská 2, 128 01 Prague 2, Czech Republic ** Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic

  2. Motivation of our work • three years of our air monitoring revealed frequent (30% of days) bimodal pattern of diurnal variation of NOx, NMHC, CH4, CO partially SO2 • first mode 8-9 a.m. traffic rush hours • second mode 8-10 p.m. NO rush hours • ? ARE THESE MEASUREMENTS SITE SPECIFIC ? • ? DOES AEROSOL BEHAVE SIMILARY? • ? WHAT ARE LIKELY SOURCES?

  3. Parameters determined • 5 mins averages • 14 – 710 nm aerosol size distribution (SMPS) • 15 mins averages • NO, NO2 , CO, SO2, CH4, Non-Methane HC, O3 (Horiba 360) • temperature, humidity, UV-A,B, wind speed/direction • hourlyaverages • PM10 by b-attenuator, • traffic volumes • natural gas consumption in near-by stationary sources

  4. Sampling site • roof-top aerosol/gasses sampling in University botanical garden in the Prague city center • at height about 25 m above the street • no street canyon conditions • duration 1.9.2004 – 31.12.2004

  5. PRAGUE 2 Hospital heating plant University Botanic garden sampling site Wind direction

  6. University Botanic garden, roof-top sampling inlets

  7. Roof-top sampling configuration

  8. Diurnal variation of CO, NO, NO2, SO2, NMHC, CH4 in Botanical garden in Prague center, 5.10.2004

  9. Diurnal variation of PM10 concentrations averaged over half a year 2004 at the CHMI sites in Prague center Calculated from data: www.chmi.cz

  10. Diurnal variation of PM10(Beta), PM0.72(SMPS) and total particle number (14-710 nm) in Botanical garden, Prague center 5.10.2004

  11. ? SPECIFIC SITE ? • Recorded bimodal pattern is NOT site specific solely for our station but appeared at other sites situated near river valley • Similar pattern in diurnal variation also recorded in other cities in Europe with similar urban architecture and local geography ? AEROSOL TEMPORAL CHANGES? Temporal variations of aerosol mass/number concentrations also exhibit similar pattern as gaseous components measured

  12. ? SOURCES ? • nucleation: NO up to 10 of true nucleation events (banana shape) recorded within measured period • long-range transport:NO particleresidence time too short, fast changes of number concentrations, bimodal pattern during low wind speed • primary emissions from: • traffic • natural gas burning in major sources in proximity to the sampling site: Hospital heating plant Botanical garden boiler apartment/office boilers

  13. Hourly averages of particle number size distribution 5.10.2005, Prague. Number

  14. Hourly averages of particle mass size distribution 5.10.2005, Prague. Mass

  15. Hourly averages of traffic volumes at the intersection near University Botanical garden during working days (yellow) and weekends (green)

  16. Data source: www.udi.cz

  17. Diurnal variation of natural gas burnup in Hospital heating plant and Botanic garden boiler in Prague center on 5.10.2004

  18. Diurnal pattern of 20 min values (Sep-Dec 2004) of natural gas burnup by heating boiler in the Botanic garden

  19. Estimated diurnal pattern of output of gas burning boilers in residential districts

  20. Summary of peak values of gaseous precursors, aerosol concentrations and different sources outputs in Prague

  21. CONCLUSIONS • bimodal pattern of diurnal variation of aerosol concentration can be ascribed to traffic and natural gas burning as primary aerosol emission sources • precise traffic and gas burning apportionment of total aerosol burden in urban atmosphere requires further data on gas burning boilers in residential areas

  22. Acknowledgment Traffic counts performed by L.Betuš and V.Klapšťová. The station was built and maintained with help of M.Civiš. The study was done within the scheme of project “Comprehensive characterization of atmospheric aerosol in Prague” No. 205/03/1560 of the Czech Grant Agency.

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