Twenty years of ambient observations of nitrogen oxides and specified hydrocarbons in air masses dominated by traffic emissions in Germany

Christian Ehlers, Dieter Klemp, Franz Rohrer, Djuro Mihelcic, Robert Wegener, Astrid Kiendler-Scharr and Andreas Wahner Research Centre Jülich, Institute IEK-8:Troposphere, 52428 Jülich, Germany

Ambient observations VOC detection • VOC and OVOC • detection range from C2 to C13 (+ CO) • sensitivity: low ppt level

• NOx detection – in situ measurements – chemiluminescence detector – mobile and fixed stations 2016-04-12

C. Ehlers | Forschungszentrum Jülich, IEK-8

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Urban background-concentrations • •

Identification of local sources Estimation of possible reductions

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Example: tunnel-studies Düsseldorf, Rheinufertunnel Urban, 2010

Bonn, Bad Godesberger Tunnel Ehlers, 2013

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Example: Berlin, 2014 05. 08. 2014 NOx-concentration

[Submitted: Mobile BAERLIN2014: Sources and sinks - The influence of land surface types and horizontal heterogeneity on air pollutant levels in Berlin, B. Bonn, E. von Schneidemesser, D. Andrich, J. Quedenau, H. Gerwig, A. Lüdecke, J. Kura, A. Pietsch, C. Ehlers, D. Klemp, C. Kofahl, R. Nothard, A. Kerschbaumer, W. Junkermann, R. Grote, T. Pohl, K. Weber, B. Lode, P. Schönberger, G. Churkina, T.M. Butler, and M.G. Lawrence , acp-2016-57]

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Beispiel: Berlin, 2014 Airport Tegel: NOx-concentration

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Comparison with model-results CO-concentration • •

Good agreement for „backgroundconcentration“ Peak-concentrations can not be covered with 1x1 km resolution

Measurement: CO (1 second resolution) Modell: EURAD-IM, 1x1 km resolution 7

Ozone production - dependence of NOx and VOC 25

P(O3) [ppb/h]

20

15

10

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𝑅𝑅𝑉𝑉𝑉𝑉𝑉𝑉 = � 𝑘𝑘𝑂𝑂𝑂𝑂+𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖 × 𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖

0

0.01

𝑅𝑅𝑵𝑵𝑵𝑵𝟐𝟐 = 𝑘𝑘𝑂𝑂𝑂𝑂+𝑵𝑵𝑵𝑵𝟐𝟐 × 𝑵𝑵𝑵𝑵𝟐𝟐

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0.1

1

10

100

RNO2 [s-1]

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Ozone production - dependence of NOx and VOC

𝑅𝑅𝑉𝑉𝑉𝑉𝑉𝑉 = � 𝑘𝑘𝑂𝑂𝑂𝑂+𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖 × 𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖 𝑅𝑅𝑵𝑵𝑵𝑵𝟐𝟐 = 𝑘𝑘𝑂𝑂𝑂𝑂+𝑵𝑵𝑵𝑵𝟐𝟐 × 𝑵𝑵𝑵𝑵𝟐𝟐

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German emission inventory

Figure: National Trend Tables for the German Atmospheric Emission Reporting, ANNEX 1: National sector emissions: Main pollutants, particulate matter, heavy metals and persistent organic pollutants, Excel spreadsheets DE_2015_Table_I_1990.xls - DE_2015_Table_I_2013.xls, ed. P. 10 Gniffke, Umweltbundesamt Deutschland, Dessau, 27.04.2015

German emission inventory

Current situation in urban areas: • Diesel cars are dominant source of NOx • Petrol cars are dominant source of VOC Figure: National Trend Tables for the German Atmospheric Emission Reporting, ANNEX 1: National sector emissions: Main pollutants, particulate matter, heavy metals and persistent organic pollutants, Excel spreadsheets DE_2015_Table_I_1990.xls - DE_2015_Table_I_2013.xls, ed. P. 11 Gniffke, Umweltbundesamt Deutschland, Dessau, 27.04.2015

Trend in observations

• Ratio RVOC / RNO2 decreased by factor 7.5 • VOCs were reduced more than NOx 2016-04-12

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Data Gubrist tunnel: U. Steinemann and F. Zumsteg, Verkehrs- und Schadstoffmessungen 2008 im Gubristtunnel ; report US 89 - 16 - 13, OSTLUFT, Zürich, Switzerland, update May 25, 2010.

Trend in observations

• Ratio RVOC / RNO2 decreased by factor 7.5 • VOCs were reduced more than NOx 2016-04-12

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Data Gubrist tunnel: U. Steinemann and F. Zumsteg, Verkehrs- und Schadstoffmessungen 2008 im Gubristtunnel ; report US 89 - 16 - 13, OSTLUFT, Zürich, Switzerland, update May 25, 2010.

Trend in observations

• Ratio RVOC / RNO2 decreased by factor 7.5 • VOCs were reduced more than NOx 2016-04-12

C. Ehlers | Forschungszentrum Jülich, IEK-8

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Data Gubrist tunnel: U. Steinemann and F. Zumsteg, Verkehrs- und Schadstoffmessungen 2008 im Gubristtunnel ; report US 89 - 16 - 13, OSTLUFT, Zürich, Switzerland, update May 25, 2010.

Photochemistry Germany, 21.6., clear sky, noon, 25°C, MCM 3.2

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Photochemistry Germany, 21.6., clear sky, noon, 25°C, MCM 3.2

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Conclusions Traffic emissions reduced by catalytic converter • very strong reduction in VOC • small reduction in NOx 

Significant reduction of ozone production in urban areas  Future reduction schemes should include both NOx and VOC 2016-04-12

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RVOC measured by GC-MS Contribution of large VOCs to OH-reactivity

GC-MS systems • C2 – C13 SilcoSteel® canister sampling, cryogenic enrichment • C8 – C16 sampling on Tenax® or Carbotrap® adsorbent  For exhaust samples the RVOC calculated from GCmeasurements (+ CO, NO2, HCHO) were in good agreement with results from LIF-KOH

 Contribution of C12-16 was below 3% of total reactivity

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Large hydrocarbons

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Different regimes

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Winter conditions Germany, 21.12., clear sky, noon, -5°C, MCM 3.1

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Changes in Emission Profiles

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Solvents in urban areas?

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Ozone concentration

Averaged annual surface ozone concentrations observed at the GAW stations Mace Head, Ireland (blue diamonds) [R. G. Derwent, A. J. Manning, P. G. Simmonds, T. G. Spain and S. O’Doherty, Atmospheric Environment, 2013, 80, 361–368], and Hohenpeissenberg, Germany (red circles). The data from Hohenpeissenberg for the time period until 2010 are taken from the literature [O. R. Cooper, D. D. Parrish, J. Ziemke, N. V. Balashov, M. Cupeiro, I. E. Galbally, S. Gilge, L. Horowitz, N. R. Jensen, J.-F. Lamarque, V. Naik, S. J. Oltmans, J. Schwab, D. T. Shindell, A. M. Thompson, V. Thouret, Y. Wang and R. M. Zbinden, Elementa: Science of the Anthropocene, 2014, 2:000029, 1–28]. The later data were kindly supplied by the German Weather Service and are preliminary.

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Trend in Ozone concentration Average number of hours exceeding 240 µg/m³ Ozone per year

• Fewer exceedances of ozone alarm values • Decrease in Ozone concentrations in Germany 2016-04-12

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Figure: U. Dauert, S. Feigenspan, A. Minkos and M. Langner, Luftqualität 2014, Vorläufige Auswertung, Umweltbundesamt Deutschland, Dessau-Roßlau, Januar 2015

Raw exhaust emissions

NOx and VOC emissions of diesel and petrol passenger cars without catalytic converters; replotted using published mixing ratio measurements (see [R. Pischinger, M. Kell and T. Sams, Thermodynamik der Verbrennungskraftmaschine: Der Fahrzeugantrieb, Springer, Wien, Austia, and New York, USA, 3rd edn., 2009]) multiplied with λ to be proportional to g/km and then scaled to the values of table 1 at λ = 1 for petrol and λ = 3 for diesel passenger cars.

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Petrol car emissions

Normalized cumulative emissions of CO (100%=23.8g corresponding to 0.80g/km), CO2 (262g/km), NO (0.205g/km as NO2), and VOC (0.088g/km as HC) derived during on-board measurements of a petrol car (see [D. Klemp, D. Mihelcic and B. Mittermaier, Messung und Bewertung von Verkehrsemissionen, Schriften des Forschungszentrums Jülich, Energy & Environment, volume 21, Jülich, Germany, 1st edn., 2012]) during a drive of 29.7km length 11.07.2001 in Munich (passenger petrol car, year of manufacture: 2000, 85 kW, G-Kat, exhaust norm D4)

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Diesel car emissions

Normalized cumulative emissions of CO (100%=2.09g corresponding to 0.116g/km), CO2 (180g/km), NO (0.149g/km as NO2), NO2 (0.173g/km), and VOC (0.008g/km as HC) derived during on-board measurements of a diesel car (see [D. Klemp, D. Mihelcic and B. Mittermaier, Messung und Bewertung von Verkehrsemissionen, Schriften des Forschungszentrums Jülich, Energy & Environment, volume 21, Jülich, Germany, 1st edn., 2012]) during a drive of 18.0km length 27.11.2002 executing a FTP-75-cycle (passenger diesel car, year of manufacture: 2002, 105 kW, DOC, exhaust norm EURO3)

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Inventory of passenger cars

Inventory of passenger cars (PC Diesel and PC Petrol) in Germany for the years 1960-2015 (see [Fahrzeugzulassungen: Bestand an Kraftfahrzeugen nach Umwelt-Merkmalen; Statistische Mitteilungen des Kraftfahrt-Bundesamtes FZ 13, Kraftfahrt-Bundesamt, Flensburg, Germany, 2015]); since January 1, 2008, only registered vehicles without temporary suspension respectively decommissioning are taken into account

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Annual fuel consumption

Annual fuel consumption of road traffic in Germany for the years 1960-2011 (PC: passenger cars; oV: other vehicles including HGV, LCV, and UBus (Heavy Goods Vehicles, Light Commercial Vehicles, Urban Buses); misc: miscellaneous petrol cars; natural and liquefied gas included in PC petrol; PJ: Peta Joule = 1015 Joule); replotted from TREMOD version 5.3 (see [S. Hausberger, M. Rexeis, M. Zallinger and R. Luz, Emission Factors from the Model PHEM for the HBEFA Version 3; Report Nr. I-20/2009 Haus-Em 33/08/679 from 07.12.2009, TU Graz, Graz University of Technology, Graz, Austria, 2009 ])

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Emission regulation

Vehicle emission regulation categories for passenger cars in Germany for the years 1990-2011; replotted from TREMOD version 5.3 (see [Aktualisierung ”Datenund Rechenmodell: Energieverbrauch und Schadstoff-emissionen des motorisierten Verkehrs in Deutschland 1960-2030” (TREMOD, Version 5.3) für die Emissionsberichtserstattung 2013, ed. W. Knörr, ifeu - Institut für Energie- und Umweltforschung Heidelberg GmbH, Heidelberg, Germany, 2012] and table 1)

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NOx emissions

NOx emissions (as NO2) of road traffic in Germany for the years 1960-2011 (PC: passenger cars; oV: other vehicles including HGV, LCV, and UBus (Heavy Goods Vehicles, Light Commercial Vehicles, Urban Buses), ; misc: miscellaneous petrol cars and remaining types of road traffic); replotted from TREMOD version 5.3 (see [Aktualisierung ”Daten- und Rechenmodell: Energieverbrauch und Schadstoff-emissionen des motorisierten Verkehrs in Deutschland 1960-2030” (TREMOD, Version 5.3) für die Emissionsberichtserstattung 2013, ed. W. Knörr, ifeu - Institut für Energie- und Umweltforschung Heidelberg GmbH, Heidelberg, Germany, 2012])

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Anually averaged NOx concentrations

Annually averaged NOx concentrations (NO displayed as µg/m³ NO2) close to traffic in inner city districts in Germany (replotted from [Umweltbundesamt, Entwicklung der Luftqualität in Deutschland, Umweltbundesamt Deutschland, Fachgebiet II 4.2 ”Beurteilung der Luftqualität”, Dessau-Roßlau, October 2009, pp. 5–7.])

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Vehicle kilometers

Vehicle kilometers traveled by passenger cars in Germany; replotted from TREMOD version 5.3 [Aktualisierung ”Daten- und Rechenmodell: Energieverbrauch und Schadstoff-emissionen des motorisierten Verkehrs in Deutschland 1960-2030” (TREMOD, Version 5.3) für die Emissionsberichtserstattung 2013, ed. W. Knörr, ifeu - Institut für Energie- und Umweltforschung Heidelberg GmbH, Heidelberg, Germany, 2012]. AB:Autobahn, OT:out-of-town, IT:in-town

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NOx traffic emissions

Estimated NOx traffic emissions in urban areas in Germany, this paper; for details see subsection 1.3.1. Featured categories from bottom to top are: ”PC petrol RDE=EU”: PC petrol car emissions which essentially show real-drive-emissions RDE in compliance with EU legislation, ”PC diesel EU”: intended PC diesel car emissions according to EU legislation, ”PC diesel RDE-EU”: surplus of PC diesel car real-drive-emissions RDE on top of the intended emissions according to EU legislation, ”LCV+HGV”: emissions of light-commercial-vehicles and of heavy-goods-vehicles.

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Ozone production

Vergleich der Ozonproduktionsraten, berechnet aus gemessenen Radikalkonzentrationen verschiedener Kampagnen auf dem Schauinsland (Sommer 1989,1990, 1992 und 1994 Quadrate); aus Izania, Teneriffa (1994, Dreiecke); die roten Punkte geben die gemessenen -Werte aus der BERLIOZ-Kampagne (20.07.1998 und 21.07.1998) wieder. (aus: [Mihelcic et al. 2003]). Die Daten repräsentieren 30 min-Mittelwerte und sind als Funktion der gleichzeitig gemessenen -Konzentration aufgetragen. Berücksichtigt wurden ausschließlich Tageswerte mit > 0,004 s-1. Zusätzlich eingetragen (grüne Linie) wurden die -Resultate der MCM-Modellierung des Münchener Datensatzes.

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Retention time [min]

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VOC „fingerprints“

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VOC „fingerprints“

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VOC OH-reactivity

• OH-reactivity  speed of reaction with OH – 90% of all VOCs react with OH – Reciprocal lifetime of OH [unit: s-1] • 𝑅𝑅𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖 = 𝑘𝑘𝑂𝑂𝑂𝑂+𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖 × 𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖

– Processing of an air mass can be described by proxy of total VOC reactivity with OH • 𝑅𝑅𝑉𝑉𝑉𝑉𝑉𝑉 = ∑ 𝑘𝑘𝑂𝑂𝑂𝑂+𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖 × 𝑉𝑉𝑉𝑉𝑉𝑉𝑖𝑖

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