EUROCHAMP - A European Infrastructure Project for Atmospheric Simulation Chambers: Current Progress and

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1 EUROCHAMP - A European Infrastructure Project for Atmospheric Simulation Chambers: Current Progress and Future Directions with Respect to Chemical Mechanisms Peter Wiesen Bergische Universität t Wuppertal Fachbereich C / Physikalische Chemie wiesen@uni-wuppertal wuppertal.de

2 Introduction I An important approach to better understand the complex chemical processes in the atmosphere are so-called atmospheric simulations chambers (smog chambers), which sometimes have a volume of several hundred cubic meters. Smog chambers allow to simulate quite different atmospheric conditions without the complication of transport processes.

3 Introduction II First simulation chambers go back to the 1970ties in order to study the Los-Angeles-Smog. Those studies provided fundamental knowledge about NO x and VOC reactions in the troposphere. In the last 15 years, particularly in Europe, new and significantly improved chambers have been set up with a much broarder range of applications.

4 Mechanistic developments and evaluations by simulating chemical processes in an outdoor smog chamber Major gaps in the knowledge of the mechanisms of atmospheric processes leading to photooxidant formation e.g.: Impact of biogenic VOC on the ozone budget Contribution of aromatic VOC to the photooxidant problem Emissions from alternatively fuelled vehicles and their influence on photooxidant chemistry Response of the oxidising capacity determined by OH, HO 2 and NO 3 radicals to anthropogenic emissions

5 EUPHORE SAPHIR

6 AIDA chamber Aerosol chamber at PSI, Villigen

7 However, no coordination between the different activities at the individual installations in Europe!

8 The EUROCHAMP Project A New European Project for the Integration of European Simulation Chambers for Investigating Atmospheric Processes An Integrated Infrastructure Initiative (I3)

9 General objectives of EUROCHAMP: Integration of existing environmental reaction chambers into a Europe-wide infrastructure Initiation of an effective interdisciplinary collaboration between the community of atmospheric scientist and colleagues from other disciplines (cultural heritage protection and human health) Start of the project: June 1, 2004 Project duration: : 60 months (long-term integration aspect!!) EC contribution: : 3.9 M M

10 EUROCHAMP Partners (contractors( contractors) involved in EUROCHAMP: BUW (co( co-ordinator) EC-JRC FZJ CEAM UBAY UCC CNRS-LCSR PSI FZK LEEDS SP UPAR

11 EUROCHAMP Users (associates( associates) involved in EUROCHAMP: 1 TUW 2 UHEI 3 FORD 4 OSLO 5 UHEL 6 IFT* 7 NIC 8 IASI 9 WUT 12 USZ 13 DOM 14 ISQ 15 UCD 16 ABK 17 UBIRM 18 UMIST 19 IMW 20 IIA 10 LVP 21 CERT 11 UWIEN 22 DRI *new partner in 2007

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13 EUROCHAMP activities (contd( contd.): Two joint research activities - development and refinement of analytical equipment (characterisation of oxygenated VOC s, radical measurements, nitric acid measurements, characterisation of aerosols) - development of chemical modelling techniques (techniques for the evaluation and development of oxidant mechanisms and models, techniques for the evaluation and development of aerosol models, development and deployment of statistical tests and sensitivity analysis methods)

14 THE EUROCHAMP Central DATABASE for model validation Structure showing the the Data Transfer between the the Individual Institutes and and the the Central Search Engine BUW FZK Central Search Database Internet Connection Users Layout of the database structure linking network connections of the individual host institutes with the central database, and its access by the Internet through the EUROCHAMP homepage.

15 Smog chambers and aerosols

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20 How well do we understand OH radical formation (in chambers and) in the atmosphere?

21 OH sources and sinks (simplified) O 3 + hυ (λ < 340 nm) O ( 1 D) + O 2 Sources: Sinks: O ( 1 D) + M O ( 3 P) + M M=(N 2 or O 2 ) O ( 1 D) + H 2 O OH + OH HONO + hυ (λ < 400nm) OH + NO HCHO + hυ (λ < 370 nm) H + HCO H 2 + CO H + O 2 + M HO 2 + M (+NO) OH + NO 2 HCO + O 2 HO 2 + CO (+NO) OH + NO 2 Alkenes + O 3 OH + Products OH + NO + M HONO + M OH + NO 2 + M HNO 3 + M

22 The OH radical is a key species in atmospheric chemistry: - OH chemistry controls the removal rate of most air pollutants - OH chemistry leads to the formation of ozone Main sources of OH: -O- O 3 photolysis - HCHO photolysis -VOC s- + O 3 - HONO photolysis Known/measured sources and sinks of OH are often not balanced e.g.: unknown OH-reactivity (Di Carlo et al., 2004)

23 Since the first unequivocal detection (Perner&Platt, 1979) nitrous acid (HONO) is known to be a major OH source in the morning (e.g. Alicke et al., 2003): HONO + h hν NO + OH However, during the day HONO was almost always below the detection limit in old studies, in good agreement with the photo- stationary state (PSS) of known sources and sinks (only( few pptv!), including the measured night-time time sources Nevertheless, using the measured HONO in the morning and the theoretical HONO during daytime, an integrated HONO contribution to the OH formation of up to 34 % was estimated! (Alicke et al., 2002)

24 Santiago de Chile

25 Meßergebnisse Diurnal variation (10 min values) March 8-20, 2005 HONO [pptv] HONO [pptv] NO [ppbv] NO2 ppbv] NO, NO2 [ppbv] - Typical rush hour peak (direct emissions) - Very high HONO concentrations during daylight hours (up( to 2.5 ppbv) :00 04:00 08:00 12:00 16:00 20:00 00:00 Zeit

26 Meßergebnisse Diurnal variation (10 min values) March 8-20, 2005 J HONO [s-1] 3,E-03 2,E-03 2,E-03 1,E-03 5,E-04 0,E+00 J(HONO) J(O1D) 00:00 02:24 04:48 07:12 09:36 12:00 14:24 16:48 19:12 21:36 00:00 Zeit 3,E-05 2,E-05 2,E-05 1,E-05 5,E-06 0,E+00 J O 1 D [s-1] - Typical diurnal variation of J(NO 2 ) and J(O 1 D) - With the photoysis frequencies J(HCHO) and J(HONO) can be calculated (Holland et al., 2003)

27 4000 Diurnal variation of HONO (March 15-19, 2005) 3500 HONO PSS ohne k(het) HONO exp HONO [pptv] Additional HONO source during daytime!! Zeit

28 Diurnal variation of OH production rates (March 15-19, 2005) 1,E+09 1,E+08 P(OH) [cm -3 s -1 ] 1,E+07 1,E+06 1,E+05 1,E+04 Summe P(OH) P OH(HONO)netto P OH(alkenes) P OH (HCHO) P OH(O3) 1,E Zeit

29 averaged OH production rates, March 11-20, 2005 OH-Produktion am Tag P OH (Alkene): 30 % P OH (O 3 ): 4 % P OH HONO: 54% P OH (HCHO): 12 %

30 HONO photolysis is sometimes the most important OH radical source (Santiago 54% through HONO photolysis In good agreement with recent field results: New York: 59% (Ren( et al., 2003) Jülich: 33% (Kleffmann( et al., 2005) Hohenpeissenberg: 40% (Acker et al., 2006)

31 Do current models take the OH production through HONO photolysis during daytime properly into account? How?

32 How well do we understand HONO formation in the atmosphere?

33 From new HONO measurements with ultra-sensitive new HONO instruments a daytime HONO sources was postulated in order to explain high HONO daytime concentrations. - Switzerland rural: pptv (Neftel et al., 1996) - Wuppertal urban: pptv (Kleffmann et al., 2002) - New York state rural: ~ 50 pptv (Zhou Zhou et al., 2002) - Karlsruhe urban: pptv (Kleffmann et al., 2003) - New York urban: pptv (Ren et al., 2003) - Santiago urban: Up 2500 pptv (Wiesen et al., 2007)

34 Daytime formation of nitrous acid as a major source of hydroxyl radicals in a forest Jörg Kleffmann*, Traian Gavriloaiei*, Andreas Hofzumahaus #, Frank Holland #, Ralf Koppmann #, Lutz Rupp #, Eric Schlosser #, Manfred Siese # & Andreas Wahner # *Physikalische Chemie Wuppertal # Forschungszentrum Jülich Geophysical Research Letters, 32,, 2005 Highlight of the recent literature in Science, 308, 2005

35 Field campaign Measurement site: tower, 38 m, Forschungs-zentrum Jülich, ECHO- campaign, 2003 HONO: LOPAP (new instrument) OH/HO 2 : LIF radiation: J (HONO),J (HCHO), J (O1D),J (NO2) NO x : Chemiluminescence HCHO: Hantzsch -Method O 3 : UV-Absorption VOC s: GC

36 Field campaign Averaged [HONO] PSS only ~ 11 pptv (<<measured!) HONO / pptv Messung PSS Modell Additional HONO source of 500 pptv/h necessary 13:20 13:40 14:00 14:20 Zeit / h(cet)

37 How is HONO formed during daytime?

38 Photoenhanced Uptake of Gaseous NO 2 on Solid Organic Compounds: A Photochemical Source of HONO C. George a, R. S. Strekowski a, J. Kleffmann b, K. Stemmler c and M. Ammann c a UCBL-CNRS, Villeurbanne, France b Bergische Universität Wuppertal, Wuppertal, Germany c Paul Scherrer Institut, Villigen, Switzerland Faraday Discussions, 130, 2005

39 Photosensitized Reduction of Nitrogen Dioxide on Humic Acid as a Source of Nitrous Acid K. Stemmler a, M. Ammann a, C. Dondors a, J. Kleffmann b and C. George c a Paul Scherrer Institut, Villigen, Switzerland b Bergische Universität Wuppertal, Wuppertal, Germany c UCBL-CNRS, Villeurbanne, France Nature, 440, 2006

40 Lab studies: a) heterogeneous sources Characteristic elements of humic stubstances (Averett et al., 1989) O HO OMe COOH MeO COOH

41 Lab studies: a) heterogeneous sources 1) proxies: NO 2 (20 ppb) + organic mixture ( nm) O absorber OMe HO MeO COOH COOH electron donor HONO bzw. NO2 [ppbv] HONO NO 2 Lampen an NO 2 durch Flußreaktor Lampen aus NO 2 durch "Bypass" 00:00 00:20 00:40 Zeit [min]

42 Lab studies: a) heterogeneous sources Proposed mechanism: OH NO 2 HONO hν NO Reduziertes aromatisches Zwischenprodukt H O Elektronendonor O R2 C R1 e, H + R OH R R2 R2 O 3 O * R1 Aromatischer Lichtabsorber R1 hν Organische Oberfläche Very efficient formation of HONO on humic acids, yield almost 100 %!

43 Lab studies: a) heterogeneous sources Proposed HONO formation on humic acids/soils NO 2 HONO hν OH NO Atmosphäre photochemisch aktivierte Huminsäuren* HO HO COOH HO COOH e -, H + O HO Huminsäuren sind Gemische von partiell oxidierten aromatischen Makromolekülen aus dem Abbau von Biota O oxidierte Huminsäuren O R OH H N O R Erdoberfläche

44 The Photolysis of Ortho-Nitrophenols Nitrophenols: : A new Gas Phase Source of HONO I. Bejan a, Y. Abd El Aal a, I. Barnes a, T. Benter a, B. Bohn b, P. Wiesen a and J. Kleffmann a * a Bergische Universität Wuppertal b Forschungszentrum Jülich Phys. Chem. Chem. Phys., 8, 2006

45 Lab studies: a) gas phase chemistry Fast photochemical formation of HONO 5 4 HONO 3M2NP lamps off HONO [ppbv] M2NPsource connected blank: lamps lamps on off lamps on M2NP [ppmv] 0 0:00 2:00 time [hh:mm] 4:00 0

46 Lab studies: a) gas phase chemistry HONO formation [Nitrophenol] HONO formation independent of S/V reactor HONO formation light intensity NO 2 photochemistry could be excluded (no NO 2 - formation during photolysis experiments) Formation rate is dependent on the carrier gas HONO formation was observed for all nitro- phenols investigated

47 Lab studies: a) gas phase chemistry Proposed mechanism O + HONO products d) uni-molecular decomposition H O I O N O O H O N II O a) + hν b) + M (O 2 >N 2 >Ar>He) O H O N III O ** c) energy transfer O H O N III O * e) + O 2 O O O * + HONO products

48 How can models can properly take into account these complex mechanisms of HONO formation and ist direct impact on the OH radical budget?

49 Measurement and investigation of chamber radical sources in the European Photoreactor (EUPHORE) J. Zádor,, T. Turányi,, K. Wirtz and M.J. Pilling, J. Atmos. Chem.. 55(2), (2006) Zur Anzeige wird der QuickTime Dekompressor TIFF (Unkomprimiert) benötigt. Parameterization of HONO source and its impact on the OH radical formation in the EUPHORE chamber

50 Thank you very much for your attention Zur Anzeige wird der QuickTime Dekompressor TIFF (Unkomprimiert) benötigt.