Atmos. Chem. Group Meeting Rocky Mountain National Park 2010 Grand Teton National Park 2011 HR-ToF-AMS Aerosol Composition Observations Misha Schurman 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Outline Motivation Instrument Overview ROMANS 2010 Data Analysis and Quality Verification Aerosol Composition Data TETONS 2011 Data Future Work 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Time-resolved concentration, size, and composition of aerosols are useful for investigating: Pollution (Toxicity/Health Effects) Plume Processing/Photochemistry Nucleation/Coagulation Radiative Forcing Properties Direct: est. -0.1to -1.0 W/m2 from ‘fossil fuel aerosols’ (IPCC AR4) Indirect: CCN functionality Identifying organic aerosol components contributes to our knowledge of aerosol formation and processing, source apportionment, and appropriate mitigation strategies. Environmental News Network http://www.amysgarage.com NASA EOSDIS: http://earthdata.nasa.gov 4/13/2012 Atmos. Chem. Group Meeting

Relevant AMS Features Lens focuses particle beam; 40-600 nm have T.E. = 1 Skimmer discards most gases PToF region sizes particles Simultaneous Vaporization & Ionization ToF-MS detection with variable flight path (V or W) (Drewnick et al. 2005) ToF Governing Principle: ½ mv2 Sampling: V Mode: sizing, lower D.L. W Mode: High res spectra, higher D.L. chopopen - chopclosed = net aerosol 30 min HEPA/2-3 days checks inlet integrity 4/13/2012 Atmos. Chem. Group Meeting

Quality Assurance and Control Field: MultiChannel Plate (MCP) detector Flow Rate Aerodynamic Lens Ionization Efficiency (for nitrate) CPC-mass-based verification/correction Sizing: PSL or DMA-NH4NO3 with known dm, ρi, and Shape factor dva = (ρi / ρ0) * S * dm Servo (Chopper) Position Data Analysis: UMR: m/z calibration, baseline check, airbeam correction, fragmentation checks Filtering: flawed runs, calibrations, filter periods, events HR: residuals; are ‘family’ spectra sensical? PMF: S:N filtering, outliers in MS? 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting QA/QC: RoMANS Basic Checks High Resolution Na+ ± 10 ppm PMF ~5% 4/13/2012 Atmos. Chem. Group Meeting

Results: PILS, URG, AMS Comparison ROM 2010 Results: PILS, URG, AMS Comparison Figure 1: Time series of inorganic particulate components from HR-ToF-AMS, PILS-IC, and URG (denuder-filter system). PILS-IC agrees well with AMS (SO4: m=1.00, r2=0.88; NO3: m=1.29, r2=0.76) 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: Timeline ROM 2010: High Resolution Analysis (V Mode) Figure 2: Time series of particulate organic, sulfate, nitrate, and ammonium concentrations over the study duration. 11.5 μg/m3 0.9 μg/m3 0.2 μg/m3 0.1 μg/m3 Organics dominate and are correlated with sulfate concentrations. Nitrate and ammonium are very low. Organics and others not always t-correlated: evidence for multiple organic types 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Organic Aerosol Types using Positive Matrix Factorization (PMF)? Receptor-only factorization; iterative least-squares algorithm breaks total mass spectra into “factors” until residual is minimized. Assume factors have constant MS profiles and time-variable contributions to total mass. User must determine the most probable # of factors based on: Q (quality of fit parameter) and other statistics Dissimilarity of factors (spectral and timeline) Comparison to ‘established’ factors : database of spectral profiles Correlation with other aerosol components (inorganics) Ulbrich et al. 2009 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting ROM 2010: High Res (W Mode) Results: Positive Matrix Factorization (PMF): BBOA Figure 6: Mass spectra of organic aerosol types determined by Positive Matrix Factorization (Paatero and Tapper, 1994). Biomass Burning Organic Aerosol (BBOA) typified by levoglucosan combustion product C2H4O2+. 0.47 Fraction of Signal BBOA indicators: m/zs 29, 43, 44, 55, with 60, 73 Our 60 is smaller than others, but not inconsistent with all BBOA studies, and campfires were observed nearby. Does not resemble Biogenic SOA (rules out traffic/BVOC mix, etc.) † Figure 2: “Spectra of…PMF factors (interpreted as the denoted source profiles) calculated by…PMF.” (Lanz et al. 2007) † Jülich Plant Aerosol Chamber O3-OH BSOA experiment 4/13/2012 Atmos. Chem. Group Meeting † (Kiendler-Scharr et al., 2009)

Atmos. Chem. Group Meeting Results: PMF: SV- and LV-OOA ROM 2010: High Res (W Mode) †“Spectra of…PMF factors (interpreted as the denoted source profiles) calculated by…PMF.” (Lanz et al. 2007) *(Kiendler-Scharr et al., 2009) † Figure 6: Mass spectra of organic aerosol types determined by Positive Matrix Factorization (Paatero and Tapper, 1994). Semi-Volatile Oxidized Organic Aerosol (SV-OOA) has moderately oxidized CH3CO+; and Low Volatility Oxidized Organic Aerosol (LV-OOA) is dominated by CO2+. 28 * * † † Classic SV- and LV-OOA spectral markers consistent with urban sources. Both quite oxidized (from 43/44 ratio and frag fraction) No mass spec indicators of Biogenic SOA influence (27, 29, w/ 43,44) Future delta analysis will look for BSOA influence (vs ‘plain’ urban) 4/13/2012 Atmos. Chem. Group Meeting † (Kiendler-Scharr et al., 2009)

Atmos. Chem. Group Meeting ROM 2010: High Resolution (W Mode) Results: PMF Factor Timeline LV-OOA dominates SV-OOA events with and w/o commensurate BBOA event BBOA events from nearby campfires Factor’s mass spec is static: to explore oxidations changes, size distributions, define factor-dominated periods Figure 7: Timeline of organic aerosol factor concentrations. Semi-Volatile Oxidized Organic Aerosol (SV-OOA) and Low Volatility Oxidized Organic Aerosol (LV-OOA) are generally correlated with each other in varying proportions. Biomass Burning Organic Aerosol (BBOA) is low with high concentrations events. Pie chart shows study average fractional contributions. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: Positive Matrix Factorization (PMF) ROM 2010: High Resolution (W Mode) f43 and f44 for periods dominated by the given factor: Ng et al., 2011 Triangle plot describes degree of oxidation: upper left corner is most oxidized Markers sized by time; linear movement during certain periods indicate oxidation of existing or introduction of new air mass? PMF-derived factors agree well with other studies 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: Diurnal Profiles ROM 2010: High Resolution 1 2 Figure 3: Diurnal concentrations averaged over the study duration. Mean influenced by outliers (NO3, SO4, NH4) Inconsistent diurnal variation: Event driven mean Consistent variation in organics: Afternoon up-slopes from front range/ boundary layer compression may cause LV-OOA Second SV-OOA feature from BBOA signal ‘misattribution’? Regular campfires at local camp cause 10pm BBOA feature CO2(44) and C2H3O(43) driving overall organic diurnal feature C2H4O2(60) enhancement at 22h supports BBOA pattern (scattered events @ 16h drive mean increase) 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting ROM 2010: High Resolution Analysis Results: Wind Direction and Species Concentration Inorganic species associated with SE winds. Organics show little trend with wind direction. Complex terrain makes wind direction an inadequate tracer for air mass origin and precludes HYSPLIT use. We have other evidence for organic sources and types: MS, r2 w/ inorganics, size distributions Figure 4: Concentrations of inorganic species with wind direction. Figure 8: Concentrations of organic aerosol types with wind direction. BBOA spikes reflect isolated fires; LV-OOA and SV-OOA are disperse, suggest SE directionality. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: PMF Factor ‘Size Distributions’ SMPS size distribution indicating AMS lens transmission range Ezra Levin Organics + Sulfate smaller than Ammonium + Nitrate May indicate different mixtures of OA and inorganics ALL LV-OOA SV-OOA LV-OOA events have larger particles (~450 nm) than other organic types (~350 nm). LV-OOA more monodisperse – has undergone ageing and coagulation? SV-OOA ~350 nm fairly broad distribution, smaller than inorgs BBOA slightly smaller (~300 nm) BBOA more poly disperse – closer to source, less processing/coagulation time? BBOA 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: Case Studies 2 1 8/6-8/2010: 10 pm BBOA events, afternoon enhancement on day 2: BBOA events start small (~200 nm), become more poly disperse. 7/8-11/10: Afternoon SV-OOA events feature broader size distribution. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: PMF Factors and Inorganic Species ROM 2010: HR Analysis (W Mode) Timeline Correlation (r2) LVOOA SVOOA BBOA SO4 0.77 0.18 0.05 NO3 0.33 0.41 0.02 NH4 0.76 0.72 0.03 NO3 - NH4: r2 = 0.89 SO4 - NH4: r2 = 0.97 SO4 - NO3 : r2 = 0.34 Figure 10: Time series of organic factors and inorganic species LV-OOA, sulfate, and ammonium are correlated SV-OOA and ammonium are correlated; maybe nitrate (low concentration) Inorganics correlated with each other; size evidence of mixture w/ LV-OOA BBOA events are higher in amplitude, not coincident with other species. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting RoMANS: Conclusions Oxidized organics (LV-OOA and SV-OOA) dominate submicron particulate mass, with some biomass burning organic aerosol (BBOA): LV-OOA and SV-OOA transport from the Front Range is indicated by afternoon concentration increase probably associated with upslope flow, highly oxidized nature, large mode and relatively narrow size distribution, and correlation with inorganic tracers. BBOA largely from nearby campfires. Organic nitrogen is negligible (average 0.03 µg/m3, ON =(Org/OM:OC)*N:C*(14/12))). Inorganic species also indicate transport from the Front Range: Afternoon concentration increase. SE wind direction. Concentration correlation with SV- and LV-OOA. Internal mixture of LV-OOA and Inorganics indicated by consistent size distributions and time-series correlation. SV-OOA is mixed with these, possibly externally. External mixture between BBOA and other species suggested by inconsistent time-series and size distributions. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting QA/QC: Tetons Problem with W mode: low AB makes low sensitivity (high noise). Got great fits, so can use for chemical info, but: Use V mode for quantitation 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: AMS Timeline TET 2011: UMR (V Mode) Study Avg 1.6 μg/m3 0.3 μg/m3 0.2 μg/m3 0.08 μg/m3 D.L. = 0.003 µg/m3 Organics dominate All species have low concentrations 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: AMS Timeline TET 2011: UMR (V Mode) Various mixtures of org/inorgs – composition constant for days-weeks In general neutral or even “basic”; acidic event on 8/15/11 coincident with high concentrations of all species Acidic 8/15/11 event 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: Diurnal Profiles TET 2011: High Res (W Mode) Total Organics 1 1 Some nighttime enhancement – boundary layer compression? Midday organic and sulfate increase – transport? 1: Mean influenced by event/s, but only for CO2 (not 43, etc.); indicates spectral change, different OA type? 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Results: Organic Aerosol: LV-OOA TET 2011: High Res (W Mode) Oxidized: all mass from most oxidized fragment LV-OOA signatures: 28, 44>43, 55 43/44 daily fluctuations: less oxidized in afternoon? No BSOA spectral markers Organic event (8/15/11): increase in 44/43 SV-OOA? 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting TETONS: Conclusions Low species concentrations (organics 1.6µg/m3; inorgs 0.08-0.3 1.6µg/m3) Afternoon and nighttime enhancement: compare with other datasets Linear relationships (though varied slopes) b/w organics, inorganics may indicate internal mixtures (also, quite oxidized) Mass spectral features = LV-OOA 8/15/11 Event: Mass spectrum and CO2 diurnal pattern indicate enhanced degree of oxidation. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Future Work TET PMF Delta fragment series analysis (ROM and TET) Delta describes important series of fragments Each m/z has a delta value, weighted avg of m/z ranges Patterns emerge for biogenic, diesel, other sources (Kiendler-Scharr et al., 2009) 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Acknowledgements Collett Group Kriedenweis Group National Park Service Salvation Army High Peak Camp Grand Targhee Ski Resort 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting References Allan, J., et al. (2004), Submicron aerosol composition at Trinidad Head, California, during ITCT 2K2: Its relationship with gas phase volatile organic carbon and assessment of instrument performance, J. Geophys. Res., 109, D23S24, doi:10.1029/2003JD004208. Alfarra, M.R., Prevot, A.S.H., Szidatt, S., Sandradewi, J., Weimer, S., Lanz, V.S., Schreiber, D., Mohr, M., and Baltensperger, U. (2007). “Identification of the mass spectral signature of organic aerosols from wood burning emissions.” Environ. Sci. Technol. 14: 5770-5777 Drewnick, F., S. S. Hings, P. DeCarlo, J. T. Jayne, M. Gonin, K. Fuhrer, S. Weimer, J. L. Jimenez, K. L. Demerjian, S. Borrmann and D. R. Worsnop (2005). "A New Time-of-Flight Aerosol Mass Spectrometer (TOF-AMS): Instrument Description and First Field Deployment." Aerosol Science and Technology 39(7): 637 - 658. Farmer, D. K., Matsunaga, A., Docherty, K. S., Surratt, J. D., Seinfeld,J. H., Ziemann, P. J., and Jimenez, J. L.(2010), “Response of anaerosol mass spectrometer to organonitrates and organosulfatesand implications for atmospheric chemistry.” P. Natl. Acad. Sci.107(15), 6670–6675 Fry, J. L., A. Kiendler-Scharr, A. W. Rollins, P. J. Wooldridge, H. F. S. S. Brown3, W. Dub´e, A. Mensah, M. d. Maso, R. Tillmann, H.-P. Dorn, T. Brauers and R. C. Cohen (2009). "Organic nitrate and secondary organic aerosol yield from NO3 oxidation of beta-pinene evaluated using a gas-phase kinetics/aerosol partitioning model." Atmos. Chem. Phys. 9: 1431-1449. Kiendler-Scharr, A., Zhang, Q., Hohaus, T., Kleist, E., Mensah, A., Mentel, T. F., Spindler, C., Uerlings, R., Tillmann, R., and Wildt, J.: Aerosol Mass Spectrometric Features of Biogenic SOA: Observations from a Plant Chamber and in Rural Atmospheric Environments, Environ. Sci. Technol., 43, 8166–8172, doi:10.1021/es901420b, 2009. Lanz, V. A., Alfarra, M. R., Baltensperger, U., Buchmann, B., Hueglin, C., and Prévôt, A. S. H. (2007). “Source apportionment of submicron organic aerosols at an urban site by factor analytical modeling of aerosol mass spectra.” Atmos. Chem. Phys. 7:1503-1522. Lanz, V.A., M. R. Alfarra, U. Baltensperger, B. Buchmann, C. Hueglin, S. Szidat, M.N. Wehrli, L. Wacker, S. Weimer, A. Caseiro, H.Puxbaum, A. S. H. Prevot (2008). “Source Attribution of Submicron Organic Aerosols during Wintertime Inversions by Advanced Factor Analysis of Aerosol Mass Spectra.” Environmental Science & Technology 42(1): 214-220. Malm, W. C., B. A. Schichtel, M. G. Barna, K. A. Gebhart, J. L. Collett Jr. and S. M. Kreidenweis (2007). Source Apportionment of Sulfur and Nitrogen Species at Rocky Mountain National Park using Modeled Conservative Tracer Releases and Tracers of Opportunity. Air and Waste Managament Association. Pittsburgh, PA. Mohr, C., S. Weimer, R. Richter, P. F. DeCarlo, R. Chirico, M. F. Heringa, A. S. H. Prévôt, and U. Baltensperger (2009). "Source apportionment of ambient aerosol applying PMF on AMS mobile and stationary data." Geophysical Research Abstracts 11. Neff, J. C., E. A. Holland, F. J. Dentener, W. H. McDowell and K. M. Russell (2002). "The origin, composition and rates of organic nitrogen deposition: A missing piece of the nitrogen cycle?" Biogeochemistry 57-58(1): 99-136. Schneider, J., S. Weimer, F. Drewnick, S. Borrmann, G. Helas, P. Gwaze, O. Schmid, M. O. Andreae and U. Kirchner (2006). "Mass spectrometric analysis and aerodynamic properties of various types of combustion-related aerosol particles." International Journal of Mass Spectrometry 258: 37-49. Ulbrich, I. M., M. R. Canagaratna, Q. Zhang, D. R. Worsnop and J. L. Jimenez (2009). "Interpretation of organic components from Positive Matrix Factorization of aerosol mass spectrometric data." Atmos. Chem. Phys., 9: 2891-2918. Zhang, Q., Worsnop, D. R., Canagaratna, M. R., and Jimenez, J. L. (2005b). “Hydrocarbon-like and oxygenated organic aerosols in Pittsburgh: insights into sources and processes of organic aerosols.” Atmos. Chem. Phys. 5:3289-3311. Zhang, Q., M. R. Alfarra, D. R. Worsnop, J. D. Allan, H. Coe, M. R. Canagaratna and J. L. Jimenez (2005c). "Deconvolution and Quantification of Hydrocarbon-like and Oxygenated Organic Aerosols Based on Aerosol Mass Spectrometry." Environmental Science & Technology 39(13): 4938-4952. 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting ROM 2010: UMR (V Mode) 4/13/2012 Atmos. Chem. Group Meeting

Atmos. Chem. Group Meeting Supplementary Unscaled TET IE/AB ROM diurnal O/C Detec. Limit (µm/m3)* Resolution (m/Δm) Mass Range (m/z) HR-ToF-AMS V Mode 0.003 ~2000 1-1200 HR-ToF-AMS W Mode 0.05 ~4000 *typical for NO3. Values from Aerodyne Research, Inc. 4/13/2012 Atmos. Chem. Group Meeting

Is AMS appropriate for the campaign? Strengths Quantitative High Time Resolution Size + Composition HR = unequivocal fragment ID Good Detection Limits Weaknesses Limited particle size range Extensive fragmentation hinders parent ID Direct AON not possible Time intensive data analysis Detec. Limit (µm/m3)* Resolution (m/Δm) Mass Range (m/z) HR-ToF-AMS V Mode 0.003 ~2000 1-1200 HR-ToF-AMS W Mode 0.05 ~4000 *typical for NO3. Values from Aerodyne Research, Inc. 4/13/2012 4/29/2011 Atmos. Chem. Group Meeting Atmos. Chem. Group Meeting 31

Atmos. Chem. Group Meeting TET Spare Figs 4/13/2012 Atmos. Chem. Group Meeting