References

ACP

Atmospheric Chemistry and Physics

ACP

Atmos. Chem. Phys.

1680-7324

Copernicus Publications

Göttingen, Germany

10.5194/acp-11-2933-2011

Determining the spatial and seasonal variability in OM/OC ratios across the US using multiple regression

Simon

¹ Bhave

P. V.

² Swall

J. L.

² Frank

N. H.

¹ Malm

W. C.

US EPA, Office of Air Quality Planning and Standards, Research Triangle Park, NC, USA

US EPA, National Exposure Research Laboratory, Atmospheric Modeling and Analysis Division, Research Triangle Park, NC, USA

National Park Service, Colorado State University/Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, USA

30 03 2011

11 6 2933 2949

2011

This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/

This article is available from https://acp.copernicus.org/articles/11/2933/2011/acp-11-2933-2011.html

The full text article is available as a PDF file from https://acp.copernicus.org/articles/11/2933/2011/acp-11-2933-2011.pdf

Data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network are used to estimate organic mass to organic carbon (OM/OC) ratios across the United States by extending previously published multiple regression techniques. Our new methodology addresses common pitfalls of multiple regression including measurement uncertainty, colinearity of covariates, dataset selection, and model selection. As expected, summertime OM/OC ratios are larger than wintertime values across the US with all regional median OM/OC values tightly confined between 1.80 and 1.95. Further, we find that OM/OC ratios during the winter are distinctly larger in the eastern US than in the West (regional medians are 1.58, 1.64, and 1.85 in the great lakes, southeast, and northeast regions, versus 1.29 and 1.32 in the western and central states). We find less spatial variability in long-term averaged OM/OC ratios across the US (90% of our multiyear regressions estimate OM/OC ratios between 1.37 and 1.94) than previous studies (90% fell between 1.30 and 2.10). We attribute this difference largely to the inclusion of EC as a covariate in previous regression studies. Due to the colinearity of EC and OC, we find that up to one-quarter of the OM/OC estimates in a previous study are biased low. Assumptions about OC measurement artifacts add uncertainty to our estimates of OM/OC. In addition to estimating OM/OC ratios, our technique reveals trends that may be contrasted with conventional assumptions regarding nitrate, sulfate, and soil across the IMPROVE network. For example, our regressions show pronounced seasonal and spatial variability in both nitrate volatilization and sulfate neutralization and hydration.

References 1

Aiken, A., Decarlo, P. F., Kroll, J. H., Worsnop, D. R., Huffman, J. A., Docherty, K. S., Ulbrich, I. M., Mohr, C., Kimmel, J. R., Sueper, D., Sun, Y., Zhang, Q., Trimborn, A., Northway, M., Ziemann, P. J., Canagaratna, M. R., Onasch, T. B., Alfarra, M. R., Prévôt, A. S.H., Dommen, J., Duplissy, J., Metzger, A., Baltensperger, U., and Jimenez, J. L.: O/C and OM/OC ratios of primary, secondary, and ambient organic aerosols with high-resolution time-of-flight aerosol mass spectrometry, Environ. Sci. Technol., 42, 4478–4485, <a href="http://dx.doi.org/10.1021/es703009q">https://doi.org/10.1021/es703009q</a>, 2008.

Chan, T. W., Huang, L., Leaitch, W. R., Sharma, S., Brook, J. R., Slowik, J. G., Abbatt, J. P. D., Brickell, P. C., Liggio, J., Li, S.-M., and Moosmüller, H.: Observations of OM/OC and specific attenuation coefficients (SAC) in ambient fine PM at a rural site in central Ontario, Canada, Atmos. Chem. Phys., 10, 2393–2411, <a href="http://dx.doi.org/10.5194/acp-10-2393-2010">https://doi.org/10.5194/acp-10-2393-2010</a>, 2010.

Chen, X. and Yu, J. Z.: Measurement of organic mass to organic carbon ratio in ambient aerosol samples using a gravimetric technique in combination with chemical analysis, Atmos. Environ., 41, 8857–8864, <a href="http://dx.doi.org/10.1016/j.atmosenv.2007.08.023">https://doi.org/10.1016/j.atmosenv.2007.08.023</a>, 2007.

Chhabra, P. S., Flagan, R. C., and Seinfeld, J. H.: Elemental analysis of chamber organic aerosol using an aerodyne high-resolution aerosol mass spectrometer, Atmos. Chem. Phys., 10, 4111–4131, <a href="http://dx.doi.org/10.5194/acp-10-4111-2010">https://doi.org/10.5194/acp-10-4111-2010</a>, 2010.

El-Zanan, H. S., Lowenthal, D. H., Zielinska, B., Chow, J. C., and Kumar, N.: Determination of the organic aerosol mass to organic carbon ratio in IMPROVE samples, Chemosphere, 60, 485–496, <a href="http://dx.doi.org/10.1016/j.chemosphere.2005.01.005">https://doi.org/10.1016/j.chemosphere.2005.01.005</a>, 2005.

El-Zanan, H. S., Zielinska, B., Mazzoleni, L. R., and Hansen, D. A.: Analytical determination of the aerosol organic mass-to-organic carbon ratio, J. Air Waste Manage., 59, 58–69, <a href="http://dx.doi.org/10.3155/1047-3289.59.1.58">https://doi.org/10.3155/1047-3289.59.1.58</a>, 2009.

EPA regional planning orgnizations, available at: <a href="http://epa.gov/visibility/regional.html#thefive">http://epa.gov/visibility/regional.html#thefive</a>, 2010.

Frank, N. H.: Retained nitrate, hydrated sulfates, and carbonaceous mass in Federal Reference Method fine particulate matter for six eastern US cities, J. Air Waste Manage., 56, 500–511, 2006.

Fuller, W. A.: Measurement error models, John Wiley & Sons, New York, USA, 1987.

Gilardoni, S., Russell, L. M., Sotooshian, A., Flagan, R. C., Seinfeld, J. H., Bates, T. S., Quinn, P. K., Allan, J. D., Williams, B., Goldstein, A. H., Onasch, T. B., and Worsnop, D. R.: Regional variation of organic functional groups in aerosol particles on four US east coast platforms during the International Consortium for Atmospheric Research on Transport and Transformation 2004 campaign, J. Geophys. Res.-Atmos., 112, D10S27, <a href="http://dx.doi.org/10.1029/2006jd007737">https://doi.org/10.1029/2006jd007737</a>, 2007.

Hand, J. L. and Malm, W. C.: Review of the IMPROVE equation for estimating ambient light extinction coefficients – final report, Colorado State University, CIRA, 146, 2006.

Hering, S. and Cass, G.: The magnitude of bias in the measurement of PM2.5 arising from volatilization of particulate nitrate from Teflon filters, J. Air Waste Manage., 49, 725–733, 1999.

Huang, X.-F., He, L.-Y., Hu, M., Canagaratna, M. R., Sun, Y., Zhang, Q., Zhu, T., Xue, L., Zeng, L.-W., Liu, X.-G., Zhang, Y.-H., Jayne, J. T., Ng, N. L., and Worsnop, D. R.: Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer, Atmos. Chem. Phys., 10, 8933–8945, <a href="http://dx.doi.org/10.5194/acp-10-8933-2010">https://doi.org/10.5194/acp-10-8933-2010</a>, 2010.

Hyslop, N. P. and White, W. H.: An evaluation of interagency monitoring of protected visual environments (IMPROVE) collocated precision and uncertainty estimates, Atmos. Environ., 42, 2691–2705, <a href="http://dx.doi.org/10.1016/j.atmosenv.2007.06.053">https://doi.org/10.1016/j.atmosenv.2007.06.053</a>, 2008.

Jimenez, J. L., Canagaratna, M. R., Donahue, N. M., Prévôt, A. S. H., Zhang, Q., Kroll, J. H., DeCarlo, P. F., Allan, J. D., Coe, H., Ng, N. L., Aiken, A. C., Docherty, K. S., Ulbrich, I. M., Grieshop, A. P., Robinson, A. L., Duplissy, J., Smith, J. D., Wilson, K. R., Lanz, V. A., Hueglin, C., Sun, Y. L., Tian, J., Laaksonen, A., Raatikainen, T., Rautiainen, J., Vaattovaara, P., Ehn, M., Kulmala, M., Tomlinson, J. M., Collins, D. R., Cubison, M. J., Dunlea, E. J., Huffman, J. A., Onasch, T. B., Alfarra, M. R., Williams, P. I., Bower, K., Kondo, Y., Schneider, J., Drewnick, F., Borrmann, S., Weimer, S., Demerjian, K., Salcedo, D., Cottrell, L., Griffin, R., Takami, A., Miyoshi, T., Hatakeyama, S., Shimono, A., Sun, J. Y., Zhang, Y. M., Dzepina, K., Kimmel, J. R., Sueper, D., Jayne, J. T., Herndon, S. C., Trimborn, A. M., Williams, L. R., Wood, E. C., Middlebrook, A. M., Kolb, C. E., Baltensperger, U., and Worsnop, D. R.: Evolution of organic aerosols in the atmosphere, Science, 326, 1525–1529, <a href="http://dx.doi.org/10.1126/science.1180353">https://doi.org/10.1126/science.1180353</a>, 2009.

Kiss, G., Varga, B., Galambos, I., and Ganszky, I.: Characterization of water-soluble organic matter isolated from atmospheric fine aerosol, J. Geophys. Res.-Atmos., 107, 8339, <a href="http://dx.doi.org/10.1029/2001jd000603">https://doi.org/10.1029/2001jd000603</a>, 2002.

Kleindienst, T. E., Jaoui, M., Lewandowski, M., Offenberg, J. H., Lewis, C. W., Bhave, P. V., and Edney, E. O.: Estimates of the contributions of biogenic and anthropogenic hydrocarbons to secondary organic aerosol at a southeastern US location, Atmos. Environ., 41, 8288–8300, <a href="http://dx.doi.org/10.1016/j.atmosenv.2007.06.045">https://doi.org/10.1016/j.atmosenv.2007.06.045</a>, 2007.

Liu, S., Takahama, S., Russell, L. M., Gilardoni, S., and Baumgardner, D.: Oxygenated organic functional groups and their sources in single and submicron organic particles in MILAGRO 2006 campaign, Atmos. Chem. Phys., 9, 6849–6863, <a href="http://dx.doi.org/10.5194/acp-9-6849-2009">https://doi.org/10.5194/acp-9-6849-2009</a>, 2009.

Lowenthal, D. H. and Kumar, N.: PM2.5 mass and light extinction reconstruction in IMPROVE, J. Air Waste Manage., 53, 1109–1120, 2003.

Lowenthal, D., Zielinska, B., Mason, B., Samy, S., Sambourova, V., Collins, D., Spencer, C., Taylor, N., Allen, J., Kumar, N.: Aerosol characterization studies at Great Smoky Mountains National Park, summer 2006, J. Geophys. Res.-Atmos., 114, D08205, <a href="http://dx.doi.org/10.1029/2008jd011274">https://doi.org/10.1029/2008jd011274</a>, 2009.

Malm, W. C. and Hand, J. L.: An examination of the physical and optical properties of aerosols collected in the IMPROVE program, Atmos. Environ., 41, 3407–3427, <a href="http://dx.doi.org/10.1016/j.atmosenv.2006.12.012">https://doi.org/10.1016/j.atmosenv.2006.12.012</a>, 2007.

Malm, W. C., Sisler, J. F., Huffman, D., Eldred, P. A., and Cahill, T. A.: Spatial and seasonal trends in particle concentration and optical extinction in the United States, J. Geophys. Res.-Atmos., 99, 1347–1370, 1994.

Malm, W. C., Day, D. E., Carrico, C., Kreidenweis, S. M., Collett, J. L., McMeeking, G., Lee, T., Carrillo, J., and Schichtel, B.: Intercomparison and closure calculations using measurements of aerosol species and optical properties during the Yosemite Aerosol Characterization Study, J. Geophys. Res.-Atmos., 110, D14302, <a href="http://dx.doi.org/10.1029/2004jd005494">https://doi.org/10.1029/2004jd005494</a>, 2005.

McDade, C. E.: IMPROVE standard operating procedure, Crocker Nuclear Laboratory, University of California, Davis, CASOP 351-2, 258, 14–18, 2008.

McDow, S. R. and Huntzicker, J. J.: Vapor adsorption artifact in the sampling of organic aerosol – face velocity effects, Atmos. Environ., 24A, 2563–2571, 1990.

Murphy, D. M., Cziczo, D. J., Froyd, K. D., Hudson, P. K., Matthew, B. M., Middlebrook, A. M., Pelier, R. E., Sullivan, A., Thomson, D. S., and Weber, R. J.: Single-particle mass spectrometry of tropospheric aerosol particles, J. Geophys. Res.-Atmos., 111(15), D23S32, <a href="http://dx.doi.org/10.1029/2006jd007340">https://doi.org/10.1029/2006jd007340</a>, 2006.

Pang, Y., Turpin, B. J., and Gundel, L. A.: On the importance of organic oxygen for understanding organic aerosol particles, Aerosol Sci. Tech., 40, 128–133, <a href="http://dx.doi.org/10.1080/02786820500423790">https://doi.org/10.1080/02786820500423790</a>, 2006.

Pitchford, M., Malm, W. C., Schichtel, B., Kumar, N., Lowenthal, D., and Hand, J.: Revised algorithm for estimating light extinction from IMPROVE particle speciation data, J. Air Waste Manage., 57, 1326–1336, <a href="http://dx.doi.org/10.3155/1047-3289.57.11.1326">https://doi.org/10.3155/1047-3289.57.11.1326</a>, 2007.

Polidori, A., Turpin, B. J., Davidson, C. I., Rodenburg, L. A., and Maimone, F.: Organic PM2.5 Fractionation by polarity, FTIR spectroscopy, and OM/OC ratio for the Pittsburgh aerosol, Aerosol Sci. Tech., 42, 233–246, <a href="http://dx.doi.org/10.1080/02786820801958767">https://doi.org/10.1080/02786820801958767</a>, 2008.

R Development Core Team: R: A language and environment for statistical computing, R Foundation for Statistical Computing, available at: <a href="http://www.R-project.org">http://www.R-project.org</a> (last access: October 2010), ISBN 3-900051-07-0, Vienna, Austria, 2010.

Reff, A., Turpin, B. J., Offenberg, J. H., C. P., Weisel, Zhang, J., Morandi, M., Stock, T., Colome, S., and Winer, A.: A functional group characterization of organic PM2.5 exposure: Results from the RIOPA study, Atmos. Environ., 41, 4585–4598, <a href="http://dx.doi.org/10.1016/j.atmosenv.2007.03.054">https://doi.org/10.1016/j.atmosenv.2007.03.054</a>, 2007.

Reff, A., Bhave, P. V., Simon, H., Pace, T. G., Pouliot, G. A., Mobley, J. D., and Houyoux, M.: Emissions inventory of PM2.5 trace elements across the United States, Environ. Sci. Technol., 43, 5790–5796, <a href="http://dx.doi.org/10.1021/es802930x">https://doi.org/10.1021/es802930x</a>, 2009.

Russell, L. M.: Aerosol organic-mass-to-organic-carbon ratio measurements, Environ. Sci. Technol., 37, 2982–2987, <a href="http://dx.doi.org/10.1021/es026123w">https://doi.org/10.1021/es026123w</a>, 2003.

Russell, L. M., Takahama, S., Liu, S., Hawkins, L. N., Covert, D. S., Quinn, P. K., and Bates, T. S.: Oxygenated fraction and mass of organic aerosol from direct emission and atmospheric processing measured on the R/V Ronald Brown during TEXAQS/GoMACCS 2006, J. Geophys. Res.-Atmos., 114, D00F05, <a href="http://dx.doi.org/10.1029/2008jd011275">https://doi.org/10.1029/2008jd011275</a>, 2009.

Saylor, R. D., Edgerton, E. S., and Hartsell, B. E.: Linear regression techniques for use in the EC tracer method of secondary organic aerosol estimation, Atmos. Environ., 40, 7546–7556, <a href="http://dx.doi.org/10.1016/j.atmosenv.2006.07.018">https://doi.org/10.1016/j.atmosenv.2006.07.018</a>, 2006.

Simon, H., Beck, L., Bhave, P. V., Divita, F., Hsu, Y., Luecken, D., Mobley, J. D., Pouliot, G. A., Reff, A., Sarwar, G., and Strum, M.: The development and use of EPA's SPECIATE database, Atmos. Pollut. Res., 1, 196–206, 2010.

Sun, Y., Zhang, Q., Macdonald, A. M., Hayden, K., Li, S. M., Liggio, J., Liu, P. S. K., Anlauf, K. G., Leaitch, W. R., Steffen, A., Cubison, M., Worsnop, D. R., van Donkelaar, A., and Martin, R. V.: Size-resolved aerosol chemistry on Whistler Mountain, Canada with a high-resolution aerosol mass spectrometer during INTEX-B, Atmos. Chem. Phys., 9, 3095–3111, <a href="http://dx.doi.org/10.5194/acp-9-3095-2009">https://doi.org/10.5194/acp-9-3095-2009</a>, 2009.

Surratt, J. D., Gomez-Gonzalez, Y., Chan, A. W. H., Verylen, R., Shahgholi, M., Kleindienst, T. E., Edney, E. O., Offenberg, J. H., Lewandowski, M., Jaoui, M., Maenhaut, W., Claeys, M., Flagan, R. C., and Seinfeld, J. H.: Organosulfate formation in biogenic secondary organic aerosol, J. Phys. Chem.-A, 112, 8345–8378, <a href="http://dx.doi.org/10.1021/jp802310p">https://doi.org/10.1021/jp802310p</a>, 2008.

Turpin, B. J. and Lim, H.-J.: Species contributions to PM2.5 mass concentrations: Revisiting common assumptions for estimating organic mass, Aerosol Sci. Tech., 35, 602–610, 2001.

Turpin, B. J., Huntzicker, J. J., and Hering, S. V.: Investigation of organic aerosol sampling artifacts in the Los Angeles basin, Atmos. Environ., 28, 3061–3071, 1994.

Watson, J. G., Chow, J. C., Chen, L.-W. A., Kohl, S. D., Tropp, R. J., Trimble, D., Chancellor, S., Sodeman, D., and Ozgen, S.: Assessment of carbon sampling artifacts in the IMPROVE, STN/CSN, and SEARCH networks, Desert Research Institute, Reno, NV, 2008.

Wexler, A. S. and Clegg, S. L.: Atmospheric aerosol models for systems including the ions H{$}+, NH4+, Na+, SO42-, NO3-, Cl-, Br-, and H2O, J. Geophys. Res.-Atmos., 107, 4207, <a href="http://dx.doi.org/10.1029/2001jd000451">https://doi.org/10.1029/2001jd000451</a>, 2002.

White, W. H.: On the theoretical and empirical-basis for apportioning extinction by aerosols – a critical-review, Atmos. Environ., 20, 1659–1672, 1986.

White, W. H.: Statistical considerations in the interpretation of size-resolved particulate mass data, J. Air Waste Manage., 48, 454–458, 1998.

White, W. H.: IMPROVE data advisory: Shift in EC/OC split with 1   January   2005 TOR hardware upgrade, 2007.

White, W. H.: Chemical markers for sea salt in IMPROVE aerosol data, Atmos. Environ., 42, 261–274, <a href="http://dx.doi.org/10.1016/j.atmosenv.2007.09.040">https://doi.org/10.1016/j.atmosenv.2007.09.040</a>, 2008.

White, W. H.: IMPROVE data advisory, Inconstant bias in XRF sulfur, 2009a.

White, W. H.: IMPROVE data advisory: Under-correction of chloride concentrations for filter blank levels – historical advisory, Applies to downloads before 23 November 2009, 2009b.

White, W. H. and Roberts, P. T.: On the nature and origins of visibility-reducing aerosols in the Los Angeles air basin, Atmos. Environ., 11, 803–812, 1977.

Yu, L. E., Shulman, M. L., Kopperud, R., and Hildemann, L. M.: Fine organic aerosols collected in a humid, rural location (Great Smoky Mountains, Tennessee, USA): Chemical and temporal characteristics, Atmos. Environ., 39, 6037–6050, <a href="http://dx.doi.org/10.1016/j.atmosenv.2005.06.043">https://doi.org/10.1016/j.atmosenv.2005.06.043</a>, 2005.

Yu, S., Bhave, P. V., Dennis, R. L., and Mathur, R.: Seasonal and regional variations of primary and secondary organic aerosols over the continental United States: Semi-empirical estimates and model evaluation, Environ. Sci. Technol., 41, 4690–4697, <a href="http://dx.doi.org/10.1021/es061535g">https://doi.org/10.1021/es061535g</a>, 2007.

Zhang, Q., Jimenez, J. L., Canagartna, M. R., Allan, D., Coe, H., Ulbrich, I., Alfarra, M. R., Takami, A. Middlebrook, A. M., Sun, Y. L., Dzepina, K., Dunlea, E., Docherty, K., DeCarlo, P. F., Salcedo, D., Onasch, T., Jayne, J. T., Miyoshi, T., Shimono, A., Hatakeyama, S., Takegawa, N., Kondo, Y., Schneider, J., Drewnick, F., Borrmann, S., Weimer, S., Demerjian, K., William, P., Bower, K., Bahreini, R., Cottrell, L., Griffin, J. R., Rautianen, J., Sun, J. Y.,Z hang, Y. M., and Worsnop, D. R.: Ubiquity and dominance of oxygenated species in organic aerosols in anthropogenically-influenced Northern Hemisphere midlatitudes, Geophys. Res. Lett., 34, L13801, <a href="http://dx.doi.org/10.1029/2007gl029979">https://doi.org/10.1029/2007gl029979</a>, 2007.