World Library  

QR link for Determining the Spatial and Seasonal Variability in Om/Oc Ratios Across the US Using Multiple Regression : Volume 10, Issue 10 (21/10/2010)
Add to Book Shelf
Flag as Inappropriate
Email this Book

Determining the Spatial and Seasonal Variability in Om/Oc Ratios Across the US Using Multiple Regression : Volume 10, Issue 10 (21/10/2010)

By Simon, H.

Click here to view

Book Id: WPLBN0003986445
Format Type: PDF Article :
File Size: Pages 48
Reproduction Date: 2015

Title: Determining the Spatial and Seasonal Variability in Om/Oc Ratios Across the US Using Multiple Regression : Volume 10, Issue 10 (21/10/2010)  
Author: Simon, H.
Volume: Vol. 10, Issue 10
Language: English
Subject: Science, Atmospheric, Chemistry
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2010
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Frank, N. H., Swall, J. L., Bhave, P. V., Simon, H., & Malm, W. C. (2010). Determining the Spatial and Seasonal Variability in Om/Oc Ratios Across the US Using Multiple Regression : Volume 10, Issue 10 (21/10/2010). Retrieved from http://community.ebooklibrary.org/


Description
Description: US EPA, National Exposure Research Laboratory, Atmospheric Modeling and Analysis Division, Research Triangle Park, NC, USA. 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, and dataset 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 1.8 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 predicted OM/OC ratios between 1.37 and 1.94) than previous studies (90% of OM/OC estimates from a previous regression study 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 believe that up to one-quarter of the OM/OC estimates in a previous study are biased low. 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.

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

Excerpt
Aiken, A., Decarlo, P. F., Kroll, J. H., et al.: 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, doi:10.1021/es703009q, 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, doi:10.5194/acp-10-2393-2010, 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, doi:10.1016/j.atmosenv.2007.08.023, 2007.; El-Zanan, H. S., Lowenthal, D. H., Zielinska, B., et al.: Determination of the organic aerosol mass to organic carbon ratio in IMPROVE samples, Chemosphere, 60, 485–496, doi:10.1016/j.chemosphere.2005.01.005, 2005.; Lowenthal, D. H. and Kumar, N.: PM2.5 mass and light extinction reconstruction in IMPROVE, J. Air Waste Manage., 53, 1109–1120, 2003.; El-Zanan, H. S., Zielinska, B., Mazzoleni, L. R., et al.: Analytical determination of the aerosol organic mass-to-organic carbon ratio, J. Air Waste Manage., 59, 58–69, doi:10.3155/1047-3289.59.1.58, 2009.; EPA regional planning orgnizations: http://epa.gov/visibility/regional.html#thefive, last access: 14 October, 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., et al.: 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, doi:10.1029/2006jd007737, 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.; 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, doi:10.1016/j.atmosenv.2007.06.053, 2008.; Jimenez, J. L., Canagaratna, M. R., Donahue, N. M., et al.: Evolution of oganic aerosols in the atmosphere, Science, 326, 1525–1529, doi:10.1126/science.1180353, 2009.; Kiss, G., Varga, B., Galambos, I., et al.: Characterization of water-soluble organic matter isolated from atmospheric fine aerosol, J. Geophys. Res.-Atmos., 107, 8339, doi:10.1029/2001jd000603, 2002.; Kleindienst, T. E., Jaoui, M., Lewandowski, M., et al.: Estimates of the contributions of biogenic and anthropogenic hydrocarbons to secondary organic aerosol at a southeastern US location, Atmos. Environ., 41, 8288–8300, doi:10.1016/j.atmosenv.2007.06.045, 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, doi:10.5194/acp-9-6849-2009, 2009.; Malm, W. C., Sisler, J. F., Huffman, D., et al.: Spatial and seasonal trends in particle concentration and optical extinction in the United-States, J. Geophys. Res.-Atmos., 99, 1347–1370, 1994.; Malm, W.

 

Click To View

Additional Books


  • Seeking for the Rational Basis of the Me... (by )
  • Tropospheric Ozone Over Equatorial Afric... (by )
  • Sources and Distribution of Trace Specie... (by )
  • Stratospheric Brono2 Observed by Mipas :... (by )
  • Improved Total Atmospheric Water Vapour ... (by )
  • Marine Boundary Layer Over the Subtropic... (by )
  • Spatial, Temporal, and Vertical Variabil... (by )
  • Lightning NoX Emissions Over the USA Inv... (by )
  • Vertical Variation of Optical Properties... (by )
  • Sensitivities in Global Scale Modeling o... (by )
  • Contributions from Transport, Solid Fuel... (by )
  • 2003 Megafires in Australia: Impact on T... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.