Faculty and Staff

Robert Yokelson

Robert Yokelson

Research Professor

Office: Science Center 418 (Clapp Building)
Email: bob.yokelson@umontana.edu

Personal Summary

Dr. Yokelson carried out his Ph.D. research with Dr. W. A. Chupka at Yale University studying excited states of O2 by multiphoton laser spectroscopy in tandem with molecular beam mass spectrometry. He carried out postdoctoral studies with A. R. Ravishankara at the National Oceanic and Atmospheric Administration Aeronomy Lab ( NOAA ) studying atmospheric photochemistry and kinetics using a variety of time-resolved absorption techniques.

Research Interests

Research Interests - Rationale and Overview

Biomass burning is an important part of the natural ecology of forests and other biomes throughout the world, a crucial component of the agricultural systems that feed much of the world's population, a cost-effective land-management tool, and a source of renewable energy used by about one-half of our planets inhabitants for cooking and heating homes and/or powering industries such as brick kilns. Biomass burning is also a significant source of atmospheric trace gases and particles contributing 20-80% of the total emissions for many important chemical species. These emissions can dominate a region or be heavily mixed with complex urban or biogenic emissions. Uncertainty in the initial characteristics and subsequent transformations of emissions from many sources is a major limiting factor in models of regional-global atmospheric chemistry, radiative transfer, and climate change. The complex mixture of reactive emissions from fires and other sources presents a very challenging measurement problem. To better characterize these emissions, and their transformations, one of our mainstay approaches has been custom-built (frequently updated) measurement systems that capitalize on the ability of Fourier transform infrared spectroscopy (FTIR) to measure a wide variety of organic and inorganic reactive and stable compounds in real time. We have an open-path FTIR system for ground-based and laboratory measurements and closed-cell FTIR systems for airborne measurements and highly mobile ground-based measurements (with concurrent canister and filter sampling). Deployment of these instruments in the laboratory and in important fire environments around the globe (Africa, Alaska, Brazil, continental US, Indonesia, Mexico, Nepal, etc) is helping us better understand the initial impact of fires, smoke plume evolution, and source apportionment. We are always eager to deploy other new techniques with potential to advance the state-of-knowledge (see below). By purchasing or renting, and collaborating with many other research groups we also generate expanded analytical and scientific (modeling) capability.

Recent projects include the first use of high resolution time of flight chemical ionization mass spectrometry (PTR-TOF-MS) dedicated to biomass burning, which improved our knowledge of the low volatility gases that are readily transformed into aerosol during atmospheric aging. This was part of a large-scale project involving close to 50 scientists from numerous institutions (FLAME-4, Stockwell et al., 2014; 2015). In 2013 we contributed to the NASA SEAC4RS (https://espo.nasa.gov/missions/seac4rs/content/SEAC4RS) and the DOE BBOP (http://campaign.arm.gov/bbop/) large-scale aircraft campaigns, which provided the first comprehensive chemical characterization of US wildfire emissions. In 2015 we deployed FTIR, whole air sampling, filter sampling, and photoacoustic extinctiometers on important combustion sources that were previously only sampled minimally. This quantified dozens of important gases, black and brown carbon, etc for sources including: peat fires in Indonesia and cooking and crop residue fires, garbage burning, brick kilns, poorly tuned motorcycles, diesel generators, etc in Nepal. The Nepal Air Monitoring and Source Testing Experiment (NAMASTE) had many US and international partners, a fixed supersite in Kathmandu, a modeling component, and a goal of supporting mitigation strategies for air quality in Asia and the developing world. Our Indonesian project includes collaborative work on long-term peatland hydrology, LIDAR overflights and other fuel consumption measurements, fire scene investigations, and peat chemistry.

Our group is a primary provider of data and frequent updates for an NCAR website that provides emission factors for different types of global biomass burning, daily gridded fire emissions at 1 km resolution, and globally gridded garbage burning emissions (http://bai.acd.ucar.edu/Data/fire/).

research group

September 2015 group “photo” L>R: Markus Müller (postdoc), Chelsea Stockwell (graduate student), Ted Christian (scientific staff), Vanessa Selimovic (graduate student).

Research Results

2009-2012 Field Measurements in US (to be updated here).

Informal captioned photo galleries for these missions are up on my Facebook page.

2012 FLAME-4 measurements of biomass burning emissions with advanced instrumentation

2011 South Carolina Regional Emissions and Aging Measurements (SCREAM)

2010 Arizona

2010 North Carolina

2009: San Luis Obispo Biomass Burning experiment (SLOBB)

Below are links to completed projects: the first link in each row leads to a written summary of the project (with links to non-technical, captioned photo galleries). The second link in each row goes direct to the captioned photo gallery

2006-7 Field Measurements in México - view photo gallery
2004 Field Measurements in Brazil - The Tropical Forest and Fire Emissions Experiment (TROFFEE) - view photo gallery
2003 Laboratory Instrument Intercomparison with NCAR
2001 Laboratory Instrument Intercomparison with Max Planck Institute and UC Irvine - view photo gallery
2000 Field Measurements in Southern Africa (SAFARI 2000) - view photo gallery
1999 Measurements of Residual Smoldering Combustion (RSC) in Oregon - view photo gallery
1997 Field Measurements in Alaska and North Carolina

R. J. Yokelson - Links of Interest

Selected Publications

H-index: 41, 35 (Google Scholar, ResearcherID: C-9971-2011). Papers in preparation include: Yellowstone geothermal emissions; US fire emissions, plume evolution, and modeling; instrument comparisons, and historically undersampled Asian combustion sources measured in 2012-2015.

76) Carrico, C., Prenni, A., Kreidenweis, S., Levin, E., McCluskey, C., DeMott, P., McMeeking, G., Nakao, S., Stockwell, C. and Yokelson, R. J.: Rapidly evolving ultrafine and fine mode biomass smoke physical properties: Comparing laboratory and field results, submitted to J. Geophys. Res., 2015JD024389, 2015. 

75) Toon, O., Maring, H., Dibb, J., Ferrare, R., Jacob, D., Jensen, E., Luo, Z., Mace, G., Pan, L., Pfister, L., Rosenlof, K., Redemann, J., Reid, J. S., Singh, H., Yokelson, R. J., Minnis, P., Chen, G. Jucks, K., and Pszenny, A.: Studies of emissions and atmospheric composition, clouds and climate coupling by regional surveys, 2013 (SEAC4RS), submitted to J. Geophys. Res., 2015JD024297, 2015.

74) Gilman, J. B., Lerner, B. M., Kuster, W. C., Goldan, P. D., Warneke, C., Veres, P. R., Roberts, J. M., de Gouw, J. A., Burling, I. R., and Yokelson, R. J.: Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from temperate fuels common in the United States, Atmos. Chem. Phys. Discuss., 15, 21713-21763, doi:10.5194/acpd-15-21713-2015, 2015.

73) May, A. A., Lee, T., McMeeking, G. R., Akagi, S., Sullivan, A. P., Urbanski, S., Yokelson, R. J., and Kreidenweis, S. M.: Observations and analysis of organic aerosol evolution in some prescribed fire smoke plumes, Atmos. Chem. Phys., 15, 6323-6335, doi:10.5194/acp-15-6323-2015, 2015.

72) Alvarado, M. J., Lonsdale, C. R., Yokelson, R. J., Akagi, S. K., Coe, H., Craven, J. S., Fischer, E. V., McMeeking, G. R., Seinfeld, J. H., Soni, T., Taylor, J. W., Weise, D. R., and Wold, C. E.: Investigating the links between ozone and organic aerosol chemistry in a biomass burning plume from a prescribed fire in California chaparral, Atmos. Chem. Phys., 15, 6667-6688, doi:10.5194/acp-15-6667-2015, 2015.

71) Saide, P. E., Peterson, D., da Silva, A., Anderson, B., L.D., Z., Diskin, G., Sachse, G., Hair, J., Butler, C., Fenn, M., Jimenez, J. L., Campuzano-Jost, O., Perring, A., Schwarz, J., Markovic, M. Z., Russell, P., Redemann, J., Shinozuka, Y., Streets, D. G., Yan, F., Dibb, J., Yokelson, R., Toon, O. B., Hyer, E., and Carmichael, G. R.: Revealing important nocturnal and day-to-day variations in fire smoke emissions through a multiplatform inversion, Geophys. Res. Lett., 42, 3609-3618, doi:10.1002/2015GL063737, 2015.

70) Hatch, L. E., Luo, W., Pankow, J. F., Yokelson, R. J., Stockwell, C. E., and Barsanti, K. C.: Identification and quantification of gaseous organic compounds emitted from biomass burning using two-dimensional gas chromatography–time-of-flight mass spectrometry, Atmos. Chem. Phys., 15, 1865-1899, doi:10.5194/acp-15-1865-2015, 2015.

69) Stockwell, C. E., Veres, P. R., Williams, J., and Yokelson, R. J.: Characterization of biomass burning emissions from cooking fires, peat, crop residue, and other fuels with high-resolution proton-transfer-reaction time-of-flight mass spectrometry, Atmos. Chem. Phys., 15, 845-865, doi:10.5194/acp-15-845-2015, 2015.

68) Xiao, Q., Saikawa, E., Yokelson, R. J., Chen, P., Li, C., and Kang, S.: Indoor air pollution from burning yak dung as a household fuel in Tibet, Atmos. Environ., 102, 406-412, doi:10.1016/j.atmosenv.2014.11.060, 2015.

67) Jayarathne, T., Stockwell, C., Yokelson, R., Nakao, S., Stone, E.: Emissions of fine particle fluoride from biomass burning, Environ. Sci. Technol., 48, 12636−12644, doi:10.1021/es502933j, 2014.

66) Sullivan, A. P., May, A. A., Lee, T., McMeeking, G. R., Kreidenweis, S. M., Akagi, S. K., Yokelson, R. J., Urbanski, S. P., and Collett Jr., J. L.: Airborne characterization of smoke marker ratios from prescribed burning, Atmos. Chem. Phys., 14, 10535-10545, doi:10.5194/acp-14-10535-2014, 2014.

65) Wiedinmyer, C., Yokelson, R. J., and Gullett, B. K.: Global emissions of trace gases, particulate matter, and hazardous air pollutants from open burning of domestic waste, Environ. Sci. Technol., 48, 9523-9530, doi:10.1021/es502250z, 2014.

64) Levin, E. J. T., McMeeking, G. R., DeMott, P. J., McCluskey, C. S., Stockwell, C. E., Yokelson, R. J., and Kreidenweis, S. M.: A new method to determine the number concentrations of refractory black carbon ice nucleating particles, Aerosol Sci. Technol., 48, 1264-1275, doi:10.1080/02786826.2014.977843, 2014.

63) May, A., McMeeking, G., Lee, T., Taylor, J., Craven, J., Burling, I., Sullivan, A., Akagi, S., Collett, Jr., J., Flynn, M., Coe, H., Urbanski, S., Seinfeld, J., Yokelson, R. J., and Kreidenweis, S.: Aerosol emissions from prescribed fires in the United States: A synthesis of laboratory and aircraft measurements, J. Geophys. Res., 119, 11826–11849, doi:10.1002/2014JD021848, 2014.

62) Stockwell, C. E., Yokelson, R. J., Kreidenweis, S. M., Robinson, A. L., DeMott, P. J., Sullivan, R. C., Reardon, J., Ryan, K. C., Griffith, D. W. T., and Stevens, L.: Trace gas emissions from combustion of peat, crop residue, domestic biofuels, grasses, and other fuels: configuration and Fourier transform infrared (FTIR) component of the fourth Fire Lab at Missoula Experiment (FLAME-4), Atmos. Chem. Phys., 14, 9727-9754, doi:10.5194/acp-14-9727-2014, 2014.

61) Saleh, R., Robinson, E. S., Tkacik, D. S., Ahern, A. T., Liu, S., Aiken, A. C., Sullivan, R. C., Presto, A. A., Dubey, M. K., Yokelson, R. J., Donahue, N. M., and Robinson, A. L.: Brownness of organics in aerosols from biomass burning linked to their black carbon content, Nat. Geosci., 7, 647-650, doi:10.1038/ngeo2220, 2014.

60) Liu, S., Aiken, A. C., Arata, C., Dubey, M. K., Stockwell, C. E., Yokelson, R. J., Stone, E. A., Jayarathne, T., Robinson, A. L., DeMott, P. J., and Kreidenweis, S. M.: Aerosol single scattering albedo dependence on biomass combustion efficiency: Laboratory and field studies, Geophys. Res. Lett., 41, 742–748, doi:10.1002/2013GL058392, 2014.

59) Akagi, S. K., Burling, I. R., Mendoza, A., Johnson, T. J., Cameron, M., Griffith, D. W. T., Paton-Walsh, C., Weise, D. R., Reardon, J., and Yokelson, R. J.: Field measurements of trace gases emitted by prescribed fires in southeastern US pine forests using an open-path FTIR system, Atmos. Chem. Phys., 14, 199-215, doi:10.5194/acp-14-199-2014, 2014.

 58) Yokelson, R. J., Andreae, M. O., and Akagi, S. K.: Pitfalls with the use of enhancement ratios or normalized excess mixing ratios measured in plumes to characterize pollution sources and aging, Atmos. Meas. Tech., 6, 2155-2158, doi:10.5194/amt-6-2155-2013, 2013.

57) Johnson, T. J., Sams, R. L., Profeta, L. T. M., Akagi, S. K., Burling, I. R., Yokelson, R. J., and Williams, S. D.: Quantitative IR spectrum and vibrational assignments for glycolaldehyde vapor: Glycolaldehyde measurements in biomass burning plumes, J. Phys. Chem. A, 117, 4096−4107, doi.org/10.1021/jp311945p, 2013.

56) Hosseini, S., Urbanski, S., Dixit, P., Li, Q., Burling, I., Yokelson, R., Johnson, T., Shrivastava, M. K., Jung, H., Weise, D., Miller, W., and Cocker III, D.: Laboratory characterization of PM emissions from combustion of wildland biomass fuels, J. Geophys. Res., 118, 9914–9929, doi:10.1002/jgrd.50481, 2013.

55) Akagi, S. K., Yokelson, R. J., Burling, I. R., Meinardi, S., Simpson, I., Blake, D. R., McMeeking, G. R., Sullivan, A., Lee, T., Kreidenweis, S., Urbanski, S., Reardon, J., Griffith, D. W. T., Johnson, T. J., and Weise, D. R.: Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes, Atmos. Chem. Phys., 13, 1141-1165, doi:10.5194/acp-13-1141-2013, 2013.

54) Yokelson, R. J., Burling, I. R., Gilman, J. B., Warneke, C., Stockwell, C. E., de Gouw, J., Akagi, S. K., Urbanski, S. P., Veres, P., Roberts, J. M., Kuster, W. C., Reardon, J., Griffith, D. W. T., Johnson, T. J., Hosseini, S., Miller, J. W., Cocker, D. R., Jung, H., and Weise, D. R.: Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires, Atmos. Chem. Phys., 13, 89-116, doi:10.5194/acp-13-89-2013, 2013.

53) Reid, J. S., Hyer, E. J., Johnson, R., Holben, B. N., Yokelson, R. J., Zhang, J., Campbell, J. R., Christopher, S. A., Di Girolamo , L., Giglio, L., Holz, R. E., Kearney, C., Miettinen, J., Reid, E. A., Turk, F. J., Wang, J., Xian, P., Zhao, G., Balasubramanian, R., Chew, B. N., Janai, S., Lagrosas, N., Lestari, P., Lin, N.-H., Mahmud, M.. Nguyen, A. X., Norris, B., Oahn, N. T.K., Oo, M., Salinas, S. V., Welton, E. J., Liew, S. C.: Observing and understanding the Southeast Asian aerosol system by remote sensing: An initial review and analysis for the Seven Southeast Asian Studies (7SEAS) program, Atmos. Res., 122, 403-468, doi:10.1016/j.atmosres.2012.06.005, 2013.

52) Akagi, S. K., Craven, J. S., Taylor, J. W., McMeeking, G. R., Yokelson, R. J., Burling, I. R., Urbanski, S. P., Wold, C. E., Seinfeld, J. H., Coe, H., Alvarado, M. J., and Weise, D. R.: Evolution of trace gases and particles emitted by a chaparral fire in California, Atmos. Chem. Phys., 12, 1397-1421, doi:10.5194/acp-12-1397-2012, 2012.

51) Burling, I. R., Yokelson, R. J., Akagi, S. K., Urbanski, S. P., Wold, C. E., Griffith, D. W. T., Johnson, T. J., Reardon, J., and Weise, D. R.: Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States, Atmos. Chem. Phys., 11, 12197-12216, doi:10.5194/acp-11-12197-2011, 2011.

50) Simpson, I. J., Akagi, S. K., Barletta, B., Blake, N. J., Choi, Y., Diskin, G. S., Fried, A., Fuelberg, H. E., Meinardi, S., Rowland, F. S., Vay, S. A., Weinheimer, A. J., Wennberg, P. O., Wiebring, P., Wisthaler, A., Yang, M., Yokelson, R. J., and Blake, D. R.: Boreal forest fire emissions in fresh Canadian smoke plumes: C1-C10 volatile organic compounds (VOCs), CO2, CO, NO2, NO, HCN and CH3CN, Atmos. Chem. Phys., 11, 6445-6463, doi:10.5194/acp-11-6445-2011, 2011.

49) Roberts, J. M., Veres, P. R., Cochran, A. K., Warneke, C., Burling, I. R., Yokelson, R. J., Lerner, B., Holloway, J. S., Fall, R., and de Gouw, J.: Isocyanic acid in the atmosphere: Sources, concentrations and sinks, and potential health effects, PNAS, 108, 8966-8971, doi: 10.1073/pnas.1103352108, 2011.

48) Yokelson, R. J., Burling, I. R., Urbanski, S. P., Atlas, E. L., Adachi, K., Buseck, P. R., Wiedinmyer, C., Akagi, S. K., Toohey, D. W., and Wold, C. E.: Trace gas and particle emissions from open biomass burning in Mexico, Atmos. Chem. Phys., 11, 6787-6808, doi:10.5194/acp-11-6787-2011, 2011.

47) Wiedinmyer, C., Akagi, S. K., Yokelson, R. J., Emmons, L. K., Al-Saadi, J. A., Orlando, J. J., and Soja, A. J.: The Fire INventory from NCAR (FINN): a high resolution global model to estimate the emissions from open burning, Geosci. Model Dev., 4, 625-641, doi:10.5194/gmd-4-625-2011, 2011.

46) Akagi, S. K., Yokelson, R. J., Wiedinmyer, C., Alvarado, M. J., Reid, J. S., Karl, T., Crounse, J. D., and Wennberg, P. O.: Emission factors for open and domestic biomass burning for use in atmospheric models, Atmos. Chem. Phys., 11, 4039-4072, doi:10.5194/acp-11-4039-2011, 2011.

45) Chang-Graham, A. L., Profeta, L. T. M., Johnson, T. J., Yokelson, R. J., Laskin, A., and Laskin, J.: A case study of water soluble metal containing organic constituents of biomass burning aerosol, Environ. Sci. Technol., 45, 1257–1263, doi:10.1021/es103010j, 2011.

44) Warneke, C., Roberts, J. M., Veres, P., Gilman, J., Kuster, W. C., Burling, I., Yokelson, R. J., de Gouw, J. A.: VOC identification and inter-comparison from laboratory biomass burning using PTR-MS and PIT-MS, Int. J. Mass Spectrom. Ion Proc., 303, 6-14, doi: 10.1016/j.ijms.2010.12.002, 2011.

43) Veres, P., Roberts, J. M., Burling, I. R., Warneke, C., de Gouw, J., and Yokelson, R. J.: Measurements of gas-phase inorganic and organic acids from biomass fires by negative-ion proton-transfer chemical-ionization mass spectrometry, J. Geophys. Res., 115, D23302, doi:10.1029/2010JD014033, 2010.

42) Burling, I. R., Yokelson, R. J., Griffith, D.W.T., Johnson, T. J., Veres, P., Roberts, J.M., Warneke, C., Urbanski, S.P., Reardon, J., Weise, D.R., Hao, W.M., and de Gouw, J.: Laboratory measurements of trace gas emissions from biomass burning of fuel types from the southeastern and southwestern United States, Atmos. Chem. Phys., 10, 11115-11130, doi:10.5194/acp-10-11115-2010, 2010.

41) Johnson, T. J., Profeta, L. T. M., Sams, R. L., Griffith, D. W. T., and Yokelson, R. J.: An infrared spectral database for detection of gases emitted by biomass burning, Vibrational Spectroscopy 53, 97-102, 2010.

40) Roberts, J. M., Veres, P., Warneke, C., Neuman, J. A., Washenfelder, R. A., Brown, S. S., Baasandorj, M., Burkholder, J. B., Burling, I. R., Johnson, T. J., Yokelson, R. J., and de Gouw, J.: Measurement of HONO, HNCO, and other inorganic acids by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS): application to biomass burning emissions, Atmos. Meas. Tech., 3, 981-990, doi:10.5194/amt-3-981-2010, 2010.

39) Christian, T. J., Yokelson, R. J., Cárdenas, B., Molina, L. T., Engling, G., and Hsu, S.-C.: Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico, Atmos. Chem. Phys., 10, 565-584, 2010.

38) Crounse, J. D., DeCarlo, P. F., Blake, D. R., Emmons, L. K., Campos, T. L., Apel, E. C., Clarke, A. D., Weinheimer, A. J., McCabe, D. C., Yokelson, R. J., Jimenez, J. L., and Wennberg, P. O.: Biomass burning and urban air pollution over the Central Mexican Plateau, Atmos. Chem. Phys., 9, 4929-4944, 2009.

37) Yokelson, R., Crounse, J. D., DeCarlo, P. F., Karl, T., Urbanski, S., Atlas, E., Campos, T., Shinozuka, Y., Kapustin, V., Clarke, A. D., Weinheimer, A., Knapp, D. J., Montzka, D. D., Holloway, J., Weibring, P., Flocke, F., Zheng, W., Toohey, D., Wennberg, P. O., Wiedinmyer, C., Mauldin, L., Fried, A., Richter, D., Walega, J., Jimenez, J. L., Adachi, K., Buseck, P. R., Hall, S. R., and Shetter, R.: Emissions from biomass burning in the Yucatan, Atmos. Chem. Phys., 9, 5785-5812, 2009.

36) Neto, T.G.S., J.A. Carvalho Jr., C.A.G. Veras, E.C. Alvarado, R. Gielow, E.N. Lincoln, T.J. Christian, R.J. Yokelson, and J.C. Santos, Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire, Atmos. Environ., 43, 438-446, 2009.

35) Yokelson, R.J., T.J. Christian, T.G. Karl, and A. Guenther, The tropical forest and fire emissions experiment: Laboratory fire measurements and synthesis of campaign data, Atmos. Chem. Phys., 8, 3509-3527, 2008.

34) Yokelson, R.J., S.P. Urbanski, E.L. Atlas, D.W. Toohey, E.C. Alvarado, J.D. Crounse, P.O. Wennberg, M.E. Fisher, C.E. Wold, T.L. Campos, K. Adachi, P.R. Buseck, and W.M. Hao, Emissions from forest fires near Mexico City, Atmos. Chem. Phys., 7, 5569-5584, 2007.

33) Yokelson, R.J., T. Karl, P. Artaxo, D.R. Blake, T.J. Christian, D.W.T. Griffith, A. Guenther, and W.M. Hao, The tropical forest and fire emissions experiment: Overview and airborne fire emission factor measurements, Atmos. Chem. Phys., 7, 5175-5196, 2007.

32) Karl, T.G., T.J. Christian, R.J. Yokelson, P. Artaxo, W.M. Hao, and A. Guenther, The tropical forest and fire emissions experiment: Method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning, Atmos. Chem. Phys., 7, 5883-5897, 2007.

31) Karl, T.G., A. Guenther, R.J. Yokelson, J. Greenberg, M.J. Potosnak, D.R. Blake, and P. Artaxo, The tropical forest and fire emissions experiment: Emission, chemistry, and transport of biogenic volatile organic compounds in the lower atmosphere over Amazonia, J. Geophys. Res., 112, D18302, doi:10.1029/2007JD008539, 2007.

30) Christian, T.J., R.J. Yokelson, J.A. Carvalho Jr., D.W.T. Griffith, E.C. Alvarado, J.C. Santos, T.G.S. Neto, C.A.G. Veras, and W.M. Hao, The tropical forest and fire emissions experiment: Trace gases emitted by smoldering logs and dung on deforestation and pasture fires in Brazil, J. Geophys. Res., 112, D18308, doi:10.1029/2006JD008147, 2007.

29) Mason, S.A., J. Trentmann, T. Winterrath, R.J. Yokelson, T.J. Christian, L.J. Carlson, T.R. Warner, L.C. Wolfe, M.O. Andreae, Intercomparison of two box models of the chemical evolution in biomass-burning smoke plumes, J. Atmos. Chem., 55, 273-297, doi:10.1007/s10874-006-9039-5 2006.

28) Trentmann, J., R.J. Yokelson, P.V. Hobbs, T. Winterrath, T.J. Christian, M.O. Andreae, and S.A. Mason, An analysis of the chemical processes in the smoke plume from a savanna fire, J. Geophys.Res.,110, D12301, doi:10.1029/2004JD005628, 2005.

27) Sinha, P., P.V. Hobbs, R.J. Yokelson, D.R. Blake, S. Gao, and T.W. Kirchstetter, Emissions from miombo woodland and dambo grassland savanna fires, J. Geophys. Res., 109, D11305, doi:10.1029/2004JD004521, 2004.

26) Tabazadeh, A., R.J. Yokelson, H.B. Singh, P.V. Hobbs, J.H. Crawford, and L.T. Iraci, Heterogeneous chemistry involving methanol in tropospheric clouds, Geophys. Res. Lett., 31, L06114, doi:10.1029/2003GL018775, 2004. (AGU Journal Highlight.)

25) Christian, T.J., B. Kleiss, R.J. Yokelson, R. Holzinger, P.J. Crutzen, W.M. Hao, T. Shirai, and D.R. Blake, Comprehensive laboratory measurements of biomass-burning emissions: 2, First intercomparison of open-path FTIR, PTR-MS, GC-MS/FID/ECD, J. Geophys. Res., 109, D02311, doi:10.1029/2003JD003874, 2004.

24) Korontzi, S., D.E. Ward, R.A. Susott, R.J. Yokelson, C.O. Justice, P.V. Hobbs, E.A.H. Smithwick, and W.M. Hao, Seasonal variation and ecosystem dependence of emission factors for selected trace gases and PM2.5 for southern African savanna fires, J. Geophys. Res., 108, 4758, doi:10.1029/2003JD003730, 2003.

23) Sinha, P., P.V. Hobbs, R.J. Yokelson, D.R. Blake, S. Gao, and T.W. Kirchstetter, Distributions of trace gases and aerosols during the dry biomass burning season in southern Africa, J. Geophys. Res., 108, 4536, doi:10.1029/2003JD003691, 2003.

22) Christian, T. J., B. Kleiss, R. J. Yokelson, R. Holzinger, P. J. Crutzen, W. M. Hao, B. H. Saharjo, and D. E. Ward, Comprehensive laboratory measurements of biomass-burning emissions: 1. Emissions from Indonesian, African, and other fuels, J. Geophys. Res., 108, 4719, doi:10.1029/2003JD003704, 2003.

21) Yokelson, R.J., T.J. Christian, I.T. Bertschi, and W.M. Hao, Evaluation of adsorption effects on measurements of ammonia, acetic acid, and methanol, J. Geophys. Res. 108, 4649, doi:10.1029/2003JD003549, 2003.

20) Sinha, P., P.V. Hobbs, R.J. Yokelson, T.J. Christian, T.W. Kirchstetter, and R. Bruintjes, Emissions of trace gases and particles from two ships in the southern Atlantic Ocean, Atmos. Env., 37, 2139-2148, 2003.

19) Sinha, P., P.V. Hobbs, R.J. Yokelson, I.T. Bertschi, D.R. Blake, I.J. Simpson, S. Gao, T.W. Kirchstetter, and T. Novakov, Emissions of trace gases and particles from savanna fires in southern Africa, J. Geophys. Res., 108, 8487, doi:10.1029/2002JD002325, 2003.

18) Hobbs, P.V., P. Sinha, R.J. Yokelson, T.J. Christian, D.R. Blake, S. Gao, T.W. Kirchstetter, T. Novakov, and P. Pilewskie, Evolution of gases and particles from a savanna fire in South Africa, J. Geophys. Res., 108, 8485, doi:10.1029/2002JD002352, 2003.

17) McMillan, W.W., M.L. McCourt, H.E. Revercomb, R.O. Knuteson, P. Antonelli, T.J. Christian, B. Doddridge, P.V. Hobbs, J. Lukovich, P. Novelli, S. Piketh, L. Sparling, D. Stein, R.J. Swap, and R.J. Yokelson, Tropospheric carbon monoxide measurements from the Scanning High-Resolution Interferometer Sounder on 7 September 2000 in southern Africa during SAFARI 2000, J. Geophys. Res., 108, 8492, doi:10.1029/2002JD002335, 2003.

16) Bertschi, I.T., R.J. Yokelson, J. G. Goode, D.E. Ward, R.E. Babbitt, R. A. Susott, and W.M. Hao, Trace gas and particle emissions from fires in large-diameter and belowground biomass fuels, J. Geophys. Res., 108, 8472, doi:10.1029/2002JD002100, 2003.

15) Bertschi, I.T., R.J. Yokelson, D.E. Ward, T.J. Christian, and W.M. Hao, Trace gas emissions from the production and use of domestic biofuels in Zambia measured by open-path Fourier transform infrared spectroscopy, J. Geophys. Res., 108, 8469, doi:10.1029/2002JD002158, 2003.

14) Yokelson, R.J., I.T. Bertschi, T.J. Christian, P.V. Hobbs, D.E. Ward, and W.M. Hao, Trace gas measurements in nascent, aged, and cloud-processed smoke from African savanna fires by airborne Fourier transform infrared spectroscopy (AFTIR), J. Geophys. Res., 108, 8478, doi:10.1029/2002JD002322, 2003. (Impact Factor in top 1%)


13) Swap, R.J., H.J. Annegarn, J.T. Suttles, J. Haywood, M.C. Helmlinger, C. Hely, P.V. Hobbs, B. N. Holben, J. Ji, M.D. King, T. Landmann, W. Maenhaut, L. Otter, B. Pak, S. J. Piketh, S. Platnick, J. Privette, D. Roy, A.M. Thompson, D. Ward, and R. Yokelson, The Southern African Regional Science Initiative (SAFARI 2000): Overview of the dry season field campaign, South African J. Sci., 98, 125-130, 2002.

12) Mason, S.A., R.J. Field, R.J. Yokelson, M.A. Kochivar, M.R. Tinsley, D.E. Ward, and W.M. Hao, Complex effects arising in smoke plume simulations due to inclusion of direct emissions of oxygenated organic species from biomass combustion,  J. Geophys. Res., 106, 12527-12539, 2001.

11) Goode, J.G., R.J. Yokelson, D.E. Ward, R.A. Susott, R.E. Babbitt, M.A. Davies, and W.M. Hao, Measurements of excess O3, CO2, CO, CH4, C2H4, C2H2, HCN, NO, NH3, HCOOH, CH3COOH, HCHO, and CH3OH in 1997 Alaskan biomass burning plumes by airborne Fourier transform infrared spectroscopy (AFTIR), J. Geophys. Res., 105, 22147-22166, 2000.

10) Yokelson, R.J., J.G. Goode, D.E. Ward, R.A. Susott, R.E. Babbitt, D.D. Wade, I. Bertschi, D.W. T. Griffith, and W.M. Hao, Emissions of formaldehyde, acetic acid, methanol and other trace gases from biomass fires in North Carolina measured by airborne Fourier transform infrared spectroscopy (AFTIR), J. Geophys. Res., 104, 30109-30125, 1999.

9) Goode, J.G., R.J. Yokelson, R.A. Susott, and D.E. Ward, Trace gas emissions from laboratory biomass fires measured by open-path Fourier transform infrared spectroscopy: Fires in grass and surface fuels, J. Geophys. Res., 104, 21237-21245, 1999.

8) Yokelson, R.J., J.B. Burkholder, and A.R. Ravishankara, Photodissociaton of ClONO2: 2. Time-resolved absorption studies of product quantum yields, J. Phys. Chem., 101, Part A, 6667-6678, 1997.

7) Yokelson, R.J., D.E. Ward, R.A. Susott, J. Reardon, and D.W.T. Griffith, Emissions from smoldering combustion of biomass measured by open-path Fourier transform infrared spectroscopy, J. Geophys. Res., 102, 18865-18877, 1997.

6) Yokelson, R.J., D.W.T. Griffith, and D.E. Ward, Open-path Fourier transform infrared studies of large-scale laboratory biomass fires, J. Geophys. Res., 101, 21067-21080, 1996.

5) Yokelson, R.J., J.B. Burkholder, L. Goldfarb, R.W. Fox, M.K. Gilles, and A.R. Ravishankara, Temperature dependent rate coefficient for the Cl + ClONO2 reaction, J. Phys. Chem., 99, 13976-13983, 1995.

4) Yokelson, R.J., J.B. Burkholder, R.W. Fox, R.K. Talukdar, and A.R. Ravishankara, Temperature dependence of the NO3 absorption spectrum, J. Phys. Chem., 98, 13144-13150, 1994.

3) Burkholder, J.B., R.L. Mauldin III, R.J. Yokelson, S. Solomon, and A.R. Ravishankara, Kinetic, thermochemical, and spectroscopic study of Cl2O3, J. Phys. Chem., 97, 7597-7605, 1993.

2) Yokelson, R.J., R.J. Lipert, and W.A. Chupka, Identification of the ns and nd Rydberg states of O2 for n = 3 - 5, J. Chem. Phys., 97, 6153-6167, 1992.

1)      Yokelson, R.J., R.J. Lipert, and W.A. Chupka, Identification of the nd D and S states and the 1,3Fg ¬¬ X3Sg- transition of O2 by resonant multiphoton ionization, J. Chem. Phys., 97, 6144-6152, 1992.