Office of Research and Development Publications

National Risk Management Research Laboratory (NRMRL) Research Publications

Records 1 to 25 of 29 records from ORD-NRMRL published between 10/07/2012 and 10/07/2017 from author John Walker, Jr.

2017
Wu, Z., Johnt Walker, AND L. Zhang. Development, evaluation and application of a modified micrometeorological gradient method for long-term estimation of gaseous dry deposition over forest canopies. Ozone Dry Deposition: Constraints from multiplatform observations and multi-scale modeling, Palisades, New York, October 05 - 06, 2017.
2016
Beaulieu, J., B. Deemer, J. Harrison, C. Nietch, S. Waldo, AND Johnt Walker. Accounting For Greenhouse Gas Emissions From Flooded Lands. Presented at AGU Fall Meeting, San Francisco, CA, December 12 - 16, 2016.
Rumsey, I. C. AND J. T. WALKER. Application of an online ion chromatography-based instrument for gradient flux measurements of speciated nitrogen and sulfur. Atmospheric Measurement Techniques. Copernicus Publications, Katlenburg-Lindau, Germany, 9(6):2581-2592, (2016).
Waldo, S., J. Beaulieu, AND Johnt Walker. Investigating physical controls on methane and carbon dioxide fluxes over reservoirs using the eddy covariance method. Presented at American Geophysical Union Fall Meeting, San Francisco, CA, December 12 - 16, 2016.
Waldo, S., J. Beaulieu, AND Johnt Walker. Investigating physical controls on methane and carbon dioxide fluxes over reservoirs using the eddy covariance method-abstract. AGU Fall Meeting, San Francisco, CA, December 12 - 16, 2016.
Walker, Johnt, X. Chen, D. Schwede, R. Daly, A. Djurkovic, D. Kirchgessner, C. Oishi, AND M. Puchalski. Investigation of ammonia air-surface exchange processes in a deciduous montane forest in the southeastern U.S. Presented at National Atmospheric Deposition Program Fall Meeting, Santa Fe, New Mexico, October 31 - November 04, 2016.
Chen, X., Johnt Walker, AND Chris Geron. Laboratory and field based evaluation of chromatography related performance of the Monitor for Aerosols and Gases in Ambient Air (MARGA). Presented at National Atmospheric Deposition Program Fall Meeting, Santa Fe, New Mexico, October 31 - November 04, 2016.
Beaulieu, J., C. Nietch, S. Waldo, AND Johnt Walker. Methane emissions from reservoirs. To be Presented at Ohio River Basin Water Quality Workshop, Cincinnati, Ohio, December 06 - 08, 2016.
Li, Y., B. Schichtel, Johnt Walker, D. Schwede, X. Chen, C. Lehmann, M. Puchalski, D. Gay, AND J. Collett, Jr. The Increasing Importance of Deposition of Reduced Nitrogen in the United States. PNAS (PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES). National Academy of Sciences, WASHINGTON, DC, 113(21):5874-5879, (2016).
Walker, Johnt. The Measurement and modeling of the contribution of ammonia to total nitrogen deposition from canopy to regional scale. Presented at Invited Seminar - College of Charleston, Charleston, SC, March 03, 2016.
Walker, Johnt AND A. Leytem. USDA-EPA Collaborative Ammonia Research. Presented at USDA Agricultural Air Quality Task Force, Arlington, VA, April 07, 2016.
Sullivan, R., P. Crippa, A. Hallar, L. Clarisse, S. Whitburn, M. Van Damme, W. Leaitch, Johnt Walker, A. Khlystov, AND S. Pryor. Using satellite-based measurements to explore spatiotemporal scales and variability of drivers of new particle formation. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES. American Geophysical Union, Washington, DC, 121(20):12217-12235, (2016).
George, I., R. Black, Johnt Walker, Chris Geron, J. Aurell, M. Hays, W. Preston, AND B. Gullett. Volatile and semivolatile organic compounds in laboratory peat fire emissions. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 132:163-170, (2016).
2015
Oishi, C., C. Miniat, K. Novick, S. Brantley, J. Vose, AND Johnt Walker. Climate and Vegetation Effects on Temperate Mountain Forest Evapotranspiration. Presented at 2015 American Geophysical Union Annual Meeting, San Francisco, CA, December 14 - 18, 2015.
Spence, P., Johnt Walker, W. Robarge, B. Preston, AND D. Osmond. Comparing Nitrous Oxide Emissions from Three Residential Landscapes under Different Management Schemes Following Natural Rainfall Events. Urban Ecosystems. Springer Science+Business Media B.V, Dordrecht, Netherlands, 18:1-17, (2015).
Almand-Hunter, B., Johnt Walker, N. Masson, L. Hafford, AND M. Hannigan. Development and validation of inexpensive, automated, dynamic flux chambers. Atmospheric Measurement Techniques. Copernicus Publications, Katlenburg-Lindau, Germany, 8(1):267-280, (2015).
Walker, Johnt. Measurement and modeling of the contribution of ammonia to total nitrogen deposition from canopy to regional scale. Presented at American Meteorological Society, phoenix, AZ, January 04 - 08, 2015.
Yu, F., G. Luo, S. Pryor, P. Pillai, S. Lee, J. Ortega, J. Schwab, A. Hallar, W. Leaitch, V. Aneja, J. Smith, Johnt Walker, O. Hogrefe, AND K. Demerjian. Spring and summer contrast in new particle formation over nine forest areas in North America. Atmospheric Chemistry and Physics. Copernicus Publications, Katlenburg-Lindau, Germany, 15(24):13993-14003, (2015).
2014
Rumsey, I., K. A. Cowen, Johnt Walker, T. J. Kelly, E. A. Hanft, K. Mishoe, C. Rogers, R. Proost, G. M. Beachley, G. Lear, T. Frelink, AND R. P. Otjes. An assessment of the performance of Monitor for AeRosols and GAses in ambient air (MARGA): a semi-continuous method for soluble compounds. Atmospheric Chemistry and Physics. Copernicus Publications, Katlenburg-Lindau, Germany, 14:5639-5658, (2014).
Walker, Johnt, D. Schwede, J. Bash, AND C. Oishi. Comparison of Aerodynamic Resistance Parameterizations and Implications for Dry Deposition Modeling. National Atmospheric Deposition Program, Indianapolis, IN, October 22 - 24, 2014.
Walker, Johnt, W. Robarge, AND R. Austin. Modeling of Ammonia Dry Deposition to a Pocosin Landscape Downwind of a Large Poultry Facility. AGRICULTURE, ECOSYSTEMS & ENVIRONMENT. Elsevier Science Ltd, New York, NY, 185(0):161-175, (2014).
2013
Walker, Johnt. Bias in modeled bi-directional NH3 fluxes associated with temporal averaging of atmospheric NH3 concentrations. Spring meeting of the National Atmospheric Deposition Program, Madison, WI, April 22 - 25, 2013.
Novick, K., Johnt Walker, S. Chan, C. Sobek, AND J. Vose. Eddy covariance measurements in complex terrain with a new fast response, closed-path analyzer: spectral characteristics and cross-system comparisons. AGRICULTURAL AND FOREST METEOROLOGY. Elsevier Science Ltd, New York, NY, 181:17-32, (2013).
George, I., R. Black, Johnt Walker, M. Hays, D. Tabor, AND B. Gullett. Emissions of volatile organic compounds and particulate matter from small-scale peat fire. American Geophysical Union Fall Meeting, San Francisco, CA, December 09 - 13, 2013.
George, I., R. Black, Johnt Walker, M. Hays, B. Preston, D. Tabor, AND B. Gullett. Emissions of volatile organic compounds and particulate matter from small-scale peat fires. American Geophysical Union Fall Meeting, San Francisco, CA, December 09 - 13, 2013.