Current Research

I conduct research to quantify atmospheric-biospheric interactions, including the use of eddy covariance technology to study the exchange of trace gases (carbon dioxide, water, ozone) between the atmosphere and the earth's surface (vegetation, soil, and snow). I also research issues involving the physical processes governing CO2 transport in soils and snowpacks and the impact of fire on soil physical properties and microbial populations.

Research Interests

Develop a better understanding of an ongoing spruce beetle epidemic can have on carbon and water cycles at a high elevation subalpine forest.Develop physically-based computer models to improve predictions of and insights into the long-term impacts on soils that extreme heating during a prescribed burn or wildfires can cause.

Past Research

My research focuses on some of the long-term impacts that relatively short-lived, but extreme, events or environmental conditions can have on vegetation and soils. Such events alter ecosystem benefits and resources, such as the potential for carbon sequestration, stream flow amounts and timing, and soil water availability, for decades to centuries. Quantifying these impacts on water and carbon is critical for long-term resource planning and sustainability.

Why This Research is Important

** Theory and practice of eddy covariance(1) A perspective on thirty years of the Webb, Pearman and Leuning density corrections ,(2) The canopy horizontal array turbulence study (CHATS) ** Carbon cycling and climate Climate control of terrestrial carbon exchange across biomes and continents **Fire and soils Advancing investigation and modeling of first-order fire effects on soils ** Beetle impacts on high elevation siteEvapotranspiration response of a high elevation Rocky Mountain (Wyoming, USA) forest to a bark beetle epidemic

Education

• University of Wisconsin, Madison, Ph.D. Meteorology 1978
• University of Wisconsin, Madison, M.S. Meteorology 1973
• University of Wisconsin, Madison, M.S. Physics 1970
• University of Missouri, Columbia, B.S. Physics 1969

Professional Organizations

• American Geophysical Union, Member (1988 - Current)
• American Meteorological Society, Member (1978 - Current)
• European Geophysical Union, Member (2008 - 2008)
• Journal of Geophysical Research: Atmospheres, Associate Editor (2005 - 2008)
• Association of Fire Ecology, Member (2007 - 2007)
• American Meteorological Society, Member (2002 - 2005)
• Air and Waste Management Association, Member (1994 - 1994)
• American Society of Agronomy, Member (1992 - 1993)
• American Meteorological Society, Member (1987 - 1989)

Awards & Recognition

Featured Publications & Products

• Lee, Xuhui; Massman, William J. 2011. A perspective on thirty years of the Webb, Pearman and Leuning density corrections.
• Pendall, Elise; Ewers, Brent; Norton, Urszula; Brooks, Paul; Massman, W. J.; Barnard, Holly; Reed, David; Aston, Tim; Frank, John. 2010. Impacts of beetle-induced forest mortality on carbon, water and nutrient cycling in the Rocky Mountains.
• Yi, Chuixiang; Ricciuto, Daniel; Li, Runze; Wolbeck, John; Xu, Xiyan; Nilsson, Mats; Frank, John; Massman, William J. 2010. Climate control of terrestrial carbon exchange across biomes and continents.
• Massman, William J.; Frank, John M.; Mooney, Sacha J. 2010. Advancing investigation and physical modeling of first-order fire effects on soils.
• Frank, John M.; Massman, William J.; Ewers, Brent E.; Williams, David G. 2019. Bayesian analyses of 17 winters of water vapor fluxes show bark beetles reduce sublimation.
• Massman, W. J.; Forthofer, J. M.; Finney, M. A. 2017. An improved canopy wind model for predicting wind adjustment factors and wildland fire behavior.
• Frank, John M.; Massman, William J.; Swiatek, Edward; Zimmerman, Herb A.; Ewers, Brent E. 2016. All sonic anemometers need to correct for transducer and structural shadowing in their velocity measurements.
• Frank, John M.; Massman, William J.; Ewers, Brent E. 2016. A Bayesian model to correct underestimated 3-D wind speeds from sonic anemometers increases turbulent components of the surface energy balance.
• Massman, William. 2015. A non-equilibrium model for soil heating and moisture transport during extreme surface heating: The soil (heat-moisture-vapor) HMV-Model Version.

Publications

• Sun, Jielun ; Massman, William J.; Banta, Robert M.; Burns, Sean P. 2021. Revisiting the surface energy imbalance.
• Massman, William J. 2021. The challenges of an in situ validation of a nonequilibrium model of heat and moisture dynamics during fires.
• Burns, Sean P.; Frank, John M.; Massman, William J.; Patton, Edward G.; Blanken, Peter D. 2021. The effect of static pressure-wind covariance on vertical carbon dioxide exchange at a windy subalpine forest site.
• Frank, John M.; Massman, William J. 2020. A new perspective on the open-path infrared gas analyzer self-heating correction.
• Frank, John M.; Massman, William J.; Chan, W. Stephen; Nowicki, Keith ; Rafkin, Scot C. R. 2020. Coordinate rotation-amplification in the uncertainty and bias in non-orthogonal sonic anemometer vertical wind speeds.
• Clifton, Olivia E.; Fiore, Arlene M.; Massman, William J.; Baublitz, Colleen B.; Coyle, Mhairi ; Emberson, Lisa ; Fares, Silvano ; Farmer, Delphine K.; Gentine, Pierre ; Gerosa, Giacomo ; Guenther, Alex B.; Helmig, Detlev ; Lombardozzi, Danica L.; Munger, J. William; Patton, Edward G.; Pusede, Sally E.; Schwede, Donna B.; Silva, Sam J.; Sorgel, Matthias ; Steiner, Allison L.; Tai, Amos P. K. 2020. Dry deposition of ozone over land: Processes, measurement, and modeling.
• Massman, William J. 2020. Impacts of non-ideality and the thermodynamic pressure work term p v on the surface energy balance.
• Pastorello, Gilberto ; Carlo Trotta, ; Eleonora Canfora, ; Housen Chu, ; Danielle Christianson, ; Frank, John ; Massman, William ; Urbanski, Shawn . 2020. The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data.
• Chen, Xuelong ; Massman, William J.; Su, Zhongbo . 2019. A column canopy air turbulent diffusion method for different canopy structures.
• Fullhart, Andrew T.; Kelleners, Thijs J.; Speckman, Heather N.; Beverly, Daniel ; Ewers, Brent E.; Frank, John M.; Massman, William J. 2018. Measured and modelled above- and below-canopy turbulent fluxes for a snow-dominated mountain forest using GEOtop.
• Chu, Housen ; Baldocchi, Dennis D.; Poindexter, Cristina ; Abraha, Michael ; Desai, Ankur R.; Bohrer, Gil ; Arain, M. Altaf; Griffis, Timothy ; Blanken, Peter D.; O'Halloran, Thomas L.; Thomas, R. Quinn; Zhang, Quan ; Burns, Sean P.; Frank, John M.; Christian, Dold ; Brown, Shannon ; Black, T. Andrew; Gough, Christopher M.; Law, Beverly E.; Lee, Xuhui ; Chen, Jiquan ; Reed, David E.; Massman, William J.; Clark, Kenneth ; Hatfield, Jerry ; Prueger, John ; Bracho, Rosvel ; Baker, John M.; Martin, Timothy A. 2018. Temporal dynamics of aerodynamic canopy height derived from eddy covariance momentum flux data across North American flux networks.
• Berryman, E. M.; Frank, J. M.; Massman, W. J.; Ryan, M. G. 2018. Using a Bayesian framework to account for advection in seven years of snowpack CO2 fluxes in a mortality-impacted subalpine forest.
• Smits, Kathleen M.; Kirby, Elizabeth; Massman, William J.; Baggett, Scott. 2016. Experimental and modeling study of forest fire effect on soil thermal conductivity.
• Kelleners, Thijs J.; Koonce, Jeremy; Shillito, Rose; Dijkema, Jelle; Berli, Markus; Young, Michael H.; Frank, John M.; Massman, William. 2016. Numerical modeling of coupled water flow and heat transport in soil and snow.
• Chen, Fei; Zhang, Guo; Barlage, Michael; Zhang, Ying; Hicke, Jeffrey A.; Meddens, Arjan; Zhou, Guangsheng; Massman, William J.; Frank, John. 2015. An observational and modeling study of impacts of bark beetle-caused tree mortality on surface energy and hydrological cycles.
• Speckman, Heather N.; Frank, John M.; Bradford, John B.; Miles, Brianna L.; Massman, William J.; Parton, William J.; Ryan, Michael G. 2015. Forest ecosystem respiration estimated from eddy covariance and chamber measurements under high turbulence and substantial tree mortality from bark beetles.
• Frank, John M.; Massman, William J.; Ewers, Brent E.; Huckaby, Laurie S.; Negron, Jose F. 2014. Ecosystem CO2/H2O fluxes are explained by hydraulically limited gas exchange during tree mortality from spruce bark beetles.
• Schlaepfer, Daniel R.; Ewers, Brent E.; Shuman, Bryan N.; Williams, David G.; Frank, John M.; Massman, William J.; Lauenroth, William K. 2014. Terrestrial water fluxes dominated by transpiration: Comment.
• Kochendorfer, John; Meyers, Tilden P.; Frank, John M.; Massman, William J.; Heuer, Mark W. 2013. Reply to comment by Mauder on "How well can we measure the vertical wind speed Implications for fluxes of energy and mass".
• Frank, John M.; Massman, William J.; Ewers, Brent E. 2013. Underestimates of sensible heat flux due to vertical velocity measurement errors in non-orthogonal sonic anemometers.
• Rafkin, S.; Banfield, D.; Dissly, R.; Silver, J.; Stanton, A.; Wilkinson, E.; Massman, W.; Ham, J. 2012. An instrument to measure turbulent eddy fluxes in the atmosphere of Mars.
• Kochendorfer, John; Meyers, Tilden P.; Frank, John; Massman, William J.; Heuer, Mark W. 2012. How well can we measure the vertical wind speed Implications for fluxes of energy and mass.
• Massman, W. J. 2012. Modeling soil heating and moisture transport under extreme conditions: Forest fires and slash pile burns.
• Leuning, Ray; van Gorsela, Eva; Massman, William J.; Isaac, Peter R. 2012. Reflections on the surface energy imbalance problem.
• Gu, Lianhong; Massman, William J.; Leuning, Ray; Pallardy, Stephen G.; Meyers, Tilden; Hanson, Paul J.; Riggs, Jeffery S.; Hosman, Kevin P.; Yang, Bai. 2012. The fundamental equation of eddy covariance and its application in flux measurements.
• Bowling, D. R.; Massman, W. J. 2011. Persistent wind-induced enhancement of diffusive CO2 transport in a mountain forest snowpack.
• Patton, Edward G.; Horst, Thomas W.; Sullivan, Peter P.; Lenschow, Donald H.; Oncley, Steven P.; Brown, William O. J.; Burns, Sean P.; Guenther, Alex B.; Held, Andreas; Karl, Thomas; Mayor, Shane D.; Rizzo, Luciana V.; Spuler, Scott M.; Sun, Jielun; Turnipsee, Andrew A.; Allwine, Eugene J.; Edburg, Steven L.; Lamb, Brian K.; Avissar, Roni; Calhoun, Ronald J.; Kleissl, Jan; Massman, William J.; U, Kyaw Tha Paw; Weil, Jeffrey C. 2011. The canopy horizontal array turbulence study.
• Nobles, M. M.; Massman, W. J.; Mbila, M.; Butters, G. 2010. Mineralogical and micromorphological modifications in soil affected by slash pile burn.
• Massman, W. J.; Nobles, M. M.; Butters, G.; Mooney, S. J. 2010. Transport of CO2 and other combustion products in soils during slash-pile burns Presentation.
• Bowling, D. R.; Massman, W. J.; Schaeffer, S. M.; Burns, S. P.; Monson, R. K.; Williams, M. W. 2009. Biological and physical influences on the carbon isotope content of CO2 in a subalpine forest snowpack, Niwot Ridge, Colorado.
• Wilson, J. D.; Massman, W. J.; Swaters, G. E. 2009. Dynamic response of the thermometric net radiometer.
• Massman, W. J.; Ibrom, A. 2008. Attenuation of concentration fluctuations of water vapor and other trace gases in turbulent tube flow.
• Massman, W. J.; Frank, J. M.; Reisch, N. B. 2008. Long-term impacts of prescribed burns on soil thermal conductivity and soil heating at a Colorado Rocky Mountain site: a data/model fusion study.
• Patton, Edward G.; Horst, Thomas W.; Lenschow, Donald H.; Sullivan, Peter P.; Oncley, Steven; Burns, Sean; Guenther, Alex; Held, Andreas; Karl, Thomas; Mayor, Shane; Rizzo, Luciana; Spuler, Scott; Sun, Jielun; Turnipseed, Andrew; Allwine, Eugene; Edburg, Steven; Lamb, Brian; Avissar, Roni; Holder, Heidi E.; Calhoun, Ron; Kleissl, Jan; Massman, William; U, Kyaw Tha Paw; Weil, Jeffrey C. 2008. The Canopy Horizontal Array Turbulence Study (CHATS).
• Oncley, Steven P.; Massman, William J.; Patton, Edward G. 2008. Turbulent pressure fluctuations measured during CHATS.
• Buker, P.; Emberson, L.D.; Ashmore, M. R.; Cambridge, H. M.; Jacobs, C. M.; Massman, W. J.; Muller, J.; Nikolov, N.; Novak, K.; Oksanen, E.; Schaub, M.; de la Torre, D. 2007. Comparison of different stomatal conductance algorithms for ozone flux modelling.
• Esquilin, Aida E. Jimenez; Stromberger, Mary E.; Massman, William J.; Frank, John M.; Shepperd, Wayne D. 2007. Microbial community structure and activity in a Colorado Rocky Mountain forest soil scarred by slash pile burning.
• Musselman, Robert C.; Lefohn, Allen S.; Massman, William J.; Heath, Robert L. 2006. A critical review and analysis of the use of exposure- and flux-based ozone indices for predicting vegetation effects.
• Massman, W. J. 2006. Advective transport of CO2 in permeable media induced by atmospheric pressure fluctuations: 1. An analytical model.
• Massman, W. J.; Frank, J. M. 2006. Advective transport of CO2 in permeable media induced by atmospheric pressure fluctuations: 2. Observational evidence under snowpacks.
• Massman, W. J.; Tuovinen, J. -P. 2006. An analysis and implications of alternative methods of deriving the density (WPL) terms for eddy covariance flux measurements.
• Buker, P.; Emberson, L. D.; Ashmore, M. R.; Gerosa, G.; Jacobs, C.; Massman, W. J.; Muller, J.; Nikolov, N.; Novak, K.; Oksanen, E.; De La Torre, D.; Tuovinen, J. -P. 2006. Comparison of different stomatal conductance algorithms for ozone flux modelling Proceedings.
• Liu, Heping; Randerson, James T.; Lindfors, Jamie; Massman, William J.; Foken, Thomas. 2006. Consequences of incomplete surface energy balance closure for CO2 fluxes from open-path CO2/H2O infrared gas analyzers.
• Massman, W. J.; Frank, J. M. 2006. Effects of controlled burns on the bulk density and thermal conductivity of soils at a southern Colorado site.
• Wieser, G.; Matyssek, R.; Musselman, R. C.; Lefohn, A. S.; Massman, W. J. 2006. Glossary: Definitions of relevancy for the 'flux concept' in ozone risk assessment.
• Massman, W. J.; Frank, J. M.; Jimenez Esquilin, A. E.; Stromberger, M. E.; Shepperd, W. D. 2006. Long term consequences of a controlled slash burn and slash mastication to soil moisture and CO2 at a southern Colorado site.
• Emberson, L. D.; Massman, W. J.; Buker, P.; Soja, G.; Van De Sand, I.; Mills, G.; Jacobs, C. 2006. The development, evaluation, and application of O3 flux and flux-response models for additional agricultural crops.
• Musselman, R. C.; Massman, W. J.; Frank, J. M.; Korfmacher, J. L. 2005. The temporal dynamics of carbon dioxide under snow in a high elevation Rocky Mountain subalpine forest and meadow.
• Massman, W. J.; Frank, J. M. 2004. An in situ investigation of the influence of a controlled burn on the thermophysical properties of a dry soil.
• Massman, W. J. 2004. Concerning the measurement of atmospheric trace gas fluxes with open- and closed-path eddy covariance systems: The density terms and spectral attenuation Chapter 7.
• Massman, W. J.; Frank, J. M. 2004. Effect of a controlled burn on the thermophysical properties of a dry soil using a new model of soil heat flow and a new high temperature heat flux sensor.
• Takle, Eugene S.; Massman, William J.; Brandle, James R.; Schmidt, R. A.; Zhou, Xinhua; Litvina, Irina V.; Garcia, Rick; Doyle, Geoffrey; Rice, Charles W. 2004. Influence of high-frequency ambient pressure pumping on carbon dioxide efflux from soil.
• Massman, W. J. 2004. Toward an ozone standard to protect vegetation based on effective dose: A review of deposition resistances and a possible metric.
• Massman, W. J.; Clement, R. 2004. Uncertainty in eddy covariance flux estimates resulting from spectral attenuation Chapter 4.
• Takle, Eugene S.; Brandle, James R.; Schmidt, R. A.; Garcia, Rick; Litvina, Irina V.; Massman, William J.; Zhou, Xinhua; Doyle, Geoffrey; Rice, Charles W. 2003. High-frequency pressure variations in the vicinity of a surface CO2 flux chamber.
• Massman, W. J.; Frank, J. M.; Shepperd, W. D.; Platten, M. J. 2003. In situ soil temperature and heat flux measurements during controlled surface burns at a southern Colorado forest site.
• Massman, W. J.; Frank, J. M.; Massman, S. M.; Shepperd, W. D. 2003. Performance of high temperature heat flux plates and soil moisture probes during controlled surface fires.
• Massman, W. J.; Finnigan, J.; Billesbach, D.; Miller, S.; Black, A.; Amiro, B.; Law, B.; Lee, X.; Mahrt, L.; Dahlman, R.; Foken, T. 2003. Summary and synthesis of recommendations of the AmeriFlux Workshop on standardization of flux analysis and diagnostics; Corvallis, Oregon; August 2002.
• Massman, W. J.; Lee, X. 2002. Eddy covariance flux corrections and uncertainties in long-term studies of carbon and energy exchanges.
• Massman, W. J. 2001. Reply to comment by Rannik on "A simple method for estimating frequency response corrections for eddy covariance systems".
• Massman, W. J. 2000. A simple method for estimating frequency response corrections for eddy covariance systems.
• Takle, E. S.; Brandle, J. R.; Schmidt, R. A.; Garcia, R.; Litvina, I. V.; Doyle, G.; Zhou, X.; Hou, Q.; Rice, C. W.; Massman, W. J. 2000. Pressure pumping of carbon dioxide from soil.
• Massman, W. J.; Sommerfeld, R. A.; Mosier, A. R.; Zeller, K. F.; Hehn, T.J .; Rochelle, S. G. 1997. A model investigation of turbulence-driven pressure-pumping effects on the rate of diffusion of CO2, N2O, and CH4 through layered snowpacks.
• Sommerfeld, Richard A.; Massman, William J.; Musselman, Robert C. 1996. Diffusional flux of CO2 through snow: Spatial and temporal variability among alpine-subalpine sites.
• Massman, William; Sommerfeld, Richard; Zeller, Karl; Hehn, Ted; Hudnell, Laura; Rochelle, Shannon. 1995. CO2 flux through a Wyoming seasonal snowpack: Diffusional and pressure pumping effects.
• Musselman, Robert C.; Wooldridge, Gene L.; Massman, William J.; Sommerfeld, Richard A. 1995. Wind and ecosystem response at the GLEES.

Research Highlights

Highlight	Title	Year
RMRS-2016-12	Ecosystem Fluxes are Underestimated Due to Measurement Tool Errors The eddy covariance technique is used worldwide to measure the exchange of energy and mass between ecosystems and the atmosphere. Ecosystem flux ...	2016
RMRS-2016-232	Modeling Soil Heat, Moisture, and Evaporation Dynamics During Fires With the increasing use of prescribed fire by land managers and increasing likelihood of wildfires due to climate change there comes the need to ...	2016
RMRS-2019-54	Spruce Beetles Reduce Sublimation, Causing Increasing Snowpack in the Wyoming Mountains Snow sublimation, the process of snow changing into water vapor in the air, is a major component of the annual water budget across the Front Ra ...	2019