University of Minnesota
College of Food, Agricultural and Natural Resource Sciences
http://www.cfans.umn.edu
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Department of Soil, Water, and Climate

Timothy Griffis

tgriffis@umn.edu | 612-625-3117SWAC-timgriffis2
www.biometeorology.umn.edu


S331 Soil Science
1529 Gortner Avenue
St. Paul, MN 55108

Education:

B.S. 1995 Brock University, St. Catharines, Ontario Climatology
Ph.D. 2000 McMaster University, Hamilton, Ontario Biometeorology


My research aims to improve the scientific understanding of the biophysical mechanisms that govern the exchange of energy and mass between the Earth’s surface and the lower atmosphere. At this interface the processes are highly complex requiring a multidisciplinary approach that draws on knowledge from boundary layer meteorology, atmospheric chemistry, ecophysiology, hydrology, and soil science. In my view, Biometeorology represents the intersection of these disciplines and has become an integral component of global change research. The underlying theory and methodological approaches allow inquiry at the leaf to regional scale, which is essential to understanding how natural and anthropogenic environmental change influence the Earth-Atmosphere system. Humans have great capacity to alter the atmospheric composition and land surface characteristics. The exact consequences of these changes to weather, climate, environmental quality, and human health continue to be the subject of much debate and uncertainty. I aim to reduce these uncertainties by advancing the science of Biometeorology through innovative research and teaching. Current research interests include:

  1. Biogeochemical and biogeophysical forcings associated with agriculture and natural ecosystems
  2. Development of micrometeorological and optical stable isotope techniques to trace the flow of carbon and water between the land and atmosphere
  3. Impacts of land use and climate variation on ecosystem and regional 13C-CO2 and 18O-CO2 discrimination and isotope disequilibrium
  4. Influence of atmospheric circulation and land surface characteristics on trends in atmospheric water vapor and its isotope composition
  5. Biophysical modeling of land-atmosphere isotopic CO2 and water vapor exchange


Classes:
ESPM 5402: Biometeorology
ESPM 3000: Climate Change: Myths, Mysteries, and Uncertainties
ESPM 4903: Directed Research in Atmospheric Science
Soils 8195: Directed Research in Atmospheric Science

Graduate Programs:
Water Resource Science
Land and Atmospheric Science

National Advisory Committees and Affiliations:
National Ecological Observatory Network (NEON), Fundamental Instrument Unit Technical Working Group, 2009- present 
Affiliate Member of the Yale-Nanjing University of Information Science and Technology (NUIST) Center on Atmospheric Environment , 2014-present

Selected Publications:

"Reconciling the differences between top-down and bottom-up estimates of nitrous oxide emissions for the US Corn Belt", T.J. Griffis, X. Lee, J.M. Baker, M.P. Russelle, X. Zhang, R. Venterea, and D.B. Millet (Global Biogeochemical Cycles, 2013, 27, doi: 10.1002/gbc.20066)

"Interannual, seasonal, and retrospective analysis of the methane and carbon dioxide budgets of a temperate peatland", D. Olson, T.J. Griffis, A. Noormets, R. Kolka and J. Chen (Journal of Geophysical Research - Biogeosciences, 2013, 118, 226-238, doi: 10.1002/jgrg.20031)

"Tracing the flow of carbon dioxide and water vapor between the biosphere and atmosphere: A review of optical isotope techniques and their application", T.J. Griffis (Agricultural and Forest Meteorology, 2013, 174-175, 85-109, doi: 10.1016/j.agrformet.2013.02.009) 

"Oxygen isotope composition of evapotranspiration and its relation to C4 photosynthetic discrimination” T.J. Griffis, X. Lee, J.M. Baker, K. Billmark, N. Schultz, M. Erickson, X. Zhang, J. Fassbinder, W. Xiao, and N. Hu (Journal of Geophysical Research - Biogeosciences, 2011, 116, G01035, doi: 10.1029/2010JG001514) 

“Influence of C4 vegetation on 13CO2 discrimination and isotopic forcing in the Upper Midwest, United States”, T.J. Griffis, J.M. Baker, S.D. Sargent, M. Erickson, J. Corcoran, M. Chen, and K. Billmark (Global Biogeochemical Cycles, 2010, 24, GB4006, doi:10.1029/2009GB003768)

"Determining the oxygen isotope composition of evapotranspiration using eddy covariance", T.J. Griffis, S.D. Sargent, X. Lee, J.M. Baker, J. Greene, M. Erickson, X. Zhang, K. Billmark, N. Schultz, W. Xiao, and N. Hu (Boundary-Layer Meteorology, 2010, doi: 10.1007/s10546-010-9529-5, 137(2), 307-326)

"Canopy-scale kinetic fractionation of atmospheric carbon dioxide and water vapor isotopes", X. Lee, T.J. Griffis, J.M. Baker, K.A. Billmark, K. Kim, L.R. Welp (Global Biogeochemical Cycles, 2009, 23, GB1002, doi:10.1029/2008GB003331)

"Direct Measurement of Biosphere-Atmosphere Isotopic CO2 Exchange using the Eddy Covariance Technique", T.J. Griffis, S.D. Sargent, J.M. Baker, X. Lee, B.D. Tanner, J. Greene, E. Swiatek, and K. Billmark (Journal of Geophysical Research- Atmospheres, 2008, 113, D08304,doi:10.1029/2007JD009297).

"Using Continuous Stable Isotope Measurements to Partition Net Ecosystem CO2 Exchange." J.Zhang, T.J.Griffis, and J.M.Baker. (Plant, Cell and Environment, 2006, 29: 483-496)

"Ecophysiological Controls on the Carbon Balances of Three Southern Boreal Forests." T.J.Griffis, T.A.Black, K.Morgenstern, A.Barr, Z.Nesic, G.Drewitt, D.Gaumont-Guay, H.McCaughey. (Agricultural and Forest Meteorology, 2003, 117:53-71)