Kevin Schaefer

Research Scientist I

PhD, Colorado State University, 2004

Specialties [top]

Remotely-sensed snow cover; vegetation phenology; soil freeze/thaw dynamics

Recent Highlights and Upcoming Expeditions [top]

• July 2009: Schaefer traveled to the North Slope of Alaska to study the carbon content in permafrost.
• March 2007: Submitted paper describing the reemergence of past soil temperature anomalies. In seasonally frozen soils, anomalous heat can be stored, isolated from diffusion processes, as variations in the amount of ground ice. Warmer soils in autumn result in shallower freeze depths in winter, requiring less energy to thaw in spring, and resulting in warmer soils the following summer. Coauthors are Tingjun Zhang (NSIDC), Pieter Tans (NOAA), Reto Stöckli (Colorado State University).
• January 2007: Participated in North American Carbon Program (NACP) investigators meeting in Colorado Springs. NACP has funded Tingjun Zhang and me to investigate how snow depth, soil temperature, freeze depth, and other winter conditions influence terrestrial plant uptake, decay, and biomass.
• April 2006: Submitted final revisions for a paper describing the Simple Biosphere/Carnegie-Ames-Stanford Approach (SiBCASA) terrestrial carbon cycle model. SiBCASA is a hybrid biophysical/biogeochemical model capable of estimating terrestrial carbon fluxes and biomass from diurnal to decadal time scales.

Current Research [top]

• Evaluating long-term soil temperature records to investigate the conditions required for soil temperature reemergence.
• Investigating techniques to use remotely sensed snow cover data to remove snow cover bias from Normalized Difference Vegetation Index (NDVI). The burial of vegetation by snow can be misinterpreted as an annual loss of vegetation in NDVI
• Improving representation of planting, growth, and harvest for agriculture ecosystems in the SiBCASA land surface parameterization. Agricultural ecosystems are highly managed and models need improved techniques to simulate crop phenology.

Current Projects [top]

Carbon Data Assimilation

Flux Tower Spatial Coherence

Impacts of Soil Freeze/Thaw Dynamics on the North American Carbon Cycle

Activities [top]

Member, American Geophysical Union (AGU)

Member, American Association for the Advancement of Science (AAAS)

Publications [top]

2010

Peters, W., M. C. Krol, G. R. van der Werf, S. Houweling, C. D. Jones, J. Hughes, K. Schaefer, et al. 2010. Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations. Global Change Biology 16(4): 1,317-1,337, doi:10.1111/j.1365-2486.2009.02078.x.

Schwalm, C. R., C. A. Williams, K. Schaefer, et al. 2010. Assimilation exceeds respiration sensitivity to drought: A FLUXNET synthesis. Global Change Biology 16(2): 657-670, doi:10.1111/j.1365-2486.2009.01991.x.

2009

Lokupitiya, E. S. Denning, K. Paustian, I. Baker, K. Schaefer, S. Verma, T. Meyers, C. J. Bernacchi, A. Suyker, and M. Fischer. 2009. Incorporation of crop phenology in simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands. Biogeosciences (6): 969-986.

Schaefer, K., T. Zhang, A. G. Slater, L. Lu, A. Etringer, and I. Baker. 2009. Improving simulated soil temperatures and soil freeze/thaw at high-latitude regions in the Simple Biosphere/Carnegie-Ames-Stanford Approach model. Journal of Geophysical Research 114, F02021, doi:10.1029/2008JF001125.

2008

Schaefer, K., G. J. Collatz, P. Tans, A. S. Denning, I. Baker, J. Berry, L. Prihodko, N. Suits, and A. Philpott. 2008. Combined Simple Biosphere/Carnegie-Ames-Stanford Approach terrestrial carbon cycle model. Journal of Geophysical Research 113, G03034, doi:10.1029/2007JG000603.

2007

Schaefer, K., T. Zhang, P. P. Tans, and R. Stöckli. 2007. Temperature anomaly reemergence in seasonally frozen soils. Journal of Geophysical Research 12, D20102, doi:10.1029/2007JD008630.

2005

Schaefer, K., A. S. Denning, and O. Leonard. 2005. The winter Arctic Oscillation, the timing of spring, and carbon fluxes in the Northern Hemisphere. Global Biogeochemical Cycles 19, GB3017, doi:10.1029/2004GB002336.

2004

Schaefer K., A. S. Denning, and O. Leonard. 2004. The winter Arctic Oscillation and the timing of snowmelt in Europe. Geophysical Research Letters 31(22), L22205.

2003

McNoldy, B., A. Chen, Z. Eitzen, R. Moore, J. Persing, K. Schaefer, and W. Schubert. 2003. Design and construction of an affordable rotating table for classroom demonstrations of geophysical fluid dynamics principles. Bulletin of the American Meteorological Society 84(12): 1,827-1,834, doi:10.1175/BAMS-84-12-1827.

Schaefer, K., A. S. Denning, N. Suits, J. Kaduk, I. Baker, S. Los, and L. Prihodko. 2002. Effect of climate on interannual variability of terrestrial CO2 fluxes. Global Biogeochemical Cycles 16(4), doi:10.1029/2002GB001928.

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Related Resources[top]

Cooperative Institute for Environmental Sciences (CIRES)