Climate Modeling


I have specific modeling experience with general circulation models (GCMs) and regional climate models (RCMs).  Most of my research with these models has focused on paleoclimate simulations and data-model comparisons, especially during the Holocene and Last Glacial Maximum (LGM).  I used the National Center for Atmospheric Research (NCAR) Community Climate Model Version 1 (CCM1) to explore the sensitivity of the climate system to different forcing mechanisms, such as ice sheets, orbital insolation, and atmospheric CO2 increases (Felzer et al., 1995, 1996, 1998, 1999) and the GENESIS model to study the hydrology of the paleoArctic environment (Felzer et al., 2000; Felzer, 2001).  During my postdoctoral research at the National Center for Atmospheric Research (NCAR), I enhanced an existing RCM (the Arctic Regional Climate System Model, ARCSyM) to model the hydrological system of the North Atlantic basin (Felzer and Thompson, 2001).  The RCM was nested within the European Centre for Medium-range Weather Forecasts (ECMWF) reanalysis to provide the meteorological drivers at the boundaries of a region with steep topographic and coastal gradients to evaluate the precipitation and storm tracks.  I also have some experience with developing one of the early heat flux correction models for the NCAR CSM, because many paleoclimate simulations at the time were run without fully dynamic ocean models.


In my role as a Climate Scenarios Coordinator for the U.S. National Assessment, I was responsible for interacting with scientists and stakeholders from regions across the United States to explain the simulations and proper use of climate model scenarios (NAST, 2000; MacCracken et al., 2003).  My work focused on understanding the climate processes responsible for regional anomalies within global warming scenarios (Felzer and Heard, 1999).  These scenarios were used by stakeholders and scientists to develop coping strategies for dealing with the consequences of climate change. 


Below are results from Lee et al. (2013) in which we used the latest NCAR model, CESM, on my own Beowulf cluster, Lehigh’s Corona cluster, and NSF’s Yellowstone cluster.  These experiments involve changes to the CLM-CN land model to explore the role of carbon dynamics in the coupled land-atmosphere system.



Figure 1: Improvement of CLM4-CN by using N-limited GPP for determination of stomatal conductance, and comparions to observed runoff values from GSWP2 (Global Soil Wetness Project 2).  Evaluations of CLM4-CN control and downregulation with GSWP2 for total runoff (mm/year), a) FLUXNET MTE, b) Control, c) Control – FLUXNET MTE, d) Downregulation – Control.


I am also currently working with graduate student Travis Andrews to test the hypothesis that irrigation in the Great Plains and Midwestern U.S. has an impact on precipitation in the Northeast U.S., using the NCAR CESM model (CAM-CLM) by conducting experiments with and without irrigation.





Felzer, B., R. J. Oglesby, H. Shao, T. Webb III, D. Hyman, W. L. Prell and J. E. Kutzbach (1995). "A systematic study of GCM sensitivity to latitudinal changes in solar radiation." Journal of Climate 8: 877-887.


Felzer, B., R.J. Oglesby, T. Webb III, and D. Hyman (1996). "Sensitivity of a general circulation model to changes in northern hemisphere ice sheets", Journal of Geophysical Research 101(D14): 19077-19092.


Felzer, B.,T. Webb III, and R.J. Oglesby (1998). "The impact of ice sheets, CO2, and orbital insolation on late Quaternary climates: Sensitivity experiments with a general circulation model", Quaternary Science Reviews, 17: 507-534.


Felzer, B., T. Webb III, and R. J. Oglesby (1999). "Climate model sensitivity to changes in boundary conditions during the Last Glacial Maximum", Paleoclimates: Data and Modeling, 3(4): 257-278 .


Felzer, B. and P. S. Heard (1999). "Precipitation differences amongst GCMs used for the U.S. National Assessment", Journal of the American Water Resources Association, 35(6): 1327-1339.


Felzer, B., Thompson, S. L., Pollard, D., and J. C. Bergengren. (2000). "GCM-simulated hydrology in the Arctic during the past 21,000 years", Journal of Paleolimnology, 24: 15-28.


Felzer, B. (2001). "Climate impacts of an ice sheet in East Siberia during the Last Glacial Maximum", Quaternary Science Reviews, 20: 437-447.


Felzer, B. and S. L. Thompson. (2001). “Evaluation of a regional climate model for paleoclimate applications in the Arctic”, Journal of Geophysical Research, 106(D21): 27407-27424.


MacCracken, M. C., Barron, E. J., Easterling, D. R., Felzer, B. S., and Karl, T. R. (2003). “Climate change scenarios for the U.S. National Assessment”, Bulletin of the American Meteorological Society, DOI: 10.1175/BAMS-84-12-1711.


National Assessment Synthesis Team. (2000). “Climate change impacts on the United States: the potential consequences of climate variability and change”, prepared as part of the USGCRP for the NSTC and the U.S. Congress, Overview and Climate Foundation chapter.


Lee, E., Barford, C. L., Kucharik, C. J., Felzer, B. S., Foley, J. A. 2011. Role of turbulent heat fluxes over land in the monsoon over East Asia. International Journal of Geosciences, 2: 420-431.


Lee, E. and Felzer, B. S. 2013. Effects of Nitrogen Limitation on Hydrological Processes in CLM4-CN. Journal of Advances in Modeling Earth Systems. 5(4): 741-754. doi:10.1002/jame.20046.