David G. Tarboton
Professor, Civil and Environmental Engineering
Utah State University
david.tarboton<at symbol>usu.edu


Utah Energy Balance (UEB) Snow Model

The Utah Energy Balance (UEB) snow model is an energy balance snowmelt model developed by David Tarboton's research group - and updated over the years. The model uses a lumped representation of the snowpack and keeps track of water and energy balance. The model is driven by inputs of air temperature, precipitation, wind speed, humidity and radiation at time steps sufficient to resolve the diurnal cycle (hourly or six hourly). The model uses physically-based calculations of radiative, sensible, latent and advective heat exchanges. In the latest versions a force-restore approach is used to represent surface temperature, accounting for differences between snow surface temperature and average snowpack temperature without having to introduce additional state variables. Melt outflow is a function of the liquid fraction, using Darcy's law. This allows the model to account for continued outflow even when the energy balance is negative. Because of its parsimony (few state variables - but increasing with later versions) this model is suitable for application in a distributed fashion on a grid over a watershed.There are a number of versions available. The more recent versions are recommended.

UEBGrid - Development Version (9/9/2012)

To facilitate collaboration and open development of UEB, I have created a Bitbucket code repository. The repository, issue tracker and wiki are public which means that anyone can access the source code and comment on issues. If you would like to contribute to and commit source code changes please email me (dtarb@usu.edu). The repository is at http://bitbucket.org/dtarb/ueb. There are some instructions for getting started using UEB from this repository under the source tab in Documentation.

UEBVeg (Posted 4/7/2012)

This version incorporates a parameterization of vegetation developed by Vinod Mahat. The improvements are described in

Mahat, V., (2011), "Effect of Vegetation on the Accumulation and Melting of Snow at the TW Daniels Experimental Forest," Ph.D. Dissertation, Civil and Environmental Engineering, Utah State University, http://digitalcommons.usu.edu/etd/1078, 181 pp.

Mahat, V. and D. G. Tarboton, (2012), "Canopy radiation transmission for an energy balance snowmelt model," Water Resour. Res., 48: W01534, http://dx.doi.org/10.1029/2011WR010438. [PDF 1.2 MB with notes on some corrections to published WRR version]. Correction http://dx.doi.org/10.1029/2012WR011964.

Updated documentation for this version has not been written. The input and output files are mostly the same as earlier versions - so the users guide for the original version below is still a good starting point in working with UEBVeg. However users should refer to the code to be certain how inputs are being used and what the output is. This is "research" code provided "as is" in the hopes that it may be useful to you. I can not guarantee that I will have time to respond to questions on its use, but I will try.

Version 2.2 (Posted around 2008)

This version adopted the Force-Restore approach for representing surface temperature and introduced a parameterization of the refreezing of liquid water near the surface. These and other improvements are described in

You, J., (2004), "Snow Hydrology: The Parameterization of Subgrid Processes within a Physically Based Snow Energy and Mass Balance Model," PhD Dissertation, Civil and Environmental Engineering, Utah State University.

Luce, C. H., (2000), "Scale Influences on the Representation of Snowpack Processes," PhD Dissertation, Civil and Environmental Engineering, Utah State University, 188 pp.

There is also a "lumped" version that applies the depletion curve parameterization developed in these dissertations.

Updated documentation for this new version has not been written. The input and output files are mostly the same as for the original version - so the users guide for the original version below is still a good starting point in working with UEB 2. However users should refer to the code to be certain how inputs are being used and what the output is. This is "research" code provided "as is" in the hopes that it may be useful to you. I can not guarantee that I will have time to respond to questions on its use, but I will try.

Original Version (posted around 1997)

The Utah Energy Balance (UEB) snow model is an energy balance snowmelt model developed by David G. Tarboton, Charlie H. Luce, Tanveer G. Chowdhury and Tom H. Jackson for the prediction of snowmelt surface water input rates. The model uses a lumped representation of the snowpack with two primary state variables, namely, water equivalence and energy content relative to a reference state of water in the ice phase at 0 C. This energy content is used to determine snowpack average temperature or liquid fraction. Snow surface age is retained as a third state variable, used for the calculation of albedo. The model is driven by inputs of air temperature, precipitation, wind speed, humidity and radiation at time steps sufficient to resolve the diurnal cycle (hourly or six hourly). The model uses physically-based calculations of radiative, sensible, latent and advective heat exchanges. An equilibrium parameterization of snow surface temperature accounts for differences between snow surface temperature and average snowpack temperature without having to introduce additional state variables. Melt outflow is a function of the liquid fraction, using Darcy's law. This allows the model to account for continued outflow even when the energy balance is negative. Because of its parsimony (only three state variables) this model is suitable for application in a distributed fashion on a grid over a watershed.

Source Code [Unix tar file. or PC Zip file.]

Presentation

  • Lecture on the Utah Energy Balance Snowmelt model presented to Snow Hydrology Class, March 2, 2004 [Powerpoint (5MB), Streaming Video (1 hr 11 min)]

    Papers

  • Mahat, V., D. G. Tarboton and N. P. Molotch, (2013), "Testing above and below canopy representations of turbulent fluxes in an energy balance snowmelt model," Water Resources Research, 49(2): 1107-1122, , http://dx.doi.org/10.1002/wrcr.20073. [PDF 7 MB]
  • Mahat, V. and D. G. Tarboton, (2012), "Canopy radiation transmission for an energy balance snowmelt model," Water Resour. Res., 48: W01534, http://dx.doi.org/10.1029/2011WR010438. [PDF 1.2 MB with notes on some corrections to published WRR version]
  • Mahat, V. and D. G. Tarboton, (2010), "Modeling the effect of vegetation on the accumulation and melting of snow," 78th Annual Meeting Western Snow Conference. Adaptive Water Management in a Changing Climate, Logan, Utah, July 19-21, http://www.westernsnowconference.org/proceedings/2010.htm. [PDF 0.3 MB]
  • Luce, C. H. and D. G. Tarboton, (2010), "Evaluation of alternative formulae for calculation of surface temperature in snowmelt models using frequency analysis of temperature observations," Hydrol. Earth Syst. Sci., 14(3): 535-543, http://www.hydrol-earth-syst-sci.net/14/535/2010/.
  • Luce, C. H. and D. G. Tarboton, (2004), "The Application of Depletion Curves for Parameterization of Subgrid Variability of Snow," Hydrological Processes, 18: 1409-1422, DOI: 10.1002/hyp.1420. [PDF 364K]
  • Luce, C. H. and D. G. Tarboton, (2001),"Modeling Snowmelt Over an Area:  Modeling Subgrid Scale Heterogeneity in Distributed Model Elements," Proceedings of MODSIM 2001, International Congress on Modelling and Simulation, Canberra, Australia, December 10-13, p.341-346. [PDF (0.4 MB)]
  • Luce, C. H. and D. G. Tarboton, (2001),"A Modified Force-Restore Approach to Modeling Snow-Surface Heat Fluxes," Proceedings of the 69th Annual Western Snow Conference, Sun Valley, Idaho. [PDF (0.5MB)]
  • Tarboton, D. G., G. Blöschl, K. Cooley, R. Kirnbauer and C. Luce, (2000), "Spatial Snow Cover Processes at Kühtai and Reynolds Creek," Chapter 7 in  Spatial Patterns in Catchment Hydrology: Observations and Modelling, Edited by R. Grayson and G. Blöschl, Cambridge University Press, Cambridge, p.158-186. [PDF (5.8 MB)]
  • Luce, C. H., D. G. Tarboton and K. R. Cooley, (1999), "Subgrid Parameterization Of Snow Distribution For An Energy And Mass Balance Snow Cover Model," Hydrological Processes, 13: 1921-1933, special issue from International Conference on Snow Hydrology, Brownsville, Vermont, 6-9 October, 1998. [PDF (388KB), Wiley Reprint]
  • Luce, C. H., D. G. Tarboton and K. R. Cooley, (1998), "The Influence of the Spatial Distribution of Snow on Basin-Averaged Snowmelt," Hydrological Processes, 12(10-11): 1671-1683. [PDF (414KB), Wiley Reprint]
  • Luce, C. H., D. G. Tarboton and K. R. Cooley, (1997),"Spatially Distributed Snowmelt Inputs to a Semi-Arid Mountain Watershed," in Proceedings of the Western Snow Conference, Banff, Canada, May 5-8, 1997. [PDF (112K)]
  • Tarboton, D. G. and C. H. Luce, (1996), "Utah Energy Balance Snow Accumulation and Melt Model (UEB)," Computer model technical description and users guide, Utah Water Research Laboratory and USDA Forest Service Intermountain Research Station. [PDF Text only (.128 MB), with graphics (3.5 MB)]
  • Tarboton, D. G., T. G. Chowdhury and T. H. Jackson, (1995),"A Spatially Distributed Energy Balance Snowmelt Model," in Biogeochemistry of Seasonally Snow-Covered Catchments, ed. K. A. Tonnessen et al., Proceedings of a Boulder Symposium, July 3-14, IAHS Publ. no. 228, p.141-155. [PDF (228 K) , Postscript (3MB) ]
  • Tarboton, D. G., (1994),"Measurement and Modeling of Snow Energy Balance and Sublimation From Snow," in Proceedings, International Snow Science Workshop, Snowbird, Utah, October 31 to November 2, Utah Water Research Laboratory working paper no. WP-94-HWR-DGT/002.