Impact of errors in the downwelling irradiances on simulations of snow water equivalent, snow surface temperature, and the snow energy balance

Abstract. \\label{sec:abstract} Snow surface temperature is a key control on energy exchanges at the snow surface, particularly net longwave radiation and turbulent energy fluxes. The snow surface temperature is in turn controlled by the balance between various external fluxes and the conductive heat flux, internal to the snowpack. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort to keep snowmelt modeling simple and parsimonious, the Utah Energy Balance (UEB) snowmelt model used only one layer but allowed the snow surface temperature to be different from the snow average temperature by using an equilibrium gradient parameterization based on the surface energy balance. Although this procedure was considered an improvement over the ordinary single layer snowmelt models, it still resulted in discrepancies between modeled and measured snowpack energy contents. In this paper we examine the parameterization of snow surface temperature in single layer snowmelt models from the perspective of heat conduction into a semi-infinite medium. We evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We also introduce a method to adjust effective conductivity to account for the presence of ground near to a shallow snow surface. These parameterizations were tested against data from the Central Sierra Snow Laboratory, CA, Utah State University experimental farm, UT, and Subnivean snow laboratory at Niwot Ridge, CO. These tests compare modeled and measured snow surface temperature, snow energy content, snow water equivalent, and snowmelt outflow. We found that with these refinements the model is able to better represent the snowpack energy balance and internal energy content while still retaining a parsimonious one layer format.

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Modeling the snow surface temperature with a one-layer energy balance snowmelt model

Hydrology and Earth System Sciences ◽

10.5194/hess-18-5061-2014 ◽

2014 ◽

Vol 18 (12) ◽

pp. 5061-5076 ◽

Cited By ~ 9

Author(s):

J. You ◽

D. G. Tarboton ◽

C. H. Luce

Keyword(s):

Energy Balance ◽

Surface Temperature ◽

Snow Water Equivalent ◽

Effective Conductivity ◽

Energy Content ◽

Single Layer ◽

Snow Surface ◽

Snow Surface Temperature ◽

Energy Exchanges ◽

Snowmelt Model

Abstract. Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort to keep snowmelt modeling simple and parsimonious, the Utah Energy Balance (UEB) snowmelt model used only one layer but allowed the snow surface temperature to be different from the snow average temperature by using an equilibrium gradient parameterization based on the surface energy balance. Although this procedure was considered an improvement over the ordinary single layer snowmelt models, it still resulted in discrepancies between modeled and measured snowpack energy contents. In this paper we evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach when they are integrated as part of a complete energy and mass balance snowmelt model. The force-restore and modified force-restore approaches have not been incorporated into the UEB in early versions, even though Luce and Tartoton have done work in calculating the energy components using these approaches. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We introduce a method to adjust effective conductivity to account for the presence of ground near to a shallow snow surface. These parameterizations were tested against data from the Central Sierra Snow Laboratory, CA, Utah State University experimental farm, UT, and subnivean snow laboratory at Niwot Ridge, CO. These tests compare modeled and measured snow surface temperature, snow energy content, snow water equivalent, and snowmelt outflow. We found that with these refinements the model is able to better represent the snowpack energy balance and internal energy content while still retaining a parsimonious one layer format.

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Does Data Availability Constrain Temperature-Index Snow Models? A Case Study in a Humid Boreal Forest

Water ◽

10.3390/w12082284 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2284

Author(s):

Achut Parajuli ◽

Daniel F. Nadeau ◽

François Anctil ◽

Oliver S. Schilling ◽

Sylvain Jutras

Keyword(s):

Surface Temperature ◽

Snow Water Equivalent ◽

Predictive Ability ◽

Data Availability ◽

Snow Surface ◽

Canopy Interception ◽

Eastern Canada ◽

Temperature Index ◽

Snow Surface Temperature ◽

Snow Water

Temperature-index (TI) models are commonly used to simulate the volume and occurrence of meltwater in snow-fed catchments. TI models have varying levels of complexity but are all based on air temperature observations. The quality and availability of data that drive these models affect their predictive ability, particularly given that they are frequently applied in remote environments. This study investigates the performance of non-calibrated TI models in simulating the subcanopy snow water equivalent (SWE) of a small watershed located in Eastern Canada, for which some distinctive observations were collected. Among three relatively simple TI algorithms, the model that performed the best was selected based on the average percent bias (Pbias of 24%) and root mean square error (RMSE of 100 mm w.e.), and was designated as the base TI model. Then, a series of supplemental tests were conducted in order to quantify the performance gain that resulted from including the following inputs/processes to the base TI model: subcanopy incoming radiation, canopy interception, snow surface temperature, sublimation, and cold content. As a final test, all the above modifications were performed simultaneously. Our results reveal that, with the exception of snow sublimation (Pbias of 5.4%) and snow surface temperature, the variables mentioned above were unable to improve TI models within our sites. It is therefore worth exploring other feasible alternatives to existing TI models in complex forested environments.

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Evaluation of alternative formulae for calculation of surface temperature in snowmelt models using frequency analysis of temperature observations

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-6-3863-2009 ◽

2009 ◽

Vol 6 (3) ◽

pp. 3863-3890 ◽

Cited By ~ 3

Author(s):

C. H. Luce ◽

D. G. Tarboton

Keyword(s):

Time Series ◽

Energy Balance ◽

Surface Temperature ◽

Energy Flux ◽

Frequency Analysis ◽

Energy Content ◽

Balance Model ◽

Snow Surface ◽

Fourier Frequency ◽

Snow Surface Temperature

Abstract. The snow surface temperature is an important quantity in the snow energy balance, since it modulates the exchange of energy between the surface and the atmosphere as well as the conduction of energy into the snowpack. It is therefore important to correctly model snow surface temperatures in energy balance snowmelt models. This paper focuses on the relationship between snow surface temperature and conductive energy fluxed that drive the energy balance of a snowpack. Time series of snow temperature at the surface and through the snowpack were measured to examine energy conduction in a snowpack. Based on these measurements we calculated the snowpack energy content and conductive energy flux at the snow surface. We then used these estimates of conductive energy flux to evaluate formulae for the calculation of the conductive flux at the snow surface based on surface temperature time series. We use a method based on Fourier frequency analysis to estimate snow thermal properties. Among the formulae evaluated, we found that a modified force-restore formula, based on the superimposition of the force-restore equation capturing diurnal fluctuations on a gradually changing temperature gradient, had the best agreement with observations of heat conduction. This formula is suggested for the parameterization of snow surface temperature in a full snowpack energy balance model.

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Evaluation of alternative formulae for calculation of surface temperature in snowmelt models using frequency analysis of temperature observations

Hydrology and Earth System Sciences ◽

10.5194/hess-14-535-2010 ◽

2010 ◽

Vol 14 (3) ◽

pp. 535-543 ◽

Cited By ~ 31

Author(s):

C. H. Luce ◽

D. G. Tarboton

Keyword(s):

Time Series ◽

Energy Balance ◽

Surface Temperature ◽

Energy Flux ◽

Frequency Analysis ◽

Energy Content ◽

Balance Model ◽

Snow Surface ◽

Fourier Frequency ◽

Snow Surface Temperature

Abstract. The snow surface temperature is an important quantity in the snow energy balance, since it modulates the exchange of energy between the surface and the atmosphere as well as the conduction of energy into the snowpack. It is therefore important to correctly model snow surface temperatures in energy balance snowmelt models. This paper focuses on the relationship between snow surface temperature and conductive energy fluxes that drive the energy balance of a snowpack. Time series of snow temperature at the surface and through the snowpack were measured to examine energy conduction in a snowpack. Based on these measurements we calculated the snowpack energy content and conductive energy flux at the snow surface. We then used these estimates of conductive energy flux to evaluate formulae for the calculation of the conductive flux at the snow surface based on surface temperature time series. We use a method based on Fourier frequency analysis to estimate snow thermal properties. Among the formulae evaluated, we found that a modified force-restore formula, based on the superimposition of the force-restore equation capturing diurnal fluctuations on a gradually changing temperature gradient, had the best agreement with observations of heat conduction. This formula is suggested for the parameterization of snow surface temperature in a full snowpack energy balance model.

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Evaluating the Utah Energy Balance (UEB) snow model in the Noah land-surface model

Hydrology and Earth System Sciences ◽

10.5194/hess-18-3553-2014 ◽

2014 ◽

Vol 18 (9) ◽

pp. 3553-3570 ◽

Cited By ~ 7

Author(s):

R. Sultana ◽

K.-L. Hsu ◽

J. Li ◽

S. Sorooshian

Keyword(s):

Energy Balance ◽

Surface Temperature ◽

Land Surface ◽

Land Surface Model ◽

Snow Accumulation ◽

Model Systems ◽

Surface Model ◽

Snow Surface ◽

Snow Surface Temperature ◽

Snow Model

Abstract. Noah (version 2.7.1), the community land-surface model (LSM) of National Centers for Environmental Predictions-National Center for Atmospheric Research (NCEP-NCAR), which is widely used to describe the land-surface processes either in stand-alone or in coupled land-atmospheric model systems, is recognized to underestimate snow–water equivalent (SWE). Noah's SWE bias can be attributed to its simple snow sub-model, which does not effectively describe the physical processes during snow accumulation and melt period. To improve SWE simulation in the Noah LSM, the Utah Energy Balance (UEB) snow model is implemented in Noah to test alternate snow surface temperature and snowmelt outflow schemes. Snow surface temperature was estimated using the force-restore method and snowmelt event is regulated by accounting for the internal energy of the snowpack. The modified Noah's SWE simulations are compared with the SWE observed at California's NRCS SNOTEL stations for 7 water years: 2002–2008, while the model's snow surface temperature is verified with observed surface-temperature data at an observation site in Utah. The experiments show that modification in Noah's snow process substantially reduced SWE estimation bias while keeping the simplicity of the Noah LSM. The results suggest that the model did not benefit from the alternate temperature representation but primary improvement can be attributed to the substituted snowmelt process.

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<i>ESCIMO.spread</i> – a spreadsheet-based point snow surface energy balance model to calculate hourly snow water equivalent and melt rates for historical and changing climate conditions

Geoscientific Model Development Discussions ◽

10.5194/gmdd-3-627-2010 ◽

2010 ◽

Vol 3 (2) ◽

pp. 627-649 ◽

Cited By ~ 2

Author(s):

U. Strasser ◽

T. Marke

Keyword(s):

Energy Balance ◽

Snow Water Equivalent ◽

Winter Season ◽

Longwave Radiation ◽

Energy Balance Model ◽

Balance Model ◽

Snow Surface ◽

Point Energy ◽

Climate Conditions ◽

Snow Water

Abstract. This paper describes the spreadsheet-based point energy balance model ESCIMO.spread which simulates the energy and mass balance as well as melt rates of a snow surface. The model makes use of hourly recordings of temperature, precipitation, wind speed, relative humidity, global and longwave radiation. The effect of potential climate change on the seasonal evolution of the snow cover can be estimated by modifying the time series of observed temperature and precipitation by means of adjustable parameters. Model output is graphically visualized in hourly and daily diagrams. The results compare well with weekly measured snow water equivalent (SWE). The model is easily portable and adjustable, and runs particularly fast: hourly calculation of a one winter season is instantaneous on a standard computer. ESICMO.spread can be obtained from the authors on request (contact: [email protected]).

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<i>ESCIMO.spread</i> – a spreadsheet-based point snow surface energy balance model to calculate hourly snow water equivalent and melt rates for historical and changing climate conditions

Geoscientific Model Development ◽

10.5194/gmd-3-643-2010 ◽

2010 ◽

Vol 3 (2) ◽

pp. 643-652 ◽

Cited By ~ 19

Author(s):

U. Strasser ◽

T. Marke

Keyword(s):

Energy Balance ◽

Snow Water Equivalent ◽

Winter Season ◽

Longwave Radiation ◽

Energy Balance Model ◽

Balance Model ◽

Snow Surface ◽

Point Energy ◽

Climate Conditions ◽

Snow Water

Abstract. This paper describes the spreadsheet-based point energy balance model ESCIMO.spread which simulates the energy and mass balance as well as melt rates at the snow surface. The model makes use of hourly recordings of temperature, precipitation, wind speed, relative humidity, and incoming global and longwave radiation. The effect of potential climate change on the seasonal evolution of the snow cover can be estimated by modifying the time series of observed temperature and precipitation by means of adjustable parameters. Model output is graphically visualized in hourly and daily diagrams. The results compare well with weekly measured snow water equivalent (SWE). The model is easily portable and adjustable, and runs particularly fast: an hourly calculation of a one winter season is instantaneous on a standard computer. ESCIMO.spread can be obtained from the authors on request.

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Longwave Radiation on Snow-Covered Mountainous Surfaces

Journal of Applied Meteorology ◽

10.1175/1520-0450-36.6.818 ◽

1997 ◽

Vol 36 (6) ◽

pp. 818-824 ◽

Cited By ~ 50

Author(s):

Christian Plüss ◽

Atsumu Ohmura

Keyword(s):

Energy Balance ◽

Surface Temperature ◽

Longwave Radiation ◽

Radiation Balance ◽

Snow Surface ◽

Atmospheric Conditions ◽

Efficient Calculation ◽

Snow Surface Temperature ◽

Sensitivity Studies ◽

Alpine Environments

Abstract Longwave radiation in snow-covered alpine environments was investigated based on LOWTRAN7 calculations. The irradiance from the sky and from the surrounding topography were determined separately in order to detect the influence of the topography on longwave radiation balance. Sensitivity studies showed that the irradiance from the surrounding terrain is determined primarily by the atmospheric conditions within the investigated area and by the surface temperature of the surrounding terrain. In snow-covered environments, the air temperature is usually above the snow surface temperature and the effects of the air between the topography and the receiving surface may be relevant. Longwave irradiance from the surrounding terrain is an important component of the energy balance at the snow surface on inclined slopes and should be considered for areal investigations. A simple parameterization that accounts for the effects of the air is proposed for efficient calculation of longwave irradiance from snow-covered topography.

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Improving the snow physics of WEB-DHM and its point evaluation at two SnowMIP alpine sites

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-7-3481-2010 ◽

2010 ◽

Vol 7 (3) ◽

pp. 3481-3519 ◽

Cited By ~ 1

Author(s):

M. Shrestha ◽

L. Wang ◽

T. Koike ◽

Y. Xue ◽

Y. Hirabayashi

Keyword(s):

Surface Temperature ◽

Liquid Water ◽

Snow Depth ◽

Hydrological Model ◽

Snow Water Equivalent ◽

Bias Error ◽

Snow Albedo ◽

Basin Scale ◽

Snow Water ◽

Snow Physics

Abstract. The snow physics of a distributed biosphere hydrological model, referred to as the Water and Energy Budget based Distributed Hydrological Model (WEB-DHM) is improved by incorporating the three-layer physically based energy balance snowmelt model of Simplified Simple Biosphere 3 (SSiB3) and the Biosphere-Atmosphere Transfer Scheme (BATS) albedo scheme. WEB-DHM with improved snow physics (WEB-DHM-S) can simulate the variability of snow density, snow depth and snow water equivalent, liquid water and ice content in each layer, prognostic snow albedo, diurnal variation in snow surface temperature, thermal heat due to conduction and liquid water retention. The performance of WEB-DHM-S is evaluated at two alpine sites of the Snow Model Intercomparison Project with different climate characteristics: Col de Porte in France and Weissfluhjoch in Switzerland. The simulation results of the snow depth, snow water equivalent, surface temperature, snow albedo and snowmelt runoff reveal that WEB-DHM-S is capable of simulating the internal snow process better than the original WEB-DHM, with the root mean square error and bias error being remarkably reduced. Although WEB-DHM-S is only evaluated at a point scale for the simulation of snow processes, this study provides a benchmark for the application of WEB-DHM-S in cold regions in the assessment of the basin-scale snow water equivalent and seasonal discharge simulation for water resources management.

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