scholarly journals A distributed surface energy-balance model for a small valley glacier. I. Development and testing for Haut Glacier d’ Arolla, Valais, Switzerland

1996 ◽  
Vol 42 (140) ◽  
pp. 77-89 ◽  
Author(s):  
N.S. Arnold ◽  
I.C. Willis ◽  
M.J. Sharp ◽  
K.S. Richards ◽  
W.J. Lawson

AbstractThis paper describes the development and testing of a distributed surface energy-balance model used to calculate rates of surface melting at Haut Glacier d’Arolla, Valais, Switzerland. The model uses a digital elevation model (DEM) of the glacier surface and surrounding topography together with meterological data collected at a site in front of the glacier to determine hourly or daily totals of the energy-balance components and hence of melting over the entire surface of the glacier with a spatial resolution of 20 m. The model can also be used to determine temporal and spatial variations in snow depth, snow-line position and glacier surface albedo. Calculations from the model are compared with observations made along the glacier centre line 1990, and in general the model performs very well. The correlation coefficients between calculated and measured snow-line elevation, albedo and ablation are 0.99, 0.85 and 0.81, respectively. The main source of error between modelled and measured values of these variables is probably inadequacies in the parameterization of albedo used in the model.

1996 ◽  
Vol 42 (140) ◽  
pp. 77-89 ◽  
Author(s):  
N.S. Arnold ◽  
I.C. Willis ◽  
M.J. Sharp ◽  
K.S. Richards ◽  
W.J. Lawson

AbstractThis paper describes the development and testing of a distributed surface energy-balance model used to calculate rates of surface melting at Haut Glacier d’Arolla, Valais, Switzerland. The model uses a digital elevation model (DEM) of the glacier surface and surrounding topography together with meterological data collected at a site in front of the glacier to determine hourly or daily totals of the energy-balance components and hence of melting over the entire surface of the glacier with a spatial resolution of 20 m. The model can also be used to determine temporal and spatial variations in snow depth, snow-line position and glacier surface albedo. Calculations from the model are compared with observations made along the glacier centre line 1990, and in general the model performs very well. The correlation coefficients between calculated and measured snow-line elevation, albedo and ablation are 0.99, 0.85 and 0.81, respectively. The main source of error between modelled and measured values of these variables is probably inadequacies in the parameterization of albedo used in the model.


2005 ◽  
Vol 51 (172) ◽  
pp. 25-36 ◽  
Author(s):  
Regine Hock ◽  
Björn Holmgren

AbstractA grid-based surface energy-balance mass-balance model has been developed to simulate snow- and ice melt in mountainous regions with an hourly resolution. The model is applied to Storglaciären, a valley glacier in Sweden, using a 30 m resolution digital elevation model. Emphasis is directed towards computing the radiation components. These are modelled individually, considering the effects of slope angle, aspect and effective horizon. A new parameterization for snow albedo is suggested, modifying the albedo of the preceding hour as a function of time after snowfall, air temperature and cloudiness. The model is used to provide the meltwater input for discharge modelling and to assess the influence of the individual components on melt. Results are validated by means of observed melt rates, patterns of snow-line retreat and proglacial discharge. In general, simulations are in good agreement with observations. In particular, the diurnal and seasonal fluctuations of discharge are simulated remarkably well.


2020 ◽  
pp. 1-16
Author(s):  
Tim Hill ◽  
Christine F. Dow ◽  
Eleanor A. Bash ◽  
Luke Copland

Abstract Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing models by: (1) deriving high-resolution (30 m) surface albedo from Landsat 8 imagery, (2) calculating shadows cast onto the glacier surface by high-relief topography to model incident shortwave radiation, (3) developing an algorithm to map debris sufficiently thick to insulate the glacier surface and (4) presenting a formulation of the SEB model coupled to a subsurface heat conduction model. We drive the model with 6 years of in situ meteorological data from Kaskawulsh Glacier and Nàłùdäy (Lowell) Glacier in the St. Elias Mountains, Yukon, Canada, and validate outputs against in situ measurements. Modelled seasonal melt agrees with observations within 9% across a range of elevations on both glaciers in years with high-quality in situ observations. We recommend applying the model to investigate the impacts of surface melt for individual glaciers when sufficient input data are available.


2009 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Luis Octavio Lagos ◽  
Derrel L. Martin ◽  
Shashi B. Verma ◽  
Andrew Suyker ◽  
Suat Irmak

2009 ◽  
Vol 48 (4) ◽  
pp. 693-715 ◽  
Author(s):  
Toru Kawai ◽  
Mohammad Kholid Ridwan ◽  
Manabu Kanda

Abstract The authors’ objective was to apply the Simple Urban Energy Balance Model for Mesoscale Simulation (SUMM) to cities. Data were selected from 1-yr flux observations conducted at three sites in two cities: one site in Kugahara, Japan (Ku), and two sites in Basel, Switzerland (U1 and U2). A simple vegetation scheme was implemented in SUMM to apply the model to vegetated cities, and the surface energy balance and radiative temperature TR were evaluated. SUMM generally reproduced seasonal and diurnal trends of surface energy balance and TR at Ku and U2, whereas relatively large errors were obtained for the daytime results of sensible heat flux QH and heat storage ΔQS at U1. Overall, daytime underestimations of QH and overestimations of ΔQS and TR were common. These errors were partly induced by the poor parameterization of the natural logarithm of the ratio of roughness length for momentum to heat (κB−1); that is, the observed κB−1 values at vegetated cities were smaller than the simulated values. The authors proposed a new equation for predicting this coefficient. This equation accounts for the existence of vegetation and improves the common errors described above. With the modified formula for κB−1, simulated net all-wave radiation and TR agreed well with observed values, regardless of site and season. However, at U1, simulated QH and ΔQS were still overestimated and underestimated, respectively, relative to observed values.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1747 ◽  
Author(s):  
Camilo Souto ◽  
Octavio Lagos ◽  
Eduardo Holzapfel ◽  
Mahesh Lal Maskey ◽  
Lynn Wunderlich ◽  
...  

A surface energy balance model was conceived to estimate crop transpiration and soil evaporation in orchards and vineyards where the floor is partially wetted by micro-irrigation systems. The proposed surface energy balance model for partial wetting (SEB-PW) builds upon previous multiple-layer modelling approaches to estimate the latent, sensible, and soil heat fluxes, while partitioning the total evapotranspiration ( E T ) into dry and wet soil evaporation ( λ E s o i l ) and crop transpiration ( T ). The model estimates the energy balance and flux resistances for the evaporation from dry and wet soil areas below the canopy, evaporation from dry and wet soil areas between plant rows, crop transpiration, and total crop E T . This article describes the model development, sensitivity analysis and a preliminary model evaluation. The evaluation shows that simulated hourly E T values have a good correlation with field measurements conducted with the surface renewal method and micro-lysimeter measurements in a micro-irrigated winegrape vineyard of Northern California for a range of fractional crop canopy cover conditions. Evaluation showed that hourly L E estimates had root mean square error ( R M S E ) of 58.6 W m−2, mean absolute error ( M A E ) of 35.6 W m−2, Nash-Sutcliffe coefficient ( C N S ) of 0.85, and index of agreement ( d a ) of 0.94. Daily soil evaporation ( E s ) estimations had R M S E of 0.30 mm d−1, M A E of 0.24 mm d−1, C N S of 0.87, and d a of 0.94. E s estimation had a coefficient of determination ( r 2 ) of 0.95, when compared with the micro-lysimeter measurements, which showed that E s can reach values from 28% to 46% of the total E T after an irrigation event. The proposed SEB-PW model can be used to estimate the effect and significance of soil evaporation from wet and dry soil areas on the total E T , and to inform water balance studies for optimizing irrigation management. Further evaluation is needed to test the model in other partially wetted orchards and to test the model performance during all growing seasons and for different environmental conditions.


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