scholarly journals Internal accumulation on Storglaciären, Sweden, in a multi-layer snow model coupled to a distributed energy- and mass-balance model

2008 ◽  
Vol 54 (184) ◽  
pp. 61-72 ◽  
Author(s):  
Carleen H. Reijmer ◽  
Regine Hock

AbstractTo investigate the internal accumulation on Storglaciären, Sweden, we couple a multi-layer snow model to a distributed energy- and mass-balance model. The snow model describes the temperature, density and water-content evolution of the snow/ice pack and includes the processes of percolation and refreezing of water. The model is run for the period 9 May–2 September 1999 and validated against weather station and mass-balance observations on the glacier. The model performs reasonably well, with an average summer mass balance for the location of stake observations of –1.56 m w.e. compared to –1.59 m w.e. observed. However, the amount of melt is overestimated in the higher parts of the accumulation area and underestimated in the lower parts of the ablation area. The modelled mass balance is most sensitive to the albedo parameterization, the chosen momentum and scalar roughness lengths and all parameters related to snowfall. The modelled internal accumulation is +0.25 m w.e., which amounts to about 20% of the winter accumulation and results in a positive net balance for 1999 of +0.23 m w.e. The modelled internal accumulation is most sensitive to the initial subsurface temperature profile and the irreducible water content.

2008 ◽  
Vol 9 (4) ◽  
pp. 695-711 ◽  
Author(s):  
Nick Rutter ◽  
Don Cline ◽  
Long Li

Abstract The National Operational Hydrologic Remote Sensing Center (NOHRSC) Snow Model (NSM) is an energy- and mass-balance model used by the National Oceanic and Atmospheric Administration’s National Weather Service for moderate-resolution spatially distributed snow analysis and data assimilation over the United States. The NSM was evaluated in a one-dimensional mode using meteorological and snowpit observations from five sites in Colorado collected during 2002–03. Four parameters estimated by the NSM [snow water equivalent (SWE), snow depth, average snowpack temperature, and snow surface temperature] were compared with snowpit observations and with estimates from another snow energy and mass-balance model, SNTHERM. Root-mean-squared differences (RMSDs) between snowpit SWE observations (January–June) at all sites and estimates from the NSM were about 11% (RMSD = 0.073 m) of the average maximum observed SWE from all sites of 0.694 m. SNTHERM exhibited only a slightly better agreement (RMSD = 0.066 m). During the winter and early spring period before snowpacks became isothermal at 273.15 K, both NSM and SNTHERM simulated significantly cooler average snowpack temperatures than observed (RMSD = 3 and 2 K, respectively). During this snow accumulation period estimates of SWE by both models were very similar. Differences in modeled SWE were traced to short periods (5–21 days) during isothermal conditions in early spring when the two models diverged. These events caused SWE differences that persisted throughout the ablation period and resulted in a range in melt-out times of 0.2–7.2 days between depth observations and modeled estimates. The divergence in SWE resulted from differences in snowmelt fluxes estimated by the two models, which are suggested to result from 1) liquid water fractions within a snowpack being estimated by the NSM using an internal energy method and by SNTHERM using a semiempirical temperature-based approach, and 2) SNTHERM, but not the NSM, accounting for the small liquid water fraction that coexists in equilibrium with snow when the snowpack surface is dry (<273.15 K).


Author(s):  
Linden B. Huhmann ◽  
Charles F. Harvey ◽  
Ana Navas-Acien ◽  
Joseph Graziano ◽  
Vesna Slavkovich ◽  
...  

1990 ◽  
Vol 26 (5) ◽  
pp. 1079-1092 ◽  
Author(s):  
Richard Barry ◽  
Marcel Prévost ◽  
Jean Stein ◽  
Andre P. Plamondon

1999 ◽  
Vol 45 (151) ◽  
pp. 559-567 ◽  
Author(s):  
Rijan Bhakta Kayastha ◽  
Tetsuo Ohata ◽  
Yutaka Ageta

AbstractA mass-balance model based on the energy balance at the snow or ice surface is formulated, with particular attention paid to processes affecting absorption of radiation. The model is applied to a small glacier, Glacier AX010 in the Nepalese Himalaya, and tests of its mass-balance sensitivity to input and climatic parameters are carried out. Calculated and observed area-averaged mass balances of the glacier during summer 1978 (June-September) show good agreement, namely -0.44 and -0.46 m w.e., respectively.Results show the mass balance is strongly sensitive to snow or ice albedo, to the effects of screening by surrounding mountain walls, to areal variations in multiple reflection between clouds and the glacier surface, and to thin snow covers which alter the surface albedo. In tests of the sensitivity of the mass balance to seasonal values of climatic parameters, the mass balance is found to be strongly sensitive to summer air temperature and precipitation but only weakly sensitive to relative humidity.


2017 ◽  
Vol 53 (4) ◽  
pp. 3146-3178 ◽  
Author(s):  
Baohong Ding ◽  
Kun Yang ◽  
Wei Yang ◽  
Xiaobo He ◽  
Yingying Chen ◽  
...  

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