Sensitivity of mass balance of five Swiss glaciers to temperature changes assessed by tuning a degree-day model

Abstract

ABSTRACT. A degree-day model is used to assess the sensitivity of the mass balance of five Swiss glaciers to temperature changes. The model uses temperature data extrapolated from nearby climate stations, and is tuned by varying precipitation to make the model fit the observed distribution of mass balance with altitude. Once the model is tuned, the effect of temperature change is simulated by recalculating the mass balance with the same parameters as before, but with a temperature increase of 1³C throughout the year. The largest mass-balance changes, involving increased ablation of 41m w.e. a1³C^1, occur at the snout, with a progressively smaller increase with altitude.The area-averaged sensitivities for the five glaciers are^0.7 to^0.9 m w.e. a^1 ³C^1. If annual precipitation also increased by 20% it would partly offset the effect of the 1³C higher temperatures but could not compensate for it.

An investigation of the thermomechanical features of Laohugou Glacier No. 12 on Qilian Shan, western China, using a two-dimensional first-order flow-band ice flow model

“…We estimate the annual surface mass balance b n of LHG12 during 1960-2013 and determine the position of ELA by b n = 0. The daily ablation at elevation z, m a (z), is calculated based on a degree-day method (Braithwaite and Zhang, 2000):…”

Glaciers and their contribution to sea level change

“…These include accumulation and ablation, summer and annual mean temperatures, duration of melt season, vertical gradient of mass balance and mass balance sensitivity to temperature and precipitation Table 4 Model results for glacier precipitation, mass balance amplitude and temperature sensitivity for different area distributions, Griesgletscher, Switzerland. Representative height defined by Raper et al (1996), modelled mass balance from Braithwaite and Zhang (2000) and area distributions from Funk et al (1996) changes. The precipitation at the ELA is also calculated for each grid square and confirms the suspicion that glacier-level precipitation is considerably larger than the grid precipitation in New et al (1999) for the seven glacier regions (Fig.…”

“…According to (3) and (4) the mass balance and its sensitivity change with the glacier area distribution. We made a test calculation of the latter effect by applying model results from Braithwaite and Zhang (2000) to different area distributions for Griesgletscher (Funk et al, 1996). Results in Table 4 show what happens if the same mass balance curve (averaged for 1961-1994) is applied to different area distributions.…”

Glacier mass variation and its effect on surface runoff in the Beida River catchment during 1957–2013

“…On the contrary, degree-day models rely upon the relationship between snow or ice melt and positive temperatures (Hock, 2003). On account of the wide availability and easy interpolation of air temperature data, the models are widely used in mass-balance estimation for a single glacier (Jóhannesson and others, 1995;Braithwaite and Zhang, 2000;Pellicciotti and others, 2005;Azam and others, 2014;Gao and others, 2015;Liu and Liu, 2016). At present, the distributed degree-day models are subjected to the considerable simplification that is necessary for operation at large scales (e.g., global or regional), and for estimation of the contribution of glaciers to sea level change (Raper and Braithwaite, 2006;Radićand Hock, 2011;Marzeion and others, 2012;Giesen and Oerlemans, 2013;Slangen and others, 2016).…”