Estimating glacier snow accumulation from backward calculation of melt and snowline tracking

Abstract Estimating precipitation to determine accumulation is challenging. We present a method that combines melt modelling and snowline tracking to determine winter glacier snow accumulation along snowlines. The method assumes that the net accumulation is zero on the transient snowlines and the maximum winter accumulation at the snowline can be calculated backwards with a temperature-index melt model. To verify the method, the accumulation model is applied for the year 2004 on Storglaciären, Sweden, for which extensive meteorological and mass-balance data are available. The measured mean snowline accumulation is 0.94 ± 0.10mw.e. for 2004. Modelled accumulation, using backward melt modelling, at the same snowlines is 0.82 ± 0.25 m w.e. The accumulation model is also compared with an often used linear regression accumulation model which yields a mean snowline accumulation of 1.02 ± 0.38 m w.e. The reduction in standard error from 0.38 m w.e. to 0.25 m w.e. shows that the backward melt modelling applied at snowlines can provide a better spatial representation of the accumulation pattern than the regression model. Importantly, the applied method requires no field measurements of accumulation during the winter and snowlines can be readily traced in remotely sensed images.

[1]  T. Schneider,et al.  Air temperature at Tarfala Research Station 1946-1995 , 1996 .

[2]  R. Hock,et al.  Modeling Climate Conditions Required for Glacier Formation in Cirques of the Rassepautasjtjåkka Massif, Northern Sweden , 2002 .

[3]  F. Pattyn,et al.  Bed properties and hydrological conditions underneath McCall Glacier, Alaska, USA , 2009, Annals of Glaciology.

[4]  Andrea Taurisano,et al.  Calibrating a surface mass-balance model for Austfonna ice cap, Svalbard , 2007, Annals of Glaciology.

[5]  P. Holmlund,et al.  Reanalysis of multi-temporal aerial images of Storglaciären, Sweden (1959–99) – Part 2: Comparison of glaciological and volumetric mass balances , 2010 .

[6]  R. Hock A distributed temperature-index ice- and snowmelt model including potential direct solar radiation , 1999, Journal of Glaciology.

[7]  Regine Hock,et al.  A distributed surface energy-balance model for complex topography and its application to Storglaciären, Sweden , 2005, Journal of Glaciology.

[8]  P. Holmlund,et al.  The Tarfala Mass Balance Programme , 1999 .

[9]  P. Holmlund Maps of Storglaciären and their use in Glacier Monitoring Studies , 1996 .

[10]  G. Blöschl,et al.  Distributed Snowmelt Simulations in an Alpine Catchment: 1. Model Evaluation on the Basis of Snow Cover Patterns , 1991 .

[11]  D. Cline Snow surface energy exchanges and snowmelt at a continental, midlatitude Alpine site , 1997 .

[12]  P. Jansson Effect of Uncertainties in Measured Variables on the Calculated Mass Balance of storglaciären , 1999 .

[13]  J. Hagen,et al.  Assessing the future evolution of meltwater intrusions into a mine below Gruvefonna, Svalbard , 2005, Annals of Glaciology.

[14]  Dorothy K. Hall,et al.  Analysis of glacier facies using satellite techniques , 1991, Journal of Glaciology.

[15]  Martin Funk,et al.  An enhanced temperature-index glacier melt model including the shortwave radiation balance: development and testing for Haut Glacier d'Arolla, Switzerland , 2005 .

[16]  Jan Magnusson,et al.  Snow accumulation distribution inferred from time‐lapse photography and simple modelling , 2010 .

[17]  P. Wagnon,et al.  Atmospheric controls of the heat balance of Zongo Glacier (16°S, Bolivia) , 2005 .

[18]  A. Gardner,et al.  Sensitivity of net mass-balance estimates to near-surface temperature lapse rates when employing the degree-day method to estimate glacier melt , 2009, Annals of Glaciology.

[19]  J. Nash,et al.  River flow forecasting through conceptual models part I — A discussion of principles☆ , 1970 .

[20]  R. Hock,et al.  Glacier-dammed lake outburst events of Gornersee, Switzerland , 2007, Journal of Glaciology.

[21]  R. Ferguson,et al.  Remote sensing of snowline rise as an aid to testing and calibrating a glacier runoff model , 1997 .

[22]  V. Schytt Snow Densities on Storglaciären in Spring and Summer , 1973 .

[23]  P. Holmlund,et al.  A re-analysis of the 58 year mass-balance record of Storglaciären, Sweden , 2005, Annals of Glaciology.

[24]  Atsumu Ohmura,et al.  Physical Basis for the Temperature-Based Melt-Index Method , 2001 .