scholarly journals Climate sensitivity of Storglaciären, Sweden: an intercomparison of mass-balance models using ERA-40 re-analysis and regional climate model data

2007 ◽  
Vol 46 ◽  
pp. 342-348 ◽  
Author(s):  
Regine Hock ◽  
Valentina Radić ◽  
Mattias De Woul
Keyword(s):  
Energy Balance ◽  
Regional Climate Model ◽  
Mass Balance ◽  
Climate Model ◽  
Regional Climate ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Temperature Index ◽  
Temperature Changes ◽  
Cumulative Mass

AbstractEstimates of glacier contributions to future sea-level rise are often computed from mass-balance sensitivities derived for a set of representative glaciers. Our purpose is to investigate how mass-balance projections and sensitivities vary when using different approaches to compute the glacier mass balance. We choose Storglaciären, Sweden, as a test site and apply five different models including temperature-index and energy-balance approaches further varying in spatial discretization. The models are calibrated using daily European Centre for Medium-Range Weather Forecasts re-analysis (ERA-40) data. We compute static mass-balance sensitivities and cumulative mass balances until 2100 based on daily temperatures predicted by a regional climate model. Net mass-balance sensitivities to a +1 K perturbation and a 10% increase in precipitation spanned from –0.41 to –0.61 and from 0.19 to 0.22ma–1, respectively. The cumulative mass balance for the period 2002–2100 in response to the climate-model predicted temperature changes varied between –81 and –92m for four models, but was –121m for the fully distributed detailed energy-balance model. This indicates that mass losses may be underestimated if temperature-index methods are used instead of detailed energy-balance approaches that account for the effects of temperature changes on all energy-balance components individually. Our results suggest that future glacier predictions are sensitive to the choice of the mass-balance model broadening the spectrum in uncertainties.

scholarly journals Forcing a Distributed Glacier Mass Balance Model with the Regional Climate Model REMO. Part I: Climate Model Evaluation

2010 ◽  
Vol 23 (6) ◽  
pp. 1589-1606 ◽  
Author(s):  
Sven Kotlarski ◽  
Frank Paul ◽  
Daniela Jacob
Keyword(s):  
Regional Climate Model ◽  
Mass Balance ◽  
Climate Model ◽  
Regional Climate ◽  
Global Radiation ◽  
High Elevation ◽  
Balance Model ◽  
Future Climate Change ◽  
Glacier Mass Balance ◽  
Mass Balance Model

Abstract A coupling interface between the regional climate model REMO and a distributed glacier mass balance model is presented in a series of two papers. The first part describes and evaluates the reanalysis-driven regional climate simulation that is used to force a mass balance model for two glaciers of the Swiss mass balance network. The detailed validation of near-surface air temperature, precipitation, and global radiation for the European Alps shows that the basic spatial and temporal patterns of all three parameters are reproduced by REMO. Compared to the Climatic Research Unit (CRU) dataset, the Alpine mean temperature is underestimated by 0.34°C. Annual precipitation shows a positive bias of 17% (30%) with respect to the uncorrected gridded ALP-IMP (CRU) dataset. A number of important and systematic model biases arise in high-elevation regions, namely, a negative temperature bias in winter, a bias of seasonal precipitation (positive or negative, depending on gridbox altitude and season), and an underestimation of springtime and overestimation of summertime global radiation. These can be expected to have a strong effect on the simulated glacier mass balance. It is recommended to account for these shortcomings by applying correction procedures before using the RCM output for subsequent mass balance modeling. Despite the obvious model deficiencies in high-elevation regions, the new interface broadens the scope of application of glacier mass balance models and will allow for a straightforward assessment of future climate change impacts.

scholarly journals Forcing a Distributed Glacier Mass Balance Model with the Regional Climate Model REMO. Part II: Downscaling Strategy and Results for Two Swiss Glaciers

2010 ◽  
Vol 23 (6) ◽  
pp. 1607-1620 ◽  
Author(s):  
Frank Paul ◽  
Sven Kotlarski
Keyword(s):  
Time Series ◽  
Regional Climate Model ◽  
Mass Balance ◽  
Meteorological Parameters ◽  
Climate Model ◽  
Regional Climate ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Mass Balance Model ◽  
Climate Station

Abstract Distributed glacier mass balance models are efficient tools for the assessment of climate change impacts on glaciers at regional scales and at high spatial resolution (25–100 m). In general, these models are driven by time series of meteorological parameters that are obtained from a climate station near a glacier or from climate model output. Because most glaciers are located in rugged mountain topography with a high spatial and temporal variability of the meteorological conditions, the challenge is to distribute the point data from a climate station or the gridbox values from a regional climate model (RCM) in an appropriate way to the terrain. Here an approach is presented that uses normalized grids at the resolution of the mass balance model to capture the spatial variability, and time series from a climate station (Robiei) and an RCM Regional Model (REMO) to provide a temporal forcing for the mass balance model. The test site near Nufenen Pass (Swiss Alps) covers two glaciers with direct mass balance measurements that are used to demonstrate the approach. The meteorological parameters (temperature, global radiation, and precipitation) are obtained for the years 1997–99 (at daily steps) from the climate station Robiei (1898 m MSL) and one grid box of the RCM REMO. The results of the mass balance model agree closely with the measured values and the specific differences in mass balance between the two glaciers and the two balance years are well captured. Despite the disparities in the meteorological forcing from the climate station and REMO, there are only small differences in the modeled mass balances. This gives confidence that the developed approach of coupling the coarse-resolution (18 km) RCM with the high-resolution (25 m) mass balance model is suitable and can be applied to other regions as well as to RCM scenario runs.

scholarly journals Simulating melt, runoff and refreezing on Nordenskiöldbreen, Svalbard, using a coupled snow and energy balance model

2012 ◽  
Vol 6 (3) ◽  
pp. 641-659 ◽  
Author(s):  
W. J. J. van Pelt ◽  
J. Oerlemans ◽  
C. H. Reijmer ◽  
V. A. Pohjola ◽  
R. Pettersson ◽  
...  
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Climate Model ◽  
Meteorological Data ◽  
Regional Climate ◽  
Energy Balance Model ◽  
Balance Model ◽  
Equilibrium Line Altitude ◽  
Mass Budget ◽  
The Impact

Abstract. A distributed energy balance model is coupled to a multi-layer snow model in order to study the mass balance evolution and the impact of refreezing on the mass budget of Nordenskiöldbreen, Svalbard. The model is forced with output from the regional climate model RACMO and meteorological data from Svalbard Airport. Extensive calibration and initialisation are performed to increase the model accuracy. For the period 1989–2010, we find a mean net mass balance of −0.39 m w.e. a−1. Refreezing contributes on average 0.27 m w.e. a−1 to the mass budget and is most pronounced in the accumulation zone. The simulated mass balance, radiative fluxes and subsurface profiles are validated against observations and are generally in good agreement. Climate sensitivity experiments reveal a non-linear, seasonally dependent response of the mass balance, refreezing and runoff to changes in temperature and precipitation. It is shown that including seasonality in climate change, with less pronounced summer warming, reduces the sensitivity of the mass balance and equilibrium line altitude (ELA) estimates in a future climate. The amount of refreezing is shown to be rather insensitive to changes in climate.

scholarly journals Mass-balance parameters derived from a synthetic network of mass-balance glaciers

2012 ◽  
Vol 58 (211) ◽  
pp. 965-979 ◽  
Author(s):  
Horst Machguth ◽  
Wilfried Haeberli ◽  
Frank Paul
Keyword(s):  
Mass Balance ◽  
Climate Model ◽  
Regional Climate ◽  
Synthetic Data ◽  
Swiss Alps ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Model Output ◽  
Equilibrium Line Altitude ◽  
Regional Climate Model Output

AbstractGlacier mass-balance parameters such as the equilibrium-line altitude (ELA) play an important role when working with large glacier samples. While the number of observational mass-balance series to derive such parameters is limited, more and more modeled data are becoming available.Here we explore the possibilities of analyzing such 'synthetic' mass-balance data with respect to mass-balance parameters. A simplified energy-balance model is driven by bias-corrected regional climate model output to model mass-balance distributions for 94 glaciers in the Swiss Alps over 15 years. The modeling results in realistic interannual variability and mean cumulative mass balance. Subsequently model output is analyzed with respect to 18 topographic and mass-balance parameters and a correlation analysis is performed. Well-known correlations such as for ELA and median elevation are confirmed from the synthetic data. Furthermore, previously unreported parameter relationships are found such as a correlation of the balance rate at the tongue with the accumulation-area ratio (AAR) and of the glacier elevation range with the AAR. Analyzing modeled data complements in situ observations and highlights their importance: the small number of accurate mass-balance observations available for validation is a major challenge for the presented approach.

scholarly journals Greenland surface mass balance simulated by a regional climate model and comparison with satellite-derived data in 1990–1991

2005 ◽  
Vol 24 (6) ◽  
pp. 623-640 ◽  
Author(s):  
Xavier Fettweis ◽  
Hubert Gallée ◽  
Filip Lefebre ◽  
Jean-Pascal van Ypersele
Keyword(s):  
Regional Climate Model ◽  
Mass Balance ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Derived Data

Combining distributed glacier mass balance and ice flow models to improve projections of mass change for debris-covered Khumbu Glacier, Nepal

2021 ◽  
Author(s):  
Anya Schlich-Davies ◽  
Ann Rowan ◽  
Duncan Quincey ◽  
Andrew Ross ◽  
David Egholm
Keyword(s):  
Mass Balance ◽  
Climate Models ◽  
Flow Model ◽  
Regional Climate ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Climate Data ◽  
Ice Flow ◽  
Flow Models ◽  
Distributed Models

<p>Debris-covered glaciers in the Himalaya are losing mass more rapidly than expected. Quantifying and understanding the behaviour of these glaciers under climate change requires the use of numerical glacier models that represent the important feedbacks between debris transport, ice flow, and mass balance. However, these approaches have, so far, lacked a robust representation of the distributed mass balance forcing that is critical for making accurate simulations of ice volume change. This study forces a 3D higher-order ice flow model, with the outputs from an ensemble of distributed models of present day and future mass balance of Khumbu Glacier, Nepal. Distributed mass balance modelling, using the open access COupled Snowpack and Ice surface energy and mass balance model in PYthon (COSIPY) model (Sauter et al., 2020), was forced by three statistically downscaled climate models from the Coordinated Regional Climate Downscaling Experiment (CORDEX) project.</p><p>Climate models were selected based on their ability to reproduce observed present-day seasonality and to account for several future climate and monsoon scenarios, the latter being of particular importance for these summer-accumulation type glaciers. Two emission scenarios, RCP4.5 and RCP8.5, were also chosen to simulate glacier change to 2100. Statistical downscaling involved Quantile Mapping and Generalized Analog Regression Downscaling, and the efficacy of these approaches was informed by present day mass balance sensitivity studies. Downscaled daily climate data were trained with data from two weather stations to aid disaggregation to an hourly resolution.</p><p>The integration of the mass balance and ice flow models posed some interesting challenges. The COSIPY model was run as if Khumbu Glacier were a clean-ice glacier (with no supraglacial debris) with sub-debris ablation resolved in the ice flow model. The value of using distributed mass balance forcing is seen in the simulated present-day velocities in the Khumbu icefall, which give a better fit to remote-sensing observations than previous simulations using a simple elevation-dependent mass balance forcing. The simulated present-day glacier extent is considerably smaller than the existing glacier outline. The debris-covered tongue, known to be losing mass at an accelerating rate, is virtually absent from these results, and is indicative of a stagnant tongue that is now or very soon to be dynamically disconnected from the active upper reaches of Khumbu Glacier.</p>

scholarly journals Modelling the impact of superimposed ice on the mass balance of an Arctic glacier under scenarios of future climate change

2005 ◽  
Vol 42 ◽  
pp. 277-283 ◽  
Author(s):  
Andrew Wright ◽  
Jemma Wadham ◽  
Martin Siegert ◽  
Adrian Luckman ◽  
Jack Kohler
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Climate Model ◽  
Global Climate Model ◽  
Balance Model ◽  
Explicit Calculation ◽  
Future Climate Change ◽  
Glacier Mass Balance ◽  
Positive Contribution ◽  
The Impact

AbstractA surface-energy/mass-balance model with an explicit calculation of meltwater refreezing and superimposed ice formation is applied to midre Lovénbreen, Spitsbergen, Svalbard. The model is run with meteorological measurements to represent the present climate, and run with scenarios taken from global climate model predictions based on the IS92a emissions scenario to represent future climates. Model results indicate that superimposed ice accounts for on average 37% of the total net accumulation under present conditions. The model is found to be highly sensitive to changes in the mean annual air temperature and much less sensitive to changes in the total annual precipitation. A 0.5˚C decade–1 temperature increase is predicted to cause an average mass-balance change of –0.43 ma–1, while a 2% decade–1 increase in precipitation will result in only a +0.02 ma–1 change in mass balance. An increase in temperature results in a significant decrease in the size of the accumulation area at midre Lovénbreen and hence a similar decrease in the net volume of superimposed ice. The model predicts, however, that the relative importance of superimposed ice will increase to account for >50% of the total accumulation by 2050. The results show that the refreezing of meltwater and in particular the formation of superimposed ice make an important positive contribution to the mass balance of midre Lovénbreen under present conditions and will play a vital future role in slowing down the response of glacier mass balance to climate change.

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