scholarly journals An efficient regional energy-moisture balance model for simulation of the Greenland ice sheet response to climate change

2009 ◽  
Vol 3 (3) ◽  
pp. 729-764
Author(s):  
A. Robinson ◽  
R. Calov ◽  
A. Ganopolski
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Mass Balance ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Balance Model ◽  
Surface Boundary ◽  
Regional Energy ◽  
Temperature And Precipitation ◽  
Moisture Balance

Abstract. In order to explore the response of the Greenland ice sheet (GIS) to climate change on long (centennial to multi-millennial) time scales, a regional energy-moisture balance model has been developed. This model simulates seasonal variations of temperature and precipitation over Greenland and explicitly accounts for elevation and albedo feedbacks. These fields are used to force a high resolution ice sheet model through the annual mean surface temperature and mass balance. The melt component of the mass balance is computed here using both a conventional positive degree day approach and a more physically-based alternative. As a validation of the model, we first simulated temperature and precipitation over Greenland for the prescribed, present-day topography of Greenland and compared them with empirical data. For the present-day climate, simulated surface boundary conditions for the GIS do not differ significantly from those of a simple parameterization used in many previous simulations. However, for a prescribed, ice-free state, the differences in simulated climatology and surface mass balance between the regional energy-moisture balance model and the conventional approach become significant, with our model showing much stronger summer warming. When coupled to a high resolution, three-dimensional ice sheet model and initialized with present-day conditions, the two melt schemes both allow sufficiently realistic simulations of the present-day GIS. However, when starting from ice-free conditions, two different equilibrium states are achieved, depending on the choice of melt scheme.

scholarly journals An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change

2010 ◽  
Vol 4 (2) ◽  
pp. 129-144 ◽  
Author(s):  
A. Robinson ◽  
R. Calov ◽  
A. Ganopolski
Keyword(s):  
Mass Balance ◽  
Climate Model ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Balance Model ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Regional Energy ◽  
Temperature And Precipitation ◽  
Moisture Balance

Abstract. In order to explore the response of the Greenland ice sheet (GIS) to climate change on long (centennial to multi-millennial) time scales, a regional energy-moisture balance model has been developed. This model simulates seasonal variations of temperature and precipitation over Greenland and explicitly accounts for elevation and albedo feedbacks. From these fields, the annual mean surface temperature and surface mass balance can be determined and used to force an ice sheet model. The melt component of the surface mass balance is computed here using both a positive degree day approach and a more physically-based alternative that includes insolation and albedo explicitly. As a validation of the climate model, we first simulated temperature and precipitation over Greenland for the prescribed, present-day topography. Our simulated climatology compares well to observations and does not differ significantly from that of a simple parameterization used in many previous simulations. Furthermore, the calculated surface mass balance using both melt schemes falls within the range of recent regional climate model results. For a prescribed, ice-free state, the differences in simulated climatology between the regional energy-moisture balance model and the simple parameterization become significant, with our model showing much stronger summer warming. When coupled to a three-dimensional ice sheet model and initialized with present-day conditions, the two melt schemes both allow realistic simulations of the present-day GIS.

scholarly journals Variations of Mass Balance of the Greenland Ice Sheet from 2002 to 2019

2020 ◽  
Vol 12 (16) ◽  
pp. 2609
Author(s):  
Yaqiong Mu ◽  
Yanqiang Wei ◽  
Jinkui Wu ◽  
Yongjian Ding ◽  
Donghui Shangguan ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Quantitative Research ◽  
Global Climate ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Rate Of Change ◽  
Ice Caps ◽  
Ice Cap ◽  
Temperature And Precipitation

The melting of the polar ice caps is considered to be an essential factor for global sea-level rise and has received significant attention. Quantitative research on ice cap mass changes is critical in global climate change. In this study, GRACE JPL RL06 data under the Mascon scheme based on the dynamic method were used. Greenland, which is highly sensitive to climate change, was selected as the study area. Greenland was divided into six sub-research regions, according to its watersheds. The spatial–temporal mass changes were compared to corresponding temperature and precipitation statistics to analyze the relationship between changes in ice sheet mass and climate change. The results show that: (i) From February 2002 to September 2019, the rate of change in the Greenland Ice Sheet mass was about −263 ± 13 Gt yr−1 and the areas with the most substantial ice sheet loss and climate changes were concentrated in the western and southern parts of Greenland. (ii) The mass balance of the Greenland Ice Sheet during the study period was at a loss, and this was closely related to increasing trends in temperature and precipitation. (iii) In the coastal areas of western and southern Greenland, the rate of mass change has accelerated significantly, mainly because of climate change.

Modelling climate change impacts on glaciers and water resources in China  using OGGM and FUSE

2021 ◽  
Author(s):  
Dan Goldberg ◽  
Louis Kinnear ◽  
Florian Kobierska-Baffie ◽  
Nans Addor ◽  
Helen He ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Water Resources ◽  
Mass Loss ◽  
Mass Balance ◽  
21St Century ◽  
General Circulation ◽  
Balance Model ◽  
High Mountain ◽  
Mountainous Regions

<p>Hundreds of millions of people depend strongly on hydrological inputs in the mountainous regions of China and central Asia. Glacier runoff is a major contributor to this hydrological forcing, yet many glaciers in the region have undergone mass loss in recent years and this mass loss is expected to continue or increase in response to climatological change. As such it is important to assess the large-scale response of High Mountain Asia glaciers to climate change , and its effects on hydrology. We present here preliminary modelling investigations of glacier change and hydrological impacts in response to high-resolution climate model projections over the 21st century as a component of the project SWARM (Impacts Assessment to Support WAter Resources Management and Climate Change Adaptation for China). Our model chain consists of i) Open Global Glacier Model (OGGM), which allows for high-resolution glacier flowline modelling of multiple glaciers, and ii) the Framework for Understanding Structural Errors (FUSE) a modular framework for snow and hydrology modelling, which we used to assemble and run three hydrological models over the whole of China. Both FUSE and OGGM are forced by an ensemble of bias-corrected CORDEX-East Asia regional climate models (in turn forced by CMIP5 general circulation models), and outputs of OGGM are provided to FUSE. We discuss our application of OGGM to 80,000 glaciers in Chinese river catchments; our efforts to calibrate the mass balance model using an expanded set of geodetic mass balance constraints; and finally the projections of glacier, snow and streamflow changes in the 21st century. In particular, we discuss the robustness and uncertainties in the projections as sampled by our multi-model ensemble.</p>

scholarly journals Higher surface mass balance of the Greenland ice sheet revealed by high-resolution climate modeling

2009 ◽  
Vol 36 (12) ◽  
Author(s):  
Janneke Ettema ◽  
Michiel R. van den Broeke ◽  
Erik van Meijgaard ◽  
Willem Jan van de Berg ◽  
Jonathan L. Bamber ◽  
...  
Keyword(s):  
High Resolution ◽  
Mass Balance ◽  
Climate Modeling ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Surface Mass Balance ◽  
Surface Mass

scholarly journals A surface mass balance model for the Greenland Ice Sheet

2005 ◽  
Vol 110 (F4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Marion Bougamont ◽  
Jonathan L. Bamber ◽  
Wouter Greuell
Keyword(s):  
Mass Balance ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Balance Model ◽  
Surface Mass Balance ◽  
Mass Balance Model ◽  
Surface Mass

scholarly journals Surface mass balance model intercomparison for the Greenland ice sheet

2012 ◽  
Vol 6 (5) ◽  
pp. 3999-4036 ◽  
Author(s):  
C. L. Vernon ◽  
J. L. Bamber ◽  
J. E. Box ◽  
M. R. van den Broeke ◽  
X. Fettweis ◽  
...  
Keyword(s):  
Mass Balance ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Balance Model ◽  
Surface Mass Balance ◽  
Equilibrium Line Altitude ◽  
Surface Mass ◽  
Process Representation ◽  
Model Average

Abstract. Four simulations of the surface mass balance (SMB) of the Greenland ice sheet (GrIS) are compared over the period 1960–2008. Total SMB estimates for the GrIS are in agreement within 34% of the four model average when a common ice sheet mask is used. When models' native land/ice/sea masks are used this spread increases to 57%. Variation in the spread of components of SMB from their mean: runoff 42% (29% native masks), precipitation 20% (24% native masks), melt 38% (74% native masks), refreeze 83% (142% native masks) show, with the exception of refreeze, a similar level of agreement once a common mask is used. Previously noted differences in the models' estimates are partially explained by ice sheet mask differences. Regionally there is less agreement, suggesting spatially compensating errors improve the integrated estimates. Modelled SMB estimates are compared with in situ observations from the accumulation and ablation areas. Agreement is higher in the accumulation area than the ablation area suggesting relatively high uncertainty in the estimation of ablation processes. Since the mid-1990s each model estimates a decreasing annual SMB. A similar period of decreasing SMB is also estimated for the period 1960–1972. The earlier decrease is due to reduced precipitation with runoff remaining unchanged, however, the recent decrease is associated with increased precipitation, now more than compensated for by increased melt driven runoff. Additionally, in three of the four models the equilibrium line altitude has risen since the mid-1990s, reducing the accumulation area at a rate of approximately 60 000 km2 per decade due to increased melting. Improving process representation requires further study but the use of a single accurate ice sheet mask is a logical way to reduce uncertainty among models.

scholarly journals Analysis of the Surface Mass Balance for Deglacial Climate Simulations

2020 ◽  
Author(s):  
Marie-Luise Kapsch ◽  
Uwe Mikolajewicz ◽  
Florian Andreas Ziemen ◽  
Christian B. Rodehacke ◽  
Clemens Schannwell
Keyword(s):  
Mass Balance ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Meridional Overturning Circulation ◽  
Balance Model ◽  
Surface Mass Balance ◽  
Equilibrium Line Altitude ◽  
Data Set ◽  
Surface Mass ◽  
Climate Conditions

Abstract. Most studies analyzing changes in the surface mass balance (SMB) of the Greenland ice sheet are limited to the last century, due to the availability of observations and the computational limitations of regional climate modeling. Using transient simulations with a comprehensive Earth System Model (ESM) we extend previous research and study changes in the SMB and equilibrium line altitude (ELA) for deglacial climate conditions. An energy balance model (EBM) is used to downscale atmospheric processes. It determines the SMB on higher spatial resolution and allows to resolve SMB variations due to topographic gradients not resolved by the ESM. An evaluation for historical climate conditions (1980–2010) shows that derived SMBs compare well with SMBs from regional modeling. Throughout the deglaciation changes in insolation dominate the Greenland SMB: 1) The increase in insolation and associated warming early in the deglaciation result in an ELA and SMB increase. The SMB increase is caused by compensating effects of melt and accumulation, as a warmer atmosphere precipitates more. After 13 ka before present (BP) melt begins to dominate and the SMB decreases. 2) The decline in insolation after 9 ka BP leads to an increasing SMB and decreasing ELA. Superimposed on these long-term changes are episodes of significant SMB/ELA decreases, related to slowdowns of the Atlantic Meridional Overturning Circulation (AMOC) that lead to cooling over most of the Northern Hemisphere. To study associated changes in the ice sheet geometry, the SMB data set is made available to the ice sheet modeling community.

scholarly journals Greenland ice sheet surface mass-balance variability: 1991–2003

2005 ◽  
Vol 42 ◽  
pp. 90-94 ◽  
Author(s):  
J.E. Box
Keyword(s):  
Mass Balance ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Atmospheric Model ◽  
Horizontal Resolution ◽  
Surface Mass Balance ◽  
Positive Trend ◽  
Surface Mass ◽  
Sheet Surface ◽  
Temperature And Precipitation

AbstractThe Polar MM5 mesoscale atmospheric model was run for 13 years (1991–2003) over Greenland at 24 km horizontal resolution (Box and others, 2004). The model physics were driven by satellite, station and weather-balloon observational data assimilation, i.e. European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis. The analysis in this study focuses on the response of the surface mass balance to its primary controls: temperature and precipitation. The results indicate coherent spatial patterns of variability and statistically significant links with temperature and precipitation and the North Atlantic Oscillation. Precipitation trends have the same spatial pattern and sign as temperature, suggesting an association of precipitation and temperature variability. Increasing temperatures contribute to an increasing ablation trend and expansion of the ablation zone despite increasing accumulation trends. The Pinatubo (Philippines) volcanic cooling in the early 1990s enhances this apparent warming trend. Only in the northeast does precipitation appear to dominate the surface mass balance, where both temperature and precipitation have decreased. There is little evidence for a total ice-sheet surface mass-balance trend, although the meltwater runoff has a positive trend and, combined with iceberg discharge and basal melting estimates, suggests the ice sheet as a whole is in a state of net mass loss over this period.

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