Sentences with phrase «for ice sheet modelling»

Late Quaternary deglaciation of the Amundsen Sea: Implications for ice sheet modeling.

Not exact matches

«The widespread loss of Antarctic ice shelves, driven by a warming ocean or warming atmosphere, could spell disaster for our coastlines — and there is sound geological evidence that supports what the models are telling us,» said Robert M. DeConto of the University of Massachusetts Amherst, a co-author of the study and one of the developers of the ice - sheet model used.

Another promising approach involves combining physics, statistical modeling and computing to derive sound projections for the future of ice sheets.

Noise and biases are accounted for in the model that ultimately produces ice sheet data.

Recent modelling by researchers from the Potsdam Institute for Climate Impact Research in Germany, as well as studies of past climate, suggest that the planet will soon have warmed enough to melt Greenland's ice sheet entirely — if it hasn't already become warm enough.

Over the current century, the model projects that the average albedo for the entire ice sheet will fall by as much as 8 percent, and by as much 10 percent on the western edge, where the ice is darkest today.

Research by the UK Centre for Polar Observation and Modelling (CPOM) at the University of Leeds has produced the first complete map of how the ice sheet's submarine edge, or «grounding line,» is shifting.

The international team of co-authors, led by Peter Clark of Oregon State University, generated new scenarios for temperature rise, glacial melting, sea - level rise and coastal flooding based on state - of - the - art climate and ice sheet models.

The revised estimate for sea - level rise comes from including new processes in the 3 - dimensional ice sheet model, and testing them against past episodes of high sea - levels and ice retreat.

The international research initiative IceGeoHeat led by the GFZ German Research Centre for Geosciences establishes in the current online issue of Nature Geoscience that this effect can not be neglected when modeling the ice sheet as part of a climate study.

This model reconstruction has already proven a vital constraint for understanding complex systems beyond the ice sheet realm.

Bed topography data are vital for computer models used to project future changes to ice sheets and their contribution to sea level rise.

But the large volumes of data on Arctic sea and land ice that IceBridge has collected during its nine years of operations there have also enabled scientific discoveries ranging from the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed to improvements in snowfall accumulation models for all of Greenlaice that IceBridge has collected during its nine years of operations there have also enabled scientific discoveries ranging from the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed to improvements in snowfall accumulation models for all of GreenlaIce Sheet are thawed to improvements in snowfall accumulation models for all of Greenland.

The consequences of global sea level rise could be even scarier than the worst - case scenarios predicted by the dominant climate models, which don't fully account for the fast breakup of ice sheets and glaciers, NASA scientists said today (Aug. 26) at a press briefing.

The ice sheets themselves are the biggest challenge for climate modelling since we don't have direct evidence of the many of the key processes that occur at the ice sheet base (for obvious reasons), nor even of what the topography or conditions are at the base itself.

A 3 - D model for the Antarctic ice sheet: a sensitivity study on the glacial - interglacial contrast.

Constraints such as these are important for numerical models that attempt to replicate and predict the past and future behaviour of the Antarctic Ice Sheet.

Alley, R.B. Towards a hydrological model for computerized ice - sheet simulations.

The heights of the rectangular bars denote best estimate values guided by published values of the climate change agents and conversion to radiative perturbations using simplified expressions for the greenhouse gas concentrations and model calculations for the ice sheets, vegetation and mineral dust.

Thomas, R.H., and C.R. Bentley, A model for Holocene retreat of the West Antarctic ice sheet, Quaternary Research, Vol.

For example, some exciting work being done by David Pollard and Rob DeConto suggests that processes such as ice - cliff collapse and ice - shelf hydrofracturing may play important roles in future ice sheet behavior that have not been well incorporated into most ice sheet models.

Willis, M J, Wilson, T J, James, T S, Mazzotti, S, (2009), GPS Constraints on Glacial Isostatic Adjustment Models and Implications for Ice Sheet Mass Balance in West Antarctica, Eos Trans.

Inputs needed for a typical Antarctic ice sheet model are the elevation of the bed beneath the ice sheet, air temperature, snowfall and the heat input from the rock below (geothermal heat flux).

Many ice sheet models are now freely available, for example, Elmer, Glimmer - CISM, ISSM, PISM, SICOPLIS, making it possible for a wider community to be able to use these models to answer a wide range of scientific questions.

Willis, M J, Wilson, T J, James, T S, Mazzotti, S, Bevis, M G, Kendrick, E C, Brown, A, (2010) Geodetically - Constrained Glacial Isostatic Adjustment models of Antarctica: Implications for the Mass Balance of the West Antarctic Ice Sheet, Abstract G34A - 03 presented at 2010 Fall Meeting, AGU, San Francisco, Calif., 13 - 17 Dec..

Models of mountain (alpine) glaciers are applied to solve similar problems to those models used for polar ice sheets, but typically have a higher resolution (a smaller grid size) and need to consider the effects of steep and often variable bed slopes, and the transverse stresses found in valley glaModels of mountain (alpine) glaciers are applied to solve similar problems to those models used for polar ice sheets, but typically have a higher resolution (a smaller grid size) and need to consider the effects of steep and often variable bed slopes, and the transverse stresses found in valley glamodels used for polar ice sheets, but typically have a higher resolution (a smaller grid size) and need to consider the effects of steep and often variable bed slopes, and the transverse stresses found in valley glaciers.

This information is vital for numerical models, and answers questions about how dynamic ice sheets are, and how responsive they are to changes in atmospheric and oceanic temperatures.

Scientific knowledge input into process based models has much improved, reducing uncertainty of known science for some components of sea - level rise (e.g. steric changes), but when considering other components (e.g. ice melt from ice sheets, terrestrial water contribution) science is still emerging, and uncertainties remain high.

Numerical computer modelling of the glacier for these different time periods will help us understand whether this part of the ice sheet is susceptible to rising sea level, warming oceans or increased atmospheric temperatures.

Model studies for climate change between the Holocene and the Pliocene, when Earth was about 3 °C warmer, find that slow feedbacks due to changes of ice sheets and vegetation cover amplified the fast feedback climate response by 30 — 50 % [216].

«These are two of the largest and most rapidly changing glaciers in Antarctica, so the potential for their evolution to influence each other is important to consider in modeling ice sheet behavior and projecting future sea level rise,» Dustin Schroeder, a Stanford geophysicist who led the study, told Earther.

Statements such as «They come to believe models are real and forget they are only models» reveals he has never had a conversation with a climate modeller — our concerns about ice sheets for instance come about precisely because we aren't yet capable of modelling them satisfactorily.

For example, how much confidence can we really have in results from ice sheet models, which very likely miss important mechanisms (e.g., due to limited understanding of ocean - ice shelf interactions, calving physics and influence of small - scale topography)?

For example, this one at the NY Times: Climate Model Predicts West Antarctic Ice Sheet Could Melt Rapidly.

Proposed explanations for the discrepancy include ocean — atmosphere coupling that is too weak in models, insufficient energy cascades from smaller to larger spatial and temporal scales, or that global climate models do not consider slow climate feedbacks related to the carbon cycle or interactions between ice sheets and climate.

The periods considered were mainly the Pleistocene ice age cycles, the LGM and the Pliocene, but Paul Valdes provided some interesting modeling that also included the Oligocene, the Turonian, the Maastrichtian and Eocene, indicating the importance of the base continental configuration, ice sheet position, and ocean circulation for sensitivity.

«This uncertainty is illustrated by Pollard et al. (2015), who found that addition of hydro - fracturing and cliff failure into their ice sheet model increased simulated sea level rise from 2 m to 17 m, in response to only 2 °C ocean warming and accelerated the time for substantial change from several centuries to several decades.»

Or is the freshwater flux to the ocean from the melting ice sheet for some reason not represented in the models as a forcing on the circulation?

Re 42 Gavin, it seem we have to wait a bit more to see polar ice sheets growing for more heat when yr models have continuously overestimated polar amplification, please see:

The essence of the comment is a model that we put together that (I think) is the simplest that you can derive that includes a carbon cycle, ice sheets, and allows for the standard «Charney» sensitivity (ECS) and the ESS to vary independently.

For example, Hansen's recent paper on Scientific Reticence is quite explicit that much of important physics of ice sheets is not included in the models, hence his raising of matters to do with nonlinear behaviour (eg disintegration) of ice sheets.

• Current global model studies project that the Antarctic ice sheet will remain too cold for widespread surface melting and is expected to gain in mass due to increased snowfall.

But again the «models» estimate includes an observed ice sheet mass loss term of 0.41 mm / year whereas ice sheet models give a mass gain of 0.1 mm / year for this period; considering this, observed rise is again 50 % faster than the best model estimate for this period.

The models we have for ice sheet dynamics are quite new, and we have no way of testing them.

On unreliability of models see O'Reilly et al. (2012), pp. 721 - 22; «there is still no robust, credible model for the interaction of melting ice sheets with the ocean,» Holland and Holland (2015).

In light of this prediction and global climate model forecasts for continued high - latitude warming, the ice sheet mass budget deficit is likely to continue to grow in the coming decades.

It is possible that effective climate sensitivity increases over time (ignoring, as for equilibrium sensitivity, ice sheet and other slow feedbacks), but there is currently no model - independent reason to think that it does so.

With a much - needed GRACE follow - on mission being planned and expected to launch around 2017, observation and modelling of Antarctic GIA will continue to give us insights into the ice sheet history — from the LGM through to the present — and hence provide the context for any future changes.

«A Model for Holocene Retreat of the West Antarctic Ice Sheet.»

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