Sentences with phrase «on ice sheet models»

In parallel we need significant investment in research on ice sheet models.

Sea level from equations (3.3) and (3.4) is shown by the blue curves in figure 2, including comparison (figure 2c) with the Late Pleistocene sea - level record of Rohling et al. [47], which is based on analysis of Red Sea sediments, and comparison (figure 2b) with the sea - level chronology of de Boer et al. [46], which is based on ice sheet modelling with the δ18O data of Zachos et al. [4] as a principal input driving the ice sheet model.

Not exact matches

Materials scientists hope their computer model results will spark further research into the effects of carbon dioxide on fracturing in glaciers and ice sheets

This allowed them to calculate the redistribution of mass on Earth's surface due to the melting of the Greenland and Antarctic ice sheets and mountain glaciers, and model the shift in Earth's axis.

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.

Modeling studies on geoengineering to reflect sunlight away from the Earth suggest that modifying the planet's reflectivity could slow the meltdown of the Greenland ice sheet in the short term, but not stop it entirely, and could still allow an eventual total meltdown in the next millennia or so.

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.

But most of all, she wanted to know whether Pappalardo's model of Europa's ice sheet jibed with all he had learned from almost 30 years of studying ice on Earth.

Based on the southern core we thought this was a localized low heat - flux region — but our model shows that a much larger part of the southern ice sheet has low heat flux.

Many older models of Greenland assumed that its massive ice sheet sat on bedrock that was relatively flat, even though scientists did not know the full thickness of the ice.

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.

Combining the speed and thickness measurements allowed the scientists to determine how much ice was flowing into the ocean, while the climate model allowed them to estimate how much snow was falling on the ice sheet.

In this model of Titan, however, the roots extending below the ice sheet are so much bigger than the bumps on the surface that their buoyancy is pushing them up against the ice sheet.

Based on a model that excludes ice sheet flow due to a lack of basis in published literature, it is estimated that sea level rise will be, in a low scenario, 18 to 38 cm (7 to 15 inches) and in a high scenario, 26 to 59 cm (10 to 23 inches).

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

SALSA will gather data from permanent GPS stations to better understand subglacial water flow's influence on the larger ice sheet system and improve subglacial lake modeling through comparing our model's estimates against geochemical data.

170 (Symposium on Physical Basis of Ice Sheet Modelling, Vancouver), p. 313 - 322, 1987.

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.

A new study combines the latest observations with an ice sheet model to estimate that melting ice on the Antarctic ice sheet is likely to add 10 cm to global sea levels by 2100, but it could be as much as 30 cm.

One recent modeling study focused on this mode of instability estimated that the Antarctic ice sheet has a 1 - in - 20 chance of contributing about 30 centimeters (1.0 feet) to global average sea - level rise over the course of this century and 72 centimeters (2.4 feet) by the end of the next century.

reconstructing sea - level and ice - sheet changes on timescales ranging from the 20th century, to the late Holocene, to the last 150 thousand years, through statistical and geophysical modeling of geological and observational records;

No longer do we need to rely on guesswork and computer modeling, because satellite images reveal a dramatic disappearance of glaciers, Antarctic ice shelves and polar ice sheets.

Hansen et al. recently explored the effect of stratification of meltwater water on storminess, sea surface temperature and sea level rise and found that, among other things, their model predicted strong feedbacks in ice sheet exposure to destabilizing influences.

(By the way, the I.P.C.C. didn't exclude the ice - sheet dynamics but they did say that the models currently were not good enough to do anything but to linearly extrapolate, and therefore they simply assumed the flow from Greenland and Antarctica based on the period 1993 - 2003.)

In a more recent paper, our own Stefan Rahmstorf used a simple regression model to suggest that sea level rise (SLR) could reach 0.5 to 1.4 meters above 1990 levels by 2100, but this did not consider individual processes like dynamic ice sheet changes, being only based on how global sea level has been linked to global warming over the past 120 years.

This result would be strongly dependent on the exact dynamic response of the Greenland ice sheet to surface meltwater, which is modeled poorly in todays global models.Yes human influence on the climate is real and we might even now be able to document changes in the behavior of weather phenomena related to disasters (e.g., Emanuel 2005), but we certainly haven't yet seen it in the impact record (i.e., economic losses) of extreme events.

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?

When are we going to see «the physics» of ice sheets on Greenland and Antarctica added to the models?

Along with David Schilling, I had developed a model to reconstruct former ice sheets with ice elevations based on the strength of ice - bed coupling determined by glacial geology.

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.

This result would be strongly dependent on the exact dynamic response of the Greenland ice sheet to surface meltwater, which is modeled poorly in todays global models.

Our physical patterns are based on the physics of glacier / ice sheet melt (static equioibrium fingerprints), glacial isostatic adjustment models, and an ensemble of GCMs to inform the ocean dynamic contribution.

So, if some of these ideas on termination of glaciations are correct (ice - sheet temperature, ocean circulation and CO2), and all of these are omitted from the current model, it leaves open the possibility that a more comprehensive model would get a different result.

Ricarda Winkelmann et al. modeled the response of the Antarctic ice sheet to a wide range of future carbon emissions scenarios over the long - term (previous simulations have mainly looked at changes that might occur on a shorter timescale).

Beadling, R., 2016: Impact of the melting of the Greenland ice sheet on the Atlantic meridional overturning circulation in 21st century model projections.

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).

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.

Well it depends on whether you are talking about Climate Sensitivity (Charney sensitivity... which is modelled) or Earth System Sensitivity (where things like ice sheet extent, vegetation cover etc are regarded as able to respond quickly to warming).

These values have been estimated using relatively simple climate models (one low - resolution AOGCM and several EMICs based on the best estimate of 3 °C climate sensitivity) and do not include contributions from melting ice sheets, glaciers and ice caps.

We used an ensemble of ice sheet model runs and plausible Earth models to place bounded constraints on our mass change estimate.

We quantify sea - level commitment in the baseline case by building on Levermann et al. (10), who used physical simulations to model the SLR within a 2,000 - y envelope as the sum of the contributions of (i) ocean thermal expansion, based on six coupled climate models; (ii) mountain glacier and ice cap melting, based on surface mass balance and simplified ice dynamic models; (iii) Greenland ice sheet decay, based on a coupled regional climate model and ice sheet dynamic model; and (iv) Antarctic ice sheet decay, based on a continental - scale model parameterizing grounding line ice flux in relation to temperature.

Paleontological records indicate that global mean sea level is highly sensitive to temperature (7) and that ice sheets, the most important contributors to large - magnitude sea - level change, can respond to warming on century time scales (8), while models suggest ice sheets require millennia to approach equilibrium (9).

But those projections were based on climate model simulations that did not consider melting of the Greenland Ice Sheet and may, therefore, be too conservative.

A goal of 2C as calculated by current models is not protective of permafrost, clathrates, or ice sheets on a 50 year planning horizon from time of crossing the 1C mark.

To assure the model was realistic, the scientists drew on observations of changes in the altitude of the ice sheet surface made by NASA's IceSat satellite and airborne Operation IceBridge campaign.

And Dr Bougamont said: «There are two sources of net ice loss: melting on the surface and increased flow of the ice itself, and there is a connection between these mechanisms that isn't taken into account by standard ice sheet models.»

Pfeiffer, M. & Lohmann, G. Greenland ice sheet influence on last interglacial climate: global sensitivity studies performed with an atmosphere — ocean general circulation model.

Computer models suggest that just small amounts of melting in the coming decades could destabilize the entire ice sheet on the western part of the frozen continent, researchers at the Potsdam Institute for Climate Impact Research in Germany say in a new study.

Mistakes in computer models are taken to be the final word on the paucity of evidence of manmade climate change, and an anomalous measurement of Greenland's ice sheet spells the end of the world.

(sarc) The correct answer to all political questions about TCR global sun - induced ozone recovery sensitivity (50 % undefined or rather obscurely neglecting the modelling of bark beetles and their modelled «black carbon» on ice sheets.)