Sentences with phrase «models over ice sheets»

Improving digital elevation models over ice sheets using AVHRR - based photoclinometry.

Not exact matches

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.

«Sea - level rise could nearly double over earlier estimates in next 100 years: Researchers model effects of melting Antarctic ice sheets.»

«The primary uncertainty in sea level rise is what are the ice sheets going to do over the coming century,» said Mathieu Morlighem, an expert in ice sheet modeling at the University of California, Irvine, who led the paper along with dozens of other contributors from institutions around the world.

They could then plug that information into models to see how much ice Greenland lost over the 20th century, as well as how that loss varied over time and at different points around the ice sheet.

«Climate models show that ice - sheet melt will dominate sea - level rise over the coming centuries, but our understanding of ice - sheet variations before the last interglacial 125,000 years ago remains fragmentary.

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.

Experiments of this type are however challenging as ice sheets evolve over multi-millennial timescales, which is beyond the practical integration limit of most Earth system models.

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.

What this model shows is that if orbital variations in insolation impact ice sheets directly in any significant way (which evidence suggests they do Roe (2006)-RRB-, then the regression between CO2 and temperature over the glacial - interglacial cycles (which was used in Snyder (2016)-RRB- is a very biased (over) estimate of ESS.

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).

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.

But over the last decade or so, glaciologists have come to appreciate that ice sheets are not gigantic lumps of «static» ice; warming effects can cause them to act erratically and to move much faster than simple models suggest.

Ritz, C., Rommeleare, V. & Dumas, C. Modeling the evolution of Antarctic ice sheet over the last 420,000 years: implications for altitude changes in the Vostok region.

A new international study is the first to use a high - resolution, large - scale computer model to estimate how much ice the West Antarctic Ice Sheet could lose over the next couple of centuries, and how much that could add to sea - level riice the West Antarctic Ice Sheet could lose over the next couple of centuries, and how much that could add to sea - level riIce Sheet could lose over the next couple of centuries, and how much that could add to sea - level rise.

«The novel aspect of our work is the use of a high - resolution ice - sheet model over a larger area and longer time - scale than previously attempted.

«Models traditionally have projected that this difference doesn't become negative (i.e. net loss of Antarctic ice sheet mass) for several decades,» Mann said, adding that detailed gravimetric measurements, which looks at changes in Earth's gravity over spots to estimate, among other things, ice mass.

It is surprising, therefore, that the gross underestimation of pole ward energy transport by the computer models is not reflected as cooling and expansion of the ice sheets over the polar regions.

Such models also indicate that warming would initially cause the Antarctic ice sheet as a whole to gain mass owing to an increased accumulation of snowfall (*; some recent studies find no significant continent - wide trends in accumulation over the past several decades; Lemke et al., 2007 Section 4.6.3.1).

In fact, the two researchers say previous climate models underestimated the potential sea level rise over the next 100 years, as well as the melting of the Antarctic ice sheet.

Another eminent glaciologist, Aslak Grinsted, of the Centre for Ice and Climate at the University of Copenhagen, says the IPCC did not provide an «explicitly» higher estimate of sea - level rise over the next century «because we do not have models that reliably can predict how probable a collapse of the Antarctic ice sheet Ice and Climate at the University of Copenhagen, says the IPCC did not provide an «explicitly» higher estimate of sea - level rise over the next century «because we do not have models that reliably can predict how probable a collapse of the Antarctic ice sheet ice sheet is.

Nevertheless, improvements in ice - sheet models over recent decades have led to closer agreement with satellite observations, keeping track with their increasing contribution to global sea - level rise.

«The IPCC did not provide an «explicitly» higher estimate of sea - level rise over the next century «because we do not have models that reliably can predict how probable a collapse of the Antarctic ice sheet is.

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.

A plethora of research articles has appeared over the past year reporting new observations of the Greenland and West Antarctic ice sheets along with associated modeling results.

Currently, «even the best models out there disagree on cloudiness over Greenland and its effect on the ice sheet,» said the new study's lead author, Kristof Van Tricht of the University of Leuven in Belgium, in an email to The Post.

It's a finding that should be reflected in current climate models to help scientists make more accurate predictions about future Greenland melt — and could become even more important in the coming years if cloud cover over the ice sheet were to increase as a result of climate change.