Sentences with phrase «on ice sheet»

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.

Other factors being investigated are the impact of lakes on Greenland's glacial surfaces, the effect of dust and soot on the ice sheet (which have been shown to have a major impact in accelerating melting in Himalayan glaciers), and how surface meltwater affects ice flow into the ocean (previous research has shown that is speeds it and is increased by short term weather extremes).

What is alarming is that the volume of water and the extent and rapidity of its movement is suprisingly much greater than previously believed, and that a possible, perhaps likely, effect of this on ice sheet dynamics is to make the ice sheets less stable and more likely to respond more quickly to global warming than previously expected.

«The grounding line is buried under a thousand or more meters of ice, so it is incredibly challenging for a human observer on the ice sheet surface to figure out exactly where the transition is,» Rignot explained in a NASA news release.

Much of it lies here in the Palouse but I'm rather sure that much of it ended up on the ice sheet.

Adding the mass of ice that had accumulated over hundreds of thousands of years on the ice sheet to the mass of seawater that freezes on the surface seems pretty useless to me.

However, with the new evidence that changes in atmospheric and thus oceanic circulation may have obscured changes in sea level (http://environment.newscientist.com/article/dn12547-flatter-oceans-may-have-caused-1920s-sea-rise.html), is there any evidence that the previously apparently static sea levels caused groups to self - censor data on ice sheet melting?

The conventional view has been that meltwater permeates the ice from the surface and pools under the based on the ice sheet.

The worry has been that with further global warming such meltwater would increase and have a catastrophic effect on the ice sheet, lubricating its base and making it slide quickly into the ocean.

The questions on ice sheet dynamics have still not been answered, so there is no agreed upon answer.

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.

Using satellite and field work after an extreme melt event in Greenland, a UCLA - led study finds that melt - prone areas on its ice sheet develop a remarkably efficient drainage system of stunning blue streams and rivers that carry meltwater into moulins (sinkholes) and ultimately the ocean.

An ice sheet forcing does not depend sensitively on the ice sheet shape or on how many ice sheets the ice volume is divided among and is nearly linear in sea - level change (see electronic supplementary material, figure S4, and [5]-RRB-.

We will explain more on ice sheet collapse later, but prior to about 1900, we know sea level was stable for several thousand years.

The surface mass balance of the glacier is the difference of accumulating snow on the ice sheet (its income) and snow and ice losses from melting and calving (its expenditures).

The dark band in this ice core from West Antarctica is a layer of volcanic ash that settled on the ice sheet approximately 21,000 years ago.

A warming climate could also increase algal growth in the future, potentially boosting algae's influence on ice sheet melting, he said.

The magnitude and importance of snowfall on ice sheet mass balance is illustrated by the story of Glacier Girl.

Lakes of summer meltwater tend to form on the ice sheet surface: if the ice below fractures, these lakes can drain in a matter of hours.

Until now, though, most of the focus has been on ice sheet dynamics — how quickly Greenland's glaciers are flowing into the sea.

«(F) the cryosphere, including effects on ice sheet mass balance, mountain glacier mass balance, and sea - ice extent and volume;

As Csatho explains in her News and Views piece, the scientists reprocessed the old snapshots using modern photogrammetric methods, enabling the team to tease out details that provided insight on the ice sheet's historical boundaries.

Geothermal conditions impart a significant control on the ice sheet's transient response, particularly during phases of rapid retreat.

«Fortunately we could see from the PROMICE.dk stations on the ice sheet that it had been well above melting, even above 10oC.

Schaefer, for whom this was an opportunity to embark on ice sheet research, believes their collaboration is a great example of what can happen when everything works together to support academic women.

Surface melt on an ice sheet not only directly reduces the ice sheet mass but also can accelerate ice flow and even leads to further melting.

Nonetheless, a recent probabilistic assessment based on IPCC projections and expert elicitations on ice sheet behavior assigns a 0.5 % chance that global SLR will exceed 6.3 m by 2200 under RCP 8.5 (46), suggesting that all but the highest committed levels discussed here could be attained in the relatively near term.

For a calculation on volcanic effect on ice sheet using recently published paper on Thwaites, see here and for an update which reduces it further, see here

Surface melt on the ice sheet is constrained by the albedo, but a lake is dark and could absorb much more solar radiation.

There will be some clear failures where there are reasons to suspect that some of the (up to now) excluded physics is dominant (i.e. Heinrich events that rely on ice sheet dynamics), but pretty much everything else is fair game — as long of course there is a good hypothesis to test.

In this case, Marco Tedesco, director of the Cryospheric Processes and Remote Sensing Laboratory at City College of New York, is preparing to use a customized bait boat equipped with cameras, sonar and other systems to survey the huge blue lakes of meltwater forming each summer high on the ice sheet there.

Chris Mooney has filed a nice Washington Post piece on ice sheet dynamics and several ways to visualize the most common unit of what's moving to the sea — gigatons (each a billion tons): Read more...

Chris Mooney has filed a nice Washington Post piece on ice sheet dynamics and several ways to visualize the most common unit of what's moving to the sea — gigatons (each a billion tons):

Polar amplication is of global concern due to the potential effects of future warming on ice sheet stability and, therefore, global sea level (see Sections 5.6.1, 5.8.1 and Chapter 13) and carbon cycle feedbacks such as those linked with permafrost melting (see Chapter 6)... The magnitude of polar amplification depends on the relative strength and duration of different climate feedbacks, which determine the transient and equilibrium response to external forcings.

Do the RC team plan to comment on the new science paper (linked by Gavin in the comments) on ice sheet melting?

If one could go back to the site of Chicago, Illinois, 18,000 years ago, you would be standing on an ice sheet over two miles thick, and you would be in a climate just like the Arctic is today.

«Most ice cores are collected from the middle of the ice sheet where it rarely ever melts, or on the ice sheet edge where the meltwater flows into the ocean,» Karina Graeter, the lead author of the study as a graduate student in Dartmouth's Department of Earth Sciences, said in a statement.

Much of it lies here in the Palouse but I'm rather sure that much of it ended up on the ice sheet.

the idea of sea - level influence on ice sheet dynamics is not new, but as you indicate, references are not easily googleable.

Here's a video showing the discovery of a meteorite weighing 18 kg on the ice sheet, by scientists working at Princess Elisabeth Antarctica.

Water is darker than snow, but dust as well as soot from wildfires can also be swept up from far off locales and deposited on the ice sheet.

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

It is based on the misconception that the factor preferring isotopes is at the «precipitation / freeze» end of the process when it is actually at the evaporation end, i.e. not dependent on local conditions on the ice sheet.

What is alarming is that the volume of water and the extent and rapidity of its movement is suprisingly much greater than previously believed, and that a possible, perhaps likely, effect of this on ice sheet dynamics is to make the ice sheets less stable and more likely to respond more quickly to global warming than previously expected.

This sea level rise estimate is larger than that provided by the last IPCC report, but highlights the need for further research on ice sheet variablity and ice sheet response to climate change, both now and in the past.

«Based on the likely location of ice deposits during this period of Mars» history, and the amount of meltwater that could have been produced by Lyot ejecta landing on an ice sheet, we think this is the most plausible scenario for the formation of these valleys» said David Weiss, a recent Ph.D. graduate from Brown and the study's lead author.

«At the same time, the mass loss on the ice sheet is not very large compared to how much mass they store.»

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.

There also was an assumption that many melting glaciers on the ice sheet's periphery eventually would retreat to higher ground on this flat bedrock, cutting off contact with warm ocean waters and slowing down the ice sheet's shedding.

That base layer can warp and lift the ice above it, which is formed by snow deposited on the ice sheet's surface.