Sentences with phrase «ice mass loss by»

Recent Greenland ice mass loss by drainage system from satellite gravity observations.

Not exact matches

By lubricating the bedrock, it will speed the flow of the overlying ice, perhaps increasing the rate of ice - mass loss in West Antarctica.

«By refining the spatial pattern of mass loss in the world's second largest — and most unstable — ice sheet, and learning how that pattern has evolved, we are steadily increasing our understanding of ice loss processes, which will lead to better - informed projections of sea level rise.»

«It doesn't change our estimates of the total mass loss all over Greenland by that much, but it brings a more significant change to our understanding of where within the ice sheet that loss has happened, and where it is happening now.»

Complementary analyses of the surface mass balance of Greenland (Tedesco et al, 2011) also show that 2010 was a record year for melt area extent... Extrapolating these melt rates forward to 2050, «the cumulative loss could raise sea level by 15 cm by 2050 ″ for a total of 32 cm (adding in 8 cm from glacial ice caps and 9 cm from thermal expansion)- a number very close to the best estimate of Vermeer & Rahmstorf (2009), derived by linking the observed rate of sea level rise to the observed warming.

The Greenland, and possibly the Antarctic, ice sheets have been losing mass recently, because losses by ablation including outlet glaciers exceed accumulation of snowfall.

However, the idea is simple, and I've talked about this much in many presentations this winter: Take the amount of ice you need to get rid of from Greenland to raise sea level 2 m in the next century, reduce it by your best estimate of the amount that would be removed by surface mass balance losses, and try to push the rest out of the aggregate cross-sectional area of Greenland's marine - based outlet glaciers.

The lower trend found by our study is consistent with the median projected sums of thermal expansion and glacier mass loss, implying that no net contribution from polar ice sheets is needed over 1901 - 1990.

Over the time period of our survey, the ice sheet as a whole was certainly losing mass, and the mass loss increased by 75 % in 10 years.

Ice mass loss in Greenland 2003 - 2009 as measured by GRACE amounts to 223 + / - 29 Gt / yr.

The Greenland ice sheet gains mass via snowfall and losses mass via the production of icebergs and by melt of ice in the ice marginal zone.

It has come to the point that if we continue losing mass in those areas, the loss can generate a self - reinforcing feedback whereby we will be losing more and more ice, ultimately raising sea levels by tens of feet.»

A rise in global mean sea level of between 0.09 and 0.88 metres by 2100 has been projected, mainly due to the thermal expansion of sea water and loss of mass from ice caps and glaciers».

SLR by 2100 is more likely to come from ice mass loss from West Antarctica (WAIS) where warm ocean currents are already melting ice at glacier mouths and attacking areas of the WAIS resting on the seabed.

Gravity measurements of the ice - mass loss in Greenland and Antarctica are complicated by glacial isostatic adjustment.

By all means show the detail once we have people's attention but what needs to be understood is the total ice mass loss.

The ice mass loss rate increased by 250 percent between April 2002 to April 2004 and May 2004 to April 2006.

We suggest that mass loss from disintegrating ice sheets probably can be approximated better by exponential mass loss than by linear mass loss.

Yet the rate of ice loss from these two polar realms, as identified by satellite measurements of the change in gravity of the ice masses, has more than doubled over the last decade.

If both Greenland and West Antarctica shed the entirety of their ice burden, global sea levels would rise by 12 to 14 m. Although these icecaps would not disintegrate within a century, the loss of even a third of their mass — quite plausible if the rate of polar ice loss continues to double each decade — would force up the oceans by at least 4 m, with disastrous socioeconomic and environmental consequences.

Spread of ice mass loss into northwest Greenland observed by GRACE and GPS.

These authors use an ice sheet model within a Bayesian statistical framework — in which critical processes are guided by expert synthesis — to simulate the mass loss from the entire Antarctic ice sheet to 2200.

Annual net balance on eight North Cascades glaciers during the 1984 - 1994 period has been determined by measurement, of total mass loss from firn and ice melt and, of residual snow depth at the end of the summer season.

This week in the journal Nature, Csatho writes a «News and Views» analysis that comments on the latest research in this area: A new study in Nature by Kristian K. Kjeldsen, Niels J. Korsgaard, Kurt H. Kjær and colleagues, who used aerial photographs, remote - sensing observations and geological evidence to estimate the Greenland Ice Sheet's mass loss during three time periods since the start of the 20th century: 1900 - 83, 1983 to 2003 and 2003 - 10.

Just yesterday we had an example of a scientist who projected that Himalayan glaciers were losing ice at an an amazing rate correcting himself and cutting his own mass loss estimate by 30 %.

«The most reliable indication of the imminence of multi-meter sea level rise may be provided by empirical evaluation of the doubling time for ice sheet mass loss.»

However, despite this, the team reckon to have perhaps isolated a «global warming» signal in the accelerated run off of the Greenland Ice Mass — but only just, because the runoff at the edges is balanced by increasing central mass — again, they focus upon recent trends — a net loss of about 22 cubic kilometres in total ice mass per year which they regard as statistically not significant — to find the «signal», and a contradiction to their ealier context of air temperature cyclIce Mass — but only just, because the runoff at the edges is balanced by increasing central mass — again, they focus upon recent trends — a net loss of about 22 cubic kilometres in total ice mass per year which they regard as statistically not significant — to find the «signal», and a contradiction to their ealier context of air temperature cyclice mass per year which they regard as statistically not significant — to find the «signal», and a contradiction to their ealier context of air temperature cycles.

In contrast to the lack of observed acceleration in the ocean thermal expansion, there has been a significant acceleration in the mass contributions, dominated by the increased GIS [Greenland ice sheet] mass loss.»

We hypothesize that ice mass loss from the most vulnerable ice, sufficient to raise sea level several meters, is better approximated as exponential than by a more linear response.

Although Zwally calculated the net «mass gains from snow accumulation exceeded losses from ice discharge by about 112 and 82 Gt / year respectively during the 1992 - 2001 and 2003 - 08 measurement periods», he also reported that the rate of ice loss along the west Antarctic coast and the peninsula had increased from 64 GT / year to 135 GT / year during those same periods.

A leading theory, presented by Dr. Bill McGuire, Hugh Tuffin, J. Maclennan, Peter Huybers and many others is that changes in stress to the Earth's crust caused by the loss of billions of tons of mass by ice sheets and the displacement of those billions of tons into the world's ocean system spurred previously stable magma systems into a chaotic displacement.

Ocean waters melting the undersides of Antarctic ice shelves are responsible for most of the continent's ice shelf mass loss, a new study by NASA and university researchers has found.

Each circular graph is proportional in area to the total ice mass loss measured from each ice shelf, in gigatons per year, with the proportion of ice lost due to the calving of icebergs denoted by hatched lines and the proportion due to basal melting denoted in black.

Ice, Cloud and land Elevation Satellite (ICESat) data (2003 — 08) show mass gains from snow accumulation exceeded discharge losses by 82 ± 25 Gt a − 1, reducing global sea - level rise by 0.23 mm a − 1.

At present, most mass loss from ice sheets occurs at their marine margins, through iceberg production and melting by the ocean.

Mass Gains of the Antarctic Ice Sheet Exceed Losses http://ntrs.nasa.gov/search.jsp?R=20120013495 SCAR ISMASS Workshop, July 14, 2012 «During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt / yr (2.5 % of input), as derived from ICESat laser measurements of elevation chaIce Sheet Exceed Losses http://ntrs.nasa.gov/search.jsp?R=20120013495 SCAR ISMASS Workshop, July 14, 2012 «During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt / yr (2.5 % of input), as derived from ICESat laser measurements of elevation chaice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt / yr (2.5 % of input), as derived from ICESat laser measurements of elevation chaice discharge by 49 Gt / yr (2.5 % of input), as derived from ICESat laser measurements of elevation change

Jet Propulsion Laboratory — June 13, 2013 PASADENA, Calif. — Ocean waters melting the undersides of Antarctic ice shelves are responsible for most of the continent's ice shelf mass loss, a new study by NASA and university researchers has found.

Ice - sheet volume is controlled by the balance between mass input and mass loss; mass input is almost entirely due to snowfall, and mass loss is from iceberg calving supplied by flow of the ice sheet, or runoff of melt watIce - sheet volume is controlled by the balance between mass input and mass loss; mass input is almost entirely due to snowfall, and mass loss is from iceberg calving supplied by flow of the ice sheet, or runoff of melt watice sheet, or runoff of melt water.

Current total ice - loss in Greenland is running at an estimated 200 Gte / yr and Antarctica at 150 Gte / yr (with ice mass gain in the east and loss in the west — with some estimates of a net gain)-- at that rate of 1mm / yr, by 2100 the global ice - loss would raise sea level by a little over 3 inches.

The modest increase in ice discharge over the past 7 years is contrasted by high rates of ice sheet mass loss and distinct spatial patters of elevation lowering.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120013495.pdf During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt / yr (2.5 % of input), as derived from ICESat laser measurements of elevation change.

«Ice sheets now appear to be contributing modestly to sea level rise because warming has increased mass loss from coastal areas more than warming has increased mass gain from enhanced snowfall in cold central regions,» the report by a team led by Professor Richard Alley of Pennsylvania State University in the US says.

We argue that ice sheets in contact with the ocean are vulnerable to non-linear disintegration in response to ocean warming, and we posit that ice sheet mass loss can be approximated by a doubling time up to sea level rise of at least several meters.

«Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE.»

Velicogna, I. Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE.

We can estimate the potential magnitude of the ice mass biases by noting that if the average velocity prediction bias of ~ 5 mm / yr evident in Figure 5 is developed over ~ 2 × 10 ^ 6 km2, an area somewhat smaller than that of West Antarctica, this would cause an apparent but spurious ice loss of ~ 33 Gt yr - 1, which is a significant fraction of all published ice mass rates derived from GRACE [Velicogna and Wahr, 2006; Chen et al., 2006; Ramillien et al., 2006; Sasgen et al., 2007a].

However, detecting acceleration is difficult because of (i) interannual variability in GMSL largely driven by changes in terrestrial water storage (TWS)(7 ⇓ — 9), (ii) decadal variability in TWS (10), thermosteric sea level, and ice sheet mass loss (11) that might masquerade as a long - term acceleration over a 25 - y record, (iii) episodic variability driven by large volcanic eruptions (12), and (iv) errors in the altimeter data, in particular, potential drifts in the instruments over time (13).

Its ability to limit mass loss of the ice sheet by retaining meltwater could be smaller than previously assumed.»

There has been no reduction in the surface area of grounded ice in the Greenland and Antarctic Ice Sheets, although the mass appears to have declined recently, at least in Greenland, if we can believe the GRACE results, which show more mass loss than earlier satellite altimetry measurements by Johannessen / Zwally (GRL) and Davis / Wingham (Antarctica), which showed net growth over the period 1993 - 20ice in the Greenland and Antarctic Ice Sheets, although the mass appears to have declined recently, at least in Greenland, if we can believe the GRACE results, which show more mass loss than earlier satellite altimetry measurements by Johannessen / Zwally (GRL) and Davis / Wingham (Antarctica), which showed net growth over the period 1993 - 20Ice Sheets, although the mass appears to have declined recently, at least in Greenland, if we can believe the GRACE results, which show more mass loss than earlier satellite altimetry measurements by Johannessen / Zwally (GRL) and Davis / Wingham (Antarctica), which showed net growth over the period 1993 - 2003.