Not exact matches
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.
Although CryoSat - 2 is designed to measure changes in the
ice sheet elevation, these can be translated into horizontal motion at the grounding line using knowledge of the
glacier and sea floor geometry
and the Archimedes principle of buoyancy — which relates the thickness of floating
ice to the height of its
surface.
Sunlight tends to bounce off the white, reflective
surfaces of
glaciers and ice sheets, but the darker
surfaces of dirty ground
ice can absorb greater amounts of solar radiation.
The data 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 the resulting rise in sea level.
The two main forces that conspire to destroy Earth's massive polar
ice sheets are heat, which melts their
surfaces via sunlight
and warm air,
and gravity, which drives
glaciers to slide to the sea.
It is difficult to obtain fossil data from the 10 % of Earth's terrestrial
surface that is covered by thick
glaciers and ice sheets,
and hence, knowledge of the paleoenvironments of these regions has remained limited.
The research published in Nature Communications found that in the past, when ocean temperatures around Antarctica became more layered - with a warm layer of water below a cold
surface layer -
ice sheets and glaciers melted much faster than when the cool
and warm layers mixed more easily.
Unlike the great
ice sheet of Antarctica, the Greenland
ice sheet is melting both on its
surface and also at outlet
glaciers that drain the
ice sheet's mass through deep fjords, where these
glaciers extend out into the ocean
and often terminate in dynamic calving fronts, giving up gigaton - sized icebergs at times.
This bundle contains 11 ready - to - use
Ice Age Worksheets that are perfect for students who want to learn more about An ice age which is a period of long - term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glacie
Ice Age Worksheets that are perfect for students who want to learn more about An
ice age which is a period of long - term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glacie
ice age which is a period of long - term reduction in the temperature of Earth's
surface and atmosphere, resulting in the presence or expansion of continental
and polar
ice sheets and alpine glacie
ice sheets and alpine
glaciers.
would a plausible physical explanation be that the deep ocean
and ice sheets are still responding somewhat to the post-glacial temperature increase (eg, T - T0, 0 > 0), but that the faster components of SLR like the
surface oceans
and glaciers were actually responding to the decrease in temperature since the early Holocene?
Other factors would include: — albedo shifts (both from
ice > water,
and from increased biological activity,
and from edge melt revealing more land,
and from more old dust coming to the
surface...); — direct effect of CO2 on
ice (the former weakens the latter); — increasing,
and increasingly warm, rain fall on
ice; — «stuck» weather systems bringing more
and more warm tropical air ever further toward the poles; — melting of sea
ice shelf increasing mobility of
glaciers; — sea water getting under parts of the
ice sheets where the base is below sea level; — melt water lubricating the
ice sheet base; — changes in ocean currents -LRB-?)
That would also imply that (T - T0 (t)-RRB- must be negative during the pre-900 period when SLR = 0... would a plausible physical explanation be that the deep ocean
and ice sheets are still responding somewhat to the post-glacial temperature increase (eg, T - T0, 0 > 0), but that the faster components of SLR like the
surface oceans
and glaciers were actually responding to the decrease in temperature since the early Holocene?
Geoengineering proposals fall into at least three broad categories: 1) managing atmospheric greenhouse gases (e.g., ocean fertilization
and atmospheric carbon capture
and sequestration), 2) cooling the Earth by reflecting sunlight (e.g., putting reflective particles into the atmosphere, putting mirrors in space to reflect the sun's energy, increasing
surface reflectivity
and altering the amount or characteristics of clouds),
and 3) moderating specific impacts of global warming (e.g., efforts to limit sea level rise by increasing land storage of water, protecting
ice sheets or artificially enhancing mountain
glaciers).
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.
All
ice types, including massive
ice sheets, mountain
glaciers and Arctic sea
ice (frozen sea -
surface), are for the most part melting far faster than predicted three years ago.
Hydrological application of remote sensing:
Surface states -
ice sheets,
glaciers and sea -
ice extent
and properties.
Although CryoSat - 2 is designed to measure changes in the
ice sheet elevation, these can be translated into horizontal motion at the grounding line using knowledge of the
glacier and sea floor geometry
and the Archimedes principle of buoyancy — which relates the thickness of floating
ice to the height of its
surface.
Endless stories about
glaciers melting, polar bears,
ice sheets in Greenland
and Antarctica
and sea
ice form the view that there is virtually no
ice left on the
surface of the planet.
And older climate models did not include dynamic ice sheet vulnerabilities — like high latent - heat ocean water coming into contact with the submerged faces of sea - fronting glaciers, the ability of surface melt water to break up glaciers by pooling into cracks and forcing them apart (hydrofracturing), or the innate rigidity and frailty of steep ice cliffs which render them susceptible to rapid toppli
And older climate models did not include dynamic
ice sheet vulnerabilities — like high latent - heat ocean water coming into contact with the submerged faces of sea - fronting
glaciers, the ability of
surface melt water to break up
glaciers by pooling into cracks
and forcing them apart (hydrofracturing), or the innate rigidity and frailty of steep ice cliffs which render them susceptible to rapid toppli
and forcing them apart (hydrofracturing), or the innate rigidity
and frailty of steep ice cliffs which render them susceptible to rapid toppli
and frailty of steep
ice cliffs which render them susceptible to rapid toppling.
Losses from
surface melting, water runoff, the breakup of
glaciers into the ocean (calving),
and the transformation of solid
ice into water vapor (sublimation) exceed any gains through snowfall.2, 3,4,5 The Greenland
ice sheet loses most of its mass on the perimeter, through a dozen fast - moving
glaciers, including Helheim.5, 6
Cryosphere All regions on
and beneath the
surface of the Earth
and ocean where water is in solid form, including sea
ice, lake
ice, river
ice, snow cover,
glaciers and ice sheets,
and frozen ground (which includes permafrost).
To say nothing of the warming trends also noticed in, for example: * ocean heat content * wasting
glaciers * Greenland
and West Antarctic
ice sheet mass loss * sea level rise due to all of the above * sea
surface temperatures * borehole temperatures * troposphere warming (with stratosphere cooling) * Arctic sea
ice reductions in volume
and extent * permafrost thawing * ecosystem shifts involving plants, animals
and insects
The planet's
glaciers and ice sheets cover about 11 % of the planet's
surface and hold about 70 % of the world's fresh water.
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).
They report in the journal Science that a succession of aerial surveys combined with multiple satellite observations has established that the base of the
glacier is being eroded rapidly by a mix of warmer ocean water
and increasing amounts of meltwater from the
surface of the Greenland
ice sheet.
Record droughts in many areas of the world, the loss of arctic sea
ice — what you see is an increasing trend that is superimposed on annual variablity (no bets on what happens next year, but the five - to - ten year average in global temperatures, sea
surface temperatures, ocean heat content — those will increase —
and ice sheet volumes, tropical
glacier volumes, sea
ice extent will decrease.
The data 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 the resulting rise in sea level.
The land ECV breakout group was asked to consider 10 ECVs related to
surface observations:
glaciers and ice caps /
sheets, snow cover, soil moisture, fire disturbance, lakes, biomass, land cover,
surface albedo, fraction of absorbed photosynthetically active radiation (FPAR),
and leaf area index (LAI).
The observed effects of cryosphere reduction include modification of river regimes due to enhanced glacial melt, snowmelt advance
and enhanced winter base flow; formation of thermokarst terrain
and disappearance of
surface lakes in thawing permafrost; decrease in potential travel days of vehicles over frozen roads in the Arctic; enhanced potential for
glacier hazards
and slope instability due to mechanical weakening driven by
ice and permafrost melting; regional ocean freshening; sea - level rise due to
glacier and ice sheet shrinkage; biotic colonisation
and faunal changes in deglaciated terrain; changes in freshwater
and marine ecosystems affected by lake -
ice and sea -
ice reduction; changes in livelihoods; reduced tourism activities related to skiing,
ice climbing
and scenic activities in cryospheric areas affected by degradation;
and increased ease of ship transportation in the Arctic.
Arctic sea
ice, Antarctic
and Greenland
ice sheets, global
glacier mass, permafrost area,
and Northern Hemisphere snow cover are all decreasing substantially, while ocean
surface temperatures, sea level,
and ocean acidification are rising [36].
These OMITTED / POORLY Represented processes include the following: oceanic eddies, tides, fronts, buoyancy - driven coastal
and boundary currents, cold halocline, dense water plumes
and convection, double diffusion,
surface / bottom mixed layer, sea
ice — thickness distribution, concentration, deformation, drift
and export, fast
ice, snow cover, melt ponds
and surface albedo, atmospheric loading, clouds
and fronts,
ice sheets / caps
and mountain
glaciers, permafrost, river runoff,
and air — sea
ice — land interactions
and coupling.
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).
The icePod system will consist of a suite of imaging sensors mounted in an external pod carried on New York Air National Guard LC - 130's to map the
surface and subsurface
ice topography of
ice sheets,
ice streams
and outlet
glaciers.