Greenland's
ice becoming 'Swiss cheese' due to global warming, New York Times
says
Scientists
are studying the flow of water from rivers like these that
criss-cross Greenland's ice sheet, trying to determine how much water
moves through sinkholes to beneath the sheet and flow into the nearby
ocean, and how much refreezes before then. Photo acquired July 19,
2015. (Maria-Jose
Vinas)
27
October, 2015
Scientists studying the surface of the Greenland ice sheet have found that global warming is creating new rivers that disappear into sinkholes called "moulins" that drain through ice tunnels into the ocean, their melted water adding to the world's rising seas, the New York Times reported Tuesday (Oct. 27).
The
ice sheet has become porous, "like Swiss cheese," Laurence
Smith, head of the University of California, Los Angeles, geography
department, and leader of the Greenland science team, told the
reporters.
The Greenland
research is
part of the effort of thousands of scientists supported by close to
$1 billion in federal research dollars a year aimed at determining
the speed of rising sea levels in the 21st Century and other problems
caused by climate change.
Congress
directs that money through the National Science Foundation, NASA and
the National Oceanic and Atmospheric Administration, the New York
Times story said.
"But
the research is under increasing fire by some Republican leaders in
Congress, who deny or question the scientific consensus that human
activities contribute to climate change," said
the story by
reporters Coral Davenport, Josh Haner, Larry Buchanan and Derek
Watkins
Those
critics include Rep. Lamar Smith, R-Texas, chairman of the House
science committee, who has tried to cut $300 million from NASA's
earth science budget and is raising questions about 50 National
Science Foundation Grants.
The
Times' four-reporter team tracked the efforts of one team of
scientists whose funding could be targeted by such critics.
The
researchers needed ground-truth from a
trip to one of the large rivers and
sinkholes on the ice sheet to help direct computer model estimates of
the amount of water flowing into the ocean from thousands of similar
rivers, the story said, with the information they glean being used to
test broader world climate model predictions for sea rise.
Smith
said the experiments might actually find that the meltwater is
refreezing within the thick ice layer, which could mean the sheet
actually is melting more slowly than predicted.
The New York Times piece
Greenland ice sheet melts: Planetary Emergency Issued by NASA
SAN
FRANCISCO — Greenland's disappearing ice shifted gears in the past
decade, switching from shrinking glaciers to surface melting,
researchers reported here last week at the American Geophysical
Union's annual meeting.
Instead
of losing ice where massive glaciers meet the sea, Greenland now
sends meltwater rushing into the ocean via a vast network of lakes
and rivers, according to several studies. The results do not mean
that glaciers have stopped their speedy flow, only that surface
melting now exerts a more powerful influence on ice loss, researchers
said.
"We
no longer see giant icebergs calving" from glaciers, releasing
ice into the sea, said Lora Koenig, a glaciologist at the National
Snow and Ice Data Center, who led one of the new studies. "The
majority of water is coming from surface melt.
Greenland,
one of the largest ice sheets in the world, is melting. In fact, it
is melting ahead of schedule as the world warms. Scientists are
working hard to deepen their understanding of this ice sheet’s
behavior so that we can predict how fast and how much of the ice
sheet will melt in the coming decades and centuries.
It
might seem obvious that in a warming world, the Greenland ice sheet
will melt. But, what seems obvious and simple can be more complex
when investigated more deeply. With respect to Greenland, it is
expected that warmer temperatures increase melting but warmer
temperatures can also mean more snowfall, as there is more moisture
in warm air which can then fall as snow. So, it has been a question
of which of these two competing processes would win out. Would
Greenland get smaller because of melting or would it grow as more
snow fell?
Over
the past few years, the verdict has become clear. The Greenland ice
sheet is losing mass at an increasing rate. In fact, Greenland
currently contributes twice as much as the Antarctic to rising sea
levels.
A
new study, just published in Nature Geoscience, makes an important
new contribution to our understanding of the forces at play in
Greenland. Dr Samuel Doyle and an international team captured the
wide-scale effects of an unusual week of warm, wet weather in late
August and early September, 2011. They found that weather cyclonic
led to extreme surface runoff – a combination of ice melt and rain
– that overwhelmed the ice sheet’s basal drainage system. This
drive a marked increase in ice flow across the entire western sector
of the ice sheet that extended 140 km into the ice sheet’s
interior.
The
cyclonic weather system delivered heat and rain to the western edge
of the Greenland ice sheet and under these warm, wet, cloudy
conditions the way that the ice sheet receives energy for melt is
very different to that under the more typical clear sky conditions.
As we all know from a cloudy day, clouds block a certain amount of
sunshine, but under certain conditions they can absorb the outgoing
longwave radiation and re-radiate it back to the surface. This is why
a cloudy night is often warmer than when the sky is clear. The same
thing happens on the ice sheet.
In
fact during the August 2011 weather event, melt continued throughout
both day and night creating exceptionally high daily melt totals for
this time of year. Moisture in the atmosphere also reduces the rate
at which the air cools as it rises over the ice sheet, allowing warm
temperatures and therefore melt and rain to attain abnormally high
elevations. The heat released by condensation and by rain refreezing
in the snowpack enhanced melt even further.
Even
given these factors, the water runoff from melt and rain did not
exceed mid-summer peak values when ice flow was relatively slow. This
is because the ice sheet’s drainage system continually adapts to
melt inputs: in mid-summer an efficient drainage system forms and the
ice sheet can easily accommodate high water inputs. This isn’t the
case in late summer though, as the drainage system rapidly freezes
shut when air temperatures fall below zero.
The
influence of such intense rainfall events has not, until now, been
considered in assessments of the melt and flow response of any ice
sheet. This is an important omission because cyclonic conditions are
predicted to increase in the future, therefore likely playing an
increasing role in driving ice mass loss from the Greenland ice
sheet.
Since
the 1980s when rainfall measurements began in the west Greenland town
of Kangerlussuaq, the focus of the study, the proportion of
precipitation now falling as rainfall rather than snow has both
increased and extended into the late summer and autumn in line with
increased circulation and moisture availability within a warmer, more
energetic atmosphere.
From Harold Hensel, via Facebook
The incredible images of 'dark snow' in Greenland tainted by massive forest fires - and experts say it is yet another sign of glacial change
- 'Dark ice' effect caused by soot from forest fires, which then means ice melts faster
- Taken using a drone by Dutch and Welsh research team in Greenland
- Researchers admit they were 'stunned' by the extent of the dark ice
Sept 2014
Update of Dr. Malcolm Light and Sam Carana's methane graph showing the point when methane becomes the dominate controlling factor of the climate.
The second poster shows a design to decompose methane in the atmosphere. The Lucy Project would be especially useful to decompose methane from a sudden burst in the East Siberian and Laptev Sea. The abstract for the Lucy Project has been accepted and published by the American Meteorological Society. It will be presented at the Annual Meeting in New Orleans on January 18th, 2016 in New Orleans.
There are heavy amounts of methane hydrates in the Laptev Sea. There are also "torches" of methane here. Dr. Shakova says that between the Laptev and East Siberian Sea, there are 50 billion tons of "free" methane here available to come up at any time. A sudden burst of this methane would be overwhelming. There are about 5 to 6 billion tons of methane in the atmosphere now. It is imparitive that we have a method of decomposing methane ready
The Gakkle Ridge just happens to be right under this area. It is an earthquake prone area also.
Meanwhile we have a (relative) heat wave in Greenland
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