Antarctica Conumdrum

Nov 30, 2006
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Contrary to previous "scientific consensus", it appears that the ice mass of Antarctica is actually increasing and effectively slowing sea level rise. This poses some interesting questions. More detailed studies to follow to confirm these results and provide more accuracy, but this one appears to be a huge myth buster.

http://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses

Oct. 30, 2015

NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses

A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008.

“We’re essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica,” said Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published on Oct. 30 in the Journal of Glaciology. “Our main disagreement is for East Antarctica and the interior of West Antarctica – there, we see an ice gain that exceeds the losses in the other areas.” Zwally added that his team “measured small height changes over large areas, as well as the large changes observed over smaller areas.”

Scientists calculate how much the ice sheet is growing or shrinking from the changes in surface height that are measured by the satellite altimeters. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean, the surface height changes and the ice-sheet mass grows or shrinks.

But it might only take a few decades for Antarctica’s growth to reverse, according to Zwally. “If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they’ve been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years -- I don’t think there will be enough snowfall increase to offset these losses.”

The study analyzed changes in the surface height of the Antarctic ice sheet measured by radar altimeters on two European Space Agency European Remote Sensing (ERS) satellites, spanning from 1992 to 2001, and by the laser altimeter on NASA’s Ice, Cloud, and land Elevation Satellite (ICESat) from 2003 to 2008.

Zwally said that while other scientists have assumed that the gains in elevation seen in East Antarctica are due to recent increases in snow accumulation, his team used meteorological data beginning in 1979 to show that the snowfall in East Antarctica actually decreased by 11 billion tons per year during both the ERS and ICESat periods. They also used information on snow accumulation for tens of thousands of years, derived by other scientists from ice cores, to conclude that East Antarctica has been thickening for a very long time.

“At the end of the last Ice Age, the air became warmer and carried more moisture across the continent, doubling the amount of snow dropped on the ice sheet,” Zwally said.

The extra snowfall that began 10,000 years ago has been slowly accumulating on the ice sheet and compacting into solid ice over millennia, thickening the ice in East Antarctica and the interior of West Antarctica by an average of 0.7 inches (1.7 centimeters) per year. This small thickening, sustained over thousands of years and spread over the vast expanse of these sectors of Antarctica, corresponds to a very large gain of ice – enough to outweigh the losses from fast-flowing glaciers in other parts of the continent and reduce global sea level rise.

Zwally’s team calculated that the mass gain from the thickening of East Antarctica remained steady from 1992 to 2008 at 200 billion tons per year, while the ice losses from the coastal regions of West Antarctica and the Antarctic Peninsula increased by 65 billion tons per year.

“The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away,” Zwally said. “But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for.”

“The new study highlights the difficulties of measuring the small changes in ice height happening in East Antarctica,” said Ben Smith, a glaciologist with the University of Washington in Seattle who was not involved in Zwally’s study.

"Doing altimetry accurately for very large areas is extraordinarily difficult, and there are measurements of snow accumulation that need to be done independently to understand what’s happening in these places,” Smith said.

To help accurately measure changes in Antarctica, NASA is developing the successor to the ICESat mission, ICESat-2, which is scheduled to launch in 2018. “ICESat-2 will measure changes in the ice sheet within the thickness of a No. 2 pencil,” said Tom Neumann, a glaciologist at Goddard and deputy project scientist for ICESat-2. “It will contribute to solving the problem of Antarctica’s mass balance by providing a long-term record of elevation changes.”
 

fskimospy

Elite Member
Mar 10, 2006
86,726
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Contrary to previous "scientific consensus", it appears that the ice mass of Antarctica is actually increasing and effectively slowing sea level rise. This poses some interesting questions. More detailed studies to follow to confirm these results and provide more accuracy, but this one appears to be a huge myth buster.

http://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses

I was unaware that there was a scientific consensus about Antarctic ice levels? That would be a very specific consensus, indeed. If you're referring to scientific consensus, that would be on anthropogenic climate change, which the author of that paper is in full agreement with, and mentions is in fact causing ice melting in Antarctica that is accelerating as the climate continues to warm.

From the paper's author:
"Climate warming is taking place in the Antarctic, but to a lesser extent than it is in the Arctic or the rest of the world," he told VICE News. "It's affecting part of Antarctica, the peninsula and West Antarctica, which are losing mass faster now than they did 10-15 years ago. But the large interior of Antarctica is gaining mass."

The study also stopped in 2008, and more recent satellite measurements show net ice loss in Antarctica in the seven years since:

antarctic_iceloss_2002-2014.jpg.CROP.original-original.jpg


So can you point to precisely what scientific consensus this is contrary to and precisely what myth was 'busted'?
 
Nov 30, 2006
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So can you point to precisely what scientific consensus this is contrary to and precisely what myth was 'busted'?
The myth I'm talking about is the commonly held belief that Antarctica is contributing to sea level rise...it isn't.
 

Paratus

Lifer
Jun 4, 2004
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It's an interesting piece all right but as usual you cherry picked the conclusions you wanted.

The researchers noted that the deposit of snow has been constant but that ice loss has been increasing, doubling over the last two decades. The data also only goes through 2008 after which the rate of loss continued to increase. The authors note that in less than 20 years the rate of loss will be greater than snow deposition.

The study also needs to be cross correlated with other satellite readings which show more ice loss using different methods, (Specifically NASAs Grace satellite). One of the difference is that using satellite altimeter data which this study used doesn't take into account the varying density of the newly formed snow and ice. Snow compacts into ice the deeper it is meaning the top layers contain less H2O than lower layers.

Either way Greenland is losing over twice as much per year than Antartica.

landiceloss_2002-2015.jpg.CROP.original-original.jpg


So an interesting finding that climate scientists will use to improve our understanding of the climate and "skeptics" will cherry pick to prove to themselves how right they are.

Carry on.
 
Nov 30, 2006
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It's an interesting piece all right but as usual you cherry picked the conclusions you wanted.

The researchers noted that the deposit of snow has been constant but that ice loss has been increasing, doubling over the last two decades. The data also only goes through 2008 after which the rate of loss continued to increase. The authors note that in less than 20 years the rate of loss will be greater than snow deposition.

The study also needs to be cross correlated with other satellite readings which show more ice loss using different methods, (Specifically NASAs Grace satellite). One of the difference is that using satellite altimeter data which this study used doesn't take into account the varying density of the newly formed snow and ice. Snow compacts into ice the deeper it is meaning the top layers contain less H2O than lower layers.

Either way Greenland is losing over twice as much per year than Antartica.

landiceloss_2002-2015.jpg.CROP.original-original.jpg


So an interesting finding that climate scientists will use to improve our understanding of the climate and "skeptics" will cherry pick to prove to themselves how right they are.

Carry on.
I bolded the actual statement from the lead author of the study. But hey...what the fuck does he know? Phil Plait is clearly the 'go to' guy for climate science information! I see that you neglected to provide the link to his Slate blog you used as the source of your graphs as well as the points you regurgitated. And I never knew that astronomers were so well versed in climate science. Nice source!
 
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momeNt

Diamond Member
Jan 26, 2011
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“The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away,” Zwally said. “But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for.”

Umm, lemme guess. RAIN?

I answered that without a PhD, with a GRE level education.

Scientists, paid to sit around and be idiots, that's what that stands for.
 

Paratus

Lifer
Jun 4, 2004
17,318
14,990
146
Contrary to previous "scientific consensus", it appears that the ice mass of Antarctica is actually increasing and effectively slowing sea level rise. This poses some interesting questions. More detailed studies to follow to confirm these results and provide more accuracy, but this one appears to be a huge myth buster.

http://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses

I bolded the actual statement from the lead author of the study. But hey...what the fuck does he know?

I'm not arguing the authors conclusion I'm arguing with yours. ;)
 

Paratus

Lifer
Jun 4, 2004
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14,990
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Umm, lemme guess. RAIN?

I answered that without a PhD, with a GRE level education.

Scientists, paid to sit around and be idiots, that's what that stands for.


Rain comes from the evaporation of sea and ground water. It then returns to the sea and ground. You may remember this from third grade science.

Or is my sarcasm meter on the fritz? :hmm:
 

alien42

Lifer
Nov 28, 2004
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neither conundrum nor myth buster found, just a joker with comprehension problems.
 

momeNt

Diamond Member
Jan 26, 2011
9,290
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Rain comes from the evaporation of sea and ground water. It then returns to the sea and ground. You may remember this from third grade science.

Or is my sarcasm meter on the fritz? :hmm:

Okay, so where is the extra water coming from? Are we combining hydrogen and oxygen and dumping it in ocean? Is that what everybody means by man made sea level rising?
 

momeNt

Diamond Member
Jan 26, 2011
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352
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I'm not sure who I should congratulate more, the OP for posting an article with almost 10 year old data, or NASA? Both are full of scientists.... sorry I mean shit.
 
Nov 30, 2006
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I'm not sure who I should congratulate more, the OP for posting an article with almost 10 year old data, or NASA? Both are full of scientists.... sorry I mean shit.
Study was just published...apparently the satellite data analysis was quite difficult.
 

Paratus

Lifer
Jun 4, 2004
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Okay, so where is the extra water coming from? Are we combining hydrogen and oxygen and dumping it in ocean? Is that what everybody means by man made sea level rising?

Did you miss the graph of Greenland? Water also expands as it heats. The oceans are warmer.

Antartica is also contributing water, however this study suggests that snowfall more than makes up for Antarticas contribution for the time being.
 

K7SN

Senior member
Jun 21, 2015
353
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I'm not arguing the authors conclusion I'm arguing with yours. ;)

That is just one of the Earth self-correcting mechanisms that are understudied when we concentrate so much on the current warm phase of Climate Change and not the relative significance of anthropogenic inducted climate change factors. I was having fun and learning while debating with you in a previous thread; want to challenge my conclusion and continue in our polite debate.
 
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Nov 30, 2006
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“The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away,”
The statement from the lead author of the study carries zero weight with him...he apparently prefers to get his climate science "facts" from an astronomer who blogs for Slate.
 

JSt0rm

Lifer
Sep 5, 2000
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The statement from the lead author of the study carries zero weight with him...he apparently prefers to get his climate science "facts" from an astronomer who blogs for Slate.


How about we just have a cleaner environment for all. I recently read a comment from someone on a news site that went something liek this:

"who cares about tigers? We have no use for them and they are dangerous. We do need wood though."


we are doomed.
 

Paratus

Lifer
Jun 4, 2004
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You regurgitated a graph and talking points from a blog on a liberal rag that was authored by an astronomer. You see anything wrong with this picture?

http://www.slate.com/blogs/bad_astronomy/2015/11/03/antarctic_ice_still_losing_mass.html

The comments about the differences between laser altimetery and gravitational measurements come from Robin Bell at Columbia and Gavin Schmidt at NASA.

They suggest a potential area for further study which you yourself said should happen. So why are your panties in a bunch?
 

buckshot24

Diamond Member
Nov 3, 2009
9,916
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How about we just have a cleaner environment for all.
We can have a cleaner environment to go visit the millions who potentially will lose their lives by restricting the usage of fossil fuel energy.