|
Post by william on Aug 20, 2010 13:21:03 GMT
|
|
|
Post by steve on Aug 20, 2010 13:52:50 GMT
hunter
I said there were at least two other methods for analysing the data in addition to GRACE. Have you and Icefisher started the weekend early this week?
William,
Antarctica seems to be cooling in some places and warming in others. Also, we probably don't know what is happening in the ocean.
Regardless of whether it is cooling or warming, Antarctica will always lose ice through the flow and calving of glaciers - the ice does not have to melt. Whether Antarctica loses mass will depend more on the rate of loss of ice through calving compared with the rate of precipitation of fresh snow.
Re: the Liu and Curry paper, the press release seemed to be more about the mechanism for maintaining sea ice while the ocean warmed rather than on temperature reconstructions of the sea surface temperature (which mostly derive from elsewhere). But the paper just seems to be mostly a model analysis with emphasis on the hydrological cycle. Not that exciting really.
|
|
|
Post by nautonnier on Aug 20, 2010 14:36:40 GMT
hunter I said there were at least two other methods for analysing the data in addition to GRACE. Have you and Icefisher started the weekend early this week? William, Antarctica seems to be cooling in some places and warming in others. Also, we probably don't know what is happening in the ocean. Regardless of whether it is cooling or warming, Antarctica will always lose ice through the flow and calving of glaciers - the ice does not have to melt. Whether Antarctica loses mass will depend more on the rate of loss of ice through calving compared with the rate of precipitation of fresh snow. Re: the Liu and Curry paper, the press release seemed to be more about the mechanism for maintaining sea ice while the ocean warmed rather than on temperature reconstructions of the sea surface temperature (which mostly derive from elsewhere). But the paper just seems to be mostly a model analysis with emphasis on the hydrological cycle. Not that exciting really. Steve have you any concept of the sheer size of Antarctica? Its around about the size of the continental US and Mexico. It has a peninsula that is warming apparently due to volcanism that is around the size of UK. Not 'several places' warming. So this is like the entire continental US and Mexico getting colder but volcanoes warming Cancun - and you give this as a reason for 'loss of ice' ? The paper on the affect of warming southern oceans appears to have missed the fact that the southern oceans are actually cooling. Not only that the amount of sea ice around Antarctica has been growing at a steady rate. It is strange that although the increase in ice can be seen to be true - GRACE does not appear to notice it. Perhaps some validation checks should be made.
|
|
|
Post by steve on Aug 20, 2010 15:16:41 GMT
nautonnier
I don't see the relevance of the size of Antarctica. The idea that the peninsula is warming due to volcanic activity is laughable. Some of the references provided in the wikipedia page mentioned by William support what I have said (some places warming, some cooling - I will add that "some" doesn't just mean the peninsular).
I haven't really commented on the temperature of the southern ocean, I've observed that the slight upward sea ice trend is regarded as proof of cooling whereas the downward land ice trend is ignored or wished away. I am regularly informed that the far more spectacular ice loss in the Arctic is substantially due to unfortunate winds, so I don't see why there is such a different standard of proof down south.
I hope I have misunderstood you. GRACE has the ability to identify the reductions in land ice. It would not be able to identify a change in sea ice as it is a gravity sensor.
|
|
|
Post by sigurdur on Aug 20, 2010 15:21:21 GMT
Steve said: "I hope I have misunderstood you. GRACE has the ability to identify the reductions in land ice. It would not be able to identify a change in sea ice as it is a gravity sensor. "
It measures what it has been programed to measure Steve. Grace can be used as one metric at this point.
|
|
|
Post by william on Aug 20, 2010 17:03:45 GMT
Steve,
There is no evidence or mechanism to explain increased flow and calving of the Antarctic Ice Sheet.
The Greenland ice sheet surged and then stopped surging. Why the Greenland ice sheet surged and then stopped surging is not known.
When the Greenland ice sheet surged, some researchers extrapolated the increase to justify a goofy sea level rise. When the Greenland ice sheet stopped surging the goofy analysis was not corrected.
The GRACE Antarctic ice sheet loss is in the center of the ice sheet. There is no explanation as to how that section can lose mass.
There is something else that is affecting the GRACE measurement.
|
|
|
Post by sigurdur on Aug 20, 2010 17:14:43 GMT
Steve, There is no evidence or mechanism to explain increased flow and calving of the Antarctic Ice Sheet. The Greenland ice sheet surged and then stopped surging. Why the Greenland ice sheet surged and then stopped surging is not known. When the Greenland ice sheet surged, some researchers extrapolated the increase to justify a goofy sea level rise. When the Greenland ice sheet stopped surging the goofy analysis was not corrected. The GRACE Antarctic ice sheet loss is in the center of the ice sheet. There is no explanation as to how that section can lose mass. There is something else that is affecting the GRACE measurement. William: Now we are getting to the nuts and bolts of this. I don't know if I can find it, but there was some question as to Graces' programming, that there might be something a bit off in it. Read it about a year ago and figured someone would fix it.
|
|
|
Post by socold on Aug 20, 2010 18:07:51 GMT
"It has a peninsula that is warming apparently due to volcanism"
hahaha
|
|
|
Post by sigurdur on Aug 20, 2010 18:22:12 GMT
"It has a peninsula that is warming apparently due to volcanism" hahaha Socold: While that idea might have a small amount of merit, I don't think that is the root cause of the peninsula warming.
|
|
|
Post by socold on Aug 20, 2010 18:33:01 GMT
|
|
|
Post by icefisher on Aug 20, 2010 18:54:59 GMT
I haven't really commented on the temperature of the southern ocean, I've observed that the slight upward sea ice trend is regarded as proof of cooling whereas the downward land ice trend is ignored or wished away. I am regularly informed that the far more spectacular ice loss in the Arctic is substantially due to unfortunate winds, so I don't see why there is such a different standard of proof down south. Well you have to admit Steve that the alleged west Antarctic ice loss isn't a measurement of ice at all. As you pointed out Grace is a "gravity sensor". Changes in gravity mass in the region of antarctica isn't uniform across antarctica, isn't anomolous in the same direction, is very minor and less than gravity changes in many other non-ice sectors of the globe. The new satellite is sending back tantalizing images of big changes at plate boundaries like in Indonesia. West antarctica where the biggest negative (alleged ice) anomaly is occurring is also a plate boundary. The average coolness in antarctica the growing sea ice provide nice offsets to alleged ice loss. Yet to be learned are these LIA cycles and what triggers them and how frequent they are and what their amplitudes are. I think it is incredibly tantalizing that we are undergoing the solar changes we are, that we have the Livingston Penn work on sunspots and a possible minima not seen for a couple of hundred potentially in the works. As Akasofu sagely points out focusing on the cause and processes of natural variations is crucial in segregating any AGW signal even as you prefer to just reject the notion out of hand and simply look to a single suspect via heavy cherry picking of science. There is nothing more anti-science than ignoring the hundreds of studies on historic global temperature records and focus exclusively on a handful of studies that comes from a handful of conspirators and trust fund gigolos whose primary empowerment has been politics and whoring. It is one thing to measure thinning ice and another to understand what is causing it. Apparently nobody even thought of that until the sun started doing some unique things.
|
|
|
Post by scpg02 on Aug 20, 2010 20:49:46 GMT
Yet to be learned are these LIA cycles and what triggers them and how frequent they are and what their amplitudes are. We may need several thousand years of data to learn that.
|
|
|
Post by astroposer777 on Aug 20, 2010 21:40:07 GMT
Figure 1: Ice mass changes (solid lines with circles) and their best-fitting linear trends (dashed line) for the West Antarctica Ice Sheet (red) and East Antarctica Ice Sheet (green) for April 2002 to August 2005 (Velicogna 2007). It must have snowed more in the east than in the west. Since the data for Antarctica is very limited in its scope, I guess any hypothesis is valid.
|
|
|
Post by nautonnier on Aug 20, 2010 22:19:08 GMT
"It has a peninsula that is warming apparently due to volcanism" hahaha "Under the frozen continent's western-most ice sheet, the volcano erupted about 2,300 years ago yet remains active, according to a study published Sunday in an online issue of the journal Nature Geosciences.
"We believe this was the biggest eruption in Antarctica during the last 10,000 years," said study co-author Hugh Corr, a glaciologist for the British Antarctic Survey (BAS). "It blew a substantial hole in the ice sheet, and generated a plume of ash and gas that rose around 12 kilometers (7.5 miles) into [the] air."
Although ice buried the unnamed volcano, molten rock is still churning below. David Vaughan, a glaciologist with the BAS and a co-author of the new study, said the discovery might explain the speeding up of historically slow-moving glaciers in the region.
“This eruption occurred close to Pine Island Glacier on the West Antarctic Ice Sheet," Vaughan said. "The flow of this glacier towards the coast has speeded up in recent decades, and it may be possible that heat from the volcano has caused some of that acceleration." "www.livescience.com/environment/080120-antarctic-volcano.html"Scientists Find Active Volcano in Antarctica By KENNETH CHANG Published: January 21, 2008 Here is another factor that might be contributing to the thinning of some of the Antarctica’s glaciers: volcanoes. In an article published Sunday on the Web site of the journal Nature Geoscience, Hugh F. J. Corr and David G. Vaughan of the British Antarctic Survey report the identification of a layer of volcanic ash and glass shards frozen within an ice sheet in western Antarctica. For Antarctica, “This is the first time we have seen a volcano beneath the ice sheet punch a hole through the ice sheet,” Dr. Vaughan said. Heat from a volcano could still be melting ice and contributing to the thinning and speeding up of the Pine Island Glacier, which passes nearby, but Dr. Vaughan doubted that it could be affecting other glaciers in West Antarctica, which have also thinned in recent years. Most glaciologists, including Dr. Vaughan, say that warmer ocean water is the primary cause."[/i] www.nytimes.com/2008/01/21/world/21volcano.html"Scientists Discover Undersea Volcano Off AntarcticaScienceDaily (May 31, 2004) — ARLINGTON, Va. -- Scientists working in the stormy and inhospitable waters off the Antarctic Peninsula have found what they believe is an active and previously unknown volcano on the sea bottom The international science team from the United States and Canada mapped and sampled the ocean floor and collected video and data that indicate a major volcano exists on the Antarctic continental shelf, they announced on May 5 in a dispatch from the research vessel Laurence M. Gould, which is operated by the National Science Foundation (NSF) Evidence of the volcano came as an unintended bonus from a research plan to investigate why a massive ice sheet, known as the Larsen B, collapsed and broke up several years ago. Scientists hope to understand whether such a collapse is unique or part of a cycle that extends over hundreds of thousands of years. "Highly sensitive temperature probes moving continuously across the bottom of the volcano revealed signs of geothermal heating of seawater. The heating was noticed especially near the edges of the feature where the freshest rock was observed." "These observations, along with historical reports from mariners of discolored water in the vicinity of the submerged peak, indicate that the volcano has been active recently."[/i] www.sciencedaily.com/releases/2004/05/040527235943.htm"Surprise! There’s an active volcano under Antarctic ice"wattsupwiththat.com/2008/01/22/surprise-theres-an-active-volcano-under-antarctic-ice/"Antarctic volcanoes punching holes in the ice "The Antarctic Peninsula is a bit like Britain for its changing maritime weather. Its climate is the most variable of all Antarctica, and the one that is showing fast warming. The ice cap that still smothers the peninsula has grown and shrunk rapidly over the last few million years in response to climate change. At the same time, there have been loads of volcanoes. Tuyas all over the place and rapid ice cap fluctuation are a key to understanding the climate of the past."www.royalnavy.mod.uk/operations-and-support/surface-fleet/antarctic-patrol-ship/hms-endurance/antarctic-volcanoes/And of course if there are magma chambers and moving magma GRACE would pick that up. Still braying like an ass SoCold???
|
|
|
Post by icefisher on Aug 21, 2010 0:16:23 GMT
Still braying like an ass SoCold??? Here is a real nice animation of 7 years of antarctica elevation fluctuation. Its peanuts compared to now much land masses heave annually around the equator where there is no ice. Its 11mb with 79 frames so I didn't post it as an image. upload.wikimedia.org/wikipedia/commons/1/15/Global_Gravity_Anomaly_Animation_over_LAND.gifThey have no idea of what the cause of the teensy fluctuation of the antarctica which just goes to show how far they go to make their case. A butterfly opens it wings in Brazil and its global warming in Texas. Its the Al Gore sandpile theory in action. His creed is you can make a political campaign and fill his pocketbook with anything you want to make a campaign issue on just by playing upon people's fears. . . .he is just one of the world's most successful snake oil salesmen.
|
|