Antarctica melting?

By: Dr. Jeff Masters , 6:44 PM GMT on March 07, 2006

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Melting ice in Antarctica produced global sea level rises of 0.4 mm/year between 2002 and 2005, according to a new study published March 2, 2006 in the on-line journal Science Express. The study, titled "Measurements of Time-Variable Gravity Show Mass Loss in Antarctica", by University of Colorado researchers Isabella Velicogna and John Wahr, used satellite data from two NASA satellites called the Gravity Recovery and Climate Experiment (GRACE). The satellites measured the changing pull of gravity from the two large ice sheets covering Antarctica to determine how much ice was on the continent, and how fast the ice was changing. Most of the melting discovered was from the West Antarctic Ice Sheet. This is the smaller of the two ice sheets covering Antarctica, and holds enough ice to raise global sea levels 20 feet should it completely melt. The rock on which the West Antarctic ice rests is below sea level, and the sheet could be melting on its underside due to warming ocean waters penetrating there and melting it from both below and along the edges. The study found little melting of the huge East Antarctic Ice Sheet (which would raise global sea levels 200 feet if it were to melt). This ice sheet is on rock high above sea level, so warmer ocean waters cannot affect it. Additionally, the East Antarctic Ice Sheet has average temperatures so cold that even a 5-10C increase in temperatures is not expected to seriously threaten it.

The net Antarctic melting reported comes as a surprise, since the "official" prediction from the latest 2001 report from the Intergovernmental Panel on Climate Change is that global warming should cause increased precipitation over Antarctica this century. This increased precipitation is expected to exceed Antarctica's melting enough to decrease global sea level. This decrease in sea level by 2100 is predicted to be about 3 inches (8 cm), � 4 inches (10 cm), but would be offset by increases in sea level due to thermal expansion of the seas due to warmer water temperatures, plus melting of Greenland and glaciers on other continents.

As I reported in my blog on Greenland's greenhouse, total global sea level rise in recent years has been between 1.5 and 2.9 mm/year. Thus, the .4 mm/year contribution from Antarctica found by the new study represents a significant portion of this rise. However, another study published in December 2005 in the Journal of Glaciology titled, "Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992-2002" found a rate of melting for Antarctica five times smaller, for the earlier period 1992-2002. This research, performed by a team led by NASA scientist H. Jay Zwally, used satellite radar altimetry data from the European Remote-sensing Satellites ERS-1 and -2, and found a net melting of only .08 mm/year from Antarctica. Did Antarctica's melting really increase 5-fold in past three years? If so, is this a short term fluctuation, or indication of a long term trend? I'm of the opinion that's it's too soon to tell. It is extremely difficult to do mass balance studies of these huge ice sheets, since it requires finding a small change in a very large number. The same problem affects the recent estimates of Greenland's mass balance. The new study from the Journal of Glaciology also reported that between 1992 and 2002, the total mass of the Greenland Ice Sheet increased and thus Greenland caused a .03 mm/year decrease in sea level. This result is in contradiction to the two studies I quoted in my Greenland blog, by Box et al. (2004), who found that Greenland contributed to a net increase in global sea level of 1.5 mm/year, and Rignot et al. (2006), who found a .23 mm/year rise for the year 1996, increasing to .57 mm/year by 2005. I'd like to see at least three to five more years of satellite measurements before concluding that Antarctica or Greenland are undergoing significant melting. The European Space Agency is launching a satellite called CryoSat in March 2009 that should help answer these questions. If you want a more technical discussion of the issues, realclimate.org published a nice analysis last week.

Coverage in the press
It was interesting to watch the reaction of the press to the release of the new study. The New York Times titled their article, "Loss of Antarctic Ice Increases", and did a reasonable job covering some of the uncertainties. The USA Today was a bit more alarmist, headlining their article, "Study: Antarctic ice sheet in 'significant decline'". The Washington Post had a very alarmist title to their article, "Antarctic Ice Sheet Is Melting Rapidly". The facts and uncertainties involved in the making ice sheet balance measurements do not support this claim, as of now. Although any news of an increase in melting from Antarctica or Greenland is worthy of concern, I thought that in general, the media's headlines on the matter were too alarmist, given the uncertainties involved.

My next blog will be Thursday, when perhaps I'll be able to talk about Phoenix's first rain in 142 days. They've got a 20% chance of rain on Wednesday!

Jeff Masters

References
Box, J.E., D.H. Bromwich, and L-S Bai, 2004. Greenland ice sheet surface mass balance 1991-2000: Application of Polar MM5 mesoscale model and in situ data. J. Geophys. Res., 109, D16105, doi:10.1029/2003JD004451.

Rignot, E., and P. Kanagaratnam, "Changes in the Velocity Structure of the Greenland Ice Sheet" Science 311, 986-990, 17 February 2006, DOI: 10.1126/science.1121381

Is E.T coming? (Due)
This is a photo of myself during an Aurora Polaris. See the Alberto's comments for more information.
Is E.T coming?
Antartica (darryl2)
Antartica

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67. Lermanetdotcom
12:40 PM GMT on January 08, 2007

I would appreciate a 2nd opinion on the imagery that I have collected here:

http://www.lermanet.com/antarcticmelt/

There appears to be substantial volcanism occurring along the transantarctic mountains near ross island. Email to alerma@verizon.net

thanks

arnie lerma
66. Inyo
7:14 PM GMT on March 09, 2006
wow, four hour days, that must have been nuts. I wonder if convection was decreased due to less time in the sun, or if it just went all night. I guess back then the atmosphere wasnt in any way similar back then so who knows.

as for cyclonebuster, if i had any respect for your knowledge of physics or science in the past, it is gone now. If the tunnels are as well thought out as your 'theories' on the earth flipping over, they are a lost cause for sure.
Member Since: September 3, 2002 Posts: 42 Comments: 873
65. jeffB
5:27 PM GMT on March 09, 2006
As far as polar ice mass being redistributed toward the equator, yes, there would be a measurable effect, but only because we're really good at measuring really small changes. I'm not up to doing a back-of-the-envelope calculation, but I think we're talking far less than a millisecond even if ALL the polar ice melts.
Member Since: July 8, 2005 Posts: 0 Comments: 42
64. jeffB
5:24 PM GMT on March 09, 2006
I haven't heard about the dams having an effect on the Earth, but it would make sense. Just like the Indian Ocean Tsunami increased the day length by like 1/4 second or even less.

A lot less -- 2.68 microseconds, not 250,000. :-)
Member Since: July 8, 2005 Posts: 0 Comments: 42
63. HurricaneMyles
4:28 PM GMT on March 09, 2006
You're right in most aspect Inyo. The melting of ice is going to have a neglibible effect on the Earth. It's happened before, it will happen again, and without any consequences on the orbit or rotation of the Earth.

I haven't heard about the dams having an effect on the Earth, but it would make sense. Just like the Indian Ocean Tsunami increased the day length by like 1/4 second or even less.

Also the Earth has slowed down by a factor of 6. The Earth originaly spun so fast that a day took about 4 hours according to a study I once read. Due to the pull of the moon and the sun, we have slowed down to 24 hours in a day in the last 4 billion years. I dont remember how much we're slowing down now, but we aren't slowing very fast.

A slower Earth isn't really a bad thing, anyways. If we adjusted the calander for it we'd be gaining time during the day, while having less days in a year, doesnt sound too bad to me. This will take millions of years though, so dont expect a calander change in our lifetimes.

Member Since: January 12, 2006 Posts: 5 Comments: 827
61. MichaelSTL
3:25 PM GMT on March 09, 2006
A lot of added mass? The mass of the Earth is 5.979x10^24 kilograms (5,979,000,000,000,000,000,000,000 kg). How much effect on the mass at the Equator do you think that all of the meltwater would have (and it would be distributed across all of the oceans, not just the Equator)?
Member Since: February 22, 2006 Posts: 94 Comments: 32744
58. Cregnebaa
1:34 PM GMT on March 09, 2006
Cyclone it's all relative terms, an ice skater with their arms out has a diameter of say 6feet arms in 2feet, hense the large change in spin.

I don't think the ice melting will add another 16,000 miles of extra diameter.

Pony was agreeing it would affect the spin speed but only by a tiny amount
Member Since: October 19, 2005 Posts: 6 Comments: 323
55. Inyo
8:47 AM GMT on March 09, 2006
I agree that a lot of intellectuals tend liberal, one take might be that they are being 'indoctrined' but another take could be that smarter people just tend to be liberal :)

but on a more serious note, no, there is no way that melting glaciers are going to significantly affect the earth's movements relative to the sun or other planets. Keep in mind that huge ice sheets have covered the earth and melted back to nothing literally hundreds if not thousands of time in the earth's history. The earth didn't flip over, fly into the sun, or careen off into deep space any of those 100 times, why would it do it now?

There are tiny effects, i remember reading somewhere that all the dams on earth have changed the earth's rotation VERY slightly by moving mass around. however, i think most scientists agree that the effects of this are completely insignificant compared to volcanos, comets, solar fluxuations, natural variations in the earth's tilt, and levels of co2 in the atmosphere.

the earth is naturally slowing down in rotation, i think in the earth's history the day's length has increased by a couple of hours. However, the sun will go nova and incinerate the earth far before the effects of the rotation slowing would make a difference.

Also, since no orbit is truly stable, the moon will eventually either fall onto the earth or careen off into space. However, again, this will be long after the sun is gone and the earth is a cold, empty rock.
Member Since: September 3, 2002 Posts: 42 Comments: 873
54. Skyepony (Mod)
3:59 AM GMT on March 09, 2006
As far as the glaciers melting causing the earth to gain mass at the equator, your right on ~ it's refered to as pumpkin earth. Different thing affect the speed though, that bad tsunomi sped it up ever so slightly.
Member Since: August 10, 2005 Posts: 192 Comments: 38650
53. ForecasterColby
3:49 AM GMT on March 09, 2006
Water in contact with land does not cause friction, because land and water are not moving relative to one another.

Inyo, not all science tends liberal - but as a group, intellectuals (which scientists are definetly among) tend liberal, both in all the polls and studies I've seen and in my own experience.
50. Inyo
2:24 AM GMT on March 09, 2006
While I am (at times) beginning to wonder about the validity of the warnings we see, I am often drawn to dismiss them because they tend to come from fanatical screaming political operatives - loonies who will burn and destroy private property or worse to make their point.

What about the loonies who burn and destroy public property to make their point? I'm no fan of the idiotic eco-terrorists who clearly cause more harm to their cause than most toxic waste dumps. However, its important to remember that there are wackos from both 'sides' messing things up here.

It is very hard to keep ones opinion out of science, and i've seen papers biased both towards conservative and liberal agendas. I reject the notion that 'all science tends liberal', too...
Member Since: September 3, 2002 Posts: 42 Comments: 873
48. Cregnebaa
9:43 PM GMT on March 08, 2006
Between Bermuda and Florida
Member Since: October 19, 2005 Posts: 6 Comments: 323
47. globalize
9:18 PM GMT on March 08, 2006
Okay, I'll start. It will form very near where the little cutoff low formed a week or so ago, and head north.
That's my prediction.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
46. KatrinaRitaWilmaZeta
8:19 PM GMT on March 08, 2006
if any one like to talk about a little bit of global warming come on over i may not have march but its a little
45. globalize
8:06 PM GMT on March 08, 2006
Enough with global warming philosophy!
Where will the first hurricane to seriously affect the western hemisphere form this season? Who has a prediction?
Member Since: August 30, 2005 Posts: 0 Comments: 1150
44. KatrinaRitaWilmaZeta
7:26 PM GMT on March 08, 2006
my new blog is update and some news on it so come on by and drop me a post
43. StellarCyclone
7:21 PM GMT on March 08, 2006
While the current natural effects may not lead to global extinction, "life" is likely to get unpleasant on a large scale. "Global unpleasantness" will likely not be handled very well by us humans. Our usual methods of handling large scale unpleasantness: economic exploitations, wars, etc., could easily bring "us" to the brink of our own global extinction. Being an optimist, I believe we will find a better way by learning from one another and developing ethically and spiritually. But there's certainly no guarantee that this will become the dominant trend which brings us back to the prospect of large scale oppression or extinction.
42. ForecasterColby
7:11 PM GMT on March 08, 2006
Another thing to just note - the same people spouting "OMG GLOBAL WARMING WE ALL GONNA DIE!!" were pretty much the same ones spouting "OMG GLOBAL COOLING WE ALL GONNA DIE!!" two decades ago.
41. HurricaneMyles
6:38 PM GMT on March 08, 2006
globalize,

Life is not going to go extinct from global warming. It is far too tenacious then to fall to hotter temperatures. It has survived ice ages, which is far more hostile conditions then hot temperatures. Humans have a chance to go, but more likely from an ice age then global warming. A warmer Earth is not going to become completely desert, which other then icy tundra, is the hardest place for humans to survive. Any other type of landscape, we can deal with pretty well.

As far as relating today to the dark ages, that's a bit of a stretch. We may still have religious fanatics, but we aren't burning witches, persecuting scientists, banning books, or charging people who work on the Sabbath day as criminals. Plus we're just a little more advanced in tech then we were then. Besides that, yeah, we're in the dark ages.
Member Since: January 12, 2006 Posts: 5 Comments: 827
40. globalize
5:48 PM GMT on March 08, 2006
HurricaneMyles... I think you are right about a possible return to 'dark age' mentality, but in actual fact are we not already there? Look at the people in high places in government, politics, to the supposed right or left...and they are showing you their best side!!
But I think you are wrong about life extinct on the earth, human life in particular. Being physically the most dense life form, human beings are also the most sensitive to these changes.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
39. KatrinaRitaWilmaZeta
5:31 PM GMT on March 08, 2006
any one see theboldman around ????
38. gcain
4:24 PM GMT on March 08, 2006
I'm not a scientist, but I recently took an Alaska cruise and seeing the melting conditions of the great glaciers there will cause any thinking person to be alarmed about "global warming, etc." Whether we (humans) are to blame or not, I'm not sure...the impact on the future of the human condition is more to the point. I can only imagine it's like trying to get a freight train to stop...once it gets moving, stopping is a long slow process...so it will go with global warming at either pole. I guess we can just sort of sit around and watch, or governments (and scientists) can begin to find some possible solutions (if there are any)...or at least begin thinking about solutions to the conditions that will result. Being in my 60s I doubt that I will have to worry too much about it, but generations in the future might see some tangible results in land use, climate, food production, expansion of extreme ecological conditions, etc...I just hope we are not going to look like Nero and his fiddle--and Rome burned! Sometimes, we cannot afford to just keep collecting data to be absolutely sure we have all the answers...Data is great but if it is not used to modify some behavior or to generate some action, then it is meaningless--except for someone's dissertation...
37. HurricaneMyles
4:24 PM GMT on March 08, 2006
Globalize,

Life is not going to go extinct because of global warming. The Earth has been much warmer before, with much more CO2 in the atmosphere, and life thrived. I think the question is whether human civilization will do what it normally does, and fight each other over the problem, instead of trying to figure out how to deal with it. If we choose the former, we drive ourselves back to the dark ages, or worse.
Member Since: January 12, 2006 Posts: 5 Comments: 827
36. jeffB
4:12 PM GMT on March 08, 2006
cyclonebuster, if you really want to come up with a tunnel proposal that people will take seriously, you have to get familiar with basic concepts like conservation of momentum, thermal equilibrium, and so forth.

For example, water at the ocean surface can be cooler than deeper water due to radiation, evaporation, and probably even conduction to the air, although I'd expect the first two to dominate. I don't have enough physics background to put numbers on it, but it seems pretty clear that these factors are larger than the factor of convection from below.
Member Since: July 8, 2005 Posts: 0 Comments: 42
35. globalize
3:57 PM GMT on March 08, 2006
Probably, the laws of physics which apply to gravity, bodies in motion and at rest are not very sensitive to the form of matter. Look at the planets which are in a primarily gaseous state, which whirl and orbit right on.
Global warming probably will not take the earth out of orbit and set it jetting toward the Sun, but will just make life more difficult, perhaps impossible for living creatures here. And whether the warming earth is a result of man's actions or not is irrelevant. If people, and their governments looked on the environment as relevant, the question as to whether man is causing the problem could be answered.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
34. Baynative
3:04 PM GMT on March 08, 2006
Will the real issue be lost to politics?

Do some people discount the message because of the messenger?

While I am (at times) beginning to wonder about the validity of the warnings we see, I am often drawn to dismiss them because they tend to come from fanatical screaming political operatives - loonies who will burn and destroy private property or worse to make their point.

Subsequently, when I read a seemingly well researched position from a college professor I immediately look to see what institution he or she represents. Some institutions discount the message, in my mind because of their deportment in other political disciplines.

When a university tenures and supports outspoken fanatics with questionable resume's and backgrounds such as Ward Churchill at CU or Angela Davis at UC, what does it say about other departments or spokespersons and their agandas?

I know everyone should be judged on their own merits but distinguishing the philosophy of the institution from the integrity of one individual isn't easy - for me.
33. michalp
1:50 PM GMT on March 08, 2006
>> What if the ice melts and changes the ocean currents and higher water levels creates more friction on the land masses and slows the Earth down over time.

that makes little sense. momentum has to be conserved.

What could happen though is similar forces to the ones that cause the jet stream could, perhaps, in theory, slow the earth. All that water at the poles is doesn't have much momentum, so when it melts and flows away from the poles it will have to speed up to go with the spin of the earth, similar to what causes the jet stream. This could in theory slow the earth. I don't expect the effect to be much worse than an el nino though.
31. Inyo
7:24 AM GMT on March 08, 2006
i dont think all of the pink has melted.. its just starting to melt in those areas right?


Posted By: cyclonebuster at 3:12 AM GMT on March 08, 2006.
Inyo,
The Earth being round used to be myth also at one time.


Well, the romans knew it was round, people just forgot during the Dark Ages and silly myths took over.

Ever stood on a really tall mountain? Anyone who's done that knows the earth is at least curved.

anyway even if there were some mechanism to flip the earth over (there isnt), the spin of the earth has a very stabilizing effect like a gyroscope. So anything other than slight wobbles in the axis are an impossibility barring the moon falling onto the earth or something.. and if that happened it wouldnt matter which way it was spinning.
Member Since: September 3, 2002 Posts: 42 Comments: 873
30. Fshhead
7:04 AM GMT on March 08, 2006
Any possibility of the Earth flipping over on its axis if one pole melts at a faster rate than the other?

Well, maybe if we put all the alarmists on the south pole...


Hey..... Your not putting me on the south pole LOL
Member Since: November 19, 2005 Posts: 9 Comments: 9960
29. Fshhead
6:57 AM GMT on March 08, 2006
Skepony,
That really shows the melting!!!!!!!!!!!!
That's ALOT of water!!!!!!!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
28. Skyepony (Mod)
4:19 AM GMT on March 08, 2006
Greenland's ice ~ credit University of Colorado
Member Since: August 10, 2005 Posts: 192 Comments: 38650
27. KatrinaRitaWilmaZeta
4:13 AM GMT on March 08, 2006
i have more new on Antarctica icy on my blog as well so any one like to come take a look at it come to my blog and drop me a post
26. Skyepony (Mod)
4:01 AM GMT on March 08, 2006
Think about the differnce, in time, between winter solctice (Dec 15th) & the coldest part of the year. That's how long it takes for the atmosphere to feel the full effects of the sun shining on the earth for the shortest ammount in a day. The ocean is much thicker than the atmosphere so the effects of winter take even longer to show themselves.
Member Since: August 10, 2005 Posts: 192 Comments: 38650
24. Skyepony (Mod)
3:36 AM GMT on March 08, 2006
The cold fronts are cooling only the surface, it takes time for all that heat to rise & disapate. At 200 meters the gulf stream is about as hot as the surface.
Member Since: August 10, 2005 Posts: 192 Comments: 38650
23. DenverMark
3:31 AM GMT on March 08, 2006
Inyo,
I'm hoping a fair amount of moisture makes it into Colorado's southwestern mountains, too. At least some snow is forecast there on and off for the next five days. Our snowpack up in northern Colorado is normal or a little above, but it's only 40% of normal in the San Juan Mountains.

We're expecting 2-4" of snow in Denver tomorrow. Yes, maybe even Phoenix can get a little rain out of this.
Member Since: February 11, 2006 Posts: 125 Comments: 6988
21. Skyepony (Mod)
3:14 AM GMT on March 08, 2006
Check out how much higher the 100 meter temps are compared to the SST.
Member Since: August 10, 2005 Posts: 192 Comments: 38650
19. DenverMark
3:00 AM GMT on March 08, 2006
Checking the trusty Wikipedia, the March Hurricane of 1908 did reach Cat 2. Hurricane Able in May 1951 reached Cat 3. I'd agree with HurricaneMyles, SST's are not warm enough for a Cat 5, even as crazy as the last couple of years have been.
Member Since: February 11, 2006 Posts: 125 Comments: 6988
18. Inyo
2:58 AM GMT on March 08, 2006
yeah there is a zero percent chance of the earth flipping over. remember, gravity goes towards the center of the earth, not towards the south.

It's a fair question for someone with no science background but didnt you claim to have done all that physics associated with the tunnels, etc? The earth flipping over, tsunamis causing hurricanes, magnetic pole reversals causing hurricanes, etc, are all myths.

Also... i hope phoenix gets that rain this Thursday. Here in southern California, we have a much higher likelihood of rain.. and snow. Snow levels could skim the tops of the higher valleys.. and like i posted earlier, Vegas has a shot of snow too. It would be weird for this time of the year... but not unheard of i would imagine. Fresno has seen snow as late as around march 26th. They may get some this weekend too.
Member Since: September 3, 2002 Posts: 42 Comments: 873
17. ForecasterColby
2:43 AM GMT on March 08, 2006
Carina was, with 155 mph winds, over an area that at the time had a max potential of 135.

Any possibility of the Earth flipping over on its axis if one pole melts at a faster rate than the other?

Well, maybe if we put all the alarmists on the south pole...

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.