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Antarctica melting?

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

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

Climate Change

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

One must always remember that with incomplete data, anyone can conclusively prove anything they want by discarding "unreliable data"--i.e., data that did not support their pet hypothesis. Good science keeps an open mind to all options that are testable, then waits for a conclusive pattern to emerge, without having to massage the numbers.
CryoSat was lost due to launch vehicle failure on Oct. 8, 2005. A replacement is scheduled for 2009.
The recent spate of reports indicating increasing melting at Antarctica and Greenland may not yet be definitive--but they do worry me.

I remember back in the early 1980s reading reports that greenhouse warming and icemelt could cause a 1 meter rise in sea level by 2075. Then in the late 1980s and 1990s a lot of studies predicted that increased snowfall on ice sheet would slow down sea level rise to less than half that. Now melting seems to be happening more quickly than predicted. Maybe the old studies were right!
By the way, look at the area capable of supporting a Category 5 in the Caribbean, as well as the Category 4 potential in the central Gulf of Mexico...


Posted By: gippgig (12.77.66.19) at 2:18 PM EST on March 07, 2006.
CryoSat was lost due to launch vehicle failure on Oct. 8, 2005. A replacement is scheduled for 2009.


Thanks, I had the wrong year in there, I changed it to 2009.

Jeff Masters
Michael, I dont know where that analysis comes from (web page please) but the water temps here on the GA coast are in the 13-14 C range (55-58F) and could not possibly support tropical cyclones despite what your chart says. At the National Data Buoy Center Link I could find no buoys in the Gulf of Mexico with an 80F reading, and temps in the 70s will not sustatin major hurricanes. The warmest reading I found in the Caribbean was 80.1F So I am curious what methodology is used to create that chart.
The media is in the alarmist business. Reporting on anything in a calm manner using only the facts would be a betrayal of their principles.
StSimonsIslandGAGuy - See this page.
There maps are using the absolute maximum potential with absolutely perfect conditions for tropical cyclone intensity. They are assuming that a cyclone could become 100% efficient( most likely impossible). Look at the SST reading, 26.5C, which is 79.7F, or around the accepted absolute minimum SST a storm needs. That is where Cat 4+ is possible in the Caribbean over to Africa. I guess, like the late Nov/Dec storms that formed under the 80F SST threshold, atmospheric heat distribution could be even more favorable, allowing for more intensification, up to a Cat 3 outside the Caribbean in the GoM and up the gulf stream. Remember these are with absolute perfect conditions, so dont expect a Cat 5 anytime we have SST barely near 80F.
I will just point out at this point that Wilma did indeed hit the max potential - and Carina smashed it to bits.
ForecasterColby,
Are you saying that Carina got above its supposed maximum intensity?
Maximum Potential Intensity for the South Indian Ocean still shows the effects of Carina's passage in an area of lower maximum intensity; however, it can still support a Category 5 storm (it has warmed back up some since Carina dissipated). It is likely that the area where Carina passed through was able to support a Category 5 storm before, as the surrounding (uncooled) areas can now.

Scroll down here
Folks, don't know if you saw this on other sites, however i saw additional information indicating that increased solar storms will put our weather sats at risk greater risk, particularly since they're underfunded at present and subject to NASA funding cuts. What are your thoughts?

More Solar Storms on the Horizon
By Richard A. Kerr
ScienceNOW Daily News
6 March 2006

Astronauts, power grid operators, and satellite managers had better watch out come 2012. Based on a computer simulation of the sun's interior, solar scientists warned today that in 6 years the activity of dark spots on the surface will, with a single exception, be greater than it has been at any point since 1880. The accompanying solar storms could play havoc with satellite communications and threaten space station astronauts.
The key to an accurate prediction of solar activity is the realization that the sun's magnetic memory extends back not just one but up to three 11-year sunspot cycles, say solar physicists Mausumi Dikpati, Peter Gilman, and Giuliana de Toma of the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. Predictions based on just the present strength of the magnetic field near the sun's poles--that is, the lingering remnants of the previous cycle's sunspots--call for an especially weak sun spot cycle.

But the NCAR researchers ran their new model of the solar interior fed with observations since 1880 to see how far back past cycles influence the coming one. They found that it takes roughly 20 years for the magnetic remnants of past sunspots to recirculate deep into the interior, to be amplified by the twisting action of the sun's rotation, and to rise back to the surface near the equator as the next cycle's sun spots. Given the model's impressively accurate "hindcasting" of the size and timing of past cycles, Dikpati told a media teleconference today that she is confident "predicting the next solar cycle will be 30% to 50% stronger than the last solar cycle." The next cycle will begin 6 to 12 months later than average, in late 2007 or early 2008, according to the model, and peak in 2012.

The model-based prediction "is exciting stuff, the first new thing to come along" in decades, says Ernest Hildner, the recently retired director of the Space Environment Center in Boulder, the federal group charged with forecasting solar activity. It's especially exhilarating, solar astronomer David Hathaway of NASA's Marshall Space Flight Center in Huntsville, Alabama, told the teleconference, because "it finally answers the 150-year-old question: What causes the sunspot cycle?"

If the sun is gearing up for an especially active maximum, managers of everything from the global positioning system--which solar storms can disrupt--to low-orbiting satellites--which storms can drag down--could begin taking the threat into account. But exciting as the forecast is, other promising techniques have failed their first test predicting the future, says Hildner: "You still have to wait and see."

WOW, that pic of the Aurora Polaris is really kewl. I would have loved to have seen that for real!!!!
Dr.Masters,
I appreciate your reporting the latest data without putting a "spin" on it like the media do. If the trend of more melting in Antarctica continues, it is certainly cause for concern. But good science doesn't sell as well as doomsday scenarios!
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...
18. Inyo
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.
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.
Check out how much higher the 100 meter temps are compared to the SST.
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.
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.
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.
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
Greenland's ice ~ credit University of Colorado
Skepony,
That really shows the melting!!!!!!!!!!!!
That's ALOT of water!!!!!!!!!!!!!!!
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
31. Inyo
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.
>> 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.
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.
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.
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.
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.
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...
any one see theboldman around ????
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.
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.
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.
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.
my new blog is update and some news on it so come on by and drop me a post
Enough with global warming philosophy!
Where will the first hurricane to seriously affect the western hemisphere form this season? Who has a prediction?
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
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.
Between Bermuda and Florida
50. Inyo
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...
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.
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.
55. Inyo
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.
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
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)?
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.

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. :-)
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.
66. Inyo
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.

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