Notices
Results 1 to 14 of 14
Like Tree3Likes
  • 1 Post By sculptor
  • 1 Post By adelady
  • 1 Post By adelady

Thread: Antarctic ice: Now we know WHY the extent increases under warming conditions.

  1. #1 Antarctic ice: Now we know WHY the extent increases under warming conditions. 
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    I always knew that scientists predicted that Antarctic sea ice cover would increase (for a while) under global warming. Now they've measured it and proved the mechanism.

    The new research also helps explain why observed changes in the amount of sea-ice cover are so different in the two Polar Regions. The Arctic has experienced dramatic ice losses in recent decades while the overall ice extent in the Antarctic has increased slightly. However, this small Antarctic increase is actually the result of much larger regional increases and decreases, which are now shown to be caused by wind-driven changes. In places, increased northward winds have caused the sea-ice cover to expand outwards from Antarctica. The Arctic Ocean is surrounded by land, so changed winds cannot cause Arctic ice to expand in the same way.
    Read the whole thing Why Antarctic sea ice cover has increased under the effects of climate change

    Yet another example of predictions being borne out by observations. (And the value of satellites.) Nice work!


    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Masters Degree
    Join Date
    Jul 2010
    Location
    Australia
    Posts
    719
    Antarctic sea ice has been a bit of a puzzle. One explanation on offer was more snowfall around the edges, giving more insulation to sea ice. Not sure to what extent that may still be playing a role. Another was changes to the Ozone hole inducing changes to atmospheric circulation but modelling failed to support it. Yet this looks like empirical evidence of change to atmospheric circulation. So science does a bit of one stepping back, two forward.


    I do wonder if the scientists' urge to home in on this apparent paradox - warming and more sea ice extent - has been given a bit of extra impetus by the climate science doubters and deniers using Antarctic sea ice as a talking point. Much as the Medieval Warming thing attracts attention beyond it's significance outside the walls of academia. Although studying both is increasing understanding of regional effects of global changes in the heat balance of the planet, independent of the level of tankthink media noise, maybe when it comes to funding, that noise has a small but statistically significant effect. Or perhaps it's an illusion of cause and effect, generated by both dedicated deniers and dedicated scientists both seeking out the paradoxes and discrepancies, each for their own reasons, one to find cause to foster doubt, the other to fill the gaps in knowledge.


    Reply With Quote  
     

  4. #3  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    I do wonder if the scientists' urge to home in on this apparent paradox - warming and more sea ice extent - has been given a bit of extra impetus by the climate science doubters and deniers using Antarctic sea ice as a talking point.
    I wouldn't have thought so. The models have always shown that Antarctic sea ice would increase for a while.

    I've never known why and I'm not sure the modellers did either. It's not as though the computers show the hows and the whys of everything that's going on the way a schoolteacher might do - "now when I pick up the ..... this way, you'll see ....." .

    After all, there have been various items linking changes in Hadley cell expansion and the Antarctic circumpolar current to ozone hole shrinkage before. I think this paper's emphasis on a more specific relationship between the ice, the water and the wind is more satisfying. Just like Hansen et al's paper on summer extremes, papers based on current observations give more 'handle' for non-experts to get an understanding.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  5. #4  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    I read that article awhile ago......not much detail, no mention of the westerlies?
    as/re the winds
    if the polar(hadley like) cell is narrowed, is it more likely to increase or decrease in intensity?

    from what I've read in other places, the expanding sea ice may not be increasing in volume, just surface area and location as the cold winds at the pole blow down then outward and drag the surface ice along with them.

    Is the icepack over east antarctica increasing?
    ............
    as/re the arctic, it seems that the beaufort gyre is bulging up as more fresh water from siberian rivers is being diverted into the gyre.(also attributed to winds)

    both of these changes, seem like they should be inherently unstable?

    as the beaufort (which sits atop the beaufort or canadian deep) bulges, it seems likely that it will expand, which may lead to "warm" pacific waters being carried up it's siberian side and out into the atlantic, instead of following the coast eastward over alaska and canada? Which could warm the north and northeast (and east?) of greenland while the canadian arctic and baffin bay chill?

    so many changes------new, or just now known by better instrumentation.

    see:
    Poles Apart: A Tale of Two Oceans — Polar Oceans — Beyond Penguins and Polar Bears

    ESA Portal - Satellites detect abundance of fresh water in the Arctic

    NSIDC Reports That Antarctica is Cooling and Sea Ice is Increasing | Watts Up With That?

    and

    D'Aleo- NAM or AO Explains Recent Winters and Supports 2011/12 Forecast
    on this last, note the changes to the hadley,etc... cells and increased moisture at 60+ degrees.
    this hypothetical change in the cells does not support an increase in pressure at the poles.........which would have accounted for the aforementioned winds
    .......
    so, i'm taking this last with a grain of salt.........(for now)
    Reply With Quote  
     

  6. #5  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    if the polar(hadley like) cell is narrowed
    Hadley cells are expanding, just as was predicted for a warming climate. And they're not polar. They're the circulation system that picks up moisture around the equator and lofts it up and over the major lower latitude deserts - Australia, Africa, USA south west are the most obvious exemplars of this - and results in precipitation in temperate latitudes.

    The third graphic on the side of this page is the neatest representation of Hadley cells Hadley cell - Wikipedia, the free encyclopedia , as well as showing the other circulation cells from equator to poles.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  7. #6  
    The Enchanter westwind's Avatar
    Join Date
    Jan 2012
    Posts
    1,079
    adelady, there is a Hadley Cell dump right over my Backyard, except it is not Tropical, but Sub-Antartic. Near the Melbourne Airport, to give you a location, we are experiencing cold Southerlies. Have been for weeks. Temperatures around 18/19 Celcius Max. Mornings cold. Guess the Metrology ( Weather Bureau ), is that everything is normal for this time of the year.

    It'll be snowing come Xmas at this rate.

    And what about all my scattered seed that I have high hopes for? Hibernation? What respectable vegetable seed would pop up in this weather?

    I'm getting desperate adelady, don't know wether to invest in a cooler or heater. What say you?
    Words words words, were it better I caught your tears, and washed my face in them, and felt their sting. - westwind
    Reply With Quote  
     

  8. #7  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    adelady
    i wrote "hadley like" for those who might not know that there are hadley cells, ferrel cells, and polar cells, which like the beaufort and makarov gyres spin in oposite directions, but with the touching sides moving in the same direction, so the normal polar cell has the same rotational direction as the hadley cell

    jeeeeeeeeeeezzzzzzzzzzzzzzzzzz
    once, all 3 were refered to as hadley cells, then the ferrel cell was called the temperate cell, and now is called the ferrel cell by most people
    (3 years ago, it still had a different name in a translated article from europe(but I don't remember that name)---------which doesn't actually matter)
    a rose by any other name would smell as sweet

    words, words, words
    only communicate if communication and understanding is/are actually desired

    now
    about the velocity of the air movement about the polar cell, and it's hypothesized break down as/per the last linked page?????
    what say you?
    Last edited by sculptor; November 16th, 2012 at 11:01 PM.
    westwind likes this.
    Reply With Quote  
     

  9. #8  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    Oh my giddy aunt. Sculptor! I just noticed those last 2 references of yours. If you want serious, high quality information on the science of climate, you need to find much better material than you'll ever get from WUWT or D'Aleo. I've never yet seen anything from W... that didn't make either a trivial mistake or a complete travesty of whatever scientific paper or official report they were referring to. D'Aleo is well-known as an outright denier of the science of climate.

    If you want good climate stuff without going to Skeptical Science or RealClimate, you'd be better off with John Nielsen-Gammon (the Texas State Climatologist) at his blog Climate Abyss | Weather and climate issues with John Nielsen-Gammon | a Chron.com blog - he's not a physicist and he often doubts or contests the more well-known people, but he's always good value. Open Mind | Science, Politics, Life, the Universe, and Everything is also pretty good as long as you're prepared to skip the highly technical statistical stuff (way beyond my pay grade).

    For the icy parts of the world, Jason Box is a cryologist at Meltfactor.org and Mauri Pelto is a glaciologist reporting on individual glaciers one by one at From a Glaciers Perspective .
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  10. #9  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    Sorry westwind. Blame the el Nino non-oscillation. They were talking about the prospects of a neutral or el Nino summer. It seems we're on the La Nina side of neutral for the time being.

    Nevertheless, my first, not very abundant, crop of cherries is looking absolutely fan.tas.tic. just now. We'll have to make a serious decision on Tuesday. 36C predicted for Wednesday, I'm not thrilled about the cherries' chances of surviving the heat/wind and - or the attentions of thirsty parrots. Still, I reckon getting any crop off a cherry tree within 14 months of planting is an outstanding effort, especially in what passes for soil around here.
    westwind likes this.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  11. #10  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    ok
    here's a nasa youtube showing the changes developing in the arctic

    simplistic but kinda shows the basics of the developing makarov gyre and it's interaction with the beaufort, and shunting of the the pacific waters more rapidly toward the northern end of greenland, with the potential(as previously mentioned) to chill the canadien arctic while warming northern and northeastern greenland----------------one might well say that change is afoot, and whither it shall go is a curiousity-----------
    The 2 gyres remind me of the time I aced the meteorology final at SIU when I noticed a high pressure sitting over the south east, and a large powerful low moving east over Texas to set up in the western mississippi valley-----the temperature outside was then(friday) near freezing, and I predicted a high of 53 the following monday, and nailed it, while all my classmates predicted a continuation of the then current cold. The 2 rotatating air masses pushed and pulled warm gulf air up the mississippi valley to southern Illinois university where I was currently studying. (much like the rotating cylinders on the old style wringer washing machines pulled clothes between them squeezing out the water)
    So, I expect much the same as the newly forming makarov gyre establishes itself next to the beaufort gyre---------
    can you spell northern greenland ice melt?
    With these mechanisms set up, all we need is to see the west antarctic ice sheet detach from the ground, and sea level rise, and vast amounts of (warmer) pacific water rushing through berengia and then through the arctic ocean, and northern greenland will become quite balmy(compared to today).

    Breaking NASA Arctic Ocean Currents Changed Increasing Climate Change - YouTube

    as/re sites linked
    at least I didn't link the surfer site---------whodathunk surfers would be watching or interested in the arctic ocean? But they did a nice piece on the bulging beaufort.
    .............
    I really don't much care who(which site) has the information(sometimes just wrong opinions) about the subject of my current curiousities, as long as I can get some valuable information, and a range of perspectives(some obviously biased)
    .........
    I've a revenous thirst for knowledge, and even small sips from the cups of biased information helps to satisfy my eclectic tastes.
    ,,,,,,,,
    recently, I read an article decrying the internet, which claimed that rather than people becoming better(more broadly) informed, they were just becoming more biased and opinionated because they tended to only read material from people who already had the same bias.
    ......
    let us all not persue that course of action
    Last edited by sculptor; November 17th, 2012 at 10:07 AM.
    Reply With Quote  
     

  12. #11  
    Forum Masters Degree
    Join Date
    Jul 2010
    Location
    Australia
    Posts
    719
    I really like the internet. Yes, there's plenty of stuff intended to reinforce existing prejudices, but it's usually easy to track back to the original source, say an actual science paper or the full transcript of commentary that's been quoted or discussed, something effectively impossible for someone like me without it. I can find intelligent critiques as well as the sychophantic support. I can sometimes comment and even engage in halfway intelligent discussion about the subject at hand.

    I agree with Adelady that WUWT is not a good source of information on climate, even if you go there strictly for information - they have a clear agenda and it definitely isn't to improve understanding or communicate accurately the state of the science. There are plenty of alternatives for getting informed, that link directly to or are relevant originating sources.
    Reply With Quote  
     

  13. #12  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    WUWT was strictly for the nasa maps showing two different perspectives on warming of the antarctic,
    note that the earlier map indicates even more warming around west antarctica, and both go to show how information changes and how making assumptions based on even 4 , or 8 year old information means chosing a starting point that is eccentric.

    whereas the d'aleo site offered an interesting take on the hadley/ferrel/polar cells possible changes-----(grain of salt always)

    but a place/concept from whence to seek supporting or negating information.

    I would no more take the claims from those sites at face value than I would do likewise from biased people who "know" that climate change can only have bad outcomes
    It is nice to know where the biases lie when evaluating the claims,,,,,,,,,,,,
    much like religion, each has a grain of truth burried under a mountain of bullshit
    so focus less on from whence the information comes, and focus more on the potentials of the information offered
    ......................
    that being said:
    getting back to the information offered above

    How likely is it that the developing arctic gyre transformations discussed and linked above, will accelerate the melt of the grounded ice of northern greenland, raising sea levels, and gathering more warm pacific waters and sending them to further melt the greenland ice, raising sea levels even more which could then float the west antarctic ice shelf free from it's grounding anchors, and cascade sea level rise , turning New York into the Venice of the west with gondolas plying east 49th street?
    .............
    do bookies take climate bets?
    Reply With Quote  
     

  14. #13  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    Pacific waters getting across to melt Greenland? I've always been concerned about what the Pacific waters might do in various scenarios. Now I realise that it's beside the point what any given weather event or water source might do. The perspective we need on what's happening is here Polar Science Center Arctic Sea Ice Volume Anomaly, version 2 in the final paragraph.

    It takes energy to melt sea ice. How much energy? The energy required to melt the 16,400 Km3 of ice that are lost every year (1979-2010 average) from April to September as part of the natural annual cycle is about 5 x 1021 Joules. For comparison, the U.S. Energy consumption for 2009 ... was about 1 x 1020 J. So it takes about the 50 times the annual U.S. energy consumption to melt this much ice every year. This energy comes from the change in the distribution of solar radiation as the earth rotates around the sun.To melt the additional 280 km3 of sea ice, the amount we have have been losing on an annual basis based on PIOMAS calculations, it takes roughly 8.6 x 1019 J or 86% of U.S. energy consumption.

    However, when spread over the area covered by Arctic sea ice, the additional energy required to melt this much sea ice is actually quite small. It corresponds to about 0.4 Wm-2 . That’s like leaving a very small and dim flashlight bulb continuously burning on every square meter of ice. Tracking down such a small difference in energy is very difficult, and underscores why we need to look at longer time series and consider the uncertainties in our measurements and calculations.
    What has weakened and melted the ice is the constant contact with water that is consistently warmer, marginally, imperceptibly warmer, than it was 80+ years ago. The most alarming thing about the ice, apart from the obvious expanses of open water, is its fragility. Nowadays when the ice research people go out there for the summer, they can't find places to land helicopters where they expect to. The icebreaking ships don't have to slow down even for 10m thick ice - it just collapses at first contact. It's more like enormous piled up slushy drinks than it is like the intimidating, dangerous barrier that these people are used to.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  15. #14  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    This is a nice explanation for the expansion of Antarctic sea ice. Half a dozen different experts commenting.
    Arctic versus Antarctic Sea Ice - YouTube

    The Apples & Oranges of Arctic/Antarctic Sea Ice Trend Comparisons | The Yale Forum on Climate Change & The Media gives a bit more background.
    westwind likes this.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

Similar Threads

  1. Acrtic Ice Extent about to shatter new lows
    By Lynx_Fox in forum Environmental Issues
    Replies: 22
    Last Post: August 28th, 2012, 12:30 PM
  2. Europa Jupiter's Ice Moon Vs 2 miles of Antarctic ice
    By Genesis in forum Astronomy & Cosmology
    Replies: 23
    Last Post: March 1st, 2012, 11:11 AM
  3. Replies: 17
    Last Post: June 25th, 2010, 07:04 PM
  4. Global warming, coming ice age, or neither?
    By WVBIG in forum Environmental Issues
    Replies: 12
    Last Post: September 8th, 2009, 08:03 PM
  5. Ice cap formation leads to warming?
    By SRPang89 in forum Earth Sciences
    Replies: 3
    Last Post: March 15th, 2008, 06:56 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •