Monitorização Criosfera - 2007

Tópico em 'Climatologia' iniciado por Gerofil 21 Ago 2007 às 10:52.

  1. Mário Barros

    Mário Barros
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    Furacão

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    Re: Seguimento Criosfera

    Quando chegar Janeiro os Russos e os Canadianos já tem glaciares á porta de casa :lmao::lmao: deixa que a neve tambem vai chegar para nós...
     
  2. Minho

    Minho
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    Cumulonimbus

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    Re: Seguimento Criosfera

    Nítida desaceleração do avanço dos gelos durante esta semana.


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    Pelo menos este ano a neve na Europa está presente em muita maior quantidade do que há um ano




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  3. Minho

    Minho
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    Cumulonimbus

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    Re: Seguimento Criosfera

    Esta semana a cobertura de gelo no Árctico estancou, mantendo-se uma anomalia negativa assinalável...

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    Pela Euroásia a cobertura de neve parece bastante aceitável em comparação com o ano passado.


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    Nos Estados Unidos é que a coisa não parece muito famosa....


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    No Antárctico parece mantém-se a anomalia positiva de quase 1 milhão de quilómetros quadrados


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  4. Vince

    Vince
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    Re: Seguimento Criosfera

    Mais uns gráficos do Ártico:

    Comparativo com os últimos anos (que foram fracos também)

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    Antiguidade do gelo

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  5. Mário Barros

    Mário Barros
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    Re: Seguimento Criosfera

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    O polo sul enloqueceu de vez :scared::maluco: está com uma anomalia positiva em plena Primavera austral ai ai o maldito CO2 :assobio:
     
  6. Luis França

    Luis França
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    Nimbostratus

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    Re: Seguimento Criosfera

    Mas essa anomalia positiva não é só à superfície? E em profundidade? Há dados?
     
  7. Mário Barros

    Mário Barros
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    Re: Seguimento Criosfera

    Penso que é tanto á superficie como em profundidade se não o gelo não se expandia digo eu...:unsure::unsure:

    Aqui fica o site de onde retirei a informação

    http://arctic.atmos.uiuc.edu/cryosphere/
     
  8. Vince

    Vince
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    Re: Seguimento Criosfera

    Como se refere à área, é apenas isso. Mas o Polo Sul está bastante estável e saudável, mesmo em profundidade. O Ártico é que não, apesar daquela recuperação bastante rápida em 2 meses, é obviamente apenas gelo superficial para já.
     
  9. Minho

    Minho
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    Re: Seguimento Criosfera

    Este ano sim,temos uma cobertura de neve em condições no HN...

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    A Rússia tirando o Cáucaso e o extremo asiático está com uma cobertura de neve de 100% :thumbsup:

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  10. Luis França

    Luis França
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    Re: Seguimento Criosfera

    Ice on Air

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    Here’s the station’s summary of the hour: “This summer, Arctic ice in the the Northwest passage melted enough to open up this historic travel route. We discuss the environmental, economic, and political implications of this change with Andrew Revkin, who reports on the environment for The New York Times and wrote “The North Pole Was Here” and with Michael Byers, professor of international law and politics at the University of British Columbia.”


    Radars Taken Out by Arctic Warming

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    The continuing warming and summertime retreats of sea ice around the North Pole are making life difficult for seal-hunting polar bears, eroding Inuit coastal villages and now, evidently, eroding Arctic defenses (although not weakening them, the Pentagon insists).


    Dangerous Antarctica?

    You can't go there, however, without assuming some risk: temperatures, wind, ice and whatever else nature can throw your way. The recent sinking of the cruise ship Explorer in Antarctic waters points that out most vividly.

    Temperature-wise, there isn't much difference between our cold winters and their summer, at least in the Antarctic Peninsula, where I traveled last January. Temperatures ranged from 35 to 40 degrees Fahrenheit on a calm, sunny day to much colder, at 10 degrees and lower. The coldest temperature recorded in Antarctica, or on Earth for that matter, was 129 below in 1983 at the Russian Vostok Station, 100 miles from the South Pole.

    We always dressed in layers: tall waterproof boots, layered socks, long johns and waterproof pants, layered tops, polar fleece hoods or caps, Gore Tex gloves and the ubiquitous bright red parka.
    Knowing its history, this sea did not disappoint me. Ice, ice and more ice everywhere, and icebergs bigger than our ship. Cold. Not a place to linger. Our final landing, appropriately enough, was Devil's Island. From there, we sailed straight into hell.
    Hurricane-force winds and a monstrous, heaving sea tossed our ship about like a rubber duck as we headed back across the Drake Passage to Ushuaia.

    And so, voyagers, go to Antarctica, risks and all? You bet.
     
  11. Luis França

    Luis França
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    Re: Seguimento Criosfera

    Kiss Arctic ice goodbye - by 2012

    However, for nearly the past 30 years, the data pattern of its ice sheet melt has zigzagged. A bad year, like 2005, would be followed by a couple of lesser years.
    According to that pattern, 2007 shouldn’t have been a major melt year, but it was, said Konrad Steffen, of the University of Colorado, which gathered the latest data.
    “I’m quite concerned,” he said. “Now I look at 2008. Will it be even warmer than the past year?”
    Other new data, from a NASA satellite, measures ice volume. NASA geophysicist Scott Luthcke, reviewing it and other Greenland numbers, concluded: “We are quite likely entering a new regime.”
    Melting of sea ice and Greenland’s ice sheets also alarms scientists because they become part of a troubling spiral.
    White sea ice reflects about 80 percent of the sun’s heat off Earth, NASA’s Zwally said. When there is no sea ice, about 90 percent of the heat goes into the ocean which then warms everything else up. Warmer oceans then lead to more melting.

    “That feedback is the key to why the models predict that the Arctic warming is going to be faster,” Zwally said. “It’s getting even worse than the models predicted.”
    NASA scientist James Hansen, the lone-wolf researcher often called the godfather of global warming, on Thursday will tell scientists and others at a meeting of researchers in San Francisco that in some ways Earth has hit one of his so-called tipping points, based on Greenland melt data.
    “We have passed that and some other tipping points in the way that I will define them,” Hansen said in an e-mail. “We have not passed a point of no return. We can still roll things back in time — but it is going to require a quick turn in direction.”

    Last year, Cecilia Bitz at the University of Washington and Marika Holland at the National Center for Atmospheric Research in Colorado startled their colleagues when they predicted an Arctic free of sea ice in just a few decades. Both say they are surprised by the dramatic melt of 2007.

    Ozono no Hemisfério Sul em 4 Dezembro 2007

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  12. Luis França

    Luis França
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    Re: Seguimento Criosfera

    Magma May Be Melting Greenland Ice

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    SAN FRANCISCO—Global warming may not be the only thing melting Greenland. Scientists have found at least one natural magma hotspot under the Arctic island that could be pitching in.

    In recent years, Greenland’s ice has been melting more and flowing faster into the sea—a record amount of ice melted from the frozen mass this summer, according to recently released data—and Earth’s rising temperatures are suspected to be the main culprit.

    But clues to a new natural contribution to the melt arose when scientists discovered a thin spot in the Earth’s crust under the northeast corner of the Greenland Ice Sheet where heat from Earth’s insides could seep through, scientists will report here this week at a meeting of the American Geophysical Union.

    “The behavior of the great ice sheets is an important barometer of global climate change,” said lead scientist Ralph von Frese of Ohio State University. “However, to effectively separate and quantify human impacts on climate change, we must understand the natural impacts too.”

    The corner of Greenland where the hotspot was found had no known ice streams, the rivers of ice that run through the main ice sheet and out to sea, until one was discovered in 1991. What exactly caused the stream to form was uncertain.
    “Ice streams have to have some reason for being there,” von Frese said, “and it’s pretty surprising to suddenly see one in the middle of the ice sheet.”
    The newly discovered hotspot, an area where Earth’s crust is thinner, allowing hot magma from Earth's mantle to come closer to the surface, is just below the ice sheet and could have caused it to form, von Frese and his team suggest.



    O que é que o CO2 tem a ver com o degelo? Isto parece-me muito mais plausível para explicar o aumento da velocidade do degelo...
     
  13. Gerofil

    Gerofil
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    Re: Seguimento Criosfera

    Mudança no clima global e energia: CO2 e mudança de temperatura (link)
     
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  14. Luis França

    Luis França
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    Re: Seguimento Criosfera

    Gerofil, chegaste a ler o artigo em inglês?

    Como é que o CO2 pode derreter o gelo que está submerso?? :huh: :lmao:
     
  15. Minho

    Minho
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    Re: Seguimento Criosfera

    Anomalia negativa no Norte

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    Anomalia positiva no Sul

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    O manto de neve estende-se quase até à fronteira com o México


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    Na Europa/Ásia mantém-se mais ou menos tudo na mesma

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