Monitorização Clima Global - 2009

Tópico em 'Climatologia' iniciado por Vince 6 Jan 2009 às 22:47.

  1. Vince

    Vince
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    Furacão

    Registo:
    23 Jan 2007
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    Braga
  2. Gerofil

    Gerofil
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    Super Célula

    Registo:
    21 Mar 2007
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    Estremoz (401 metros)
    A influência dos campos semi-permanentes da pressão atmosférica sobre o Atlântico Norte nas cheias no Norte do Brasil deste ano:

    Heavy Rain Floods Brazil
    [​IMG]
    CopyRight@Earth Observatatory

    Heavy rain began to fall over northern Brazil in early April 2009 and persisted for several weeks, causing the most severe flooding in more than two decades. As of May 13, at least 39 people had died and over 300,000 had been displaced from their homes, reported the Associated Press. While northeastern Brazil is usually fairly dry, it does have a summer wet season that ramps up in February, peaks in April, and quickly falls off in May. This pattern is intimately tied to the seasonal migration of a band of showers and storms that wraps around the globe near the equator, the Intertropical Convergence Zone (ITCZ). This band of rain showers shifts from north to south across the equator as the seasons change, bringing a cycle of rainy and dry periods to the tropics.
    This image shows the unusually heavy rainfall the Intertropical Convergence Zone brought to northern Brazil in 2009. The image was based on data collected by the Tropical Rainfall Measuring Mission (TRMM) satellite between April 12 and May 12, 2009, compared to average rainfall (millimeters per day) observed during that period between 1998 and 2008. Areas in which rainfall was heavier than normal are blue, while drier-than-normal regions are brown. The most prominent feature in the image is the large east-west band of very heavy rain stretching from the Atlantic Ocean in the East to the northern Andes mountains of Peru, Ecuador, and Columbia in the West. This band is a direct result of the ITCZ.
    The ITCZ is a normal rainfall pattern, so what caused the unusual rain in 2009? The anomaly image provides a clue: immediately north of the heavy rain is a strong east-west band of below-normal rainfall, shown in brown. The overall anomaly pattern shows that the ITCZ remained locked over northeastern Brazil instead of migrating northward over French Guiana, Suriname, and Guyana as it would normally do.
    One possible reason for this change in the ICTZ has to do with what is known as the North Atlantic Oscillation. The oscillation describes changes in the relative strengths of two semi-permanent atmospheric pressure features over the North Atlantic: the Icelandic Low and the Azores High. When the index is positive, the pressure features are stronger. The NAO became strongly positive at the beginning of May, indicating that the Azores High was stronger than normal. As a result, stronger-than- normal trade winds from the northern hemisphere can flow in towards the ITCZ in the southern hemisphere. These winds not only create a surge in moisture into the ITCZ, but they can also impede its movement both directly and indirectly by blowing additional warm ocean surface waters southward.
    Using both a passive microwave sensor and a space-borne precipitation radar, TRMM measures rainfall from space. For increased coverage, TRMM can be used to calibrate rainfall estimates from other additional satellites in an analysis called the TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA). This image was made from TMPA rainfall totals for Brazil and the surrounding region. Additional images and a more detailed caption are available on the TRMM website. TRMM is a joint mission between NASA and the Japanese space agency, JAXA.
    Earth Observatatory

    Versão em português: Rascunho GEO
     
  3. Kispo

    Kispo
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    Cumulus

    Registo:
    17 Ago 2008
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    Monte Abraão, Queluz (195m)
    a actividade solar parece estar a dar os seus frutos:

    [​IMG]
     
  4. Vince

    Vince
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    Furacão

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    23 Jan 2007
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    Kispo, e em Maio aconteceu o quê ? Foi o 4º Maio mais quente deste que existem registos. O sol não deu frutos ? E passou a dar de repente em Junho? Acho que não podemos a andar a olhar para as coisas desta forma olhando para dados mês a mês, tens que admitir que é um absurdo ...

    O Blog Tamino há poucos dias escreveu um bom post sobre esta coisa de olhar para series temporais muito pequenas.

     
  5. Kispo

    Kispo
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    Cumulus

    Registo:
    17 Ago 2008
    Mensagens:
    188
    Local:
    Monte Abraão, Queluz (195m)
    Vince: estás a "por palavras na minha boca que não disse"! Eu não foquei em qq tipo de pormenor do grafico! Alias a minha ideia até era verem k a temperatura global desde 2007 tem vindo a cair! Não estava a falar em dados mensais!

    Maio o 4º mês mais quante? só se for medido pelas estaçoes meteorologicas, algumas colocadas em sitios "estrategicos"! Os dados de Satelite dizem outra coisa, como por exemplo os dados da UAH que aqui coloco. Os dados RSS tb nos dão a mesma informação!
     
  6. Gerofil

    Gerofil
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    Super Célula

    Registo:
    21 Mar 2007
    Mensagens:
    8,554
    Local:
    Estremoz (401 metros)

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