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results from weakening easterly trade winds

results from weakening easterly trade winds. http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/eln/home.rxml. http://www.youtube.com/watch?v=AEoHz56jWGY El Nino Definition. http://edition.cnn.com/video/#/video/weather/2009/07/27/byrnes.ctw.aregentino.el.nino.cnn?iref=videosearch Impact .

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results from weakening easterly trade winds

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  1. results from weakening easterly trade winds http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/eln/home.rxml

  2. http://www.youtube.com/watch?v=AEoHz56jWGY El Nino Definition http://edition.cnn.com/video/#/video/weather/2009/07/27/byrnes.ctw.aregentino.el.nino.cnn?iref=videosearch Impact

  3. http://www.youtube.com/watch?v=fN_NmCpry38 El Nino phenomenon

  4. What do we already know? • Density: Warm air is less dense than cool air. Warm air rises. Cool air sinks. (convection) • Pressure: High temperature means low air pressure and low temperature means high air pressure. High pressure = fair weather. Air masses press down, Warm air cannot rise and form clouds. Low pressure = cloudy, rainy weather. Air masses move apart, warm air rises and form clouds. • Air moves from an area of high to low pressure.

  5. West Pacific: warm, air rises, low pressure East Pacific: cool, air sinks, high pressure Easterly surface wind from high to low pressure

  6. The easterly trade winds are driven by a surface pressure pattern of higher pressure in the eastern Pacific and lower pressure in the west. When this pressure gradient weakens, so do the trade winds. The weakened trade winds allow warmer water from the western Pacific to surge eastward, so the sea level flattens out.

  7. During non-El Niño years, the southeast trade winds, drag surface water westward away from shore. As surface water moves away, upwelling brings up colder waters from depths of 40-80 meters or more. This deep sea water is rich in nutrients which can sustain large fish populations.

  8. During an El Niño event, the southeast trade winds weaken and so does the amount upwelling in the eastern Pacific. The deeper thermocline means that any upwelling that does occur is unable to tap into the rich nutrients found in deeper waters. Consequently, warm nutrient-poor water predominates the region and a decrease in the fish population is observed.

  9. El Niño causes all sorts of unusual weather, sometimes bringing rain to coastal deserts of South America which never see rain during non-El Niño years. The flooding results in swarming mosquitoes and the spread of disease.

  10. Atmospheric Consequences of El Niño influencing weather patterns worldwide

  11. Why do we care: Global climate impacts continued FloodsLakeport, California (1998) FiresAustralia (1998)

  12. SOURCES: • http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/eln/home.rxml • PAGASA-DOST

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