El Niño Arrives; Expected to Persist through Winter 2009-10

July 9, 2009

By NOAA at http://www.noaanews.noaa.gov/stories2009/20090709_elnino.html

NOAA scientists today announced the arrival of El Niño, a climate phenomenon with a significant influence on global weather, ocean conditions and marine fisheries. El Niño, the periodic warming of central and eastern tropical Pacific waters, occurs on average every two to five years and typically lasts about 12 months.

NOAA expects this El Niño to continue developing during the next several months, with further strengthening possible. The event is expected to last through winter 2009-10.

“Advanced climate science allows us to alert industries, governments and emergency managers about the weather conditions El Niño may bring so these can be factored into decision-making and ultimately protect life, property and the economy,” said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator.

El Niño’s impacts depend on a variety of factors, such as intensity and extent of ocean warming, and the time of year. Contrary to popular belief, not all effects are negative. On the positive side, El Niño can help to suppress Atlantic hurricane activity. In the United States, it typically brings beneficial winter precipitation to the arid Southwest, less wintry weather across the North, and a reduced risk of Florida wildfires.

El Niño’s negative impacts have included damaging winter storms in California and increased storminess across the southern United States. Some past El Niños have also produced severe flooding and mudslides in Central and South America, and drought in Indonesia.

An El Niño event may significantly diminish ocean productivity off the west coast by limiting weather patterns that cause upwelling, or nutrient circulation in the ocean.  These nutrients are the foundation of a vibrant marine food web and could negatively impact food sources for several types of birds, fish and marine mammals.

In its monthly El Niño diagnostics discussion today, scientists with the NOAA National Weather Service Climate Prediction Center noted weekly eastern equatorial Pacific sea surface temperatures were at least 1.0 degree C above average at the end of June. The most recent El Niño occurred in 2006.

El Niño includes weaker trade winds, increased rainfall over the central tropical Pacific, and decreased rainfall in Indonesia. These vast rainfall patterns in the tropics are responsible for many of El Niño’s global effects on weather patterns.

NOAA will continue to monitor the rapidly evolving situation in the tropical Pacific, and will provide more detailed information on possible Atlantic hurricane impacts in its updated Seasonal Hurricane Outlook scheduled for release on August 6, 2009.

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.

3 Responses to “El Niño Arrives; Expected to Persist through Winter 2009-10”

  1. mmweather Says:

    NOAA expects this El Niño to continue developing during the next several months, with further strengthening possible. The event is expected to last through winter 2009-10.

    အယ္နီညိဳ စတင္ျဖစ္ေပၚေနၿပီး ေနာက္လာမဲ့ လအနည္းငယ္အတြင္း အင္အားပိုေကာင္းလာႏိုင္တယ္၊ ၂ဝဝ၉ ၂ဝ၁ဝ ခုႏွစ္ေဆာင္းရာသီအထိ ဆက္ၿပီး တည္ရွိေနႏိုင္တယ္လို႕ NOAA က အစပ်ဳိးထားပါတယ္။

    Global Tropic Hazard from July14 to July 20

  2. mmweather Says:

    အယ္နီညိဳေၾကာင့္ ျမန္မာႏိုင္ငံတြင္ လာမည့္ ဇူလိုင္လလြန္ကာလမ်ား၌ မိုးပိုရြာဘြယ္ရွိမည္ေလာ ….
    ထပ္မံေလ့လာရန္ PDF file ရယူပါ

  3. mmweather Says:

    New Type of El Nino Could Mean More Hurricanes Make Landfall
    July 2, 2009
    El Niño years typically result in fewer hurricanes forming in the Atlantic Ocean. But a new study suggests that the form of El Niño may be changing potentially causing not only a greater number of hurricanes than in average years, but also a greater chance of hurricanes making landfall, according to climatologists at the Georgia Institute of Technology. The study appears in the July 3, 2009, edition of the journal Science.

    “Normally, El Niño results in diminished hurricanes in the Atlantic, but this new type is resulting in a greater number of hurricanes with greater frequency and more potential to make landfall,” said Peter Webster, professor at Georgia Tech’s School of Earth and Atmospheric Sciences.

    That’s because this new type of El Niño, known as El Niño Modoki (from the Japanese meaning “similar, but different”), forms in the Central Pacific, rather than the Eastern Pacific as the typical El Niño event does. Warming in the Central Pacific is associated with a higher storm frequency and a greater potential for making landfall along the Gulf coast and the coast of Central America.

    Even though the oceanic circulation pattern of warm water known as El Niño forms in the Pacific, it affects the circulation patterns across the globe, changing the number of hurricanes in the Atlantic. This regular type of El Niño (from the Spanish meaning “little boy” or “Christ child”) is more difficult to forecast, with predictions of the December circulation pattern not coming until May. At first glance, that may seem like plenty of time. However, the summer before El Niño occurs, the storm patterns change, meaning that predictions of El Niño come only one month before the start of hurricane season in June. But El Niño Modoki follows a different prediction pattern.

    “This new type of El Niño is more predictable,” said Webster. “We’re not sure why, but this could mean that we get greater warning of hurricanes, probably by a number of months.”

    As to why the form of El Niño is changing to El Niño Modoki, that’s not entirely clear yet, said Webster.

    “This could be part of a natural oscillation of El Niño,” he said. “Or it could be El Niño’s response to a warming atmosphere. There are hints that the trade winds of the Pacific have become weaker with time and this may lead to the warming occurring further to the west. We need more data before we know for sure.”

    In the study, Webster, along with Earth and Atmospheric Sciences Chair Judy Curry and research scientist Hye-Mi Kim used satellite data along with historical tropical storm records and climate models.

    The research team is currently looking at La Niña, the cooling of the surface waters in the Eastern and Central Pacific.

    “In the past, La Nina has been associated with a greater than average number of North Atlantic hurricanes and La Nina seems to be changing its structure as well,” said Webster. “We’re vitally interested in understanding why El Niño-La Niña has changed. To determine this we need to run a series of numerical experiments with climate models.”

    This text derived from:
    http://www.gatech.edu/newsroom/release.html?id=3079


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