Loading ...
Sorry, an error occurred while loading the content.

JPL makes an El Nino announcement...sort of

Expand Messages
  • b1blancer_29501
    MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIFORNIA 91109.
    Message 1 of 1 , Mar 15 3:29 PM
    • 0 Attachment
      MEDIA RELATIONS OFFICE
      JET PROPULSION LABORATORY
      CALIFORNIA INSTITUTE OF TECHNOLOGY
      NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
      PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
      http://www.jpl.nasa.gov

      Contact: JPL/Alan Buis (818) 354-0474
      March 14, 2002
      NASA Headquarters/David E. Steitz (202) 358-1730

      RECENT SHIFTS IN PACIFIC WINDS MAY SUPPORT El NIÑO FORMATION

      Wind data for the Pacific Ocean obtained by NASA's Quick Scatterometer
      spacecraft -- also know as Quikscat -- are documenting episodes of
      reversed trade winds that are responsible for unseasonable cyclone
      conditions in the northwest and southwest Pacific, and which may be a
      precursor of a future El Niño.

      A research team led by Dr. W. Timothy Liu, a senior research scientist
      at NASA's Jet Propulsion Laboratory in Pasadena, Calif., used wind
      speed and direction data from Quikscat to detect a shift in the trade
      winds on February 25. The winds shifted from their normal easterly
      direction to a westerly direction, blowing from Indonesia toward the
      Americas along the equator. This trade wind shift, which lasted for
      about a week, contributed to the spawning of twin cyclones--Super
      Typhoon Mitag, which threatened the Philippines; and Tropical Cyclone
      Des, which passed through New Caledonia.

      "In addition to unusual cyclonic activity, such trade wind reversals
      typically trigger Kelvin waves of warm water, which can be an early
      indicator of future El Nino conditions," said Liu. "During periods of
      reversed trade winds, which typically last from a few days to a week
      or more, equatorial westerly winds generate a counterclockwise vortex
      in the northern hemisphere and a clockwise vortex in the southern
      hemisphere. Once spawned, the resulting Kelvin waves may travel
      across the Pacific and reach the coastline of the Americas in
      approximately one to two months, warming the waters of the eastern
      Pacific and creating El Niño conditions when the effects are
      accumulated."

      Sustained Kelvin wave activity could have a major impact on global
      weather patterns according to JPL oceanographer Dr. William Patzert.
      "If trade wind patterns continue to experience reversals through the
      spring and summer, the resulting strong, warm Kelvin waves will cross
      the Pacific like a conveyor belt, depositing warm water near South
      America where the ocean is normally cold," he said. "Such a 'warm
      pool' could alter weather all over the planet, with rains that would
      normally soak the western Pacific shifting toward the Americas, and
      places such as Indonesia and India becoming drier. We're really in a
      'wait and see' situation at this point."

      A similar westerly wind flow and twin cyclones were documented by Liu
      and his team using Quikscat data last December. The wind reversal at
      that time, which lasted 10 days, triggered a Kelvin wave that just
      recently reached South America, as revealed by NASA's Topex/Poseidon
      satellite.

      The Quikscat images are available at:

      http://www.earthobservatory.nasa.gov/Newsroom/NewImages/images.php3 .

      More details of the two westerly winds events can be found at:

      http://airsea-www.jpl.nasa.gov/enso .

      Launched June 19, 1999, the Quikscat spacecraft operates in a
      Sun-synchronous, 800-kilometer (497-mile) near-polar orbit, circling
      Earth every 100 minutes, taking approximately 400,000 measurements
      over 93 percent of Earth's surface every day.

      In recent years, data from JPL's Quikscat scatterometer have proven
      useful in improving forecasts of extreme wind events, such as
      hurricanes, and in monitoring longer-term climatic effects such as El
      Niño. Quickscat's SeaWinds scatterometer instrument is a
      specialized microwave radar that continuously measures both the speed
      and direction of winds near the ocean surface in all weather conditions.

      JPL manages Quikscat for NASA's Office of Earth Science, Washington,
      D.C. JPL also built the scatterometer instrument and provides ground
      science processing systems. NASA's Goddard Space Flight Center,
      Greenbelt, Md., managed development of the satellite, designed and
      built by Ball Aerospace & Technologies Corp., Boulder, Colo.

      More information on Quikscat is available at:

      http://winds.jpl.nasa.gov/missions/quikscat/quikindex.html .

      The U.S.-French Topex/Poseidon mission has been making precise
      measurements of ocean surface topography since 1992. These data are
      used to map ocean currents, improve the understanding of ocean
      circulation, measure global sea level change and improve global
      climate forecasts. Topex/Poseidon's ability to measure sea-surface
      height has made it an invaluable tool for studying ocean events such
      as El Niño, its little sister La Niña and the much larger and
      longer-lasting ocean event called the Pacific Decadal Oscillation.
      Topex/Poseidon is managed by JPL for NASA's Earth Science Enterprise,
      Washington, D.C.

      More information on Topex/Poseidon is available at:

      http://topex-www.jpl.nasa.gov/ .

      NASA's Earth Science Enterprise is a long-term research and technology
      program designed to examine Earth's land, oceans, atmosphere, ice and
      life as a total integrated system.
    Your message has been successfully submitted and would be delivered to recipients shortly.