September 23, 2011
Indian Ocean Oscillation Could Help Forecast Long-Term Weather
Scientists from all over the world will be gathering in the Indian Ocean starting next month to study the Madden-Julian Oscillation. This disturbance originates in the equatorial Indian Ocean every 30 to 90 days and is part of the Asian and Australian monsoons, can enhance hurricane activity in the northeast Pacific and Gulf of Mexico, trigger torrential rainfall along the west coast of North America and affect the onset of El Nino.
The campaign, known as DYNAMO (Dynamics of the Madden-Julian Oscillation is intended to improve long-range weather forecasting and global climate change computer models.
DYNAMO, the Littoral Air-Sea Processes (LASP) experiment and the ARM MJO Investigation Experiment (AMIE) are three projects contributing to the research, titled the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011. Sixteen other countries are providing facilities or staff to the international effort.
Chidong Zhang from the University of Miami and the chief scientist tells the National Science Foundation (NSF), “The Madden-Julian Oscillation has a huge impact all over the globe. It connects weather and climate, and it is important to forecasting.”
Jim Moore of the National Center for Atmospheric Research (NCAR) and director of the Dynamo project office said in a statement: “The MJO drives weather in both hemispheres even though it sits along the equator. Its origins have never been measured in such a systematic fashion before.”
Scientists are setup to measure the experimental area with many instruments. One of the instruments includes the S-POLKA radar, a dual-wavelength Doppler radar that can distinguish the sizes and shapes of precipitation particles and observe the water vapor that forms clouds, in order to observe the development of clouds and rainfall. A C-band provided by Texas A&M will estimate rainfall and heating, and a suite of mobile radars to detect different types of clouds.
Other instrumentation includes two research aircraft, four ships, moored buoys and a suite of other instruments to measure ocean temperature and salinity. Moore told the NSF, “DYNAMO and AMIE mark the first time in the modern era that we´ll be able to use remote sensing techniques, particularly radar, to measure atmospheric phenomena from individual cloud droplets to large raindrops. We have instrument capabilities for this project that we didn´t have 10 or 15 years ago.”
Image 1: The S-PolKa radar on Addu Atoll in the Indian Ocean, before the start of DYNAMO. Credit: UCAR
Image 2: The research vessel Roger Revelle will take part in the Indian Ocean experiments. Credit: Scripps Institution of Oceanography
Image 3: The P3 NOAA aircraft will fly above the Indian Ocean, taking atmospheric measurements. Credit: NOAA
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