Scientists Look to Indian Ocean for Long-Range Weather Forecast

By Laura Matthews | September 23 2011 5:37 PM

Scientists from 16 countries will converge in the Indian Ocean next month and pool their resources to conduct a six-month field study on how tropical weather developed in that ocean affects weather patterns in other parts of the world.

UCAR

This is the S-PolKa radar on Addu Atoll in the Indian Ocean, before the start of DYNAMO. DYNAMO is the name given to the six-month field study, and the acronym stands for Dynamics of the Madden-Julian Oscillation.
Scripps Institution of Oceanog

The research vessel Roger Revelle will take part in the Indian Ocean experiments.

The international team plans to use aircrafts, ships, moorings, radars, numerical models and other tools to determine how weather systems in the Indian Ocean move eastward along the equator and then proceed further around the globe.

Scientists said the goal of their work is to get a better understanding of a phenomenon in the tropics that is known as the Madden-Julian Oscillation (MJO). This disturbance begins in the equatorial Indian Ocean every 30 to 90 days and it is part of the Asian and Australian monsoon.

The MJO is a culmination from variations in wind, rainfall, water surface temperature and cloudiness, according to a report by Bart Geerts, associate professor of atmospheric science at the University of Wyoming. That report notes that the MJO does affect the intensity and break periods of the Asian and Australian monsoons.

Researchers said the disturbance can increase hurricane activity in the northeast Pacific and Gulf of Mexico, which in turn can trigger torrential rainfall along the west coast of North America and affect the onset of El Nino. They also believe the MJO is the world's greatest source of atmospheric changes in the one- to three-month time frame.

The Madden-Julian Oscillation has a huge impact all over the globe, says Chidong Zhang of the University of Miami, and chief scientist of the campaign. It connects weather and climate, and it is important to forecasting.

Jim Moore of the National Center for Atmospheric Research (NCAR) said 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, he added.

There countries providing staff, facilities, and/or observations to the international effort includes: Australia, China, France, India, Indonesia, Japan, Kenya, Korea, the Maldives, Papua New Guinea, Seychelles, Singapore, Sri Lanka, Taiwan, the United Kingdom and the United States.

All the experts from these countries believe that understanding this phenomenon will help improve long-range weather forecasts and seasonal outlooks. They also say it will enable scientists to further refine computer models of global climate.

If you can find out how an MJO event starts, you may get a couple of weeks' warning about wintertime storms in the United States, says NCAR scientist Mitchell Moncrieff who is also involved in the campaign.