Tropical weather maker in motion - The Madden-Julian Oscillation

Related news: http://www2.ucar.edu/news/5420/scientists-probe-indian-ocean-clues-worldwide-...

The Madden-Julian Oscillation is a cyclical disturbance of the tropical atmosphere with pulses that typically originate in the Indian Ocean every 30 to 60 days and travel eastward. During each pulse of the MJO,

-- regional westerly winds replace easterly trade winds near the surface

-- showers and thunderstorms increase, particularly over regions of high sea surface temperatures in the Indian and western Pacific oceans.

The MJO plays a key role in driving tropical weather and climate variations during all seasons of the year. It also interacts with other atmospheric patterns, such as the El Niño/Southern Oscillation and the North Atlantic Oscillation. that can shape weather and climate patterns across much of the globe.

In winter, for example, the onset of an MJO can set off atmospheric waves that travel across the globe and, about 10 days later, influence the location and severity of major storms on the west coast of North America, some of which cause significant flooding.

In the late summer and autumn, the MJO can enhance hurricane activity in the Gulf of Mexico.

Scientists need to better understand the MJO, both to improve long-range weather forecasts and seasonal outlooks worldwide and to perhaps make the leap to longer-term forecasts of climate that may extend years into the future.

That's the impetus behind DYNAMO (Dynamics of the Madden-Julian Oscillation) a six-month field campaign to help improve those long-range forecasts and enable scientists to further refine computer models of global climate. The National Center for Atmospheric Research is providing major observing tools to the science team and helping to oversee operations and data management for the project.

This important weather-maker pattern was first identified by NCAR scientists Roland Madden and Paul Julian in the 1970s.

More about DYNAMO: http://www.eol.ucar.edu/field_projects/field-projects/dynamo

Category:

Science & Technology

Tags:

• atmospheric pattern
• weather
• maker
• atmospheric research
• field campaign
• tropical climate
• trade winds
• Indian Ocean
• MJO
• Madden-Julian Oscillation
• NCAR
• UCAR