A monsoon is a wind that changes direction with the seasons.

Monsoons develop from changing patterns of atmospheric circulation which are caused by changes in heating and cooling of land and oceans. One of the strongest and most well-known monsoons is the one which affects India and Southeast Asia in June through September.

The summer monsoon blows southwesterly across the Indian Ocean and is extremely wet. During the summer monsoon, particularly in July, there is usually a break period in the monsoon, when the rains stop and re-start. A phenomenon known as the Madden Julian Oscillation (MJO) has been found to affect that break and the variation of the MJO is affected by the variation of the SSTs.

The MJO is the main fluctuation of atmospheric circulation that explains variations of weather in the tropics and that regulates south Asian monsoons. The variation of the MJO involves variations in wind, SST, cloudiness, and rainfall. The MJO can be characterized by a large-scale eastward movement of air in the upper troposphere with a period of about 20-70 days, over the tropical eastern Indian and western Pacific Oceans at approximately 7.5 miles (200 millibars) high in the atmosphere.

Man Li Wu, a researcher from NASA's Goddard Space Flight Center in Greenbelt, Md., and lead author of the study, used computer models that simulate the atmosphere in the region. One of the purposes of this study is to examine to what extent intra-seasonal SST variations affect the MJO.

"Changes in SSTs will affect a large scale atmospheric circulation known as the MJO in the area of southern Asia, which regulates the variability of the monsoon," Wu said.

Community Email This Article Comment On This Article Related Links MJO Goddard Space Flight Center http://www.ametsoc.org SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Dirt, rocks and all the stuff we stand on firmly Memory Foam Mattress Review SPACE MEDIA NETWORK PROMOTIONS Solar Energy Solutions Tempur-Pedic Mattress Comparison ... Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News TERRADAILY Magnetic Reconnection Region Larger Than 2.5 Million Km Found In The Solar Wind Paris (ESA) Jan 12, 2006 Using the ESA Cluster spacecraft and the NASA Wind and ACE satellites, a team of American and European scientists have discovered the largest jets of particles created between the Earth and the Sun by magnetic reconnection. This result makes the cover of this week's issue of Nature.