Stands for Madden-Julian Oscillation, also known as the 30-50 day wave. This is a periodic enhancement of rainfall over the Australian tropics, which progresses across tropical latitudes roughly every 30-50 days. Satellite cloud loops and atmospheric pressure changes can signal passage of the wave over Australia, signalling a burst in monsoon (rainfall) activity during the tropical wet season.

Madden-Julien oscillation

MADDEN-JULIAN OSCILLATION - ALSO CALLED TROPICAL INTRA-SEASONAL OSCILLA- TION - A DISTURBANCE IN TROPICAL CONVECTION - PRECIPITATION - WIND AND PRESSURE. MJO PRECIPITATION AND CLOUDINESS ARE ENHANCED ONLY IN REGIONS WHERE SSTS ARE VERY WARM - E.G. INDIAN OCEAN AND WEST PACIFIC. THE PRESSURE AND WIND DISTURBANCE ASSOCIATED WITH MJO IS OBSERVED TO MOVE FROM WEST TO EAST COMPLETELY AROUND THE GLOBAL TROPICS IN ABOUT 30 TO 60 DAYS.

MADDEN-JULIAN OSCILLATION - ALSO CALLED TROPICAL INTRA-SEASONAL OSCILLATION - A SERIES OF WAVES WITH A PERIOD AVERAGING 50 DAYS THAT MOVES SLOWLY EASTWARD NEAR THE EQUATOR ALTERNATELY ENHANCING AND SUPRESSING PRECIPITATION.

Madden Julian Oscillation. A tropical disturbance that travels eastward around the globe with a recurrence interval of 30-60 days. It is associated with convection anomalies particularly over regions of high SST over the Indian and western Pacific Oceans. The MJO is baroclinic in structure, and is accompanied by large scale (zonal wave numbers 0-3) circulation anomalies that can extend into mid-latitudes. Eastward propagation is most robust during northern winter/spring. The MJO is an important source of intraseasonal variability in the tropics.