The tropical-weather phenomenon influences cyclone activity and monsoon seasons
The Madden-Julian Oscillation (MJO) is the largest element of intraseasonal variability in tropical weather. It is characterised as an eastward movement of enhanced and suppressed tropical convection over a 30- to 60-day period, on average.
In the enhanced phase, winds at the surface converge and air rises through the atmosphere. This rising motion allows air to cool and condense, bringing more rainfall. In the suppressed phase, winds converge higher up in the atmosphere, forcing air to sink and then diverge at the surface. The sinking air warms and dries, consequently suppressing rainfall.