A 30-60 day cycle of enhanced and suppressed rainfall that moves eastward across the tropical Indian and Pacific Oceans.
phenomenaWhat is Madden-Julian Oscillation (MJO)?
The MJO is the dominant mode of intraseasonal (30-60 day) variability in the tropics. It consists of a large-scale envelope of enhanced convection (rain) and suppressed convection (dry) that propagates eastward at about 5 m/s. When the active MJO phase passes over Southeast Asia, rainfall increases markedly. When the suppressed phase is overhead, rain decreases. The MJO also modulates tropical cyclogenesis — more typhoons form during active MJO phases.
Key points
- A 30-60 day cycle of enhanced and suppressed rainfall that moves eastward across the tropical Indian and Pacific Oceans.
- Category: phenomena
Related terms
See also: madden-julian-oscillation is connected to other weather concepts. Browse the full glossary for related definitions.