Zhang, C. (PMEL), A. Adames, B. Khouidar, B. Wang, and D. Yang (2020): Four theories of the Madden-Julian Oscillation. Rev. Geophys., 58(3), e2019RG000685. https://doi.org/10.1029/2019RG000685
The Madden-Julian Oscillation (MJO) is the leading intraseasonal (20–100 days) variability in the tropics. It affects many weather-climate phenomena globally.
MJO Schematic showing the eastward moving disturbance of clouds, rainfall, winds, and pressure that circles the planet in the tropics and returns to its points of origin in 30 to 60 days, on average. Read the full description on climate.gov.