EGU2020-3136, updated on 14 Jan 2022
EGU General Assembly 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Dynamic Core of the MJO

Chidong Zhang1 and Ji-Eun Kim2
Chidong Zhang and Ji-Eun Kim
  • 1NOAA PMEL, Seattle, United States of America (
  • 2Pusan National University, Pusan, Korea (

This presentation introduces a theory in which the dynamic core of the MJO is described in terms of a harmonic oscillator that can be excited by stochastic forcing. The mechanism for selecting MJO scales comes from momentum damping. The resonant solution to the equation for a damped harmonic oscillator on an equatorial beta plane represents the equatorial Kelvin wave for small damping and large zonal wavenumbers and the MJO for large (3 – 5 days) damping and zonal wavenumber one. This theory demonstrates the distinction between the Kelvin wave and MJO and their continuous transition. In contrast to most other MJO theories that compete against each other, this theory embraces most other theories in that they provide possible sources of energy (forcing) to the dynamic core of the MJO.

How to cite: Zhang, C. and Kim, J.-E.: Dynamic Core of the MJO, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3136,, 2020.


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