Impact of MJO on rainfall in Sri Lanka and Maldives.

We have been looking at the impact of MJO on rainfall over Sri Lanka. Just representing the rainfall during a recent 30 year period when MJO amplitude was high and when it was low going by the Wheeler-Hendon RMM indices shows the significant impact of MJO. Note that the scale on one chart is twice that on the other.

The MJO in phase 1 and 2 has significant influene on Maldives rainfall with some influence in the Northern Islands in phase 3. In Sri Lanka, the MJO influence was particularly strong in phases 2 and 3. In addition, there is also a negative influence when the MJO phase is over the Pacific (phases 5-7).