The Impact of the MJO on Global Ocean Surface Wave Heights

The Madden-Julian Oscillation (MJO) is a dominant mode of tropical variability. It holds a unique place in the environmental forecasting problem by having a time scale that lies between the more traditional predictions associated with weather and climate. In this regard, it represents an important bridge in considerations of developing seamless predictions and for its unique applications to decision support. This presentation will describe recent results examining the impacts of the MJO on ocean surface wave heights, which have significant bearing on air-sea fluxes of momentum, energy, and constituents (e.g. vapor, trace gases) as well as on civil and commercial marine operations and security. The analysis is based on a compositing approach using the Wheeler and Hendon Real-Time Multi-Variate Mode MJO indices in conjunction with the NOAA WaveWatch III ocean wave analyses/prediction system, and discriminates between boreal summer and winter. Mean wave heights from the analysis system range from about 1-6 meter and the MJO modulations are on the +/- 1 meter, with particularly strong enhancements in the winter hemisphere. The results will be discussed in terms of atmospheric circulation features and teleconnections, and the utility of having predictive information of this information for supporting civil and commercial marine operations.