Relative Feedbacks between the Madden–Julian Oscillation and Tropical Cyclones

The Madden–Julian oscillation (MJO) and tropical cyclones (TCs) are two principal modes of variability in tropical convective and circulation patterns. Neither mode is independent of the other—TC activity is modulated by MJO convection and circulation, which in turn feeds back on the structure and organization of the MJO itself. Thus, relative MJO-TC relationships, including information about how each mode influences and modulates the other, are implicit in composite studies of convective and circulation patterns associated with the MJO.

Recent work suggests that the structure and evolution of MJO convective and circulation patterns are influenced by enhanced or suppressed TC activity across different regions of the globe. A composite assessment of these relationships is presented for different phases of the Real-time Multivariate MJO (RMM) index. Composites are stratified by dates in which TCs are present or absent in conjunction with suggested active MJO conditions (i.e., the RMM index exceeds one standard deviation), and, for the subset associated with active TCs, dates that correspond to recurving or non-recurving TCs. TC behavior shows sensitivity to antecedent tropical and extratropical circulation patterns associated with the MJO, and results also suggest that the subsequent structure and organization of the MJO responds to differences in TC behavior.