Intraseasonal Variabity of the Asian Summer Monsoon

Abstract:

The intraseasonal variability of the Asian summer monsoon on timescales of a few weeks and longer is usually characterized in terms of a single oscillatory mode of variability that exhibits northward phase propagation. Here it will be characterized in terms of MJO related variability and a residual. The former accounts for most of the northward propagation of so-called “active and break monsoon” episodes in the Indian Ocean sector, while the latter accounts for most of the variability of rainfall and winds farther to the east, over the South China Sea. Three time-varying, linearly independent indices are required to represent this variability, two for the MJO and one for the residual.