Ferranti, L., B. Hoskins, T. Palmer and J. Slingo, 1995: Relations between interannual and intraseasonal monsoon variability as diagnosed from AMIP integrations (ECMWF). Abstracts of the First International AMIP Scientific Conference, Monterey, California, 64.

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This study investigates monsoon variability on intraseasonal and interannual time scales and the associated monsoon predictability, using two 10-year ECMWF AMIP integrations, which differ only in their initial conditions. The results indicate that the model has large intraseasonal variability which is spatially correlated with the interannual one. Empirical orthogonal function analysis and canonical correlation analysis are used to identify the most important components of variability in the precipitation and vorticity fields. The leading pair of CCA modes is able to describe most of the model intraseasonal fluctuations. The first vorticity mode describes the weakening/strengthening of the monsoon low and the corresponding precipitation mode describes the two preferred "regimes" of the ITCZ. The continental regime is located north of 10°N and it covers most of the land while the oceanic regime is located south of 10 degreesN. The nature of the intraseasonal fluctuations appears to be mostly chaotic. The interannual variability can be also described in terms of CCA modes. The seasonal mean monsoon circulation appears to be predictable.