Persistence and Predictability Barriers for the Tropical Indian Ocean Climate

Roxana C. Wajsowicz
University of Maryland

The existence of a boreal spring persistence barrier and a contemporaneous predictability barrier to forecasting interannual variability in SST over the equatorial Pacific is well known. Observations and retrospective forecasts/hindcasts from two ensemble dynamical forecast systems (NASA/GMAO and NOAA/NCEP CFS) are used to investigate the existence of similar features over the tropical Indian Ocean with a view to forecasting Indian Ocean Dipole events, whose positive phase brings severe drought to Indonesia and flooding to east Africa. Until recently, a negligible amount of sub-surface ocean data were available to initialize the Indian Ocean. As the Indian Ocean Observing System expands, questions arise on whether there is an upper limit to the predictability of the climate. The potential predictability of the tropical Indian Ocean climate, assuming a perfect model/initial conditions/ensemble, is also investigated using the forecast systems.