Impact of ocean observation systems on ocean analyses and subseasonal forecasts of the monsoon intraseasonal oscillations

We evaluate the relative merits of different ocean observation systems (moored buoys, Argo, satellite, XBTs and others) by their impact on ocean analyses and subseasonal forecast skill of the monsoon ISO (MISO). Several ocean analyses were performed where different ocean observation platforms were withheld from the assimilation in addition to one ocean analysis where all observations were assimilated. We then use these ocean analyses products for initializing a set of subseasonal forecasts to evaluate the impact of different ocean analyses states on the forecast skill of MISO. We use the European Centre for Medium-Range Weather Forecasts (ECMWF) and JMA-MRI ensemble prediction system for the twenty-year sub-seasonal hindcast experiments. Results from these hindcast experiments will be presented to highlight changes in the ocean analyses states and their impact on the forecast skill of the MJO and monsoon intraseasonal oscillations.

Coupled air-sea interaction processes relevant to intraseasonal variability (e.g. the MISO) in the earth’s climate system are inadequately represented in regional and global coupled models. These inaccuracies could be related to the either poor parameterization of model physics or insufficient model resolution to resolve the critical processes. New efforts in observations, process understanding and translation into weather and climate models are necessary for improvements in simulation and prediction of the intraseasonal. We will discuss the merits of different ocean observation platforms in this context and also future observation and model improvement pathways.