We aim to improve the seasonal and El Nino forecast system.
In order to achieve this objective, we develop the El Nino forecasting system that consists of the atmosphere-ocean coupled general circulation model and the global ocean assimilation system. Through the El Nino hindcast experiments using that forecasting system, the seasonal predictability is examined.
(1) The atmosphere-ocean coupled general circulation model (CGCM [AGCM: TL95L40, OGCM:1x1L50]) is developed and improved in order to reduce its seasonal bias.
(2) The 3D-VAR global ocean assimilation system is developed and the oceanic initial conditions for the El Nino hindcast experiments are produced.
(3) The El Nino hindcast experiments are conducted using the momentum and heat corrections at the sea surface. The seasonal hindcast experiments using AGCM are also conducted.
(4) The seasonal predictability in the tropical and midlatitude Pacific.is examined by analyzing the results of the above CGCM and AGCM experiments.