Seasons in the Ocean
Toshio Yamagata
Frontier Research System for Global Change (FRSGC)
Tokyo, Japan
Efforts toward understanding prominent regional ocean-atmosphere phenomena are indispensable to contributing to next-generation climate models that must satisfy societal needs with predicting regional influences of basin-wide changes. Based on our achievement along the line in the last decade, I will focus here on two phenomena in the Indo-Pacific sector. One is the Sri Lanka Dome in the tropical Indian Ocean; the other is the Kuroshio south of Japan in the Pacific.
The seasonal evolution of the Sri Lanka Dome is interpreted as the oceanic response to summer monsoon winds, using outputs from a basin-wide ocean circulation model and in situ as well as satellite observations. Understanding the interannual modulation of the seasonal signal has led us to discovery of the Indian Ocean Dipole. The Kuroshio is also driven by the seasonal winds but has turned out to be much influenced by the interaction between the oceanic baroclinicity and bottom relief. This has provided a key to solve the long-standing mystery on the seasonal transport variation of this major western boundary current.
Based on the review on simulating the seasonal variations, I would like to discuss elements of predicting regional ocean climate variations.
