III. Research Program
1. Climate Variations Research Program

(1) Goal

This group studies climate variations and related oceanic phenomena in the Asia-Pacific sector including the Indian, polar and subpolar Oceans. The goal is to contribute toward establishing advanced prediction schemes. Numerical simulations using ocean and atmosphere models of various degrees of freedom as well as data analyses are particularly stressed in order to understand basic processes generating those climate variations.

a. Study on predictability and processes of short-term climate variations including seasonal changes.

Encouraged are process studies on various annual and interannual oceanic and atmospheric phenomena such as ENSO, quasi-biennial oscillation in the troposphere, monsoonal variations, Aleutian Low and storm track variations, bimodality of the Kuroshio path, the Indonesian Throughflow and the Yoshida-Wyrtki Jet in the Pacific and Indian Ocean. Interrelations among those oceanic and atmospheric phenomena should be also understood in order to contribute to increasing skills of prediction. Analyses of reanalysis data, long-term in-situ data, remote sensing data and even proxy paleoclimate data will be encouraged to understand physical processes, together with simulations using models of various degrees of freedom from atmospheric and/or oceanic GCMs to conceptual GFD models.

b. Study on predictability and processes of decadal and interdecadal climate variations.

Decadal and interdecadal climate variations have been detected in various regions of the world in recent years but our level of understanding as well as predictability skills are still far behind that for interannual variations. This is particularly the case for the Asia-Pacific sector in which counted are the well-known 1976 regime shift in the northern North Pacific, intensification of the Antarctic Circumpolar Waves and meridional circulation changes in the Pacific and Indian Oceans. In addition to those phenomena, relations among processes with different space and time scales need to be addressed. For example, a possible relation among oceanic subduction processes, storm track variations and modulation of intraseasonal variations will be classified into the latter.

Analyses of ocean and atmosphere reanalysis data, long-term in-situ data, remote sensing data and proxy paleoclimate data will be encouraged to understand physical processes, together with simulations using models of various degrees of freedom from atmospheric and/or oceanic GCMs to conceptual GFD models.

The present research subjects will contribute to the World Climate Research Program, particularly to CLIVAR/GOALS and CLIVAR/DecCen. They will also partially contribute to IGBP/PAGES. Implications for designing Asia-Pacific regional components of climate observing systems will contribute to GCOS and GOOS. The present research group will strengthen cooperation with colleagues in Asia, Europe and Pan-Pacific countries as well as domestic scientists interested in the above subjects.