Daily, intraseasonal, seasonal and interannual changes of temperature, salinity, and transport will be described. This array will detect variabilities associated with equatorial waves of a few thousand kilometers scale or less.
(2)Buoy array in the warm pool region within 2000 km length zonally, and 2, 5, 8 degree meridionally.
The buoy array will cover the warm pool region and observe the heat budget, salinity budget, and volume transport. The meridional narrow scale near the equator can detect the variations of the Equatorial Under Current with subsurface current meter buoys. The North Equatorial Counter Current can also be detected. The surface winds also have zonally long correlation length, and the array can measure variability covering 2000km in width.
(3)Buoy array along the equator in the Indian ocean.
This array will enable us to understand the relationship between the monsoonal changes in surface meteorology and the changes in the upper layer of the Indian ocean. The horizontal width will be the same as in the western Pacific. These data will also be useful to study the connection between ENSO in the Pacific and the ocean and atmosphere variability in the Indian ocean.
(4)Buoy array in mid-latitudes.
Water mass formation and its transportation processes will be studied by utilizing those data.
4. Surface buoys concept and instrumentation
4.1 Low-latitude TRITON buoy (see Fig.2)
・TRITON buoy be developed and deployed in the tropical ocean.
Under water sensors: surface current (tentatively at 10m depth), temperature and salinity (1m, 25m, 50m, 75m, 100m, 125m, 150m, 200m, 250m, 300m, 500m, 750m), pressure (300m, 750m).
Basically the sensors and which depths are designed to be compatible with a standard TAO ATLAS buoy in the western tropical Pacific. The improvement to the buoy we are developing is to add the salinity sensors down to 750m and enable real time data transfer and carry full surface meteorological sensors. We have come to know the water circulation in the western Pacific is controlled significantly by fresh water supply and the dynamic height anomaly associated with ENSO is samely affected by temperature and salinity. The depth down to 750m will be chosen because a large variability of temperature is observed deeper than 500m and the intermediate waters like the Antarctic Intermediate Water may also cause large variabilities in salinity. Surface heat and water fluxes are also very important to study the maintenance mechanism of the warm pool.
