equator in a programme of the Tropical Ocean Climate Study in conjunction with the surface buoy array. After establishing the network in the western tropical Pacific, two of buoys manufactured will be deployed in the Indian ocean in year 2000. The development for mid- and high-latitude buoys will also be started during the first phase with the deployment starting in year 2000 in the north Pacific. Those four buoys in the mid- thigh- latitude and in the Indian Ocean will be utilized for process oriented studies and be shifted the locations in order to derive the optimal scientific results.
An important first step to the understanding of the ENSO mechanism is to undertake study of the process of the growth and dissipation of the warm pool in the western Pacific, an area where the water temperature goes up to the world highest acting as an engine driving the atmosphere. We must also study the variability in low-latitude western-boundary currents such as the New Guinea Coastal and the Mindanao Currents. Other topics that should be surveyed include the relationship between the ENSO and the monsoon climate in the Indian Ocean. Pilot studies will also be planned on the relationship between ENSO and the variability in the subpolar gyre and that in the subtropical gyre including the Kuroshio Extension.
Basically the sensors and those depths on the buoy are designed to be compatible with a standard TAO ATLAS buoy in the western tropical Pacific. The improvement is to add the salinity sensors in the full depth down to 750m and enable real time data transfer and carry full surface meteorological sensors. We have come to know the heat budget in the surface mixing layer may be controlled significantly by fresh water supply at the surface. Further, the water circulation in the western Pacific may be influenced by salinity change induced by subsurface currents associated with seasonal and ENSO cycle. The depth down to 750m will be chosen because a large variability of temperature is observed deeper than 500 m 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. We hope the buoy network will greatly contribute to the progress in the above ocean climate studies through multinational efforts.
