MR01-K05

　Tropical Ocean Climate Study (TOCS)

　The EI Nino / Southern Oscillation and the variation of the Asian Monsoon affect largely to the social and economical activities in the eastern / southeastern Asian countries. To understand the role of the warm water pool in these features, the observational studies on the oceanic and atmospheric variability will be conducted.

　For the ocean, the heat, freshwater and momentum balances in the oceanic surface mixing layer will be observed using TRITON buoys and other instruments around the warm water pool in the western tropical Pacific Ocean and the eastern tropical Indian Ocean. The data will be provided to reveal the modification process of the ocean surface mixing layer, including the effect of the salinity, horizontal advection of heat and fresh water, and equatorial waves such as Kelvin waves. The data also utilized to reveal the interaction between the Pacific Ocean and the Indian Ocean through exchange of heat and fresh water by the Indonesian through flow.

　For the atmosphere, precipitating system and its environment will be observed continuously by C-band Doppler radar, radiosonde, etc. The data will be provided to reveal the structure and regulation of the precipitating system. The impact of the precipitating system (cloud, precipitation, wind, etc.) on the oceanic variation are also evaluated to reveal the air-sea interaction through the precipitating systems.

　The principle purpose of the cruise is to obtain the physical parameters on the ocean and the atmosphere. On the former half of the cruise, the major works are to recover and to deploy surface moored TRITON buoys and subsurface moored ADCP buoys. The three TRITON buoys will be recovered and deployed along 130E, and four along 137E (or 138E). The two buoys will be recovered and deployed also in the eastern Indian Ocean. CTD measurements to 1000 m depth will be carried out at and around the buoy deployment area with water sampling by twelve 12-litter bottles.

　On the other hand, the latter half of the cruise will be dedicated to the continuous fixed-point observation near the Equator. The continuous observation of the Doppler radar and short-cycle (3-hourly for shortest) radiosonde and CTD observation will be carried out for the period. The water sampling will be carried out with CTD observation, if needed.

　Western Tropical Pacific Ocean: 130E -140E, 8N - 2S

　Eastern Tropical Indian Ocean: 80E - 95E, 5N - 5S

Sekinehama → Singapore → Jakarta → Palau → Sekinehama

　Ocean Research Department, JAMSTEC

　2-15 Natsushima-cho, Yokosuka 237-0061 Japan

　Keisuke MIZUNO (Physical Oceanography)

Tel: +81-468-67-3872　Fax: +81-468-65-3202

　Kunio YONEYAMA (Meleorology)

Tel: +81-468-67-5516　Fax : +81-468-65-3202

　E-mail:yoneyamak@jamstec.go.jp

　Note: YONEYAMA will be on MIRAI during Jun.13 to Jul.6, 2000.

　　　　Please contact yoneyama@mirai.jamstec.go.jp for the period.