FORSGC/JAMSTEC Indian Ocean Activities

Subsurface ADCP Mooring System Location: 0N, 90E Data interval: 1 hours Ping interval: 6.66 sec 1 data = 27 pings average Obs. range: 8m X 50 layers 11 months 9 months 12 months Nov. 2000 Oct. 2001 Jul. 2002 Jul. 2003

Zonal currents at 0N, 90E 2001 2002 2002 2003 Period 1 Period 2

Power spectrum density of currents at 0N, 90E Broad time-scale with strong 30-50 days variability, shallower than 120 m depth 10-20 days variability above 100 m depth

Monthly mean zonal currents at 0N, 90E Typical Wyrtki jet structure

Wavelet analysis for zonal currents at 0N, 90E The contour levels are chosen so that 75%, 50%, 25%, and 5% of the wavelet power is above each level, respectively.

Wavelet analysis for meridional currents at 0N, 90E The contour levels are chosen so that 75%, 50%, 25%, and 5% of the wavelet power is above each level, respectively.

Status of TRITON Array 1. Development of TRITON Array Yoshifumi Kuroda JAMSTEC Jan 2004 1. Development of TRITON Array 2. Data from Indian Ocean TRITON 3. TRITON web page update plan 今回の話は海洋センターが実施している太平洋熱帯域の観測システムとしてのトライトンブイネットワークの現状を中心として，これまでの経緯やこれからの計画についてと，並行して実施しているアルゴフロートの展開についてです。

Configuration of the TRITON First of all, I explain the configuration of the TRITON mooring system. The mooring system is fixed on the sea bottom using 4 ton anchor. The mooring line is made up of nylon ropes and wire cable. The wire cable is connected to the surface float. The wire cable is equipped with 10 conductivity & Temperature sensors, 2 conductivity, temperature & depth sensors and 1 current meter.(click)[to 3]

Development of TRITON buoy array from 1998 to 2002 March, 1998 March, 1999 March, 2000 August, 2002 March, 2001 March, 2002 Purposes; 1. Monitoring ENSO as TAO/TRITON array 2. Air-sea interaction over the Pacific and Indian Ocean warm pool 3. Variability of temperature and salinity in the warm pool - Improvement of the predictability of El Nino

High salinity water intrusion from Arabian Sea 　　　TRITON　Temperature　1.5S90E 　　　　TRITON　Salinity　1.5S90E 28 20 35.4 Warm water accumulation associated with eastward jet in monsoon break period High salinity water intrusion from Arabian Sea 　　　TRITON　Temperature　5S95E 　　　　TRITON　Salinity　5S95E 33.8 20 35.4

1.5S90E TRITON T and S

R/V Varuna Jaya, BPPT, Indonesia

New TRITON web page to be appeared from April 2004

R/V Mirai cruise in the Indian Ocean: Summary R/V Mirai cruise in the Indian Ocean: ・ Next R/V Mirai TRITON cruise will be conducted June-July 2004 (departing on 4 July from Darwin, Australia and return on 1 August 2004 to Hachinohe, Japan). Present status of Indian Ocean TRITON at1.5S90E & 5S95E: ･ This year, we recovered and re-deployed successfully the 1.5S90E TRITON, but we could not recover nor re-deploy the 5S95E due to the strong SE monsoon winds during the June-July R/V Mirai cruise. ･ The TRITON buoy at 5S95E have been recovered on 11 November 2003 by R/V Baruna Jaya 1 of BPPT Indonesia, but no re-deployment. All the met sensors had been stolen on the buoy, but we may have the internal data record of underwater sensors. We could avoid the lost of the buoy and save the internal record data, but since then, the data gap has started until the next R/V Mirai cruise.

Data delivery: ・The data from TRITON buoys and detailed information on the project can be obtained from TRITON home page. http://www.jamstec.go.jp/jamstec/TRITON/ ・TRITON real time salinity data has been distributed through GTS since January 2003. ・Re-constructing TRITON web data display and delivery system targeting the end of April 2004 to deliver all TRITON T and S. This early version web will deal real time T and S data of no quality control using post calibration data. ・The second version can deal quality controlled T and S data will appear early 2005.

Plan for mooring array in the tropical Indian Ocean OASIS OOS Deep Sea & Shallow Water Buoys I-MAP A multi-national project to observe ocean conditions in the tropical western Indian Ocean. TAO-type buoys. LODYC Upward looking ADCP mooring at 76E on the equator. Two additional ADCPs on the top of OOS buoys, or independent locations. INSTANT An international project to measure the flow from the Pacific to the Indian Oceans. Current meters, ADCP, etc. PMEL TAO-type array on the equator at first, and expand to off-equatorial area.