INDIAN OCEAN SITES
Site: Indonesian Throughflow
Position: 3°N-12°S 116°E-125°E
Categories: operating; transport; physical
Safety distance for ship operations: varies - please contact before any planned ship operations in vicinity of these moorings. If in doubt, do not approach within 1 x water depth as most moorings have near-surface expression and a potential watch circle radius of greater than 500 m.
Short description:
· Number of stations / moorings and variables measured:
Table 1. Mooring Array
Table 2. Location of Shallow Pressure Gauges
Sensor No. Latitude Longitude Description
1 12 11.2 S 123 4.0 E Australian territorial waters
2 8 22.0 S 125 3.0 E N. Ombai Strait
3 8 38.5 S 125 6.5 E S. Ombai Strait (E.Timor waters)
4 10 49.0 S 122 41.0 E SW Roti
5 8 24.0 S 115 43.0 E W. Lombok Strait
6 8 21.0 S 116 1.5 E E. Lombok Strait
7 10 15.2 S 120 31.1 E S. Sumba
· Start date of the timeseries, service interval:
In December 2003 and January 2004 instrumented moorings were deployed in these passages. The moorings will last for three years with one servicing and redeployment cruise 1.5 years after the first deployment.
Scientific rationale:
The Indonesian Throughflow (ITF) links two oceans and in so doing provides a pathway for modifying the stratification within each of these oceans as well as sea-air fluxes that impact on such climate phenomena as ENSO and the Asian Monsoon. The complex geography of the region, with multiple narrow constrictions connecting a series of large, deep basins, leads to a circuitous ITF pathway within the Indonesia seas. En-route the Pacific inflow waters are modified before export to the Indian Ocean due to mixing, upwelling and air-sea fluxes. While a number of measurement programs have recently been undertaken in the Indonesian region, a serious shortcoming is their lack of temporal coherence: the data cover different time periods and depths in the different passages of the complex pathways linking the Pacific and Indian Oceans. This has lead to ambiguity of the mean and variable nature of the ITF, and of the transformation of the thermohaline and transport profiles within the interior seas. The INSTANT (International Nusantara STratification ANd Transport) program, involving contributions of 5 countries (USA, France, Netherlands, Australia, Indonesia), offers the opportunity to finally measure in coordinated fashion the ITF in the key throughflow passages simultaneously.
The INSTANT objectives are:
· To determine the full depth velocity and property structure of the Throughflow and its associated heat and freshwater flux;
· To resolve the annual, seasonal, and intraseasonal characteristics of the ITF transport and property flux;
· To investigate the storage and modification of the ITF waters within the internal Indonesian seas, from their Pacific source characteristics to the ITF water exported into the Indian Ocean; and
· To contribute to the design of a cost-effective, long-term monitoring strategy for the ITF.
Groups / P.I.s /labs /countries involved / responsible:
Project Leaders: see http://www.ldeo.columbia.edu/res/div/ocp/projects/instant.shtml
Country / P.I.sITF Mooring Components:
Makassar Strait / USA / Gordon, Field, Susanto [LDEO]
Lombok Strait / USA / Sprintall [SIO]
Ombai Strait / USA / Sprintall [SIO]
Timor Passage / Australia / Wijffels [CSIRO]
Timor Passage / France / Molcard, Fieux [LODYC]
Lifamatola Passage / Netherlands / van Aken [NIOZ]
Supporting/Proxy Measurements:
CTD and Underway ADCP / Indonesia / BPPT
Lesser Sunda Pressure Gauges / USA / Sprintall [SIO]
XBT Network / Australia / Wijffels, Meyers [CSIRO]
Tide Gauges / Indonesia / Bakosurtanal (survey and mapping)
Meteorological Network / Indonesia / Badan Meteorologi dan Geofisika
ARGO Floats / Australia / Wijffels [CSIRO]
Ship Facilities:
Baruna Jaya / Indonesia / BPPT
Status:
· operational since the first deployment cruises in December 2003/January 2004
· time horizon / long-term plans:moorings will last for three years with one servicing and redeployment cruise 1.5 years after the first deployment.
· funding status, source of funding: funded. See project web site for funding sources of the various components.
Technology:
The main instrumentation in the INSTANT program consists of moorings with self recording ADCPs, current meters and additional temperature/pressure and temperature/conductivity/pressure recorders. The moorings will record the current over the complete water depth. The moorings do not have real-time telemetry. During the deployment, servicing, and recovery cruises hydrographic observations (CTD) are carried out.
Data policy:
· delayed mode data: restricted access
The data policy is defined in the INSTANT letter of intent. During the project the data will be available for all participants in the INSTANT program. The data will be published in cooperation with Indonesian counterparts before 2008. After that date the data will be public.
Data management:
The data management for INSTANT has not yet been defined.
Societal value / Users / customers:
The combined data set from the international INSTANT mooring experiment and the supporting observational network will leverage our individual measurements to understand the broad spectrum of variability in the ITF, and the role that regional oceanography plays in establishing the transfer function between the Pacific inflow and the outflow into the Indian Ocean. Furthermore this comprehensive portrayal of the Indonesian throughflow and its variability will allow for development of improved global ocean and climate models, enabling more accurate predictive capability.
Role in the integrated global observing system:
The Indonesian throughflow will allow for closure of the ocean basin scale transport and heat/freshwater fluxes.
Links / Web-sites:
· for Project information : http://www.ldeo.columbia.edu/res/div/ocp/projects/instant.shtml
· for data access: when made public, the data will be available via the above project website.
Compiled/ updated by: Arnold Gordon and Bruce Huber (April 2005)
Figure: Schematic of Indonesian Throughflow pathways (Gordon, 2001). The solid arrows represent North Pacific thermocline water; the dashed arrows represent South Pacific lower thermocline water. Transports in Sv (106m3s-1) are given in red. The 10.5 Sv in italics is the sum of the flows through the Lesser Sunda passages. ME is the Mindanao Eddy; HE is the Halmahera Eddy. Inserts A-D show positions of INSTANT moorings. Insert A: 2 Makassar Strait Inflow moorings (U.S., red diamond) within Labani Channel. Insert C: Netherland’s mooring within the main channel of Lifamatola Passage (yellow triangle). Insert B, D: Sunda moorings in Ombai Strait, Lombok Strait, and Timor Passage (U.S., red diamonds; France, purple square; Australia, green circles). The positions of the shallow pressure gauge array (U.S., green X). The 100, 500, and 1000 m isobaths are shown in the inserts.
INDIAN OCEAN – page 3
Site: National Data Buoy Programme of India for insitu measurements around Arabian Sea and Bay of Bengal
Positions:
Categories: operating met-ocean observatory
Safety distance for ship operations: 1000m for deep sea; 500m for shallow water
Short description:
· 20 moorings
· Variables measured: air pressure, air temperature, wind* (spd, dir), water temperature**, conductivity**, surface current** (spd,dir), wave (full spectrum)
* sensor is at 3m above the sea surface
** sensor is at 3m below the sea surface
· Sampling interval: once in every three hours
· Start date of time series, service interval: August 1997, once in three to four months for shallow water buoys and once in six to eight months for deep sea buoys
Scientific rationale:
To provide systematic and long-term information on variety of metocean parameters important to coastal / marine environment and to improve the understanding of ocean dynamics and its variability.
Groups / P.I.s /labs /countries involved / responsible:
Department of Ocean Development / National Institute of Ocean Technology, India
Status:
· 15 operating, 40 planned in next two years
· funding status, source of funding: Government of India
Technology:
Sensor / Make / Range / Accuracy / ResolutionAir pressure / Vaisala / 800 – 1100 hPa / ± 0.1 hPa / 0.01 hPa
Air temperature / Omega Eng. / 10 – 50 °C / ± 0.1 °C / 0.01 °C
Wind * (spd, dir) / Lambrecht / 0 – 60 ms-1, 0 – 360° / ± 1.5% FS, ± 3.6° / 0.07 ms-1, 0.1°
Water temperature ** / NE Sensortec / -5 – 45 °C / ± 0.1 °C / 0.01 °C
Conductivity ** / NE Sensortec / 2 – 77 m mho cm-1 / ± 0.06 m mho cm-1 / 0.01 m mho cm-1
Surface current ** (spd, dir) / NE Sensortec / 0 – 6ms-1, 0 – 360° / ± 3% FS, ± 2° / 0.005 ms-1, 0.36°
Wave (full spectrum) / Seatex / ± 20 m, 0 – 360° / ± 10 cm, ± 5° / 1 cm, <0.1°
· moored sensors:
* Sensor is at 3 m above the sea surface; ** Sensor is at 3 m depth below the sea surface
· real-time telemetry
· SST measurement: Thermistor
Data policy:
real-time data: Near realtime data of surface met parameters available for public through GTS
Societal value / Users / customers:
India Meteorological Department, Ports, Fisheries, Research Institutes, World Meteorological Organisation
Role in the integrated global observing system:
National Data Buoy Programme deploy and currently maintain 20 moored data buoys in the Indian Seas, collect realtime met-ocean parameters and supply data/data products. The near realtime surface met parameters are disseminated to the global community through GTS. India actively participates in a variety of international ocean observation programmes like Global Ocean Observing System (GOOS), Data Buoy Co-operation Panel (DBCP) etc.
Contact Person:
Programme Director
National Data Buoy Programme
NIOT, Chennai 601302
Links / Web-sites: http://www.niot.res.in/ndbp/index.html
compiled by: K. Premkumar, Programme Director (June 2005)
Figure: View of the fully indigenised 2.2m dia Buoy
Buoy profile:
Diameter : 2.2 m
Overall height with : 6.5 m mast and keel
Weight : 700 kg.
Reserve Buoyancy : 2000 kg.
Characteristics:
· Can carry a suit of meteorological and Oceanographic sensors up to 16 nos.
· Operable from 20 m water depth to full ocean depth.
· 20 w x 4 nos solar panels ensure constant recharging of the batteries.
Site: Long-term measurements of currents in the eastern equatorial Indian Ocean
Position: 0; 93 E, 83 E and 76/77 E
Categories: observatory, physical
Safety distance for ship operations: OOS (Ocean Observing System) moorings are of subsurface nature.
Short description:
· 3 current meter moorings
· Variables measured : Current speed, direction, temperature, salinity and pressure at each depth of RCMs. The sampling interval is 1 hour. The moorings deployed in 2004 keep upward looking ADCP at 100 m depth.
· Start date of the timeseries, service interval: February 2000 (One mooring at 93E in 2000, two current meter moorings at 83E and 93E in 2001 and 3 current meter moorings at 93E, 83E and 76E in 2002. In 2003, the location of 76E current meter mooring was shifted to 77E.), annual servicing
Scientific rationale:
The sparse measurements of currents in the eastern equatorial Indian Ocean (EEIO), particularly east of 80E, compared to the western and central equatorial regions prompted the beginning of time series current measurements on longer time scale in the EEIO, characterised with an eastern boundary off Sumatra. The current and temperature measurements are planned
· to understand the variability of currents in the entire water column in the EEIO on intraseasonal, seasonal, and interannual time scales,
· to document the differences in the variability of currents and dynamics in the eastern basin from that of in the western basin (from the information available from earlier experiments prior to 2000),
· to document the variability in the EEIO response to the wind forcing,
· to address the meridional overturning circulation in the EEIO, and
· to support the Indian Ocean modelling community with the in situ data to address the feed back, if any, of EEIO dynamics on the Indian monsoon.
To supplement the time series data, hydrographic surveys were also planned (and are being undertaken) to understand the upper ocean variability by collecting multi-disciplinary data in the EEIO.
Groups / P.I.s /labs /countries involved / responsible: National Institute of Oceanography, Goa, India
Status:
1) operating
· time horizon / long-term plans: 6 years from 2000.
· funding status, source of funding: Department of Ocean Development (DOD), Government of India.
Technology:
Subsurface I-moorings; in each mooring, 6 RCMs were placed at six depths (see Table 1). In 2004 deployments, all the three moorings have an upward looking ADCP kept at 100 m depth. Also, Microcat CTDs were placed at 4000 m depth at 93E and 83E in 2002-2004. In 2004 deployment, the Microcat CTDs were placed at 200 m depth for obtaining high resolution temperature and salinity data.
Table 1: Mean depth [m] of RCMs in each deployment at each location
Station No. / 2000 / 2000-02 / 2002-03 / 2003-04 / 2004-05EQCM 1
[Eq., 93E] / 135, 280, 487, 983, 1996, 3995 / 106, 264, 462, 966, 1969, 3968 / 64, 267, 469, 972, 1983, 3986 / 76, 365, 501, 996, 1981, 3991 / To be recovered
EQCM 2
[Eq., 83E] / No Data, 385, 590, 1072, 2081, 4095 / 140, 343, 545, 1047, 2049, 4052 / 139, 339, 534, No Data, 2022, 4000 / To be recovered
EQCM 3
[Eq., 76E] / 418, 621, 823, 1326, 2330, 4134 / ------/ ------
EQCM 3
[Eq., 77E] / ------/ 168, 389, 568, 1059, 2101, 4084 / To be recovered
Data policy: Delayed mode data. Policy for data distribution is to be formulated.
Data management:
· Metadata scheme: Copy of the data will be deposited with the Department of Indian National Center for Ocean Information System (INCOIS), Hyderabad, India.
Societal value / Users / customers:
Improvement the long-term predictive capability of the Indian Monsoon Rainfall is very essential for the agriculture-dependent people of India and neighbouring Asian countries. Understanding the dynamical role of the ocean in monsoon climate is the first step toward understanding predictability. Ultimately, improved intraseasonal, seasonal and longer term climate prediction is essential for mitigation of societal impacts, by smart management of agriculture, water resources, natural resources (e.g. fisheries) and many other impacted sectors.
Role in the integrated global observing system:
Towards understanding the role of the Indian Ocean, particularly the equatorial Indian Ocean which is not studied much compared to its counterparts such as the Equatorial Pacific and Atlantic, on the Asian monsoon climate over India, a sustainable Ocean Observing System (OOS) program was initiated in 2000 by the Government of India. One aspect of this OOS Program was the deployment of current meter moorings for measuring long-term time series currents and temperature data along the equator at 3 locations. The other programs were the deployment of surface drifters, occupation of XBT lines and surface moored buoys in the Bay of Bengal and the Arabian Sea. The OOS program would constitute the Plot program of the Indian Ocean - Global Ocean Observing System (IO-GOOS). However, continuation of the current meter moorings in the EEIO for a period of 3-5 years (beyond 2007) and simultaneous time series measurements from the moorings in the western and central equatorial Indian Ocean would form an integrated ocean observatory for an understanding the regional climate predictability.