NATIONAL REPORTS

3.1 United States (M. McPhaden, NOAA/PMEL)

3.1.2 TAO Array Annual Operation Plan. Ship time support for the TAO array in calendar year 1998 is

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summarized in Figure 3 and the following table. During 1998, three ships were used to support the array: the NOAA ships KA'IMIMOANA and RON BROWN, and JAMSTEC's research vessel KAIYO. 273 days of ship time between 95°W and 165°E with JAMSTEC providing 57 days west of the date line. In 1998, 228 days on the KA'IMIMOANA, 39 days of on the RON BROWN are anticipated. Also, TAO buoy operations are scheduled in 1999 on both of JAMSTEC's KAIYO and MIRAI research vessels west of the date line.

                        Ship Time Summary
                                                      1998              1999
Western Pacific (137°E 165°E)
   Japan (KAIYO)                                 57               48
   Japan (MIRAI)                                   --                11
   U.S. (KA'IMIMOANA)                       15                15
      Subtotal West Pacific                   72                74

East Pacific (95°W 180°W)
   U.S. (KA'IMIMOANA)                      224              213
   U.S. (RON BROWN)                        34                39
   Subtotal East Pacific                      258              252

                                 TOTAL            330              326

3.1.4 Fishing Vandalism and Data Return Fishing vandalism continues to plague the TAO array with particularly low data (and equipment) return at the eastern and western margins of the array. A resolution has been drafted to the IOC which addresses the need for help from UNESCO to mitigate against this vandalism.

Data return at some sites at the equator and 2°N in the eastern and central Pacific was also affected by moorings being pulled under due to extremely strong (in some cases >4 knot) zonal currents associated with the developing La Niña in 1998.

3.1.5 Velocity Measurements. PMEL continued to maintain acoustic Doppler current profiler (ADCP) moorings at three sites along the equator at 110°W, 140°W, and 170°W. JAMSTEC continued to maintain subsurface ADCP moorings 0°, 147°E and 0°, 165°E. Each subsurface ADCP mooring is deployed for one year.

PMEL also continued to maintain surface current meter moorings at 0°, 110°W; 0°, 140°W; and 0°, 165°E. These surface current meter moorings, beginning in late 1998, are being configured as a Next Generation ATLAS with SonTek Argonaut current meters attached to the line. The SonTek current meters at present only internally record data. We anticipate though that by the end of 1999 the three sites at 110°W, 140°W and 165°W will be telemetering SonTek data via Argos. These engineering developments will allow us to retire the aging and obsolete inventory of VACM and VMCM current meters.

3.1.6 ORSTOM /PMEL Salinity Measurements. During the past year, internally recording SEACATs were placed at the surface on 17 TAO moorings between 156øE and 180øW. Instrumentation was provided by ORSTOM and PMEL. Data return from the past year was 85% and no instruments were lost. These surface salinity measurements will be continued during the next year.

3.1.7 TAO/ARM Shortwave Radiation Measurements. The TAO/ARM array of shortwave radiation measurements presently consists of seven instrumented sites along 165°E. Measurements were begun in June 1997 at four sites, expanding to another three sites in January 1998. Each site is occupied by a Next Generation ATLAS mooring instrumented with an Eppley PSP. Data are internally recorded at 2-minute intervals and transmitted to shore in real-time via Service Argos as daytime (6 am to 6 pm local time) averages. Data return has been about 85% since the beginning of the project. The TAO project intends to continue these shortwave radiation measurements for the next year with support from DOE.

3.1.8 TAO/TRMM Rainrate Measurements. With support from the NASA/TRMM Project Office, 13 NextGeneration ATLAS moorings of the TAO Array are presently instrumented with RM Young siphon rain gauges to provide estimates of rainrate over the tropical Pacific Ocean. Rainfall accumulations are internally recorded at 1-minuted intervals, and daily statistics (mean rainrate, rainrate standard deviation, and percent time raining) are transmitted to shore in real-time via Service Argos. Each TAO/TRMM site is also equipped with a surface temperature/conductivity sensor for determination of surface salinity. It is expected that this rainrate/surface salinity array will expand by about another six sites in 1999 with continued support from TRMM. The present status and plans for the TAO/TRMM rainrate array can be found on the World Wide Web at: http://www.pmel.noaa.gov/toga-tao/.trmm/. Data can be displayed and accessed from this page.

In a related study, TRMM has provided support to the TAO Project Office for two fully equipped NextGeneration ATLAS moorings with rainrate sensors to be deployed near Kwajalein in mid-1999 as part of the TRMM KWAJEX experiment. These buoys will be deployed for approximately one month within view of a shipboard rain radar system on the NOAA Ship RON BROWN.

3.1.9 Moored Bio-Optical and Chemical Measurements. Two TAO moorings (0°, 155°W and 2°S, 170°W) have been instrumented with biogeochemical sensors as part of a collaborative study between PMEL and the Monterey Bay Aquarium Research Institute (MBARI). This effort was developed under auspices of NOAA's Ocean Atmosphere Carbon Exchange Studies (OACES), a primary goal of which is to determine the spatial/temporal variability of primary production, carbon dioxide, and their relation to variations in the physical environment. Measurements on the two TAO moorings include downwelling irradiance from the buoy tower, downwelling and upwelling irradiance in the upper 30 m of the ocean, oceanic pCO2, and chlorophyll fluorescence. Data are telemetered to shore via Service Argos. Moorings are recovered and redeployed on a 1-year schedule with visits every 6-months for sensor replacements and data retrieval. The first OACES moorings in the TAO array were deployed in November 1996, and the most recent deployments were in October/November 1998.

In addition to these two sites, four other TAO sites at 2°N, 110°W, 2°N, 140°W, 2°S, 140°W, and 2°N, 180° have been instrumented by MBARI to measure downwelling irradiance from the buoy tower, upwelling radiance at 1.5 m depth, and chlorophyll fluorescence at 1.5 m depth. Data are telemetered to shore via Service Argos. These systems are serviced on a 6-month schedule and were last visited between September and December 1998.

Additional underway measurements are made from the TAO support vessel KA'IMIMOANA in support of OACES objectives during some or all mooring cruises. These measurements include photosynthetically available radiation (PAR), stimulated fluorescence, chlorophyll and nutrient extractions from CTD samples, primary productivity measurements, and pCO2 measurements in surface water and air.

3.1.10 Data and Information Dissemination. TAO data are telemetered in real-time to PMEL via Service Argos. Calibration coefficients and quality control checks are applied at PMEL. The data are then made available to the research community, to other governmental agencies, and to the public via ftp (ftp.pmel.noaa.gov/taodata) and the World Wide Web (http://www.pmel.noaa.gov/toga-tao/).

Data are also placed on the Global Telecommunications System (GTS) by Service Argos for distribution to operational centers where the data are assimilated into weather and climate forecast models. PMEL monitors TAO data transmissions on the GTS for quality control purposes. About 80 - 90% of surface and subsurface data which reaches PMEL on a daily basis via Service Argos is available on the GTS (Figure 4). It is thought that much of the missing GTS data is due to messages with transmission errors, which eventually reach PMEL in corrected form, but which in the interim are declared as bad by Service Argos.

To reduce both battery and Service Argos costs, TAO moorings transmit only 8 hours per day. This transmission schedule returns daily averaged surface and subsurface data, plus about 3 surface hourly observations per day. These hourly observations are clustered around daylight satellite passes, and thus users will notice a lack of real-time hourly data at most sites between 0600 UTC and 1200 UTC. Lags between the time of measurement and the time of data arrival at operational centers are typically about 2-3 hours, but can be significantly longer because of inherent delays in the satellite data delivery system. These delays may cause a reduction in the amount of data which are usable by some weather forecast models.

TAO Web pages provide not only for dissemination of the data (both real-time and delayed mode), but also for graphical displays, for general information on El Niño and La Niña, and for links to climate analysis and forecasting centers. These web pages served as a very effective means of informing the scientific community and general public about the evolving climate conditions in the tropical Pacific during the 1997-98 El Niño event. From January 1997 to October 1998, TAO web pages received over 25,000,000 hits, with a peak of over 3,500,000 hits in October 1997 (Figure 5).

3.1.11 NOAA Perspectives on the ENSO Observing System (Contributed by S. Piotrowicz, NOAA/Office of Oceanic and Atmospheric Research). NOAA received $4.9M in its 1998 budget for an "Operational ENSO Observing System" to support the operational ENSO prediction mission of NOAA. The major components of the observing system supported in 1998 were the TAO Array, the Voluntary Observing Ship program operated by NOAA which includes XBT observations and surface meteorological observations, NOAA's surface drifter program, and the Indo-Pacific Sea Level program operated by the University of Hawaii. Included in this budget are the satellite data transmission costs. The justification for obtaining this funding was based on providing observations for the ENSO prediction mission and not the long-term support of any particular observational program. For the foreseeable future, the major components of the ENSO Observing System, however, will remain basically the same.

The 1998 program was supported as a basic continuation of the research-funded, 1997 program. For 1999, NOAA solicited proposals from the above programs to cover a three-year period. The invitation message for those proposals stated that 10% of the total funding may be reprogrammed annually but 75% of each program's FY 1999 funding is guaranteed for three years. This was to allow for changes in the present configuration of the Observing System and/or the components of the system that might be dictated by the operational requirements or a quantitative evaluation program, while still preserving operational continuity for the implementing organizations.

A quantitative evaluation program for the ENSO observing system is being implemented through NOAA's Virtual Laboratory for Observing System Evaluation that has been established, has begun some analyses, and will continue to conduct analyses throughout the duration of the existing proposals. The results of those activities will be made available to the NOAA ENSO Systems Council. Even though the results of Virtual Laboratory activities will likely be intermittent, and probably, result in only minor recommendations early in their evolution, the above funding guidelines will allow for the implementation of significant Virtual Laboratory findings by the ENSO Observing System Director and Council. The development and inclusion of major, new observing systems (e.g., profiling floats) will probably require new funding which generally takes several years to develop. In the meantime, inflationary considerations alone imply that the ENSO prediction mission will have to be accomplished with declining resources. The above guidelines also allow adjustments due to increasing costs to maintain the existing system as well as changes in the system.

Support for ship time is not included in the 1998 appropriation for the ENSO Observing System. Platform support is included in another item in NOAA's budget. Platform time in support of the TAO Array presently amounts to a full ship-year on the KA'IMIMOANA and three additional 30 to 35 days cruises every two years on a NOAA Class I ship. This basically supports visiting the moorings in PMEL's purview semiannually. Ship support costs for TAO amount to something around $5M annually and this budget item, like the ENSO Observing System, is not likely to increase in the near future either. In 1999, the funding that supports ship time for TAO and all of NOAA research was reduced by 14% for its 1998 level. The ship time supporting TAO was not decreased as a result of this budget reduction. Other programs were reduced. It is likely that any new funding obtained for platforms in the future will be directly tied to programs whereby, if the program is not supported, increases in support for ship time are not granted. This will not affect the base budget that supports the KA'IMIMOANA, however, funding to support additional time on a NOAA or other vessel could, in the long-term, be impacted. Presently, support of the TAO array is one of NOAA's highest priorities for allocation of ship time. It would, however, be prudent to attempt to reduce the dependency on ship time beyond what is available on the KA'IMIMOANA . This must be done without compromising the ENSO prediction mission such as new technologies reducing the frequency of visiting moorings, replacing some moorings with other observing systems (floats, remote sensing, etc.) as determined by the Virtual Laboratory, and/or increasing the number of nations providing ship time in support of the ENSO prediction mission.

3.2 Japan (Y. Kuroda/M. Endoh, JAMSTEC)

JAMSTEC began the Tropical Ocean Climate Study (TOCS) program in 1993 following on the previous program JAPACS (Japanese Pacific Climate Study, 1987-1993). The objective of TOCS is to achieve the better understanding of ocean circulation in the warm pool affecting on the ENSO phenomena and global climate change.

As part of TOCS, JAMSTEC has deployed subsurface ADCP moorings to detect daily, seasonal and year-to-year changes of the equatorial and low latitude western boundary currents. Seven sites have been occupied: 0°, 142°E and 0°, 147°E since May 1994; 0°, 138°E, 2.5°S, 142°E, 2°S, 142°E, 0°, 156°E since July 1995 and 0°, 165°E since February 1997. The 2°S, 142°E site was discontinued in summer 1998. Two sites at 0°, 147°E and 0°, 165°E are deployed as part of the TAO current meter array.

JAMSTEC has conducted two cruises per year since Japanese Fiscal Year 1993 (April 1993-March 1994) using R/V KAIYO, and increased to three cruises per year since FY 97 using the R/V KAIYO and R/V MIRAI. Hydrographic and atmospheric measurements have been carried out using CTD, shipboard-ADCP, and radiosondes. These cruises also maintain the JAMSTEC subsurface ADCP array and TAO array in the western Pacific. Operation of R/V MIRAI started in October 1997, and the first TRITON buoy operations were carried out in March 1998.

* Cruises in FY 97
1998 Jan-Feb        R/V KAIYO 29 days from Majuro to Palau
1998 Mar            R/V MIRAI 26 days from Hachinohe, Japan to Sydney

* Cruises in FY 98
1998 Aug R/V KAIYO 26 days from Guam to Palau
1999 Jan-Feb R/V KAIYO 30 days from Majuro to Palau (Planned)
1999 Feb-Mar R/V MIRAI 44 days from Hachinohe, Japan to Majuro
(Planned)

* Cruises in FY 99
1999 Summer R/V KAIYO (Planned similar to summer 1998)
1999 Oct-Nov R/V MIRAI (Planned)
2000 Feb-Mar R/V MIRAI (Planned)

JAMSTEC is developing a surface moored-buoy network named TRITON (TRIangle Trans-Ocean Buoy Network) for observing oceanic and atmospheric variability in the Pacific Ocean and its adjacent seas in cooperation with interested Japanese and foreign agencies and institutions. The principal scientific objective is to understand variations of ocean circulation and heat/salt transports with emphasis on ENSO, the Asian monsoon, and decadal scale variability that influences climate change in the Pacific and its adjacent seas. In its first phase, the buoy network will be established mainly in the western tropical Pacific Ocean between 8°S and 8°N, and harmonized with TAO-ATLAS buoys which are presently maintained by NOAA's Pacific Marine Environmental Laboratory.

The fundamental functions of TRITON are (1) basin scale ENSO monitoring, and (2) measurements of heat, freshwater, momentum fluxes for improving modeling capability. A subsurface ADCP current meter array will be maintained along the equator by the Tropical Ocean Climate Study in conjunction with TRITON to measure the variability of equatorial currents. After establishing the TRITON network in the western tropical Pacific, two of buoys will be deployed in the eastern Indian Ocean as a pilot study focusing on intraseasonal ocean and atmosphere change associated with the MJO, monsoon variability, and ENSO scale variability.

JAMSTEC deployed four TRITON buoys at 8°N, 5°N, 2°N and 0°, 156°E from the R/V MIRAI in March 1998. These buoys were intended for a year long deployments. However, the buoys were recovered due to technological problems (unexpected corrosion between stainless buoy structure and galvanized steel parts, data transmission problems on a TRITON buoy caused by water intrusion into an Argos antenna tube, and some mechanical failures on CT/CTD sensors). The TRITON data collecting system worked well during the first deployments and took useful data during the recovery stage of the 1997-98 El Niño.

The TRITON buoys were deployed close to ATLAS buoys within 10-15 miles for intercomparison. The 3-month TRITON data were cross validated well with ATLAS data intercomparison, although the capability for year long TRITON deployments needs to be verified.

3.2.3 Future TRITON Plans:

1. Construction of TRITON buoys. JAMSTEC will have total 18 TRITON buoys by the end of FY 98, after addressing the technological problems found during the first deployment.
2. Deployment schedule. The TRITON buoys at 8°N, 5°N, 2°N, 0°, 2°S, 5°S along 156°E, and 5°N, 2°N, 0° along 147°E will be deployed during the February-March 1999 R/V MIRAI cruise. The array along 138°E will be deployed during the October-November 1999. The present TAO-ATLAS buoys in these sites will be replaced with TRITON buoys. Therefore, the combined TAO/TRITON array will continually cover the Pacific basin. Afterwards, the TRITON array will be expanded to 130°E.

3.2.4 Data Dissemination. TRITON data will be distributed the same as TAO data. The display and distribution software for the combined TAO/TRITON data sets has been developed based upon the TAO software. These data will be distributed from both JAMSTEC and PMEL/TAO homepages.

3.2.5 JAMSTEC Outreach in 1997-1998 Related to Fishing Activity. In 1998, JAMSTEC contacted to some Japanese fishing associations and the Japan Shipowners' Association, and asked them to distribute TRITON brochures to ship operating companies. JAMSTEC also asked the Maritime Safety Agency of Japan to announce the exact TRITON buoy locations in the World Cruise Warning System. Similarly, JAMSTEC sent TRITON brochures to fishing associations in Korea, Taiwan, and USA to distribute to ship operating companies.

JAMSTEC sent representatives to attend the annual SOPAC (South Pacific Applied Geoscience Commission) meeting where TRITON activities were described. The participants understood well the purpose and importance of the TAO/TRITON array and recommended that member countries support efforts to mitigate against fishing related mooring equipment and data loss. SOPAC has also helped to coordinate a number of activities, as described below.

JAMSTEC sent representatives to the FFA (Forum Fisheries Agencies) in 1997. FFA understood well the importance of TAO/TRITON data for research on not only climate change but also fisheries. JAMSTEC requested that FFA distribute TRITON brochures to ship operators when ships register with FFA before getting fishing licenses from each member state. FFA agreed to distribute the brochures, and also posted the exact locations of TRITON buoys in the FFA Newsletter.

JAMSTEC sent representatives to the Federated States of Micronesia (FSM) in 1997 to ask permission for year long clearance for JAMSTEC research vessels in order to maintain TRITON array. This permission was granted. JAMSTEC also asked to charter FSM cargo-passenger vessels for the emergency TRITON operations. We expect emergency charters to be possible in 1999, if necessary. Finally, JAMSTEC sent representatives to Papau, New Guinea, in 1998 to inform officials there of TRITON activities, and to request help in distributing TRITON brochures.

3.2.6 International Coordination. International coordination is vital to enable sustainable measurements by the TRITON and TOCS buoy arrays. Therefore, JAMSTEC plans the following:

1. Exchange of scientific, technological and logistical information among the various moored buoy programs;
2. Sharing logistics support for buoy maintenance, ship time, security, buoy rescue, etc.;
3. Education of fishing communities; and
4. Buoy data distribution and utilization from various moored buoy programs.

3.3 France (J. Picaut, IRD/ORSTOM and NASA/GSFC)

In addition to some transits planned with the R/V L'ATALANTE, two cruises with the IRD/ORSTOM R/V L'ALIS have been proposed by the physical oceanographic SURTROPAC group in Noumea. These two cruises intend to study the oceanic response of the South Pacific Convergence Zone during two different seasons (around April and October). These cruises should run from Noumea, along 165°E up to the equator, then along the equator to the date line, then down to Wallis Island and back to Noumea. During these cruises, one or two TAO moorings along 165°E and the date line may be replaced or at least all the surface instruments along these two meridians could be checked and eventually replaced. The first cruise has been accepted and the tentative date is from 10 October to 10 November 1999. The second cruise is requested for April 2000.

The remaining pool of SEACAT thermosalinographs from ORSTOM and NOAA/PMEL is still in use on several TAO moorings for the necessary measurement of salinity in the western equatorial Pacific. They are going to be progressively replaced by the thermosalinographs that are now part of the new generation of ATLAS, which transmits salinity data in real time, something not routinely done with the standard SEACAT.

Due to research ship limitations in the Pacific and the interest of the Euro-CLIVAR community in the Atlantic, the French participation in TAO has mostly shifted into the Atlantic Ocean with the successful deployment of several ATLAS moorings. These moorings are part of the PIRATA pilot experiment developed by Brazil, France and US. This project was made possible in part by the presence of the IRD/ORSTOM R/V ANTEA in Abidjan, Ivory Coast. As with the very successful TAO project in the Pacific, discussions are underway to maintain PIRATA after its pilot period expires.

As stated in previous TIP reports, the French community of oceanographers and meteorologists are using TAO data for research, validation, and operational purposes. In particular the ENSO migration of the western equatorial Pacific warm and fresh pool has been extensively analyzed with TAO data, other in situ data, and satellite data. Improvement of Pacific OGCMs (with and without data assimilation) and coupled models could not have been done without TAO data, which by far is the best set of data ever collected from the air-sea interface down to 500m.

3.4 Taiwan (D. Tang and H. H. Hsu, National Taiwan University)

Unfortunately, ATLAS moorings in the South China Sea were vandalized seriously by fishing boats. Two months after deployment in April 1998, only one surface mooring survived. However, the data collected so far show some very interesting features, some of which are quite different from what we expected based on climatology. The time series of upper ocean heat content displayed a marked semi-annual variation even though the wind is dominated by an annual cycle. Downwelling followed by upwelling was observed in the late boreal spring 1997 when the southwesterly monsoon intensified. This sequence was also seen in October 1997 when the northeasterly monsoon strengthened. The upwelling generally weakened but had a longer duration than the downwelling. The coherence between the upper ocean heat content and local wind stress (or wind stress curl) was low. The vorticity analysis indicates that remote effects (e. g. propagating planetary waves) on the upper ocean thermal structure could be important.

SST variations were poorly correlated with variations in sub-surface thermal structure. SST was dominated by an annual variation, high in summer and low in winter. The ENSO influence is also clearly seen in the SST, with observed temperatures 1-3°C higher than the climatological SST starting in December 1997. This high SST persists even to the present. The high-resolution thermal data shows that the internal tAppendix 6. Definition of TAO Support ide is persistently large at least in the northern South China Sea.

The sub-surface ADCP moorings were retrieved in October of 1998. The observed current velocity did not agree with the surface velocity derived from ship drift. Current velocities obtained from the three moorings varied significantly when the southwesterly wind intensified, but they generally were marginally coherent with the local wind stress over the 6 months observation period. Further study is required.

3.5 India (S. Prasanna Kumar, NIO)

Under the XBT programme 4 lines are being monitored. The Madras-Andaman and Calcutta-Andama lines are covered bi-monthly since 1990 while the Bombay-Mauritius line is covered once every three months. The Vizag-Singapore line started in 1994 is irregularly samples due to the irregular availability of ships along this route. The drifting buoy programme was started in 1991 and every year on an average 7 to 8 buoys are deployed. Apart from these ongoing programmes, two programmes that will start next year are deep ocean moored buoys and Bay of Bengal Process Study (BOBPS). Under the moored buoy programme, 3 subsurface moorings with 5 current meters on each mooring will be deployed along the equator at 73°E, 83°E, and 93°E. Under the BOBPS programme, the Bay of Bengal will be sampled from 3°N to 20°N along 87°E as well as long the east coast of India 5 times during 1999 to 2001. Physics, chemistry, biology, geology and radiochemistry will be studied from shipboard measurements.

In response to a recommendation made at TIP-6 in 1997, there were several efforts at the national level within India by the Department of Ocean Development and National Institute of Oceanography to make data from the NDBP accessible in real time. This will now be possible by the end of 1998 when the surface met data from NDBP buoys will be put on to GTS.

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