TABLE OF CONTENTS
II SCIENCE UPDATES
IV DEPLOYMENT STRATEGY FOR PACIFIC OCEAN
Acknowledgements
The meeting described in this report could not have taken place without the gracious efforts of many oceanographers from Korea. The Korean Ocean Research and Development Institute (KORDI) was the official host and scientists from there worked hard to ensure that all necessary facilities were available. They also worked hard to ensure that all meeting participants were made comfortable in what, for some, was very unfamiliar territory. Discussions were held at the Seogwipo KAL Hotel, which overlooks the East China Sea from the Korean island of Chejudo. The facilities were excellent and the surroundings were quite beautiful. Although most participants found it necessary to reach Cheju Island by first traveling to Seoul, transportation within Korea was both economical and efficient. All of these things led to a most productive and enjoyable meeting.
(a) Drifter-derived flow fields in the Western Pacific
A diverse range of flow patterns has emerged for the western Pacific. Drifters deployed throughout the region from the equator to 40 ° N and 120° E to 160° E expose great differences between currents in the southern portion of this domain, off Indonesia and the Philippine Islands, where flows are less eddy-like than further north, within the influence of the Kuroshio Current System. fig. 1 presents trajectories of drifters deployed by Dr. H. Ishii of Japan (also shown in SVP-2). Many different flow regimes can be seen in the figure. The relatively continuous current structure of the North Equatorial Current to the East of the Philippine Islands stands in stark contrast to the highly energetic eddies seen in the flow off Japan. Within the Kuroshio Current System itself, a wide variety of eddy length and time scales can be found. There is evidence of strong inertial and diurnal-period currents as well as circulations around rings with periods of 6 days. The mean currents derived from the Japanese drifter data are shown in fig. 2.
figure 1. Composite of Japanese drifter trajectories between January 1980 and August 1989.
figure 2. Mean velocity vectors in the northwest Pacific. Estimates derive from Japanese drifter observations (see fig. 1).
A number of drifters escaped the northwestern Pacific Ocean through a passage between Indonesia and the Philippines. However, the most striking result is the relative lack of communication between the ocean and the shallow seas off Taiwan, Korea and Japan. From these trajectories, as well as others from the TOGA Pan-Pacific project (fig. 3), it is clear that the main flow of the Kuroshio can be easily identified at the latitude of Taiwan and further north. However, drifters deployed south of Taiwan, nearer the Philippine Islands, often diffuse eastward into the central gyre and do not enter the Kuroshio system.
figure 3. Drifter trajectories in the western Pacific from the TOGA Pan-Pacific Drift Experiment.
Seasonal as well as geographical differences have been observed in the trajectories from the western Pacific. fig. 4 presents a composite of trajectories which derive from TOGA Pan-Pacific deployments. The figure is arranged into panels which display all of the data within successive two-month periods. The strongest westward flow is observed in the late fall and winter periods. Particularly in winter, drifters deployed off the Philippine Islands become consistently entrained into the Kuroshio system. The situation is different, however, during the summer months when the drifters were dominated by eddies and had very little net displacement. It is evident from this data set that the region north and east of the Philippine Islands is an important one for understanding the initial formation of the Kuroshio Current System.
figure 4. Drifter trajectories for two-month periods from TOGA data. Numbers indicate duration of individual trajectories in days; dots indicate stating point. Note differences between panels. For example, drifters are entrained into the Kuroshio Current System more often during winter months.
(b) Semi-permanent Eddies in the Northeast Pacific from Drifter Trajectories
Recent drifter studies in the NE Pacific Ocean have described the statistical nature of the surface flow in terms of the mean flow and its variability and the dominant eddy structure. Forty-nine mixed layer drifters were deployed in October, 1987 as part of the OCEAN STORMS Experiment. Results from that data are described by Paduan and Niiler (1990) and the trajectories are pictured in the previous report (SVP-2). During the same time period, 24 deep-drogued drifters were deployed by Canadian scientists (Thomson et al., 1990). These had long tethers with drogues positioned between 100m and 120m below the surface. The deep-drogued instruments do not follow water motions in the same way as those used in OCEAN STORMS and called for by SVP, which have a concentrated drag element at 15 m depth. They do, instead, provide an integrated measure of the flow above 120m, which is more sensitive to the density-driven geostrophic flow than to the wind-driven flow in the Ekman layer. It is interesting to compare results obtained from the two methods.
A composite of all trajectories from the 24 deep-drogued instruments is shown in fig. 5. Like the OCEAN STORMS surface deployment, the deep-drogued instruments moved eastward and northward but mean flow rates and variabilities are quite different. At 15m depth near the surface, the mean flow measures 4.4 ± 0.5 cm sec-1 and 0.7 ± 0.6 cm sec-1 to the east and north, respectively, with corresponding variances of 34 cm sec-2 and 47 cm sec-2. The deeper-drogued measurements average 0.7 ± 0.8 cm sec-1 and 1.7 ± 0.9 cm sec-1 to the east and north, respectively, with much larger variances of 73 cm sec-2 and 87 cm sec-2. The variability in the deep-drogued measurements is approximately twice that near the surface even though the deeper mean flow is smaller. This result, which at first exposure is somewhat surprising, can be attributed to the existence of more persistent eddy-like motions in the deep trajectories than in the near-surface trajectories. Although the surface tracks exhibit looping features that are associated with the eddies, they do not remain within the influence of an eddy for more than one half circuit.
figure 5. Daily positions of 24 deep-drogued, satellite-tracked drifters deployed in the northeast Pacific Ocean in June and October 1987. Solid symbols denote start locations; open symbols, end locations. Tracks cover the period up to 1 April 1989. From Thomson et al. (1990).
All of the eddies evidenced by the near-surface trajectories and most of the ones in the deep trajectories are anti-cyclonic (clockwise) eddies. The deep-drogued measurements from individual drifters show that they propagate to the west, against the mean flow, at an average propagation speed of 1.5 ± 0.4 cm sec-1. This result is substantiated by the near-surface measurements from separate drifters which show that the looping pattern over a particular eddy moves westward with time. An example of an eddy which was sampled by both near-surface and deep-drogued drifters is given in fig. 6.
figure 6. Drifter trajectories through an eddy in the northeast Pacific from instruments drogued at 15 m (upper panel; Paduan and Niiler (1991)) and 100 m (lower panel; Thomson et al. (1990)).
The differences between the motions of near-surface and deep-drogued drifters in the NE Pacific suggest that directly wind-forced currents in the region are confined largely to a layer above 100m depth. The algebraic difference between the near-surface and deep-drogued currents is a flow, which is predominantly eastward, of about 3.5 cm sec-1. It should be noted that these measurements are weighted toward the fall time period and may differ during other seasons. It is clear, however, that a lot of insights may be obtained by comparing these two data sets which, fortuitously, describe the same time and place.
(c) Results of technical and engineering studies
Through engineering studies and experience gained in the TOGA Pan-Pacific Surface Current Study in 1988 and in WOCE Heavy Weather Drifter Tests in 1989-90, the design for a WOCE/TOGA standard drifter has emerged. Plans are to add a barometer capability to this drifter through WOCE support and salinity sensors through TOGA support. The primary engineering objectives were to design a drifter whose water following characteristics were understood and to build a drifter which would survive for at least 18 months in the open ocean.
The at-sea measurement of the water following calibrations of drifters has been done by attaching two Vector Measuring Current Meters (VMCMs) to the top and bottom of the drogue. Such slip data has been gathered from holey-sock and Tristar drogues with various tethers and surface floats in the tropical, midlatitude, and northern Pacific. These specially-instrumented drifters have been released in many different wind and shear conditions since 1985, (e.g. see Niiler et al., 1987) and the slip of the drogue through the water has been related to wind and shear (Chereskin et al., 1989). A least square fit model for slip has been developed and it accounts for nearly 90% of the variance of the observed slip as a function of wind, shear and drag area ratio, R (R is the ratio of the chug area of the drogue to the drag area of the combined tether and surface float). The table below displays the best fit model coefficients. A value of R > 40 is required to reduce the slip below 2 cm sec-1 in winds of 20 m sec-1 and has been adopted as a WOCE/TOGA standard.
The construction specifications of a mechanically reliable drifter have been achieved by deploying a number of candidate designs at sea and recovering a significant number for inspection. In October 1989, 16 drifters were released near OWS PAPA and 12 were recovered in May 1990 off the Washington coast. These WOCE Heavy Weather Drifter Test results have led to the following observations: i) a subsurface float on the tether significantly reduces the shock load on the top of the drogue; ii) flexible carroting below the surface float is required; iii) largest biofouling occurs on the surface float; iv) no systematic biases of drift were found between the holey-sock and Tristar drogues; v) drogues, polypropylene coated tethering cables and fiberglass surface floats showed no perceptible wear and tear after 200 days in heavy weather. Because of the relative ease of construction and shipping, the holey-sock type drifter, with spherical surface and subsurface floats has been adopted as the standard for SVP. Detailed engineering drawings, and materials specifications of the recommended drifter will be sent to all SVP participants in December, 1990 (Sybrandy and Niiler, 1990).
The following paragraphs describe ongoing Australian drifter projects including plans for SVP (This summary was provided by Dr. John F. Middleton to the organizers of SVP-3 on 4 May, 1990 because it was not possible to have an Australian delegate present at the meeting). A summary of the 30 ARGOS-tracked drifter deployments that have been made, will be made, or are planned for 1990-1991 and beyond is given in Table 1. Deployment locations are shown in fig. 7. The project summaries given below are only tentative. More information will be available after August, 1990 when the scientists listed below from CSIRO and the Australian Bureau of Meteorology plan to meet to discuss drifter activities.
figure 7. Proposed deployment locations for Australian drifters.
The Bureau of Meteorology is currently deploying around 11 drifters each year in the southern Indian Ocean and Southern Ocean. For 1990, 9 out of 11 are drogued and all measure Mean Sea Level Pressure (MSLP), Air Temperature (AT), and Sea Surface Temperature (SST). This activity will most likely continue until 1995 although the instruments used here do not follow water to within SVP standards.
George Cresswell (CSIRO Division of Oceanography) has funds for 8 drogued drifters to be deployed in the Tasman Sea in conjunction with SVP deployments in the South Pacific and Southern Ocean. These will measure, at least, MSLP and SST and are expected to conform to the SVP water following standards.
Derek Buffage (AIMS) is continuing to deploy around 3 drifters drogued at 100m depth in the Coral Sea. At present, funds are sufficient to equip these instruments with SST sensors only and to track them for only 3 to 6 months. Funding has not yet been secured to track them for longer periods of time or to add MSLP sensors.
John Middleton (UNSW), in collaboration with George Cresswell and Neville Smith (Bureau of Meteorology), plan 3 annual deployments of a patch of 8 drifters in the Southern Ocean to study the dynamics of the frontal zone and the ACC. All drifters in this study will be drogued to SVP specifications and will measure SST. The maximum number of position fixes will be sought while these instruments remain in the Australasian region. Once outside that area, however, fixes will be sought only every third day in line with the SVP standards set up to minimize transmission costs. Since the drifters are to be deployed in clusters, it is expected that not every instrument will support a MSLP sensor. The details of deployment and MSLP measurement are to be determined in consultation with the Bureau of Meteorology. Funds for this experiment are not yet available although proposals will be forthcoming. A request for WOCE-related proposals within Australia is expected in the next few months.
TABLE I
Summary of Australian Drifter Projects and their Instrumentation
The Canadian contribution to the WOCE Surface Velocity Program will take place in the Northeast Pacific Ocean, where at least sixteen drifters will be maintained. A tentative deployment plan is shown in fig. 8, with a schedule given in Table 11.
Scientific interests include first a contribution to the WOCE Surface Velocity program, providing coverage at the recommended 500 km x 500 km level of resolution with WOCE->quality shallow drogued water followers. Planned deployments shown in Table II may be delayed by the best part of a year. Persistence of some drifters for up to a year and a half as well as contributions from the other proposed sub-programs should maintain the required number for WOCE SVP coverage.
figure 8. Tentative deployment plan for Canadian drifters. Location of Alaskan Gyre Array is shown with deep-drogued drifter locations circled. Hydrographic lines are also shown.
Following earlier work (Thomson et al., 1990), there is considerable interest in using drifters to describe the characteristics of the Alaskan Gyre and the Alaskan Stream. Additional deployments have been planned to study the large scale circulation of the Gulf of Alaska. Some of these drifters will be deep-drogued so as to compare the deeper to the surface circulation. A few drifters will be devoted to dispersion studies.
Investigators for this project are Paul LeBlond (P.I.; Univ. of British Columbia), William Large (formerly of the same university, now at NCAR), Rick Thomson (Inst. Ocean Sciences), David Krauel (Royal Roads Military College) and Gordon Swaters (Univ. of Alberta).
Funding has been received from the Natural Sciences and Engineering Council of Canada for university led WOCE research, including the SVP contribution. Exact funding levels remain under discussion but are anticipated to be within 80% of requested levels (see Table II).
TABLE II
CANADIAN SVP PROGRAM
In a collaboration between LODYC Paris and ORSTOM Noumea, the BODEGA program was funded to built and to deploy 50 surface drifters with thermistor chains in the Tropical Pacific. It is the french component of the TOGA Pan-Pacific surface current study. Specific interests are in the seasonal cycle of the South Equatorial current and in the occurrence of equatorial eastward jets. Additional interests are in the comparison of drifter measurements with other current estimates (e.g. moorings and GEOSAT altimetry).
Nine drifters were deployed in 1989 at 140° W and 169° E. Twenty eight drifters will be deployed in April 1990 and July 1990 in the Western Pacific and in August in the Central Pacific. In 1991, two additional deployments are planned with 10-12 drifters at 165° ° E in January and 2-3 along the equator in April.
A proposal from the ORSTOM Noumea group to participate in the TOGA-COARE Experiment will include a request for deployment of drifting buoys during the Intensive Operational Phase (IOP) in late 1992 to 1993. The contribution of such drifters to COARE objectives is the investigation of the space-time structure of Sea Surface Temperature and, hopefully, Sea Surface Salinity in the warm pool region and the processes responsible for their variability. During the COARE IOP, we expect that more accurate and more intensive observations of surface fluxes will be available in the COARE region. Therefore, drifters with thermistor chains will provide useful information about the diurnal cycle and about horizontal and vertical mixing which, in turn, can be tested against numerical ocean circulation models (e.g. LODYC, Paris).
Scientists at the Japanese Hydrographic Office and Science and Technology Agency are involved, and plan to be involved, in a number of drifter-related experiments. Some of these are long-term experiments which focus on specific regions of national interest but it is expected that instruments deployed as part of these experiments will, eventually, diffuse away from their deployment sites and become part of the general SVP array. Deployments to date have been made along meridional lines at 145° °E, 160° °E, and 180° °E starting north of Indonesia and ending at approximately 25° °N, 8° °N, and 7°N, respectively or within the Kuroshio to the south of Japan. A zonal deployment line at 32° °N between 150° °E and 170° °E is expected to be added as part of the Pacific Circulation Study and the Japanese contribution to SVP.
The ongoing drifter-related experiments in Japan are summarized in Table III below. The various acronyms refer to the following projects: Kuroshio Exploitation and Utilization Research (KER), Japan China Joint Research Program on Kuroshio (JRK), the Western Pacific project of the Intergovernmental ocean Oceanographic Commission (WESTPAC), the Japanese Pacific Climate Study (JAPACS), the Asian Monsoon Mechanism Study (AMMS), and the Pacific Circulation.Study (PCS). Scientists at the Hydrographic Office led by Dr. H. Ishii have been, and will continue to be, principal investigators in the TOGA Pan-Pacific study through the auspices of JAPACS.
TABLE III
Summary of Japanese Drifter-Related Projects
General Overview
The Korean program will be conducted by a study group consisting of the Korea Ocean Research Development Institute (KORDI), the National Fisheries Research Development Agency (NFRDA), Kangnung National University (KNU), and, possibly, other organizations. The numbers of instruments that are being requested are summarized in Table IV below. General descriptions of the plans put forth by scientists within the Korean agencies are as follows:
TABLE IV
Planned Drifter Deployment Schedule
(number of instruments) for
KOREA Drifter Programs within SVP
Specifics of the NFRDA Drifter Program during WOCE
1. Purposes of operation
2. Annual deployment
Exercise Stage 5-10 ea (1991)
Main Stage: 10-20 ea (1992-2000)
3. Data handling
4. Other
Recent accomplishments
During the past five years, a series of five cruises were conducted in the western tropical Pacific between 3° S and 18° N out to 160° E. The cruises were supported by the Chinese Academy of Science, South China Sea Institute of Oceanology and the Beijing Institute of Physical Meteorology and they were designed to study the physical oceanography of the region.
Goals for the WOCE period
In order to continue their participation in western Pacific oceanographic studies, the South China Sea Institute of Oceanology wishes to set up a drifting buoys program. The operation will seek to conduct the following operations:
The annual deployment levels in terms of ship and instrument resources have not yet been determined. The area of most intense interest is that part of the ocean east of the Philippine Islands.
The Kuroshio Current flows very near the east coast of Taiwan and impinges upon 200m continental shelf break to the northeast of the island causing complicated meandering of the current, upwelling, and mixing of water masses from the Pacific Ocean, East China Sea, and Taiwan Strait. To understand this scientifically and economically important region, an integrated, national project called KEEP-NET (Kuroshio Edge Exchange Processes-Northeast of Taiwan) has been established. Drifters deployed as part of WOCE/TOGA SVP will help to depict the course and variability of the Kuroshio near Taiwan and the KEEP-NET region.
For the period of January to July, 1990 a preliminary project to manufacturer two ARGOS drifters for testing has been approved. In FY90/91, the Republic of China (ROC) intends to deploy 16 drifters in four seasonal deployments within the Bashi Channel. These will be deployed in a line across the Kuroshio at 20N between 118E and 123E. For FY91-94, it is proposed that deployments be increased to 20 drifters per year but these resources will depend upon the success of the first year of drifter results.
The U.S. WOCE contributions to SVP resources in the Pacific consist of, approximately, 132 drifters plus related ARGOS tracking costs. These resources will be committed to obtaining measurements from open ocean regions of the North and South Pacific Oceans. The strategy of U.S. WOCE participants will be to monitor the coverage of the combined SVP array and to fill in locations that are not being sampled. Details of this plan are given in section IV below.
The deployment of U.S. WOCE drifters will be directed by the Global Drifter Center (GDC) at Scripps Institution of Oceanography in San Diego. The task will involve not only monitoring of the status of the SVP array, but also interacting with the Voluntary Observing Ship (VOS) network in order to place instruments onboard ships traveling through areas lacking measurements. Work has begun at the GDC to identify areas which are likely to require deployments of drifters and to identify ships of opportunity that pass through them. The GDC has the additional tasks of interpreting the results of engineering studies and recommending the design of the SVP standard drifter, as well as assisting international partners to build the drifters through exchange of technical plans and assistance. The components of U.S. effort in SVP and their relationship with the international partners and with ARGOS are shown in fig. 9. This structure is discussed further in the section on data sharing protocol below.
Funding for the U.S. WOCE contribution to SVP includes monies to support the development of an atmospheric pressure sensor to be mounted on the surface float of the SVP drifter. The engineering work will be done at the GDC. Evaluation of competing sensors and development of a suitable port design are scheduled to take place during 1990 and 1991 in the water off San Diego. Operational sensors are not expected until the 1992/1993 period and are not planned for use in the North Pacific during SVP. The extent of their use in the South Pacific and other ocean basins will depend on future funding support from WOCE and TOGA and, most importantly, interested meteorological agencies such as the National Oceanographic and Atmospheric Administration (NOAA). To foster such a cooperative venture between SVP and the world's meteorological agencies, the GDC will work together with the international Drifting Buoy Cooperation Panel (DBCP), through its technical coordinator, to advise the meteorological community of the boon SVP will bring to their data base as well as the timetable for doing so.
IV DEPLOYMENT STRATEGY FOR PACIFIC OCEAN
It is clear that most international partners within SVP are limited to deployments within regions of specific national interest to their countries. Most often these regions are nearer to the edges of ocean basins, within the boundary currents. Drifters deployed within these boundary regions will, however, be constructed and powered such that they should survive for periods long enough for them to sample many locations within the central basin as well. General areas of deployments for international partners in the Pacific, together with projected array sizes, are shown in fig. 10.
Because of the national interests of Pacific rim countries and the scientific interest generated by the drifter observations to date, it was decided that deployments should be concentrated throughout the western boundary current system of the Kuroshio and related currents. A regular and organized deployment scheme in this area will greatly enhance our understanding of the Kuroshio system and should not detract significantly from more global coverage of SVP because residence times within the western boundary region are short. The drifter trajectories described in Section II of this report have shown the region east of the Philippine Islands to be the critical formation region for the Kuroshio system, yet it is poorly understood. The international participants in SVP plan to make seasonal deployments of drifters in the passage between the Philippines and Taiwan and, if logistically possible, in the area east of the Philippines near 17 ° N, 125 ° E. The participants also agreed, however, to abide by international convention and not deploy instruments within the territorial waters of any country. A proposed deployment scheme for the western Pacific is presented in fig. 11.
figure 9. Organizational chart for the Surface Velocity Program (SVP).
WOCE/TOGA SVP PACIFIC SECTOR
1990-1993
Array size shown in boxes
figure 10. Approximate array sizes for drifters in the Pacific portion of the global Surface Velocity Program (SVP) arranged by region and by funding source (actual numbers of instruments required will be greater than the array size depending on the average instrument longevity).
Figure 11. Proposed deployment lines for the western Pacific Ocean. The total number of instruments to be deployed during calendar, year 1991 are listed with the national sponsors. Lines indicate area over which drifters will be evenly seeded. The ROC/US lines will be occupied seasonally. The three mid-ocean lines labelled USSR/US represent a proposed collaboration between those two SVP partners.
As discussed above, deployments of drifters will be coordinated by the GDC in cooperation with the Data Acquisition Center (DAC), which is comprised of the Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami and the Marine Environmental Data Service (MEDS) in Ottawa, Canada, and with all international partners. Fig. 9 presents a schematic view of this SVP organizational structure. Real-time position and temperature data will be transferred by ARGOS to the GTS network. This real-time data will not, however, utilize optimal calibration functions, nor will it be quality-controlled. All drifter data collected as part of SVP will also pass to AOML where it will be quality controlled. This quality-controlled data will be available immediately to all participants in SVP. After six months, copies of the data will be transferred to MEDS for archival and distribution to the broader scientific community. Data accepted by MEDS shall remain proprietary, however, for two years following collection during which time it will be freely available to SVP participants only. Other WOCE participants may negotiate access to the data during that time frame directly with SVP principal investigators.
MEDS Canada has agreed to perform other functions in addition to data archival and distribution in support of SVP. These include the preparation of monthly maps of buoy positions and the operation of a database of drifting buoy descriptions and principal investigators. The details of these services are being negotiated still, but it should be possible to have maps and database information made available through on-line computer services designed to support WOCE efforts such as the WOCE Data Information Unit (DIU) run by the University of Delaware.
Pearn P. Niiler
Jeff Paduan
Physical Oceanography Division
Scripps Institution of Oceanography
University of California, San Diego
La Jolla, CA 92093, USA
Tel: (619) 534-4100 Fax: (619) 534-7931
Paul H. LeBlond
Department of Oceanography
University of British Columbia
6270 University Blvd.
Vancouver, BC V6T 1W5, Canada
Tel: (604) 228-2482 or (604) 228-3278
Fax: (6O4) 228-6091
Iwao Noguchi
Ocean Surveys Division
Hydrographic Department
Maritime Safety Agency
5-3-1, Tsukiji, Chuo-ku
Tokyo 104, Japan
Tel: (03) 541-3811 ex.605
Yves du Penhoat
ORSTOM
BP. A5 Noumea Cedex
New Caledonia
Tel: (687) 26-3243 (Direct)
Tel: (687) 26-1000 Fax: (687) 26-4326
Jian-Hwa Hu
Department of Oceanography
National Taiwan Ocean University
Keelung, Taiwan
Republic of China
Tel: (032) 622192 ex.815
Fax: (032) 620724
Youhai He
South China Sea Inst. of Oceanology
Academia Sinica
164 West Xingang Road
Guangzou, PRC
Tel: 447336 Ext. Fax: (20)-451-672
Heung-Jae Lie
Physical Oceanography Lab.
Korea Ocean Research Development Inst.
Ansan P.O. Box 29
Seoul 425-600, Korea
Tel: (02) 863-4770 Fax: (0345) 82-6698
Sang-Kyung Byun
Physical Oceanography Lab.
Korea Ocean Research Development Inst.
Ansan P.O. Box 29
Seoul 425-600, Korea
Tel: (02) 863-4770 Fax: (0345) 82-6698
Moon-Sik Suk
Physical Oceanography Lab.
Korea Ocean Research Development Inst.
Ansan P.O. Box 29
Seoul 425-600, Korea
Tel: (02) 863-4770 Fax: (0345) 82-6698
Chang-Sik Kim
Environmental Engineering Lab.
Korea Ocean Research Development Inst.
Ansan P.O. Box 29
Seoul 425-600, Korea
Tel: (02) 863-4770 Fax: (0345) 82-6698
Hyun-Yeong Kim
Section of International Relations
Korea, Ocean Research Development Inst.
Ansan P.O. Box 29
Seoul 425-600, Korea
Tel: (02) 863-4770 Fax: (0345) 82-6698
Sangbok D. Hahn
Department of Oceanography and Marine Resources
Fisheries Research Development Agency
Shirang-ri, Kijang-up, Yangsan-gun
Kyongsangnam-do 626-900, Korea
Tel: (0523) 361-8052-61 Fax: (0523) 361-8076
Hyo Choi
Department of Atmospheric Sciences
Kangnung National University
San 1 Chibyun-dong, Kangnung
Kangwon-do 210-702, Korea
Tel: (0391) 40-0480 Fax: (0391) 43-7110
Chereskin, T.K., P.P. Niiler, and P.M. Poulain, 1989: A numerical study of the effect of upper-ocean shear on flexible drogued drifters. Atmos. and Oceanic Tech., 6, 243-253.
Niiler, P.P., R.E. Davis, and H.J. White, 1987: Water-following characteristics of a mixed layer drifter. Deep-Sea Res., 34, 1867-1881.
Thomson, R.E., P.H. LeBlond and W.J. Emery, 1990. Analysis of deep-drogued satellite-tracked drifter measurements in the Northeast Pacific. Atmosphere-Ocean, 28, 409-443.
Paduan, J.D., and P.P. Niiler, 1991: The structure of velocity and temperature in the northeast Pacific as measured with Lagrangian drifters in fall 1987. In Preparation.
SVP-2, 1990: Surface Velocity Program, report of the second meeting with focus on the Atlantic Sector. WOCE Report No. 50/90. WOCE International Project Office, Wormley, 50 pp.
Sybrandy, A.L., and P.P. Niiler, 1990: The WOCE/TOGA Lagrangian drifter construction manual. Scripps Institution of Oceanography, Univ. of California, San Diego, Ref 90-248, 57 pp.