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Heavy metal concentrations are low Sand Hyun Park and Chang Kyoo Park for tsunami on the open Pacific islands and the copper measured in Project of the Hydraulic Laboratory of the of Russia. The Skurshex Experiment is Musselwatch is considered safe. Cold Korean Rural Development Corpora- on Shitotan Island, which is one of the bottom waters are poor in nutrients, tion reported on the hydraulic model

tion reported on the hydraulic model disputed islands seized from Japan by while high salinity waters tend to be test on the Seamankeum tidal land the Soviet Union at the end of World richer in nutrients. Korea will be involved reclamation project. This would be a War II. Here research on seiches is in a United Nations program in mea- typical example of how field informa- being done with bottom-sitting pressuring coastal nutrients in 1997. tion from the YESEX project would be sure sensors placed in 1986. The con

The first technical session was ended used in the development of Korean cern is that resonant amplification of by a summary talk by Prof. Yong Ahn coastal regions in this area of high tidal tsunami waves in the bays may be disasPark of SNU on the sedimentation flow. The project is to reclaim just over trous if it occurs in conjunction with patterns at the eastern part of the Yellow 40,000 hectares of tidal lands with a seiching produced by other phenomSea. The Yellow Sea coast line of Korea 29-km-long sea dike. Two types of ena such as wind waves and longshore is unique as it is uniformly fine grained models will be used: (1) analog hydraulic edge waves. These studies also are with little or no sand-sized material. scale models to be built in a 100- by supplemented by the investigations of This is generally not found in regions 100-meter shed and (2) two-dimensional long waves, surf beats, and infragravity of such high tides. On the Korean side, numerical models. The proposed model waves done off Kamchatka in 1987-88. Holocene mud lies right on the bed has the following scales:

Interpretation of the data uses sophisrock. Sediment transport varies with

ticated methods of conformable mapthe season, with along-shore movement Horizontal

1:500

ping of eigen oscillation values. in the winter, probably related to the Vertical

1:80

Although the survey area was not in the northwest monsoonal winds and off- Velocity

1:8.9

Yellow Sea, the instrumentation, placeshore transport in the summer. Most of Time

1:55.9 ment strategies, and analysis techniques the material in the Yellow Sea originally Discharge

1:357,770 could be used as prototypes for the came from deposition from the Roughness

1:2.5

Yellow Sea Experiment wave monitorHwang-Ho River in China. The clay

ing component. material from China is high in smectite Another applied paper was given by (montmorillonite-swelling clay), Prof. Isao Irie, of the Civil Engineering Coastal Prediction Models whereas clay from the Korean Peninsula Department of Kyushu University, is high in chlorite (metamorphic rock) Japan. Irie talked on the recent devel- Dr. Sok Kuh Kang of KORDI, on and kaolin (granite source). Near Korea opment of port and harbor engineer- behalf of his colleagues Dr. Ki Dai Lee there is not much evidence of a signif- ing in Japan. The discussion was on Yum (KORDI), Prof. Sang Ryong Lee icant Chinese source of sediment. Since various innovative designs for multi- (Pusan National University), and Prof. 1855, the Hwang-Ho has emptied into purpose shore protection structures in

purpose shore protection structures in Jong-Yul Chung (SNU), described the the Bohai Sea, an arm of the Yellow Japan. The concept is for both expanded tidal computation of the seas adjacent Sea north of the Shandong Peninsula. civilian use as well as conventional to Korea. Their two-dimensional model There, most of the sediment is trapped port protection in the coastal zone. uses a polar coordinate system with 11 before reaching the eastern and central Such designs also include artificial head- cells. The M-tide model shows 1930 parts of the Yellow Sea.

lands; artificial multipurpose offshore co-tidal lines and three amphidromes

islands; fish attractants; and combined in the Yellow Sea. The diurnal tide has Research for Coastal

sport fishing, sightseeing, and recreation two amphidromic points. They would Development facilities on breakwaters.

like to go to 100,000 grid points in

Dr. Alexander B. Rabinovich of the future models. Thus far the question of This session concentrated on more Institute of Marine Geology and Geo- the intrusion of the Kuroshio Current ocean engineering related activities and physics, of the Russian Academy of in the summer cannot be resolved. Actual included a report on Russian activities Sciences, Yuzhno-Sakhalinsk, discussed field measurements are scarce and the in wave monitoring, outside of the the investigation of long waves on the need for an integrated tidal station Yellow Sea, which have an implication shelf of the South Kuril Islands and the network was emphasized. They do have on the type of modelling and measure- Skurshex Experiment. The experiments a 2-km gridded model of the area near ment programs that might be proposed were part of a study hoping to improve Pusan, which should resolve eddies not for the Yellow Sea Experiment. Drs. marine disaster prevention especially seen in the original model.

“Development ofa Mixed Spectral- type. The results show general agree- and the Yellow Sea. His major concern Finite Difference Model for Computa- ment in phase and magnitude of com- would be transport underwater action, tion of Wind Induced Currents in the puted sea level, but “some discrepancies” as the Yellow Sea has a shallow mean West Coast of Korea" was given by Dr. were found between calculated and depth of only 44 meters. Sixty percent Jae Kwi So of KORDI with coauthors observed waves. Swell was not consid- of sediment transport in such areas is Kwang Soo Lee (KORDI), Kyung Tae ered in these models as only local in the transitory upper layer of the Jung (KORDI), and Prof. Woo Jin Jung atmospheric terms could be used. bottom where material is settling into of Inha University. The model is a three- The project organizer, Dr. the bottom. Below the mobile fluid dimensional Davies type also in polar Dong-Young Lee, and Dr. Ki Chum Lutocline, where there is a rapid change coordinates. Eddy viscosity is used in Jeon, both of KORDI, described plans in concentration of sediment, is a an attempt to do real-time modelling. for the development of a real-time “stationary” layer overlying cohesive In the present eigenfunction model the coastal prediction system. The goal is a mud. To produce mud erosion due to eddy viscosity is fixed in the vertical. real-time user input system, probably “to and fro” shear stress produced by For the winter monsoon case the wind PC computer based, where a series of wave action, the wave period has to be stress is set at 1.6 N-m?from the north- oceanographic/ocean engineering greater than 1.2 seconds. Otherwise west. For a low eddy viscosity of questions can be answered. Ideally the the cohesive particles, which are ideally 0.0125 m2/s, the wind energy is trapped user gives the time/s of observation, arranged like sheets of paper, cannot at the surface and current reversals location, and parameter/s requested and be lifted and eventually transported. occur at depth. For a “high" eddy vis- receives the answer through a com- The question of the relative imporcosity of 0.1 m2/s, much more mixing puter search of the appropriate model tance of unidirectional flow (i.e., curoccurs and the velocity profile is more or tables stored in the database memory. rents) as opposed to wave action with uniform. The next steps are to: (1) vary Mr. Kyung Ok Ko of the Maritime respect to erosion was discussed. The the eddy viscosity with depth, (2) com- Police and Dr. Sin Young Kang of the shear stress required for erosion is lower pare with field measurements, (3) use Korea Maritime University presented, for wave action than for unidirectional the mixed Davies United Kingdom base in Korean, "Statistics of Marine Acci- flow. set, and (4) expand the scale of the dents in Korea and the Development Dr. Sinjae Yoo of KORDI reviewed model to the whole Yellow Sea. Prof. of a Drift Prediction Model in Search efforts to interpret ocean color remote Chong Mook Lee of the Pohang Insti- and Rescue.” Due to the increase in sensing of the Yellow Sea. The atmotute of Technology suggested in the maritime accidents and as a result of spheric interference, the in-water algoquestion period that a moving pressure international agreements concluded by rithm, and the calibration of producfield might be added to augment the the International Maritime Organiza- tivity estimates via chlorophyll-A inshear stress used. There also was a dis- tion, Korea has revised its own search situ measurements were investigated. cussion of how to match the boundary and rescue procedures. KORDI and The atmospheric problem is due to the conditions from the two-dimensional the Maritime Police are working jointly high proportion of dust from the Asian "big" model to the three-dimensional on the use of drift prediction models in mainland and particularly from the Gobi nearshore models of finer scales. search and rescue and are identifying Desert. Use of the National Aeronautics

The next presentation was by Prof. areas of risk through the compilation and Space Administration (NASA) Im Sang Oh of SNU for his colleagues of marine accident statistics.

standard clear water radiance method Prof. Jin Kyung Lee (SNU) and Dr.

algorithm leads to misinterpretation Ki Chun Jeon (KORDI) on storm surge Coastal Environmental

of the satellite color pictures. Relative and wave hindcasting models and Studies

error estimates for productivity are from comparisons with field data at the Yellow

200% to 960% in the Yellow Sea area, Sea. This was a pilot study for YESEX This session began with a general whereas the previous error estimations done at the end of December 1991 off discussion of the sediment siltation based on the commonly used algorithm the west coast of Korea using wave process in coastal waters by Prof. Tetsuya were only 40%. This emphasizes the height and tidal current information Kusuda of Kyushu University, Japan. importance of site specific algorithm from several on and offshore stations. Tetsuya commented that four major evaluation and the danger of reliance The hindcast models used were a finite areas of the world's oceans have exten- on some “universal” formula for sateldifference two-dimensional storm surge sive areas of cohesive mud bottoms: lite interpretation, particularly for and a decoupled shallow water wave the Baltic-North Sea area of Europe, parameters such as color/productivity the Gulf of Mexico, Southeast Asia, that have a high atmosphericand water

column variability.

Prof. Hang Soon Choi of SNU gave New measurement techniques The final talk of the session and of an overview on marine oil spill acci- besides conventional at-a-station the program was by Prof. Yoon-Hae Ye dents and development of a short-term observations were reported by Drs.

observations were reported by Drs. of Kyunghee University discussing new prediction model for oil spillspreading Soo-Yong Kim, Ki Bong Kim, and technologies of ocean data measurefor his coauthors, Mr. Chang-Sup Lee San Baek Han of the Korea Advanced ment using optical fibers. Hesuggested of the Maritime Police, Prof. Choung Institute of Science and Technology that conventional measurement sensors Mook Lee of the Pohang Institute of (KAIST) in their talk titled “Present for parameters such as temperature, Technology, and Prof. Kwang Joon Bai Status and Future Prospect of Ocean pressure, turbidity level, etc. may be of SNU. This paper supplements the Current and Sea State Measurement replaced by compact and reliable optical talk on drift prediction model use in by HF Radar.” This was mainly on fiber sensors. Also, new parameters search and rescue discussed earlier. The developments in other countries and previously impossible or difficult to validity of calculating surface currents the potential application to Korean measure in the marine environment, from a depth integrated model based waters.

such as chemical concentration, now on Ekman theory was questioned. “Measurement and Analysis of the might be monitored in real time using

"Modelling of Coastal Currents and Detail Directional Spectrum” was new optical fiber techniques. Pollutant Transport in the Western presented by Dr. Byung Cheol Oh and Coastal Water of the Yellow Sea" was his coauthors, Drs. Jae Seol Shim and Closing Discussion presented by Profs. Young Jae Ro, Kyung Soo Bakh of KORDI. This was Ik Hwan You, and Ki Won Song, all of a mathematical treatment of the data Dr. Dong-Young Lee, the organizer Chungnam National University. The from a field study of wave spectra from

from a field study of wave spectra from of the workshop, after thanking the oil spill model is under development. the east coast of Korea, not from the participants, closed the meeting by The tentative specifications are: Yellow Sea, but it was indicative of the calling for innovative thinking and

approach considered for YESEX. Two international cooperation in bringing Area

35 to 37° N. and type of wave gauges were used: (1) a together instruments, models, and

125 to 126.5° E. Datawell directional wave rider buoy analytical techniques to attack the X, Y grid spacing

3'

measuring heave, sway, and surge problem of understanding such a sysTime interval

720 s

deployed in 38 meters of water and tem as the Yellow Sea. With such a Tidal components .............

(2) a sensor (Pacer Systems) measuring good beginning he believed that a subsurface pressure and two compo

and two compo- YESEX-2 workshop would be even The planned model is vertically aver- nents of horizontal velocity, deployed more successful. aged two-dimensional transient, using in 11 meters of water. The Maximum Papers presented by title only, but shallow water wave equations forced Entropy Method was used to obtain not given, are listed in the Appendix. by water elevation at open boundaries. . the directional wave spectra. The spec- These papers will be included in the It is hoped that the model can be runon tral width in shallow water was nar- workshop proceedings. mini-computers such as a 386 or 486 PC. rower than in deeper water.

Dr. Hong-Rhyong Yoo of KORDI SUMMARY
Technologies for Coastal presented a slide show illustrating
Monitoring System

remote sensing techniques for studies The first Workshop on the Yellow

on the Korean coastal environment. Sea Experiment was a showcase for Dr. Kwang Soon Park, for his He emphasized the advantage in cov- Korean scientists, engineers, and govcoauthor Dr. Dong-Young Lee, both erage using satellite data from NOAA,

erage using satellite data from NOAA, ernment agencies concerned with of KORDI, discussed real-time wave Lansat, etc. for pollution studies and oceanic problems to demonstrate their monitoring system of the Korea Mari general circulation and investigations approaches and activities. Unfortutime and Port Administration. The of sedimentary processes in coastal

of sedimentary processes in coastal nately, the scheduled participation of system, initiated in 1987, has eight basic waters. Studies are underway on the Chinese scientists was prevented by stations in Korean waters, two of them application of radar remote sensing the long lead time for them to obtain in the Yellow Sea. The primary sta- (see above) and airborne ocean moni- exit visas. Otherwise, except for North tions have a wave riding buoy, a direc- toring sensors to see how they might be Korea, all the nations bordering on the tional wave gauge, and a pressure gauge. integrated into the existing Korean Yellow Sea would have made meanData from the sensors are cabled to the coastal monitoring system.

ingful contributions. The Yellow Sea beach, whereas data from the wave rider

Experiment is still in the formative buoy are transmitted via radio.

stages, but the Korean approach of

12

expansion of existing monitoring programs and extension using relatively low cost ships, buoys, etc. of opportunity seems a proper evolutionary phase. As with other Korean scientific endeavors, the politically astute, intimate involvement of the government, academic, and private sector groups in all facets of the planning leads both to concrete results and general long-term programmatic stability, which are critical to the success of a project as vast and as complex as the Yellow Sea Experiment. The emphasis on the uniqueness of the Yellow Sea as a fullscale test facility to examine various oceanographic problems and models should attract workers from the international community not specifically interested in the geographic location of the Yellow Sea. The fact that such a multinational project is being contemplated seriously in an area associated with bitter local enmities and with large standing armies technically at war certainly is an indication of the value of marine research as a benefit to all nations.

Pat Wilde joined the staff of the Office of Naval Research Asian Office (ONRASIA) in July 1991 as a liaison scicntist spocializing in ocean scicnccs. He rcocived his Ph.D. in gcology from Harvard University in 1965. Since 1964, he has been affiliated with the University of California, Berkelcy in a varicty of positions and departments, including Chairman of Occan Engincering from 1968 to 1975 and Head of the Marine Sciences Group at the Lawrence Berkeley Laboratory (1977-1982) and on the Berkeley campus (1982-1989). He joincd ONRASIA after being the Humboldt Prize Winner in Residence at the Technical University of Berlin. Dr. Wildc's speciality is in palcooccanography and marine gcochemistry, particularly in the Palcozoic and Anoxic environments. He maintains an interest in modern occanography through his work on deep-sca fans, coastal and deep-sca scdimcnt transport, and publication of occanographic data shccts showing the bathymetry with attendant fcatures off the West Coast of the United States, Hawaii, and Puerto Rico.

Appendix

PAPERS NOT PRESENTED

“Brief Introduction to Coastal Engineering in China,” Asian Yak, Hah University, China.

“Research Activities for Marine Disaster Prevention at the Yellow Sea in China,” Dunxin Hu and Fagao Zhang, Institute of Oceanology, Academia Sinica, China.

“NOAA Yellow Sea Project and Large Marine Ecosystem Program,” Thomas L. Laughlin, National Oceanic and Atmospheric Administration, U.S.

“Studies of the Yellow Sea Using Remote Sensing Technology,” Jiamin Hu, Institute of Estuarine and Coastal Research, China.

SUPERCONDUCTING
MAGNETOHYDRODYNAMIC SHIP
PROPULSION - A WORLDWIDE

RESEARCH EFFORT

This article summarizes observations and opinions of many of the

participants of MHDS'91, the International Symposium on
Superconducting Magnetohydrodynamic Ship Propulsion, held in Kobe,
Japan, 28-31 October 1991. As the most significant development within

the topic area is the near-completion of the magnetohydrodynamic
(MHD) experimental ship YAMATO-1, with the sponsorship of the Japan
Ship and Ocean Foundation, a large portion of this article is devoted to a

description of YAMATO-1. International activities in superconducting
MHD propulsion are also updated. The author also provides his personal

assessment of the state-of-the-art of the technology.

by Thomas F. Lin

INTRODUCTION

one sense. That is, as the experimental MHDS'91 MEETING

ship was still on the drydock, visitors Since 1985, the Ship and Ocean were able to closely examine the two The 4-day meeting focused on the Foundation of Japan has sponsored an MHD thrusters beneath the ship on following five topic areas related to extensive research and development both sides. When the ship goes on sea superconducting MHD ship propulproject in superconducting magneto- trials in the spring of 1992, a close-upsion technologies. hydrodynamic (MHD) ship propulsion, lookofthe thrusters will be impossible. resulting in the design and construc- International participants were from Specifics of YAMATO-1 tion of the experimental prototype ship, China, France, Germany, Italy, Korea, YAMATO-1. Considering the ocean Taiwan, the United Kingdom, the United The YAMATO-1 experimental ship, trading economic structure of Japan, States, the former U.S.S.R., and shown in Figure 1, was built to meet the this research and development initia- Yugoslavia. Japan by far contributed marine architectural specifications as tive appears to be prudent. The the most papers and was followed by listed in the inset. The two MHD MHDS'91 conference held in Kobe, the United States. Organizations thrusters beneath the ship on both sides Japan, at the end of October 1991, representing the United States were are the most visible features of the marked the completion of Argonne National Laboratory, the ship. They replace the conventional YAMATO-1's drydock construction. David Taylor Research Center, the propellers for propulsion. The two The Japanese hosts and international Massachusetts Institute of Technology thrusters were separately built by attendants not only joined together for (MIT), the Naval Underwater Systems Mitsubishi and Toshiba Heavy Indusin-depth discussions and exchanges on Center, Newport News Ship Building, tries. Six parallel MHD channels superconducting MHD propulsion, but the Office of Naval Research Asian arranged in a circular pattern were they also visited YAMATO-1 at Office, Pennsylvania State University, shrouded in the thruster unit, as shown Mitsubishi Heavy Industry's Kobe Physical Science Inc., and Textron in Figure 2. Each MHD channel has its shipyard. It was a unique occasion in Defense Systems.

own superconducting dipole magnet,

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