Oceanographic Literature Review

(1990) 37 (7)

The citations are those received in the editorial office during the period 1-30 April, 1990.Most are accompanied by a short annotation or abstract and, when obtainable, by the firstauthor's address. The citations are classified under six main headings and about 130sub-headings (see the table of contents). Subject and author indexes are published for the firstthree quarters of the year with an annual cumulation. See the preface for additional explanatorymaterial.

A. PHYSICAL OCEANOGRAPHY

A40. Area studies, surveys

90:3652Isoda, Yutaka, 1989. Long-period water temperature

variabilities at the upper ocean In the Japan Sea.Data analysis of ocean data buoy in 1984obtained by the Japan Meteorological Agency.Umi /0 Sora, 64(4):217-232. (In Japanese, Eng­lish abstract.) Dept. of Ocean Engng, EhimeUniv., Matsuyama, Japan.

ASO. General hydrography (distribution ofcommon oceanic properties)

90:3653Royer, T.C., 1989. Upper ocean temperature varia­

bUity In the northeast Pacific Ocean: Is it anindicator of global wanning? J. geophys. Res;94(CI2): 18,175-18,183.

Examination of very low frequency SST fluctuationsat and north of 55°N in the Pacific suggests that theydo not result from either ENSO, wind forcing orglobal warming effects. The possibility is raised thatthis variability may represent coupling of temper­ature fluctuations with solar activity and lunar tides.In any event, it is concluded that recent upper oceanwarming is probably not a result of large-scale globalchange, but is part of the VLF zonal signal, whichwill need to be understood before it is possible tomeasure the effects of high-latitude climate changes.Inst. of Mar. Sci., Univ. of Alaska, Fairbanks, AK99775-1080, USA. (emm)

ASO. Circulation

90:3654Huang, RX., 1989. Sensitivity of a multilayered

oceanic general circulation model to the sea

56& A. Physical Oceanography oLR (1990)37 (7)

surface thermal boundary condition. J. geophys.Res., 94(C12):18,OII-18,021.

For long restoring time scales, wind-driven circu­lation dominated the model solution, resembling thecirculation in the North Pacific. For short restoringtime scales, strong thermohaline circulation drivenby deep water formed at high latitude dominated thesolution, resembling that in the North Atlantic.Accordingly, other aspects of the circulation, such asthe baroclinic structure of the currents and themeridional mass flux partition, changed with therestoring time scale. Dept. of Phys. Oceanogr.,WHOI, Woods Hole, MA 02543, USA.

90:3655Janowitz, G .S., 1989. The role of the surface density

field in subtropical gyre circulation. J . FluidMech., 209:227-247.

Examined within the content of a continuouslystratified, po tential vortici ty conserving model, theventilated fluid downwelled from the mixed layer isconfined to a relatively thin layer in subtropicalregions; the maximum depths of the ventilatedregion occur in the eastern and southern regions ofthe gyre. As a consequence of the relative thinness ofthe ventilated region in the wind-driven gyre, thetransport associated with the surface density field isa small part of the total transport in subtropicalregions. Thus the surface density field and thepotential vorticity associated with ventilated fluidplaya minor role in subtropical gyre dynamics, andthe potential vorticity of unventilated recirculatingfluid is found to play the major role in subtropicalgyre dynamics. Dept. of Mar., Earth and Atmos.Sci., North Carolina State Univ. , Raleigh, NC27695-8208, USA.

90:3656Merrifield, M.A. and C.D. Winant, 1989. Shelf

circulation In the Gulf of California: a descriptionof tbe variability. J . geophys. Res; 94(C12):18,133-18,160.

The first long-term measurements (1983-84) ofwinds, temperature, bottom pressure, and currentsmade in the Gulf of California are used to describethe dynamically important spatial and temporalscales and to compare and contrast the shelfcirculation on opposite sides of the Guaymas Basin.In addition, a qualitative assessment of possibleforcing mechanisms of gulf shelf circulation and anaccount of an energetic coastal-trapped wave eventare presented. Ctr. for Coastal Studies, A-009,Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA.

90:3657Miao, Jingbang and Xingquan Liu, 1989. Some

numerical experiments on the dynamics of thewintertime circulation in the northern HuanghaiSea and the Bobai Sea. Acta oceanol. sin.(English version), 8(3): 327-336. Inst, ofOceanol., Acad. Sinica, Qingdao, People's Re­public of China.

90:3658Oskam, D ., 1990. Sea surface variability in the North

Sea as derived from Seasat aldmetry. Geophys. J .int; lOO(l):1-7.

If the marine tide model of Schwiderski is used forthe North Sea, computed variability reaches up to20-50 em toward the shores. With the use ofdedicated regional hydrodynamic models from theDutch Rijkswaterstaat or the Proudman Oceano­graphic Laboratory, the computed variability d~­creases to ± 10 em toward the shores. These muchmore realistic values also show the potential ofaltimetry to control these regional models. Facultyof Geodesy, Delft Univ. of Tech., 2629 JA Delft ,Netherlands.

90:3659Prasad, M.V.R., 1989.Some kinetic energy properties

of surface waters of north Indian Ocean. Indian J .mar. Sci; 18(4):228-231.

Source and sink regions of mechanical energy areidentified. Most of the kinetic energy of surfacecirculation is in the eddy field. Energy propagatesfrom western regions of southern Arabian Sea(source) to the southwestern region off southerncoast of India (sink). Barring isolated regions in Bayof Bengal and equatorial regions, high frequencyeddy kinetic energy predominates. In the rest of thestudy region, the Arabian Sea and isolated regions ofBay of Bengal, surface circulation consists offluctuations with periods of more than one month.Dept. of Meteorol. and Oceanogr., Andhra Univ. ,Waltair 530 003, India.

90:3660Sand well, D.T. and Bohai Zhang, 1989. Global

mesoscale variability from the Geosat exactrepeat mission: correlation with ocean depth. J .geophys. Res; 94(CI2): 17,971-17,984.

We have developed a new technique for extractingglobal mesoscale variability from satellite altimeterprofiles having large radial orbit error (-3 m),Long-wavelength radial orbit error, as well as otherlong-wavelength errors (e.g., tides, ionospheric­atmospheric delay, and electromagnetic bias) , aresuppressed by taking the derivative (slope) of each

OLR (1990) 37 (7) A. Physical Oceanography 569

altimeter profile. A low-pass filter is used to suppressthe short-wavelength altimeter noise. Twenty-tworepeat slope profiles are then averaged to produce amean sea surface slope profile having a precision ofabout 0.1 p.rad. Variations in sea surface slope, whichare proportional to changes in current velocity, areobtained by differencing individual profiles from theaverage profile. Using their techniques, dynamictopography of various ocean regions is discussed.Geol. Res. Div., A-020 Scripps Inst. of Oceanogr.,LaJolla, CA 92093, USA.

90:3661Woodberry, K.E., M.E. Luther and 1.J. O'Brien,

1989. The wind-driven seasonal circulation in thesouthern tropical Indian Ocean. J. geophys. Res;94(C12): 17,985-18,002.

The principal feature is a basin-wide clockwise gyrecomprised of the South Equatorial Current (SEC) tothe south, the South Equatorial Countercurrent(SECC) to the north, and the East African CoastalCurrent in the west. Rossby waves propagatewestward in the shear zone between the SEC and theSECC, and are obstructed and partially reflected bythe banks along the Seychelles-Mauritius Ridge(60°E). A region of high eddy activity northwest ofMadagascar is an extension of the tropical gyre andis a tropical analog to the Gulf Stream recirculationregion. Small (2 Sv) mean throughflow from thePacific to the Indian Ocean at the eastern openboundary is due to wind-forced Indian Oceandynamics alone and is within the range of obser­vations of throughflow from the Pacific. CATA, Box391, Univ. of Colorado, Boulder, CO 80309, USA.

A90. Currents

90:3662Craig, P.D., 1989.A model of diurnally forced vertical

current structure near 30° latitude. Continent.Shelf Res.; 9(11):965-980.

At 30Q latitude, the inertial frequency is equal to thefrequency of the diurnal tide, or diurnal winds suchas a sea breeze. The extension of Ekman's theory toincorporate oscillatory forcing indicates that at thelatitude where the inertial and forcing frequenciesare the same, the sense of rotation of the currentprofile with depth will change. A coastal-oceanmodel is extended to include cross-shore wind stressand a constant eddy viscosity model of verticalcurrent structure, and used to demonstrate thelatitude-dependence of the tidally and wind-forcedcurrent structure near 30° latitude. Results are bestinterpreted in a fixed reference frame, rather than

the rotating j-plane, CSIRO Div. of Oceanogr., GPOBox 1538, Hobart, Tas. 7001, Australia.

90:3663Fujimoto, Minoru, Hisao Sakamoto and Norihisa

Nakagawa, 1988. The Kuroshio large meanderand the oceanographic conditions in Nanseiregion, southwest of Japan. Umi to Sora, 64(3):129-144. (In Japanese, English abstract.)

In this report it is argued that the Kuroshio largemeander should be divided into two categoriesconsisting of the typical Kuroshio large meander(e.g., as observed from 1975-80) and the Kuroshioquasi-large meander (as observed from 1981-84), tobe distinguished on the basis of differential effectson the flow of the Kuroshio south of Shikoku.Oceanographic conditions in the Nansei regionsouthwest of Japan are also considered from thestandpoint that they should be affected by thepresence or absence of the Kuroshio large meander.Nansei Reg. Fish. Res. Lab., Kochi, Japan. (emm)

90:3664Grundlingh, M.L., LT. Hunter and E. Potgieter,

1989. Bottom currents at the entrance to FalseBay, South Africa. Continent. Shelf Res., 9(12):1029-1048. CSIR, P.O. Box 320, Stellenbosch7600, South Africa.

90:3665Hanawa, Kimio, 1988. Temperature structure and

mixed layer in the Kuroshio region over the IzuRidge. Umi 10Sora, 64(3):167-182.(In Japanese,English abstract.) Dept. of Geophys., TohokuUniv., Sendai, Japan.

90:3666Hosoyamada, Tokuzo, Arata Kaneko and Ittpei

Eguchi, 1989. ADCP observation of the oceanmixed layer on the East China Sea continentalshelf west of Kyushu. Umi to Sora, 64(ExtraNo.):265-273. (In Japanese, English abstract.)Grad. School of Engng, Kyushu Univ., Fuku­oka, Japan.

90:3667lida, Hayato, 1988. Variation of the Kuroshio system

and the subtropical gyre centering on the sub­surface salinity maximum. Umi to Sora, 64(3):183-198. (In Japanese, English abstract.)Maizuru Mar. Observ., Maizuru, Japan.

90:3668Kamachi, M., 1989. Advective surface velocities

derived from sequential images for rotational flowfield: limitations and applications of maximum

570 A. Physical Oceanography OLR (1990)37(7)

cross-correlatiob method with rotational regis­tratloe. J. geophys. Res., 94(C12):18,227-18,233.

A pattern matching method is used with theidentification of maximum cross correlation (MCC)between a template window in the first image andsearch areas in the second image. We examined thelimitations of the MCC method in the case whereeddy size (L E) is much smaller than the radius ofdeformation (L D) . The eddy is regarded as a particle;maximum detectable time period is estimated to beabout 1 day. For the case LE?:.LD, we developed theMCC method to detect a rotational motion. Derivedvelocity fields were compared with a real velocityfield in a numerical analysis of tracer and quasi­geostrophic eddy fields. The optimal template size isabout the eddy diameter which spans between themaximum velocity points. Res. Inst. for Appl.Mech., Kyushu Univ, 87, Kasuga, 816 Japan.

90:3669Kawabe, Masaki, 1988. On the study of large

meander of the Kuroshio. Umt to Sora, 64(3):157-166. (In Japanese, English abstract.)

Variations in the Kuroshio path are classified intotwo groups comprised of large meander and smallmeander paths, with the latter further subdividedinto the nearshore and offshore paths. The dynamicsof the Kuroshio path is, then described in terms ofcharacteristics of these three quasi-steady paths andthe transitions between them. The relationship of thevelocity and transport of the Kuroshio to theseindividual path/states is also considered. Ocean Res.Inst., Univ. of Tokyo, Japan. (emm)

90:3670Komar, P.D., Joan Oltman-Shay (comment) and

Cyril Galvin (reply), 1989. Discussion [of] Thecontinuity efJuation for longshore current velocitywith breaker angle adjusted for a wave-currentinteraction. Coast. Engng, Amst; 13(4):379-386.

90:3671Kumar, K.V.S. et al., 1989. Variability in current and

thermohaline structure off Visakhapatnam [India)during late June 1986. Indian J. mar. Sci;18(4):232-237. Naval Phys. and Oceanogr. Lab.,Cochin 682 004, India.

90:3672Matsuyama, Masaji et al., 1988. The warm eddy

observed east of Oki Islands in the Japan Sea. J.Tokyo Univ, Fish; 75(2):247-255. (In Japanese,English abstract.) Lab. of Mar. Environ. Sci.,Tokyo Univ. Fish., 5-7 Konan 4, Minato-ku,Tokyo, Japan.

90:3673Matthaus, W. and H. Franck, 1989. Is the positive

salinity anomaly in tbe Kattegat deep water anecessary precondition for major Baltic inflows?Gerl, Beitr. Geophys; 98(4):332-343. Akad. derWissenschaften, Inst. fur Meeresk., Seestr. 15,Rostock-Wamemunde, DDR-2530, DRG.

90:3674Minami, Hideto, 1989.On the structure of warm core

off Tokaido, south of Japan. Umi to Sora,64(4):199-216. (In Japanese, English abstract.)

This paper presents the study of a warm eddy whichbudded off the Kuroshio main current, movedwestward along the Tokaido coast, and rejoined theKuroshio off the Shionomisake during March-May,1984. The geometric characteristics, mean phasevelocity and internal current and thermal dynamicsare described in some detail. In addition, a warmstreamer which manifested itself as a clockwise spiralin the west side of the eddy is also described. KobeMar. Observ., Kobe, Japan. (emm)

90:3675Otsuka, Kazuyuki and Makoto Ishino, 1988. Inves­

tigation of current systems with drift-bottle in tbesubtropical region of the northwestern PacificOcean. J. Tokyo Univ. Fish., 75(2):275-294. (InJapanese, English abstract.) Lab. of Fish.Oceanogr., Tokyo Univ. Fish., 5-7 Konan 4,Minato-ku, Tokyo 108, Japan.

90:3676Pettigrew, N.R., 1989. Direct measurements of the

flow of Western Mediterranean Deep Water overthe Gibraltar sill. J. geophys. Res; 94(CI2):18,089-18,093.

The Gibraltar Pilot Experiment was carried out inJune 1984 in order to obtain preliminary mooredcurrent measurements in the vicinity of the sill in theStrait of Gibraltar. Bottom-mounted Doppler cur­rent measurements and moored temperature meas­urements show directly the westward transport ofWestern Mediterranean Deep Water over the sill;the net transport is estimated to be 0.2 x 1()6 m' S-I.

Inst. for the Study of Earth, Oceans, and Space,Univ, of New Hampshire, Durham, NH 03824,USA.

90:3677Prandle, D. and O.K. Ryder, 1989. Comparison of

observed (HY radar) and modelled nearshorevelocities. Continent. Shelf Res; 9(11):941-963.

Surface velocities measured by HF radar are com­pared against values obtained from numerical

OLR (1990)37(7) A. Physical Oceanography 571

models with the aim of determining the extent ofagreement by examining successively (I) the pre­dominant semi-diurnal constituents, (2) higher har­monics (including spatial gradients), and (3) resid­uals. These comparisons are used to assess theaccuracy of both the measurements and models indescribing the fine-scale horizontal structure ofnearshore tidal currents. Although the presentdeployment region possesses rather complicatedgeography, current structure and tidal dynamics,future deployments in more carefully selected re­gions will allow the present results to be extended.Proudman Oceanogr. Lab., Bidston Observ., Bir­kenhead, Merseyside L43 7RA, UK.

90:3678Ramp, S.R., 1989. Moored observations of current

and temperature on the shelf and upper slope nearring 828 foff northeastern U.S.I. J. geophys. Res.,94(CI2): 18,071-18,087.

Current and temperature variability induced at theshelf break and upper slope along the northeasternU.S. by the formation and passing of ring 82B wasexamined using data from remote sensing of the SSTfield and an array of current meters deployed in thatarea. It is argued that very low frequency currentvariability at the shelf break is due primarily to thering's Rossby wave radiation field, while tempera­ture variability can be attributed both to large-scaleperturbations of the shelf-slope front by the ring andto smaller-scale perturbations of the front whosedynamics are not yet understood. Dept. ofOceanogr., Mail Code 68Ra, Naval Postgrad.School, Monterey, CA 93943, USA. (emm)

90:3679Ridderinkhof, H., 1989. Tidal and residual flows in

the western Dutch Wadden Sea. Ill. Vorticitybalances. Neth. J. Sea Res; 24(1):9-26. Neth­erlands Inst. for Oceanic Sci., P.O. Box 59, 1790AB Den Burg, Texel, Netherlands.

90:3680Schumacher, J.D., P.J. Stabeno and A.T. Roach,

1989. Volume transport in the Alaska CoastalCurrent (Shelikof Strait). Continent. Shelf Res.,9(12):1071-1083.

Mean volume transport through the Shelikof seavalley was computed to be 0.85 X IQ6 m' S-I.

Approximately 75% of this flux flowed seawardthrough the Shelikof sea valley, with the remainderflowing along the Alaska Peninsula. Data showedthe expected increase of volume transport concom­itant with maximum freshwater discharge in autumn.The greatest monthly mean transport, however,occurred in winter and was related to wind forcing.

On time intervals of days, fluctuations in transportwere often large and generally geostrophic. Some ofthese fluctuations resulted from convergence of flowcaused by the complex interaction of storms withorography, and approximately half were accountedfor by the alongshore wind. PMEL, 7600 Sand PointWay NE, Seattle, WA 98115, USA.

90:3681Sun, X.-p., Q.-k. Yuan and Yi-p. Wang, 1988.

Analysis of the surface current path of theKuroshio. Umi to Sora, 64(3): 145-156. (In Jap­anese, English abstract.)

Variations of the surface current axis and width ofthe Kuroshio Current as well as the countercurrentsand warm eddies on the rightside of the Kuroshio inthe East China Sea are analysed, using the currentcharts published in Japan, and GEK and TISshipboard data. In addition, the paths of theKuroshio, ten patterns in all, are classified into twogroups-straight and meandering paths. First Inst.of Oceanogr., SOA, Qingdao, People's Republic ofChina. (emm)

90:3682Yoshida, Jiro et al., 1988. Observation of the

Kuroshio near the Izu Islands in October 1986. J.Tokyo Univ. Fish., 75(2):225-238. (In Japanese,English abstract.) Lab. of Mar. Environ. Sci.,Tokyo Univ. Fish., 5-7 Konan 4, Minato-ku,Tokyo, Japan.

AltO. Water masses and fronts

90:3683Carmack, E.C., R.W. MacDonald and J.E. Papa­

dakis, 1989.Water mass structure and boundariesin the Mackenzie shelf estuary. J. geophys. Res ;94(C12):18,043-18,055.

We here relate water masses resident on theMackenzie shelf to the large-scale oceanography ofthe Arctic mediterranean. Summertime exchangebetween the shelf and open ocean is largely confinedto waters lying above the main halocline, thusexcluding underlying offshore waters from thenutrient maximum layer and Atlantic layer. Indi­vidual water masses maintain their structural iden­tity as they move across the shelf and participate inthe estuarine circulation. Shelf waters are stronglyinfluenced by river inflow; however, the concept of asingle plume issuing from the river and forming astrictly two-layered structure over uniform shelfwater is misleading, since a variety of temperature,salinity, and turbidity fronts co-exist on the shelf at

572 A. Physical Oceanography OLR (1990) 37 (7)

any given time. Inst. of Ocean Sci., P.O. Box 6000,9860 West Saanich Rd., Sidney, BC V8L 4B2,Canada.

90:3684Chern, C.-S. and Joe Wang, 1989. On the water

masses at northern offshore area of Taiwan. Actaoceanogr. taiwan ; 22: 14-32.

This analysis of seasonal variations in the hydrog­raphy of the northern offshore area of Taiwan andrelated water masses is aimed at identifying sourcesof the so-called Taiwan Warm Current. Temperatureand salinity data obtained from four cruises (Sept.,Nov., 1987 and Feb., May, 1988) indicate that awestern branch of the Kuroshio contributes to theTaiwan Warm Current, while the branch flowingthrough the Taiwan Strait does not. Inst. ofOceanogr., Natl. Taiwan Univ., Taipei, Taiwan.(emm.)

90:3685Fan, Liqun, Yusong Su and Fengqi Li, 1989. Water

masses in the northern South China Sea. Actaoceanol. sin. (English version), 8(3):337-350.

Eight water masses are distinguished for the north­ern South China Sea using fuzzy cluster analysis.The conditions of formation and basic character­istics of each are described, along with their usualpatterns of growth and decline. Zhanjiang Fish. Coli,Zhanjiang, People's Republic of China. (sIr)

90:3686Macdonald, R.W. et al., 1989. Composition and

modification of water masses in the Maekenzleshelf estuary. J. geophys. Res; 94(CI2): 18,057­18,070.

Distributions of 6180, salinity, temperature, andnutrients were used to quantify water sources to theMackenzie shell in the Beaufort Sea. Comparisonwith satellite imagery confirms that runoff water isassociated with the Mackenzie plume. The season­ally variable surface layer for the shelf is viewed ascycling between a 'reverse estuary' in winter, whenthe polar mixed layer (PML) is formed, and apositive estuary in summer when shelf watersrespond to freshwater inputs. Our data coupled withriver flow imply a freshwater flushing time for theMackenzie shelf at about 150 days. To reform thePML during winter requires removal of this seasonalfresh water through flushing and ice formation,allowing continued> ice growth to produce 'new'brine and a deeper and saltier PML. A simplegeochemical model shows that autumn conditions(freshwater accumulation) and the rate of flushingare important controls on the potential of the shelf to

produce 'new' brine and that winter runoff issufficient to inhibit brine production. lnst. of OceanScL, P.O. Box 6000, 9860 West Saanich Rd., Sidney,BC V8L 4B2, Canada.

90:3687Maeda, Akio, 1989. On studies on water masses and

water movement in the East China Sea. Umi /0

Sora, 64(Extra No.):257-263. (In Japanese, Eng­lish abstract.) Dept. of Engng, KagoshimaUniv., Kagoshima, Japan.

90:3688Shaw, P.-T., 1989.The intrusion of water masses into

the sea southwest of Taiwan. J. geophys. Res;94(C12):18,213-18,226.

Water mass characteristics were analyzed to studythe Kuroshio intrusion into the sea southwest ofTaiwan. Hydrographic data were obtained fromCTD casts during May and August 1986. In May,remnants of intruding Kuroshio water were foundon the continental slope south of Penghu Channel.By August, these were replaced by South China Seawater. These results support the hypothesis of aseasonal pattern of the intrusion process: beginningin late summer, intensifying in winter, and ceasingby late spring when South China Sea waters againenter this region. Dept. of Mar., Earth, and Atmos.ScL, North Carolina State Univ., Box 8208, Raleigh,NC 27695, USA.

90:3689Wang, Joe and Ci-S. Chern, 1989. On cold water

Intrusions in the eastern Taiwan Strait during thecold season. Acta oceanogr, taiwan., 22:43-67. (InChinese, English abstract.)

90:3690Washburn, Libe et aI., 1989. lsopycnal mixing and

the distribution of partIcles across the NorthPacilic Subtropical Front fNPSF). Deep-SeaRes; 36(llA): 1607-1620.

Near-surface waters north of the NPSF have lowersalinity (S) and generally higher beam attenuationcoefficient (c) values compared with waters to thesouth. Mixing and interleaving of Sand c betweenthese water masses extends to a depth of about 200m, resulting in finestructure in Sand c on verticalscales from a few to tens of meters. lsopycnal timeseries of Sand c often are highly correlated on a2-day time scale; high correlation is most frequentlyobserved below the 1%light level and is consistentwith conservative scalar-like behavior of c. Theobserved correlation indicates that isopycnal mixingand advection processes are important in controllingparticle distributions, and thus c, in the vicinity of

OLR (1990)37(7) A. Physical Oceanography 573

the NPSF. Dept. of Geol. Sci., Univ. of SouthernCalifornia, Los Angeles, CA 90089-0740, USA.

A120. Convergences, divergences, up­welling

90:3691Byun, S.-K., 1989. Sea surface cold water near the

southeastern coast of Korea: wind effect. J.oceanol. Soc. Korea, 24(3):121-131. KOROl,Ansan P.O. Box 29, Seoul 424-600, Korea.

90:3692Djurfeldt, Leif, 1989. Circulation and mixing in a

coastal upwelling embayment; Gulf of Arauco;Chile. Continent. Shelf Res., 9(11):1003-1 016.

An analysis is presented of a set of fine scale currenttemperature and salinity profiles from a coastalup~el1ing embayment, the Gulf of Arauco, Chile,dunng the summer upwelling season in January1985. Typical circulation and mixing patterns wereidentified for normal southerly wind conditions andfor notherly wind events, which occur regularlyduring the upwelling season. Strong events of shearintensification and related internal mixing wereobserved after a northerly wind event and inter­preted in terms of passing internal Kelvin wavefronts. Nutrient flux into the surface layers due tothis particular mixing mechanism may represent animportant contribution for maintaining the tremen­dous biological production in the study area.Oceanogr. Inst., Univ. of Gothenburg, Box 4038,S-4OO 40 Gothenburg, Sweden.

90:3693Gibbs, R.I. et al., 1989. Coagulation and transport of

sediments in the Gironde Estuary. Sedimentology,36(6);987-999. Ctr, for Colloidal Sci., Coll. ofMar. Studies, Univ. of Delaware, Newark, DE19716, USA.

AlSO. Tides and sea level

90:3694Dickman, S.R., 1989. A complete spherical harmonic

approach to luni-solar tides. Geophys. J. int.,99(3):457-468.

The theory is based on Laplace tide equationsmodified to include turbulence with constant eddy

viscosity, linearized bottom friction, and oceanicloading and self-gravitation. Five zonal luni-solartides, ranging in period from 14 days to 18.6 yr, areinvestigated using the theory; such tides havetypically been difficult to compute using traditionalnumerical approaches. The polar motion andchanges in the length of day induced by theselong-period tides are calculated. The greatest limi­tation to accurate prediction of zonal tides- for anytheory-appears to be the marginal failure of all tidetheories to conserve mass globally; the use ofadditional mass constraints may be warranted. Dept.of Geol. sa, SUNY, Binghamton, NY 13901, USA.

90:3695Giese, B.S. and D.A. Jay, 1989. Modelling tidal

energetics of the Columbia River Estuary. Estuar.coast. Shelf Sci., 29(6):549-571.

Geometric and tidal features of the Columbia RiverEstuary, common to many shallow river estuariesallow it to be modelled using a one-dimensionalharmonic transport model. The tidal flow is rep­resented as a series of harmonic components whosespatial variability is determined by the model, whichalso provides a qualitative explanation for andaccurate quantitative predictions of along-channelvariations in tidal properties in terms of the momen­tum balance. The model is also used to determinethe spatial distributions of time averaged energyfluxes, and from that to draw a picture of theenergetics of the estuary as a whole. School ofOceanogr., Univ, of Washington, Seattle, WA98195,USA. (emm)

90:3696Zlotnicki, V., L.-L. Fu and W. Patzert, 1989.

Seasonal variability in global sea level observedwith Geosat altimetry. J. geophys. Res; 94(CI2):17,959-17,969.

Satellite observations of time changes in globalmesoscale sea level variances show significant,geographically coherent seasonal patterns. The NEPacific and NE Atlantic variances show the mostreliable patterns, higher than their yearly averages inboth the fall and winter. The response to windforcing appears as the major contributor to the NEPacific and Atlantic signals. The equatorial regionsalso show significant seasonal patterns, but theuncertainties in the wet tropospheric correctionprevent definitive conclusions. The western bound­ary current changes are very large but not statis­tically significant. Jet Propulsion Lab., CaliforniaInst. of Tech., 4800 Oak Grove Dr., Pasadena, CA91109, USA.

574 A. Physical Oceanography OLR (1990) 37 (7)

A160. Waves, oscillations

90:3697Bonmarin, P., 1989. Geometric properties of deep­

water breaking waves. J. Fluid Mech; 209:405­433.

The time-space evolution of a steep water wavereaching the breaking stage is observed; in partic­ular, asymmetry of the wave profile in the near­breaking region is displayed. Measurements atbreaking onset on a sample of breaking waves showa relation between the rate of asymmetry growth andbreaker type. The shape evolution of a plunging crestafter breaking has started, and the related splash-upphenomenon and its part in the air-entrainmentprocess are also observed. Inst, de MecaniqueStatist. de la Turbulence, 12 Ave. du GeneralLeclerc, 13003 Marseille, France.

90:3698Bowen, A.J. and R.A. Holman, 1989. Shear insta­

bilities of the mean longshore current. 1. Theory.J. geophys. Res., 94(C12):18,023-18,030.

A new class of nearshore waves based on the shearinstability of a steady longshore current is discussed.The dynamics depend on the conservatio~ .ofpotential vorticity but with the background vorticityfield, traditionally the role of Coriolis in larger scaleflows, supplied by the shear structure of thelongshore current. While the instability can span arange of frequencies' and wavenumbers, a repre­sentative frequency is typically in the range of10-3-10-2 Hz. Wavelengths are of the order of twicethe width of the longshore Current. Growth isexponential with an e-folding time that is typicallyhalf of a wave period. Since vorticity waves willprobably have a profound effect on cross-shoremixing as well as longshore current dissipation, w.eexpect the dynamics of barred and monotonicbeaches to show fundamental differences. Dept. ofOceanogr., Dalhousie Univ., Halifax, NS B3H 411,Canada.

90:3699Boyd, J.P., 1990. New directions in solitons and

nonlinear periodic waves: polycnoidal waves,imbricated solitons, weakly nonlocal solitarywaves, and numerical boundary value algorithms.Alb. appl. Mech., 27: 1-82.

This review describes four new strategies for ex­ploring solitary and nonlinear periodic waves whic~

go beyond the limited successes offered by tradi­tional methods (e.g., inverse scattering transform,multiple scales perturbation theory, and numericalinitial value codes). The strategies: (I) the theory of

polycnoidal waves, (2) soliton superimposition,. orthe method of 'imbricate series,' (3) direct numencalcomputation of multidimensional solitary waves,and (4) weakly nonlocal solitons are discussed. Lab.for Sci. Computation, Univ. of Michigan, AnnArbor, MI, USA. (emm)

90:3700Brown, Timothy, 1989. On the general problem of

Kelvin wave reflection at an oscillating boundary.Continent. Shelf Res; 9(10):931-937.

The author's (1987) model of Kelvin wave reflectionat an oscillating boundary is reformulated to allowan arbitrary specification of the amplitude and phaseof the boundary oscillation relative to the incomingwave. Solutions are obtained numerically by col­location and imperfect reflection is found to occur ingeneral. There are three regimes of solutions char­acterized by the size of the boundary oscillation. c/oDr. D.T. Ehrenmark, Math. Dept., City of LondonPolytech., London E.C.3, UK.

90:3701Chu, C.K. and R.L. Chou, 1990. Solitons induced by

boundary conditions. Adv. appl. Mech., 27:283­302.

Solitary waves may be generated in a variety ofmedia by a surface pressure source, such as a shipmoving on water, or boundary excitation, such as asluice opening or a wall pushing. They may alsoevolve from initial conditions. The latter correspondstheoretically to a pure initial value problem, the firstand second, to a driving term or inhomogeneousdifferential equation(s) and a mixed initial boundaryvalue problem, respectively. Ex.periments and nu­merical results, primarily for water solitons, arereviewed here. Theoretical results obtained formixed initial boundary value problems for the KdVequation and for the nonlinear Schrodinger equationare described. Dept. of Appl. Phys., Columbia Univ.,New York, NY, USA. (slr)

90:3702Dalrymple, R.A., 1989. Water waves past abrupt

channel transitions. Appl. Ocean Res; 11(4): 170­175. Dept. of Engng, Univ. of Delaware, New­ark, DE 19716, USA.

90:3703Deigaard, Rolf and Jergen Fredsee, 1989. Shear

stress distribution in dissipative water waves.Coast. Engng, Amst; 13(4):357-378.

The cases of energy dissipation in an oscillatorybottom boundary layer and of spilling breakers or

OLR (1990) 37 (7) A. Physical Oceanography 575

broken waves are considered. How energy is ex­tracted from the wave motion and transported to thelocation of dissipation is described. The shear stressdistribution depends on the location of the energydissipation. In case of no dissipation or dissipationnear the bed, the near surface shear stress is zero,whereas in case of dissipation near the surface, thenear surface shear stress is determined from thegradient in the wave energy flux. In non-uniformwaves the organized wave motion contributes sig­nificantly to the vertical momentum transfer, whichis important for determining the shear stress dis­tribution. Inst. of Hydrodyn. and Hydraulic Engng(ISVA), Tech. Univ. of Denmark, 2800 Lyngby,Denmark.

90:3704Evans, D.V., 1990. The wide-spacing approximation

applied to multiple scattering and sloshing prob­lems. J. Fluid Mech., 210:647-658.

Linear water-wave theory is used in conjunction witha wide-spacing approximation to develop closed­form expressions for the reflection and transmissioncoefficients appropriate to a plane wave incidentupon any number of identical equally spacedobstacles in two dimensions, and also to derive a realexpression from which the sloshing frequencies,which occur when the bodies are bounded by rigidwalls, can be determined. In each case the solution isin terms of known properties of radiation problemsassociated with anyone of the bodies in isolation.Dept. of Math., Univ. of Bristol, Bristol BS8 ITW,UK.

90:3705Fang, Zhongsheng, Shunsun Dai and Chengyi Jin,

1989. On the long-term joint distribution ofcbaracteristic wave height and period and itsapplication. Acta oceanol. sin. (English version),8(3):315-325.

Using scatter diagram analysis of wave height (H)and period (1), it is shown that the normal linearregression equations better predict the conditionalexpectation and standard deviation of T for a givenH than do the log-normal law-based equations.Utilizing the normal linear regression equations, theconditional distribution (P) of T for given H isobtained. Combined with the long-term marginaldistribution of the wave height, this enables estab­lishment of a new parameterized model for thelong-term joint distribution P(H, T). A method forestimating the wave period associated with anextreme wave height is given. China Ship Sci. Res.Ctr., Wuxi, People's Republic of China.

90:3706Fernandes, A.A., Y.S. Prahalad and D. Sengupta,

1989. Scattering of Rossby and Poincarll wavesoff rough lateral boundaries. Dynam, Atmos,Oceans, 14(1-2):41-64.

We present a unified treatment of wave scatteringfrom a rough boundary. The stationary nature of theboundary process is used to show that the wave fieldis also stationary, and therefore can be representedby an Ito-Wiener-Hermite series. In the cases of thereflection of Rossby and Poincare waves fromcontinental edges, the presence of new, roughness­generated trapped waves is predicted. An incomingRossby wave transfers energy to a set of Rossbywaves with wavenumbers covering a wide range. Inthe case of Poincare wave scattering, an energy sinkat the coast is attributed to the presence of a naturaltrapped mode, the Kelvin wave. Phys. Oceanogr,Div., Natl. Inst. of Oceanogr., Dona Paula, Goa 403004, India.

90:3707Galloway, J.8., M.B. Collins and A.D. Moran, 1989.

Onsbore/offsbore wind influence on breakingwaves: an empirical study. Coast. Engng, Amst;13(4):305-323.

Beach based and in-situ observations of plungingand spilling breakers, with associated localised winddata, have isolated important characteristics reogarding breaking waves in the surf zone. Offshorewinds enhance the development of plunging break­ers; onshore winds, the development of spillingbreakers. Extremely strong offshore, or onshorewinds, may reintroduce more spilling or plungingbreaker-type characteristics, respectively. WimpolLtd., Hargreaves Rd., Groundwell Indust. Estate,Swindon, Wiltshire SN2 5AZ, UK.

90:3708Hammack, Joe, Norman Scheffner and Harvey

Segur, 1989. Two-dimensional periodic waves inshallow water. J. Fluid Mech; 209:567-589.

Experimental data demonstrate the existence of afamily of gravitational water waves that propagatepractically without change of form on the surface ofshallow water of uniform depth. The surface patternsof these waves are genuinely two-dimensional andfully periodic; i.e., they are periodic in two spatialdirections and in time. The amplitudes of thesewaves need not be small; their form persists even upto breaking. The measured waves are described withreasonable accuracy by a family of exact solutions ofthe Kadomtsev-Petviashvili equation over the entireparameter range of the experiments, including waveswell outside the putative range of validity of the KP

576 A. Physical Oceanograph y OLR (1990)37 (7)

equation. These genus-2 solutions of the KP equa­tion may be viewed as two-dimens ional generali­zations of cnoidal waves. Dept. of Aerospace Engng,Mech. and Engng Sci., Univ. of Florida, Gainsville,FL 32611, USA.

90:3709Huang, M.-C., 1990. Kinematics prediction by Stokes

and Fourier wave theories. J. WatWay Port coast.Ocean Engng, Am. Soc. civ. Engrs, 116(1): 137­148.

Recent laboratory measurements of wave kinematicsindicate that the horizontal velocity under the crestis smaller than that under the trough in the range ofintermediate to deep water waves. The mathemat­ically correct fifth-order Stokes and Fourier wavetheories can better predict the measured behavior ifa zero uniform coflowing mass transport velocity isincluded in the solution algorithms. The necessarycorrection procedure when using the Stokes andFourier wave theories with. a specified Euleriancurrent to predict the wave kinematics in a closeflume with zero net flow over depth is discussed.Dept. Naval Arch. and Mar. Engng, Nat ChengKung Univ., Tainan 70101, Taiwan.

90:3710Kirkgoz, M.S., 1989.An experimental investigation of

plunging breaker boundary layers in the trans­formation zone. Coast . Engng, Arnrt7 13(4):341­356.

Particle velocities are measured at four verticalsalong the transformation zone for three differentsteepnesses of waves within the plunging breakerrange. Boundary layer flow in the transformationzone is mostly turbulent; vertical distribution ofparticle velocities does not conform to the classicalwall distribution for steady-flow boundary layers.Free-stream particle velocities beneath the crestincrease considerably as the wave progresses towardthe breaking point. The boundary layer thicknessremains constant throughout the transformationzone but decreases with increasing deep-watersteepness for the particular beach slope tested. Dept.of Civil Engng, Cukurova Univ., Adana 01330,Turkey.

90:3711Krzyscin, Janusz, 1990. A Dote on specific variability

of long surface gravity waves and drag coefficientin coastal upwelling zone. Pure appl. Geophys.,132(3):481-493.

Analytical solutions of the wave kinematic equationsand the wave energy transport equation are obtained

for the case of a long surface gravity wave propa­gating through a coastal upwelling zone. Variabili tyin the drag coefficient due to wave amplification andrefraction caused by specific surface water current isassessed with respect to the drag parameterization ofGent and Taylor (1978), and the characteristics ofand influences on drag coefficient growth towardshore are discussed. Polish Acad. of Sci., Inst . ofGeophys., P.O. Box 155,00-973 Warsaw, Pasteura 3,Poland. (emm)

90:3712Lee, S.-1. and R.H.J. Grimshaw, 1990. Upstream­

advancing waves generated by three-dimensionalmoving disturbances. Phys. Fluids A, 2(2):194­201.

Upstream-advancing waves successively generatedby various forcing disturbances moving with near­resonant speeds are found by numerically solving aforced Kadomtsev-Petviashvili equation, whichshows in its simplest form the interplay of a basiclinear wave operator, longitudinal and transversedispersion, nonlinearity, and forcing. Curved solitarywaves are found as a slowly varying similaritysolution of the KP equation, and are favorabl ycompared with the upstream-advancing waves nu­merically obtained. School of Math., Univ. of NewSouth Wales, P.O. Box I, Kensington, NSW 2033,Australia.

90:3713Mahdmina, D. and L.M. Hocking, 1990. Scattering

of a capillary gravity wave by a vertical cylinder.Phys. Fluids A, 2(2):202-208.

The scattering of a capillary gravity wave by asurface-piercing obstacle depends on the conditionapplied at the contact line between the fluid and theobstacle. A model for this condition that incor­porates the effect of dynamic contact-angle variationis used to determine the wave field close to theobstacle and at large distances from it . Solutionsdepend on the ratio between the wavelength of theincident wave and the radius of the obstacle, whichis taken to be a circular cylinder, and on the relativesize of the capillary and gravitational restoringforces. A third parameter is a constant of propor­tionality in the edge condition. Extreme values ofthis parameter relate to the special cases of or­thogonal contact and of a fixed contact line. Thestrength of the scattered wave and the angularvariation of its amplitude at large distances arecalculated for a range of values of the parameters.Dept. of Math., Univ. College London, Gower St.,London WClE 6BT, UK.

OLR (1990)37 (7) A. Physical Oceanography 577

90:3714Miller, H.C. and c.i, Vincent, 1990. FRF spectrum:

TMAwith Kitaigorodskii's f-l scaling. J. WatWayPort coast. Ocean Engng, Am. Soc. civ, Engrs,116(1):57-78.

The derivation of a mathematical function thatrepresents the spectrum of wind-generated gravitywaves in water of arbitrary depth parallels that of theTMA spectrum, except that Phillips' (1958) modelfor saturation at high frequencies is replaced byKitaigorodskii's (1983) model. In its raw form, thenew model requires four internal constraints (grav­ity, depth, wind speed, and peak frequency) and hasfour model coefficients. If three of the coefficientsare held constant at their mean values, a directrelationship to wave steepness is obtained for thefourth coefficient that is related to the peakedness ofthe spectrum. Field Res. Facility, Coastal EngngRes. Ctr., U.S. Army Engng Waterways Exper, Sta .,SR Box 271, Kitty Hawk, NC 27949-9440, USA.

90:3715Nwogu, Okey, 1989. Maximum entropy estimation of

directional wave spectra from an array of waveprobes. Appl. Ocean Res; 11(4):176-182.

The Maximum Entropy Method (MEM) yields anangular spreading funct ion at each frequency bandconsistent with the input cross-spectral densitymatrix. The method is evaluated using numericalsimulations of directional sea states and is used toanalyze three-dimensional wave bas in data. Com ­pared with the Maximum Likelihood Method, theMEM is shown to be a powerful tool for directionalwave analysis . Hydraulics Lab., Natl, Res. Council,Ottawa, Canada.

90:3716Oltman-Shay, Joan, P.A. Howd and W.A. Birke­

meier, 1989. Shear instabilities of the meanlongshore current. 2. Field observations. J. geo­phys. Res; 94(C12): 18,031-18,042.

A new type of alongshore progress ive wave withperiods and alongshore wavelengths of the order ofl(Y· seconds and meters, respectively, has beenobserved in the surf zone. These periods fall into thelower end of the much studied infragravity fre­quency band previously shown to contain surfacegravity edge and leaky waves. However, their shortwavelengths distinguish these new waves fromsurface gravity waves; they are only observed in thepresence of mean longshore current and they changecelerity and direction with the mean current. Theirrms horizontal velocities can exceed 30 cm/s. Thesewaves are consistent with a model of vorticity wavesgenerated by the shear instability of the mean

longshore current. Coli. of Oceanogr., Oregon StateUniv., Corvallis , OR 97331, USA.

90:3717Pennell, S" 1990. A note on exact relations for

solitary waves. Phys. Fluids A, 2(2) :281-284.

Free-surface solitary waves and interfacial solitarywaves in a two-fluid system with a rigid lid areknown to satisfy certain exact relations involvingintegral quantities (mass, kinetic and potentialenergy, etc.). It is shown here that similar relationsare satisfied by interfacial solitary waves in atwo-fluid system with a free upper surface and bysurface solitary waves in a 3-D one-fluid system.Dept. of Math., Univ. of Lowell, MA 01854, USA.

90:3718Proctor, R. and R.A. F1ather, 1989. Storm surge

prediction in the Bristol Channel-the floods of13 December 1981. Continent. Shelf Res., 9(10):889-918.

A secondary depression crossing southern Wales andEngland in December 1981 resulted in the highestwater levels experienced in the Bristol Channel thiscentury and severe flooding along the north Som­erset coast. Both a numerical model-based predic­tion scheme and the Lennon (1963) criteria for westcoast storm surges failed to provide adequatewarning. Numerical recons truction shows tha t thefailure of the surge model forecast was due to anincorrect pred iction by the atmospheric model usedto provide the meteorological input to the sea model.The fallibility of the Lennon criteria suggests theirreappraisal, part icularly in light of a subsequentfailure. Some of the difficulties in the identificationof storm. surge residuals within the Bristol Channelare associated with tidal measurement and predic­tion problems which are, as yet, unresolved. Proud­man Oceanogr. Lab., Bidston Observ., Birkenhead,Merseyside L43 7RA, UK.

90:3719Tayfun, M.A. and J.-M. La, 1990. Nonlinear effects

on wave envelope and phase. J. WatWay Portcoast. Ocean Engng, Am. Soc. civ. Engrs, 116(1):79-]00.

The effects of second-order nonlinearities on theenvelope and phase statistics .of long-crested seawaves are examined theoretically via the charac­teristic function expansion technique. It is foundthat, except for certain minor modifications, thestatistical distribution of envelope heights normal­ized by their rms-value is described on the wholefairly well by the conventional Rayleigh law. Incomparison, the wave phase and phase statistics are

578 A. Physical Oceanography OLR (1990)37 (7)

affected more significantly by nonlinearities, show­ing a systematic excess of values near the meanphase. Coli. of Engng Petroleum, Kuwait Univ., P.O.Box 5969, 13060 Safat, Kuwait.

90:3720Tomasson, G.G. and W.K. Melville, 1990.Nonlinear

and dispersive effects in Kelvin waves. Phys.Fluids A, 2(2):189-193.

Recent laboratory and field observations suggestthat the effects of nonlinearity and dispersion maybe significant for the evolution of Kelvin waves inrotating channels. Here it is shown that a pair ofKelvin wave modes may interact with a thirdPoincare mode to form a resonant triad. Theevolution of the triad is governed by the well-knownthree-wave interaction equations. The implicationsof this instability for naturally occurring Kelvinwaves are discussed. R.M. Parsons Lab., MIT,Cambridge, MA 02139, USA.

90:3721Tsimplis, M. and S.A. Thorpe, 1989. Wave damping

by rain. Nature, Lond., 342(6252):893-895.

Here we describe laboratory experiments whichshow that, in the absence of wind, rain preferentiallydamps short-wavelength gravity waves. The sup­pression of short waves has an effect on the seasurface similar to that of an oil film, leading to areduction in the breaking of long waves. Scatter­ometer estimates of wind speed are known to bebiased when it rains. Wind speed is determined froman empirical relation with the observed strength ofthe backscattered radar signal. Although the signalmay be influenced by atmospheric effects in rain, thevery-small-scale roughness of the surface caused byrain drops or the reduction of the lO-cm-scale waves,may also affect the signal and hence the wind-speedestimate. Dept. of Oceanogr., Univ. of Southampton,809 5NH, UK.

90:3722Tucker, M.J., 1989. An improved 'Battjes' method for

predicting the probability of extreme waves. Appl.Ocean Res; 11(4):212-218.

The Battjes method for predicting the 50 or lOO-yeardesign wave was developed to allow for the possi­bility that the highest wave may occur during thesecond highest storm or even in lower storms. It isshown that a slightly different logical approachremoves some of the problems encountered with theuse of the method; if two or more waves in a severestorm exceed Hso, then these are counted as separateevents. A formula is developed which considers eachstorm as one event, but still takes account of the

possibility of the highest wave in 50 years notcoming from the most severe storm. This formulareduces Hso by about 3% relative to the Battjesmethod. 6 Highlands, Taunton, Somerset, UK.

A170. Wind-wave interactions

90:3723Janssen, P.A.E.M., P. Lionello and L. Zambresky,

1989.On the interaction of wind and waves.Phil.Trans. R. s«, (A)329(1604):289-301.

For a given wave spectrum, results of the numericalcalculation of the steady-state wind profile arepresented. For young wind sea most of the stress inthe boundary layer is determined by the transfer ofmomentum from wind to waves, resulting in a strongcoupling between air flow and waves. For old windsea, however, there is hardly any coupling. As aconsequence, a sensitive dependence of the aero­dynamic drag on the wave age is found, explainingthe scatter in plots of the experimentally observeddrag as a function of the wind speed at 10 m. Also.the growth rate of waves by wind depends on waveage, reflecting the effect of the waves on the windprofile. Here, we present the first results of thecoupling of a simple surface-layer model with thethird-generation wave model. Wave-induced stresshas a significant impact on the results for waveheight and stress in the surface layer. Dept. ofOceanogr., Royal Netherlands Meteorol. Inst,(KNMI) De Bilt, Netherlands.

AlSO. Internal waves and tides

90:3724Artale, V., A. Provenzale and R. Santoleri, 19&9.

Analysis of internal temperature oscillations oftidal period on the Sicilian continental shelf.Continent. Shelf Res; 9(10):867-888.

EOF decomposition and cross spectral analysis ofthe moored temperature data and analysis of theCTD profiles provide information on the hydro­logical characteristics in the area. A tidally gener­ated, topographically trapped baroclinic wave withdiurnal period dominates the dynamics at all depthsbelow the surface mixed layer. Contrary to whatusually happens in the Mediterranean Sea, thesemidiurnal tide is always weaker than the diurnalcomponent, ascribed to the presence of an amphi­dromic point of the M2 tide in the vicinity of thethermistor chain. A weak inertial wave component isrecognizable in the line spectra, and the power

OLR (1990)37 (7) A. Physical Oceanography 579

spectra of temperature oscillations display a powerlaw behavior in tbe frequency range of internal waveactivity. ENEA-CRE Casaccia, P.O. Box 2400,00100 Roma, Italy.

90:3725Ostrovsky, L.A. and Yu.A. Stepanyants, 1989. Do

internal solitons exist in the ocean? RevsGeophys., 27(3):293-310.

We discuss observations of solitary waves in shallowseas and deep ocean regions accumulated over thelast two decades. The features of observed solitaryformations are compared with those developed intheory; relationships are formulated . .A summary oftheoretical models describing nonlinear internalwave propagation, including the basic evolutionequations and their soliton solutions, is presented inan appendix. Inst. of Appl. Phys., Acad. of ScL,Gorky, USSR.

90:3726Tominaga, Masahide, 1989. Theoretical elucidation

of generation of a soliton on the interface oftwo-layer fluid system with equal depth withslightly different densities. Mer, Tokyo, 27(1­2): 1-8.

Analytical treatment is conducted to seek the solitonsolution along the interface of a two-fluid system.There results a solitary wave of very small amplitudeand with very long horizontal scale. If the densitydifference is somewhat large, the amplitude in­creases. In any case, an upper limit of amplitudeexists. The case when upper layer depth is slightlylarger than tbat of the lower is also considered.Nisbimotomachi 2-11-44, Kikubunji, Tokyo, 185Japan.

90:3727Zhou, X. and R. Grimshaw, 1989. The effect of

variable currents on internal solitary waves.Dynam. Atmos. Oceans, 14(1-2): l7-39.

The effect of variable currents on internal solitarywaves is described within the context of a variablecoefficient KdV equation, and the approximateslowly varying, solitary-wave solution of this equa­tion. A number of analytical expressions are ob­tained for the variation in the solitary wave ampli­tude resulting from variable shear in the basiccurrent or from when the basic current is adepth-independent flow which is a simple repre­sentation of a geostrophic current, tidal flow orinertial wave. Inst, of Mech., Chinese Acad. of Sci.,Beijing, People's Republic of China.

A210. Ice

90:3728Garrison, DL, AR. Close and E. Reimnitz, 1989.

Algae concentrated by frazil Ice: evidence fromlaboratory experiments and field measurements.Antarct, sa, 1(4):313-316.

A number of studies bave suggested that highconcentrations of organisms in sea ice may be theresult of harvesting and concentration by frazil ice.Laboratory experiments have shown that frazil icecan concentrate organisms from two to four timesabove levels in the underlying water. The concen­trations in nature can be considerably higher. Thediscrepancy between labora tory results and fieldobservations can be explained by longer temporaland spatia! scales that allow more contact of icecrystals with particles and with one another in thesea. Small-scale circulation features, such as Lang­muir circulation may enhance the ability of frazil iceto concentrate organisms in a natural setting. Inst. ofMar. ScL, Univ. of California, Santa Cruz, CA95064, USA.

90:3729Gong, Jialong, 1989. Satellite remote sensing of

sea-ice and its operational monitoring methodalong the coast of China. Acta oceanol. sin.(English version), 8(3):379-390. Natl. Mar. En­viron. Forecasting Ctr., SOA, Beijing, People'sRepublic of China.

90:3730Hellmer, RH. and DJ. Olbers, 1989. A two­

dimensional model for the thermohaline circu­lation under an ice shelf. Antarct. Sci; 1(4):325­336.

The coupling of inflow conditions, thermohalineprocesses at the ice shelf base and the sub-ice shelfcirculation is studied with a model developed for asection perpendicular to the ice shelf edge. Differentboundary conditions appropriate to the Filchner IceShelf regime are considered. Results indicate that ingeneral, shelf water is transported toward thegrounding line, where at the ice shelf base meltingoccurs; accumulation of ice takes place at the end ofthe melting zone close to the ice shelf edge. Theaccumulation zone's location determines whether ornot the density increase by salt rejection causes anupper circulation cell and separation of the modifiedwater mass from the ice shelf base at mid-rangedepth. Moderate changes in the characteristics of theinflowing water or in sea-floor topography maydouble circulation intensity. Nonlinear processes inthe accumulation zone cause variabilities which can

580 A. Physical Oceanography OLR (1990) 37(7)

be described by an ice shelf edge oscillator influ­encing the entire circulation regime. Alfred WegenerInst. for Polar and Mar. Res., Postfach 12 OJ 6],Columbusstr., D-2850 Bremerhaven, FRG.

90:3731Jacobs, S.S. and J.e. Comiso, 1989. Sea ice and

oceanic processes on the Ross Sea continentalsbelf. J. geophys, Res; 94(CI2): 18,195-18,211.

Ice cover over the shelf was persistently lower thanabove the adjacent deep ocean, averaging 86%during winter with little month-to-month or inter­annual variability. The large spring Ross Seapolynya on the western shelf results in a longerperiod of summer insolation, greater surface layerheat storage, and later ice formation in that regionthe following autumn. Newly identified Pennell andRoss Passage polynyas near the continental shelfbreak appear to be maintained in part by divergenceabove a submarine bank and by upwelling ofwarmer water near the slope front. Warmer sub­surface water enters the shelf region year-round andwill retard ice growth and enhance heat flux to theatmosphere when entrained in the strong wintervertical circulation. Temperatures at 125 m depth ona mooring near the Ross Ice Shelf during July 1984averaged 0.15Co above freezing, sufficient to supporta vertical heat flux above 100 W1m2

, Lamont­Doherty Geol. Observ., Palisades, NY 10964, USA.

90:3732Kumar, M.R.R. and Y. Sadhuram, 1989. Surface

heat budget of a polynya in the coastal waters offQueen Maud Land, Antarctica, during australsummer. Continent. Shelf Res" 9(12):1063-1070.

Incoming solar radiation was the most importantcomponent in the surface heat budget; its meanvalue for the study period was -209 W m-2• Thelatent and sensible heat fluxes were in oppositionand nearly balanced each other out. The average netheat gain over the polynya was 141 W m-2• From themean heat storage values obtained from the tem­perature profiles, heat gain at the surface appears tobe almost lost through advection and other interiorphysical processes in the top 50 m layer of the watercolumn. This is reflected in SST, which was almoststeady during the study period. Natl, lnst. ofOceanogr., Dona Paula, Goa 403004, India.

90:3733Kwok, Ronald et al., 1990. An ice-motion tracking

system at tbe Alaska SAR facility.IEEE JI ocean.Engng, 15(1):44-54. Jet Propulsion Lab., Cali­fornia Inst. of Tech., 4800 Oak Grove Dr.,Pasadena, CA 91109, USA.

90:3734Whalley, Edward, D.D. Klugand Y.P. Handa, 1989.

Entropy of amorphous ice. Nature, Lond;342(6251):782-783.

The configurational entropy of low-density amor­phous ice has been estimated theoretically as -6.3 JK-I mol-I more than that of ice lh; this correspondsto -2.1 more configurations per molecule than inice Ih, and seems consistent with the result forvitreous silica. In principle, these entropies can beobtained from the change of heat capacity from theglass to the liquid and the entropy of freezing of theliquid at equilibrium, but such measurements havenot proved possible because the liquid generallycrystallizes too quickly. Here we show that theentropies can be estimated approximately by anothermethod: from the thermodynamics of the trans­formations of, for example, both ice Ih and low­density amorphous ice to high-density amorphousice. The entropy of low-density amorphous icerelative to ice Ih is -1 J K-I mol"; earlier estimatesof this quantity are therefore several times too high.These low values limit the amount of disorder thatcan be present in the amorphous phases. Div. ofChern., Natl. Res. Council of Canada, Ottawa KIAOR6, Canada.

A240. Optical properties

90:3735Jonasz, Miros1aw, 1990. Volume scattering function

measurementerror: effectof angular resolution ofthe nephelometer. Appl. Opt; 29(1):64-70.Technicon Instr. Corp., 511 Benedict Ave.,Tarrytown, NY 10591, USA.

90:3736Marshall, B.R. and R.C. Smith, 1990. Raman

scattering and in-water ocean optical properties.Appl. Opt; 29(1):71-84.

Inelastic (transpectra1) scattering may contributesignificantly to the in-water light field. Majormechanisms include Raman scattering and fluores­cence from a variety of sources. The Raman crosssection for liquid water is in agreement with thelower range of published values. The influence ofRaman scattering, based on predictions of a modi­fied two-stream model, is in agreement with meas­ured values of spectral reflectance and the spectraldiffuse attenuation coefficient for irradiance. In­elastic scattering has important ramifications forseveral aspects of marine biooptics, including spec­tral absorption, clear water optics, and possiblyvarious aspects of algal photobiology. Ctr. for

OLR (1990)37 (7) A. Physical Oceanography 581

Remote Sensing and Environ. Optics, Univ. ofCalifornia, Santa Barbara, CA 93106, USA.

A260. Acoustics

90:3737Ageeva, N.S. and V.D. Krupin, 1989. Mode coover­

slon in a waveguide with a continuous transition ofthe velocity profile at the boundary ~itb anabsorbing bottom layer. SOy. Phys. Acoust. (atranslation of Akust, Zh.), 35(3):229-232.

Mode characteristics are analyzed in a waveguide;sound .veloci ty at the upper boundary of theabsorbing bottom layer is equal to the sound velocityin the water and increases linearly with increasingdepth. Mode conversion takes place when thefrequency is increased. Two distinct types of modes,water modes and bottom modes, are formed in thehigh-frequency range. The types of converted modesalternate in pairs as the sound velocity gradientvaries in the sediments and the curves representingthe frequency variations of the mode attenuationcoefficients and eigenfunctions change accordingly.N.N. Andreev Acoust. Inst., Acad. of ScL, Moscow,USSR . '

90:3738Bao, X.-L., Hui Cao and Herbert Uberall, 1990.

Resonances and surface waves in the scattering ofan obliquely incident acoustic field by an infiniteelastic cyUnder. J. acoust. Soc. Am., 87(1):106­110. Dept. of Phys ., Catholic Un iv. of America,Washington, DC 20064, USA.

90:3739Brekhovskikh, L.M. et al., 1989. Acoustical methods

in ocean navigation. SOy. Phys , Acoust , (a trans­lation of Akust, Zh.), 35(3):244-247.

The use of spatial fluctuations of the amplitude ofbottom-reflected signals to determine the motion ofa ship relative to the bottom is investigated and amultielement system designed for the solution of thisproblem is described briefly . The error of meas­urement of the modulus of the displacement vector isestimated. N.N. Andreev Acoust. Inst., Acad. of ScL,Moscow, USSR.

90:3740Catipovic, J.A. and A.B. Baggeroer, 1990. Per­

formance of sequential decoding of convolutionalcodes over fully fading ocean acoustic channels.IEEE JI ocean. Engng, 15(1):1-7. WHOI, WoodsHole , MA 02543, USA.

90:3741Colton, David and Peter Monk, 1989. A new method

for solving the inverse scattering problem foracoustic waves in an inhomogeneous medium.Inverse Problems, 5(6):1013-1026. Dept. of Math.Sci., Univ. of Delaware, Newark, DE 19716,USA.

90:3742Cox, Henry, R.M. Zeskind and Matthew Myers,

1990. A subarray approach to matched-fieldprocessing. J . acoust. Soc. Am; 87(1) :168-178.BBN Syst, and Tech. Corp., 1300 North 17th St.,Arlington, VA 22209, USA.

90:3743Didenkulov, I.N. and A.G. Nechaev, 1989. Acoustic

emission tomography of the ocean. SOy. Phys,Acoust. (a translation of Akust. Zh.), 35(3):270­273.

A method of acoustic diagnostics of the ocean usingthe low-frequency noise field is discussed. Integralequations relate the intensity of the sound field tothe spatial dist ribution of noise sources . A spectraltomography scheme is considered, and its effec­tiveness is estimated. The spatial distribution of shipnoise is reconstructed on the basis of knownexperimental data. Inst. of Appl. Phys., Acad. of Sci.,Moscow, USSR.

90:3744Eliseevnin, V.A., 1989. Directivity pattern of a

steered horizontal radiating line array In awaveguide. SOy. Phys. Acoust, (a translation ofAkust, Zh.), 35(3):274-276. N .N. AndreevAcoust, Inst., Acad. of ScL, Moscow, USSR.

90:3745Foote, K.G. et al., 1990.Target strengths of Antarctic

krill (Euphausia superba) at 38 and 120 kHz. J.acoust , Soc. Am., 87(1): 16-24. Inst. of Mar. Res.,5024 Bergen, Norway.

90:3746Fox, e .G., FJ. Jones and T.-K. Lau, 1990. Con­

strained iterative deconvolution applied toSeaMARC I sidescan sonar imagery. iEEE JIocean. Engng, 15(1):24-31. PMEL, Hatfield Ma r.Sci. ce., NOAA, Newport, OR 97365, USA.

90:3747Glegg, SAL. and J.R. Yoon, 1990. Experimental

measurements of .three-dimensional propagationin a wedge-shaped ocean with pressure-releaseboundary conditions. J. acoust. Soc. Am" 87(1):101-105.

582 A. Physical Oceanography OLR (1990)37 (7)

The theoretical solution for acoustic propagation ina wedge-shaped ocean with ideal pressure-releaseboundaries predicts a well-defined beam in thedown-slope direction that diverges as the energypropagates out toward deep water. Outside of thebeam, shadow zones are Iormed, and its spatialextent is determined by the lowest mode of prop­agation. For down-slope propagation, the spatialcharacteristics of the field in a direction parallel tothe shore line are in good agreement with thetheoretical solution, and the azimuthal extent of thebeam depends on the wedge angle . In addition to theevaluation of the exact theory, measurements havebeen made of acoustic pulse propagation anddistortion in the wedge. Ctr. for Acoustics andVibrations, Florida Atlantic Univ., Boca Raton, FL33431, USA.

90:3748Gorskaya, N.S. and M.A. Raevskii, 1989. Spectrum

of low-frequency sound waves in the remotesensing of anisotropic wind waves. SOY. Phys .Acoust. (a translation of Akust, Zh.), 35(3):258­261.

The frequency spectrum of low-frequency soundwaves in multiple scattering by wind waves with anarbitrary anisotropy is invest igated. Simple analyt­ical equations are derived for the spectrum of thereceived signal. The specific features of the spectrumand the possibility of reconstructing it from wave­spectrum sensing data are discussed. Inst. of Appl.Phys., Acad. of Sci., Moscow, USSR.

90:3749Lacker, S.G. and T.L. Henderson, 1990. Wideband

monopulse sonar performance: cylindrical targetsimulation using an acoustic scattering centermodel. IEEE Jl ocean. Engng, 15(1):32-43. Appl.Res. Lab., Univ, of Texas at Austin, P.O. Box8029, Austin, TX 78713, USA.

90:3750Lataitis, R.J., G.B. Crawford and S.F. Clifford, 1990.

A simple low-frequency acoustic technique forremote measurement of the temporal ocean wavespeckum. J. acoust. Soc. Am; 87(1): 111-118.

The technique requires a vertically pointing broad­beam acoustic source and a colocated broadbeamreceiver which records the amplitude and phasefluctuations of the backscattered field. When the nnssurface wave height is much smaller than theacoustic wavelength, the temporal spectrum of theamplitude and phase fluctuations can he directlyrelated to the non directional temporal surface waveheight spectrum. The theory predicts that thetemporal wave height spectrum out to frequencies of

roughly 0.5 Hz can be retrieved. Wave PropagationLab., NOAA, Environ. Res. Lab., 325 Broadway,Boulder, CO 80303, USA.

90:3751MacLennan, D.N ., 1990. Acoustical measurement of

fish abundance. J. acoust, Soc. Am., 87(1):1-15.

An echo-integrator equation relates fish density toecho energy integrated over a time gate corre­sponding to the depth channel of interest. Param­eters include the equivalent beam angle, the expectedbackscattering cross section per fish, equipmentsensitivity, and a time-varied-gain correction factor.Variation of environmental factors (sound speed andabsorption) affects the parameter values. Moreimportant is the variation of biological factors (fishbehavior and physiology) which affects backseat­tering cross section and target strength. Verificationof the echo-integrator equation, depending upon thelinearity principle concerning the addition of signalsfrom randomly distributed multiple targets, is dis­cussed in the fisheries context. Target strengthvariation with fish size, water depth , and time isdiscussed. Dept. of Agric. and Fish. for Scotland,Mar . Lab., Victoria Rd., Aberdeen AB9 8DB,Scotland.

90:3752Nielsen, P.A. and J.B. Thomas, 1990. A comparison

of parametric and nonparametric detector per­formance levels in underwater noise. J. acoust ,Soc . Am ., 87(1):225-236. Dept. of Elect. Engng,Princeton Univ., Princeton, NJ 08544, USA.

90:3753Okomel'kova, LA. and LA. Shereshevskii, 1989.

AppUcation of oscillation theorems for the cal­culation of normal modes in a layered medium.SOY. Phys. Acousi. (a translation of Akust, Zh.),35(3):284-286. Inst. of Appl, Phys., Acad. of Sci.,Moscow, USSR.

90:3754Preston, J.R ., Tuncay Acal and Jonathan Berkson,

1990. Analysis of backscattering data in theTyrrhenJan Sea. J. acoust, Soc. Am; 87(1): 119­134. SACLANT Undersea Res. Ctr ., Viale SanBartolomeo 400, 19026 La Spezia, Italy.

90:3755Pumphrey, B.C. and L.A. Crum, 1990. Free oscil­

lations of near-surface bubbles as a source of theunderwater noise of rain. J. aCQust. Soc. Am.,87(1):142-148. Dept of Engng, CambridgeUniv., Trumpington St., Cambridge CB2 IPZ,UK.

OLR (1990) 37 (7) A. PhysicalOceanography 583

90:3756Sotirin, B.J. and J.A. Hildebrand, [990. Acoustic

navigation of a large-aperture array, J. acoust.Soc. Am., 87(1):154-167.

Large-aperture arrays produce high-resolution di­rectional information by coherently combiningsignals from individual array elements . Estimates ofarray shape and element position are requiredbecause of the dependence of signal phase onelement location. Navigation of such an array in theocean requires a known reference system in aspatially and temporally varying environment. Thispaper describes the array acoustic navigation systemand its operation during a vertical deployment fromresearch platform FLIP in the northeast Pacific. Wedescribe the hardware system and acquisition oftravel time measurements and associated errors, thenonlinear least-squares estimation of array spatialpositions, and the analysis of FLIP and arraytime-varying positions during the deployment. Mar.Phys. Lab., Scripps Inst. of Oceanogr., La Jolla , CA92093, USA.

90:3757Steele, A.K. and c.L. Byrne, 1990. High-resolution

array processing using implicit eigenvectorweighting techniques. IEEE Jl ocean. Engng,15(1):8-13. Weapons Syst. Res. Lab., DefenceSci. and Tech. Organisation, P.O. Box 1700,Salisbury , SA 5108, Australia.

90:3758Thome, P.O., 1990. Seabed generation of ambient

noise. J . acoust. Soc. Am., 87(1):149-153.

The seabed can in some circumstances contribute tomarine ambient noise conditions. This arises whennear-bed current flow, induced by tides and waves,exerts sufficient shear stress at the bottom boundaryto cause bedload transport of sediments; sound isgenerated by particle impacts. Laboratory obser­vations were taken using colliding sediments cov­ering size fractions from medium sand to largecobbles . Marine records of ambient noise conditionswere obtained over a mobile shingle bed. Compar­ison of predictions based on rigid body radiationtheory with the data has been carried out and similarresults obtained. Proudman Oceanogr. Lab., BidstonObserv., Birkenhead, Merseyside L43 7RA, UK.

90:3759Tindle, C.T. and N .G. Plump ton, 1990. Attenuation

In a saddle-point analysis of the reflected acousticfield. J. acoust. Soc. Am., 87(1):135-141. Phys.Dept. , Univ. of Auckland, New Zealand.

90:3760Tobocman, W., 1989. Inverse acoustic wave scat­

tering In two dimensions from impenetrabletargets. Inverse Problems, 5(6): 1131-1144. Phys­ics Dept. , Case Western Reserve Univ., Uni­versity Cir. , Cleveland, OH 44106, USA.

A290. Physical processes, properties (dif­fusion, turbulence, etc.)

90:3761Clayton, J.R. Jr. et al., 1990. Effects of advancing

freeze fronts on distributions of fine-grainedsediment particles in seawater- and freshwater­slush ice slurries. J. sedim. Petrology, 60(1): 145­151.

In the freshwater experiment, the horizontal migra­tions of clay-sized particles in response to a laterallyadvancing freeze front were documented; differ­ential migration of particles as a function of size wasalso noted. In the seawater-slush ice experimentinvolving downward movement of a freeze frontthrough a sediment-laden slush ice layer, resultssupport the contention that a downward congealingslush ice matrix can purge itself of at least a portionof an entrained sediment load during an evolvingfreezing process; however , most of the sedimentinitially carried by the slush ice remained. Migrationof sediment particles in congealing slush ice matricesdue to freeze front advances can be important togeological, physical and biological processes as wel1as commercial activities in arctic marine andnearshore regions. Sci. Applications IntI. Corp., 4224Campus Point Ct, San Diego, CA 92121, USA .

90:3762Dermis sis, Vassilios, 1990. Velocity distribution in

arrested saline wedges. J. WatWay Port coast.Ocean Engng, Am. Soc. civ, Engrs, 116(1):21-42.Dept. of Civ, Engng, Arist. Univ, of Thes­saloniki, Greece.

90:3763Fernando, H.J.S., 1989. Buoyancy transfer across a

diffusive interface. J. Fluid Mech ., 209: 1-34.

An experimental investigation of various aspects ofbuoyancy transfer across a diffusive density inter­face that separates stably stratified, turbulentlyconvecting layers of relatively fresh cold wateroverlying hot salty water is described. It is arguedthat the interfacial layer should possess a doubleboundary-layer structure, in which the thicknesses ofthe salt and heat interfacial layers are determined bya balance between the opposing effects of diffusion

584 A. Physical Oceanography OlR (1990)37 (7)

and entrainment. Based on this argument, a simpletheory that predicts the interfacial-layer thickness~,

the diffusive heat and salt fluxes across the densi tyinterface, and the time variation of the temperatureand salt concentrations in the convecting layers, isproposed for the case in which the convection isdriven by a constant heat flux supplied to the lowerlayer. During a certain time interval , the theory andexperiment agree well, but thereafter distinct dif­ferences can be seen. Measurements suggest thatthese differences may be due to the distortion of thedensity interface at low interfacial stabilities byturbulent eddies, which leads to a change in thebuoyancy transfer mechanism. Dept. of Mech. andAerospace Engng, Arizona Sta te Univ ., Tempe, AZ85287-6106, USA.

90:3764Heru t, Barak et al., 1990. The role of seawater

freezing in tbe fonnation of subsurface brines.Geochim. cosmochim. Acta, 54(1):13-21.

Evaporation, water-rock interaction, and ultrafiltra­tion have been suggested to explain the evolution ofcalcium chloride subsurface brines. The freezing ofseawater in polar regions and during glacial periodsis proposed here as an additional possible path ofbrine formation. Seawater was frozen to -14°C, andNa , K, Ca, Mg, Sr, Cl, S04' and Br were analyzed inthe ice and residual brines. The Na-Br-Cl rela­tionship in a given brine can be used to discrimin~te

between evaporative and freezing modes of bnneevolution. Several brines from the Canadian Shieldand one from Finland are used as examples of theseawater freezing model, and an explanation isproposed for the necessary mass production ofbrines in glacial environments. Inst, of Earth Sci.,Hebrew Univ., Jerusalem 91904, Israel.

90:3765Imberger, Jorg and J.e. Patterson, 1990. Physical

Umnology. Adv. appl, Mech; 27:303-475.

Lake hydrodynamics are governed by stratification,both caused b}' and acted upon bj:' extemal-f?r~in.!mechanisms such as wind and solar radiation,instability mechanisms, and turbulent activity ~

constrained by a stratified medium. Geographiclocation and seasonal variation also affect lakedynamics. How these physical state~/p~ocesses

interact is reviewed here. As eutrophication hasbecome a major problem in some water bodies, theUse of bubble aerators to destratify highly eutrophicreservoirs is also discussed . Ctr. for Water Res.,Univ, of Western Australia, Nedlands, WA, Aus­tralia . (slr)

90:3766Osborne, A.R., 1989. Fractal drifter trajectories in tbe

Kuroshio extension. Tellus, (A)41(5):4l6-435.

Over a period of about one year, the drif~e~s traveledalmost the entire width of the PaCIfIc Ocean,following what may be described as highly erraticpaths while on the average being advected eastwardin thezonal flow. For space scalesextending from atleast 20 to 150Ian and time scales from 1.5days to (week each of the trajectories displays fractal andscali~g behavior with a fractal di~ension of -1.3.The implication of these results I~ tha~ the near­surface Lagrangian mesoscale motlon~ l~ the Ku­roshio extension exhibit fractal properties ID a rangeof scales normally attributed to geophysical fluiddynamical turbulence. 1st. di Cos~ogeofisica delC.N.R., Corso Fiume 4, 10133 Tonno, Italy.

90:3767Peters, H., M.C. Gregg and J.M. Toole, 1989.

Meridional variability of turbulence througb theequatorial undercurrent. J. geophys. Res;94(Cl2):18,003-18,009.

Averaging the upper llO m of four meridionaltransects of the turbulent dissipation rate E and ofshear taken across the Equator, we found that E aswell as shear showed maximum values within ± 1c

latitude. A strong diurnal cycle of E aliased themeasurements; however,when E is separated into thecontributions from the thermocline and from thesurface mixed layer, consistent patterns emerge. Inthe thermocline, E was strongest where the Richard­son number was lowest, i.e., near the Equator­consistent with the production of turbulence by theshear of the undercurrent. When the mean shear waslow, after prolonged mixing by nighttime convec­tion, e was close to the similarity scaling. Wetherefore attribute the excess dissipation to shearproduction. APL, Univ. of Washington , 1013 N.E.40th St., Seattle, WA 98105, USA.

90:3768Rodhe, Johan, 1989. The large-scale miXing and tbe

estuarine circulation in the Skagerralq calcula­tionsfrom observationsof the salinity and velocityfields. Tellus, (A)4I(5):436-446.

The flow in the estuarine circulation and large-scalemixing in the Skagerrak are calculated from repeatedobservations of the salinity and velocity fields at twosections. The estimated magnitude of the upwellingof deep water associated with estuarine circulation inthe Skagerrak is 4 X 1~ mJ S- I. The lateral mixing ofsalt from the open sea into the low-salinity wateralong the Swedish and Norwegian coasts is calcu­lated to be -1.3 kg S-I m-I.The results of this paper

OLR (1990) 37 (7) A. Physical Oceanography 585

can be used to calculate transports of other con­stituents in the seawater. Dept. of Oceanogr., Univ.of Gothenburg, Box 4038, S-40040 Gothenburg,Sweden.

90:3769Ruddick, B.R., R .W. Griffiths and Graham

Symonds, 1989. Frictional stress at a sheareddouble-diffusive interlace. J . geophys, Res;94(CI2): 18,161-18,173.

Two-layer convection was set up in an annular tankwhich was rotating slowly so as to provide a basic'store' of angular momentum. The stress was con­sistent at all times with that due to molecularviscosity and was independent of the buoyancy fluxassociated with the convection. The uncertainties ofthe experimental observations, taken together withthe hypothesized stress-shear relation of Ruddick,imply a maximum turbulent Prandtl number of 0(1).Ruddick's (1985) results are reconsidered, and it isconcluded that the dependence of internal wavedecay rate of buoyancy flux observed in thoseexperiments is a result of the large eddy viscosity inthe turbulent mixed layers acting on the strain fieldof the wave. Dept. of Oceanogr., Dalhousie Univ.,Halifax, NS B3H 4Jl, Canada.

90:3770Ta ylor, John and Paul Bucens, 1989. Laboratory

experiments on the stmcture of salt fingers.Deep-Sea Res., 36(lIA): 1675-1704.

Visualization of the salt fingers using fluorescent dyemixed into the upper layer showed that they weredisordered, with new fingers being formed at theedge of the gradient region then growing into thegradient. Because of the disordered state of thefingers the average coherence between the signals fortwo vertically separated sensors was small, eventhough the separation of the sensors was of the orderof the finger width. Assuming that the verticaladvection of the mean temperature gradient withinan individual finger was balanced by horizontal heatdiffusion, we derived an estimate for the buoyancyflux due to hea t from the variance of the horizon taltemperature gradient. On average, this estimate forthe flux was 0.6 of that determined from the rate ofchange of the mean layer properties, and our resultsupports the use of this technique for estimat ing saltfinger fluxes in the ocean . Ctr. for Water Res., Univ.of Western Australia, Nedlands, WA, Australia.

90:3771Williams, J.J., P.D . Thorne and A.D. Heathershaw,

1989. Measurements of turbulence In the benthicboundary layer over a gravel bed. Sedimentology,

36(6):959-971. Proudman Oceanogr. Lab., Bid­ston Observ., Birkenhead, Merseyside L43 7RA,UK.

90:3772Yanagi, Tetsuo et al., 1989. IntermJttent outflow of

high-turbidity bottom water from Tokyo Bay Insummer. Mer, Tokyo, 27(1-2):34-40. Dept. ofOcean Engng, Ehime Univ., Matsuyama, 790Japan.

90:3773Yoo, Donghoon, 1989. Explicit modelling of bottom

friction In combined wave-current flow. Coast.Engng, Arnst., 13(4):325-340.

A direct, explicit solution technique is developed toestimate the time-mean bed shear stress and itsfrictional dissipation rate in combined wave-currentflow. Bijker's approach is widely applicable ifconsideration is given for the current velocityreduction as well as the near-bed velocity profile ofwave motion. The velocity reduction factor isrepresented by explic it expressions, further modifiedhere by considering various flow conditions in orderto improve the numerical accuracy in any flowconditions. The refined model is tested againstlaboratory data, and the computational resultsproduced by various mathematical models arediscussed . Dept. of Civil Engng, Ajou Univ., Suwon441-749, Korea.

A300. Fluid mechanics

90:3774Gratton, Julio and Fernando Minotti, 1990. Self­

similar viscous gravity currents: phase-planeformalism. J. Fluid Mech., 210:155-182.

A theoretical model for the spreading of viscousgravity currents over a rigid horizontal surface isderived , based on a lubrication theory approxima­tion, and the complete family of self-similar solu­tions of the governing equations is investigated bymeans of a phase-plane formalism developed inanalogy to that of gas dynamics. In addition to tho sestudied by other authors, a number of novelsimilarity flows are described and scaling laws forthese flows are produced. LFP, Fac. de Cienc.Exactas y Nat., Univ . de Buenos Aires , Pabellon I,Ciudad Univ., 1428 Buenos Aires , Argentina.

90:3775Huang, L.-S. and C.-M. Ho, 1990. Small-scale

transition in a plane mixing layer. J. Fluid Mech;210:475·500. NASA, Langley Res. Ctr., Hamp­ton , VA 23665, USA.

586

90:3776Pinardi, Nadia and R.F. Milliff, 1989. A note on

Consistent quasi-geostrophic boundary conditionsin partially open, simply and multiply connecteddomaibS. Dynam. Atmos. Oceans, 14(1-2):65-76.

In fully closed domains, mass conservation isexplicitly imposed as a consistency constraint on thedynamical evolution of the flow. Partially or fullyopen domains do not require an explicit constraint;in these cases, the mass conservation balance is usedas a diagnostic to describe the interaction betweenopen boundary conditions and the inflow/outflowvorticity implied by the quasi-geostrophic equation.The new formalism is carried over to multiplyconnected, partially open domains, where explicitcirculation integral constraints are required aroundisland boundaries. Implications concerning coastalapplications of quasi-geostrophic numerical modelsare outlined. IMGA-CNR, Via Emilia Est 770,41100 Modena, Italy.

90:3777Staquet, Chantal and J.J. Riley, 1989. On tbe velocity

field associated with potential vorticity. Dynam.Atmos. Oceans, 14(1-2):93-123.

In order to extend to the small but finite Froudenumber case the wave/horizontal-vortex decompo­sition, we propose two sets of equations that definediagnostically the non-propagating and propagatingparts of the motion; the former is characterized byits containing all of the potential vorticityof theflow. When expressed in an isopycnal coordinateframe, this decomposition is shown to exactlygeneralize the wave/horizontal-vortex decomposi­tion. A numerical algorithm solves the two sets ofequations in cartesian coordinates. FinalIy, thedecomposition is extended to flows with meanvelocity shear and applied to the later stage of decayof a stably stratified mixing layer. Ecole NormaleSuperieure de Lyon, Lab. de Phys., 46 allee d'Italie,69364 Lyon Cedex 07, France.

OLR (1990)37 (7)

90:3778van Heijst, O.I.F., P.A. Davies and R.G. Davis,

1990. Spin-up in a rectangular container. Phys.Fluids A, 2(2):150-159.

The spin-up from rest of (1) a homogeneous and (2)a linearly stratified fluid in a rectangular containerhas been examined. In the spin-up process leading tothe ultimate state of rigid-body rotation, three mainstages can be discerned: the starting flow (zeroabsolute vorticity), flow separation due to cyclonicvorticity generation at the walls, and a subsequentorganization of the flow into a regular array ofalternately cyclonic and anticyclonic cells. Duringthe final stage the flow in these cells graduallydecays due to the spin-down/spin-up mechanismprovided by the Ekman boundary layer present atthe bottom of each cell. With free-surface andrigid-lid upper boundary conditions, the organiza­tion of the flow was essentially different; in partic­ular, the central cell in the free-surface case is alwayscyclonic. A model for this behavior is advanced.Inst. of Meteorol. and Oceanogr., Univ. of Utrecht,Princetonplein 5, 3584 CC Utrecht, Netherlands.

90:3779Zhikharev, G.M., 1989. Stability of barotropic zonal

flow in the presence of zonally uniform bottomtopography. Dynam. Atmos. Oceans, 14(1-2): 1-16.

The topography can both stabilize and destabilizethe basic flow depending on its scale of meridionalwavelength. A large-scale basic flow is stable over aflat topography and the amplitude of the bottomvariations must exceed some critical value forinstability to occur. An intermediate-scale basic flowis unstable over a flat bottom but can be stabilized astopographic features increase. An intermediate-scalezonal flow loses its stability via steady (j-planeapproximation) or travelling (J3-plane) waves. In thecase of a large-scale basic flow, such supercriticalwave regimes may coexist with a stable zonal currentto give a hysteresis phenomenon. Lab. of SynopticProcesses, Shirshov Inst. of Oceanol., Acad, of Sei.,Krasikova 23, 117218, Moscow, USSR.

B. MARINE METEOROLOGY

810. Apparatus and methods

90:3780Maslanik, lA., J.R. Key and R.O. Barry, 1989.

Merging AVHRR and SMMR data for remote

sensing of ice and cloud in polar regions. Int. J.Remote Sens; 10(10):1691-1696. CIRES, Univ.of Colorado, Campus Box 449, Boulder, CO80309-0449, USA.