Physical oceanography

Oceanographic Literature Review

(1988) 35 (8)

The citations are those received in the editorial office during the period 1-31 May, 1988. Most are accompanied by a short annotation or abstract and, when obtainable, by the first author's address. The citations are classified under six main headings and about 130 sub-headings (see the table of contents). Subject and author indexes are published for the first three quarters of the year with an annual cumulation. See the preface for additional explanatory material.

A. PHYSICAL OCEANOGRAPHY

A10. Apparatus and methods

88:4357 Alberotanza, Luigi, Gianfranco Aldighieri, Andrea

Bergamasco and Pierluigi Cova, 1987. Devel- opment of a multiparameter acquisition system using an on-line P.C. for sea-truth measurements. Boll. Oeeanol. teor. appl., 5(3):165-172. (In Italian, English abstract.) C.N.R., ISDGM, Venezia, Italy.

88:4358 Artem'yev, A.O., 1987. Spatial and temporal analysis

of oceanic fields using a modification of the method of empirical orthogonai functions. Ocean- ology (a translation of Okeanologiia), 27(2): 147- 152. Res. Irtst. of the Arctic and Antarctic, Leningrad, USSR.

88:4359 Avramenko, A.S., E.Yu. Durovich, D.F. Kelbakiani,

E.I. Krasovskiy and B.V. Naumov, 1987. A remote shadow visualizer of seawater inhomo- geneities. Oceanology (a translation of Okeano- logiia), 27(1):114-117.

A shadow-visualization device based on the TOppler shadowgraph is described. Optical information, telemetered for digital or CRT devices at the surface, is used to build up the refractive index- (hence density-) field of the ocean on fine scales. Vavilov State Optical Inst., USSR. (fcs)

88:4360 Davies, A.M., 1988. On formulating two-dimensional

vertically integrated hydrodynamic numerical models with an enhanced representation of bed stress. J. geophys. Res., 93(C2):1241-1263.

696 A. Physical Oceanography OLR (1988) 35 (8)

A convolution method is used to calculate bed stress independently of the depth mean current in a vertically integrated hydrodynamic numerical model, allowing for example, phase lags and directional differences between the two to be considered. Comparison of the 'enhanced' model with a full three-dimensional model yields improved agreement. A method for extracting current profiles from the vertically integrated models is also described. Proud- man Oceanogr. Lab., Bidston Observ., Birkenhead, Merseyside L43 7RA, UK. (emm)

88:4361 De Mey, Pierre and A.R. Robinson, 1987. Assimi-

latiol~ of altimeter eddy fields in a limited-area quasi-geostrophic model. J. phys. Oceanogr., 17(12):2280-2293.

An original projection/extension scheme based upon empirical modes of density and pressure anomalies is used to derive initial and boundary conditions for the Harvard 6-level quasi-geostrophic open ocean model from altimeter and deeper in-situ data. The resultant simulations are compared to a year-long time series of streamfunction maps, and produce robust results under a variety of conditions designed to test the sensitivity of the assimilation scheme. Gr. de Rech. de Geod. Spatiale, Centre Natl. d'Etudes Spatiales, Toulouse, France. (emm)

88:4362 Fiscella, B., P.P. Lombardini, P. Trivero, C. Cappa

and R. Cini, 1987. Sea return at Cand Ku hands. Nuovo Cim., 10C(4):381-385. lstituto di Fisica Gen. dell'Univ., Torino, Italy.

88:4363 Gazaryan, R.M., 1987. A method for classifying

profiles of hydrological elements in the ocean. Oceanology (a translation of Okeanologiia), 27(1):103-105.

A method for classifying the profiles of the hydrological elements in the ocean uses an EOF expansion. Results are cited for the classification of the vertical profiles of the sound velocity in the ocean from environmental observations made at a weather station in the North Atlantic. It is shown that the expansion converges rapidly. Kabardino-Balkarsk State Univ., Nal'chik, USSR.

88:4364 Gus'kov, M.P., Yu.N. Kiselev and A.B. Yeryshev,

1987. Methods of recording and spectral processing of a radar signal scattered by the sea surface. Oceanology (a translation of Okeano- logiia), 27(2):239-241. Res. Inst. of Radiophys., Gor'kiy, USSR.

88:4365 Howe, B.M. and W.H. Munk, 1988. Deep-sea

moorings in a tidal current. Deep-Sea Res., 35(IA): 111-119.

A taut mooring experiences two types of response to tidal forcing. Along the axis of maximum tidal current, the mooring displacement is roughly in phase with the tidal velocity; along the minor tidal axis the mooring displacement lags the tidal velocity by roughly 90 °, and thus is more nearly in phase with the tidal displacement. For a highly idealized model, the mooring response can be written as a function of two parameters: a dimensionless tidal frequency and a dimensionless tidal displacement amplitude. The calculated mooring response can be reconciled with the observations by superposing a mean flow, which is more rapid than the tidal flow and is roughly in the direction of the minor tidal axis. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA.

88:4366 Marsden, R.F. and B.-A. Juszko, 1987. An eigen-

vector method for the calculation of directional spectra from heave, pitch and roll buoy data. J. phys. Oceanogr., 17(12):2157-2167.

Both a direct and an iterative form of this data- adaptive procedure are developed. The direct form outperforms the Longuet-Higgins et al. method, the cosine spread model and the maximum likelihood (ML) method for both simulated and real data. The iterative eigenvector (EV) method is superior to the other methods tested, including the iterative ML method for unimodal peaks when the noise-to-signal ratio is greater than 0.2 and for bimodal peaks at all noise levels. Errors of the iterative EV and iterative ML methods were lower than for both the direct EV and ML results, but the iterative EV method produced narrower, more sharply defined unimodal and bimodal spectra. Dept. of Phys,, Royal Roads Military Coll., FMO, Victoria, BC V0S 1B0, Canada.

88:4367 Ostrovskiy, A.G. and L.I. Piterbarg, 1986. On the

statistical predictability of mean monthly sea surface temperature values. Izv. Atmos. Ocean Phys. (a translation of Fir A tmos. Okeana), 22(11):916-921.

The problem of predicting the mean monthly SST values is considered within the framework of the linear theory of multidimensional stationary processes. A physical interpretation of the prediction error is given. Error values are calculated using long-term series of observations in the North Atlantic. Ways to improve the prediction are discussed. Inst. of Oceanol., Acad. of Sci., USSR.

OLR (I 988) 35 (8) A. Physical Oceanography 697

88:4368 Semovskiy, S.V. and I.M. Belkin, 1987. A statistical

climatological model for reconstructing the vertical profiles of hydrophysical variables from data at individual standard depths. Dokl. Earth Sci. Sect. (a translation of Dokl. Akad. Nauk SSSR), 287(1-6):184-186. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

88:4369 Treshnikov, A.F., V.V. Guretskiy, A.I. Danilov, N.V.

Yefremeyev, L.M. Ivanov and V.M. Smel- yanskiy, 1987. Optimal array of satellite-tracked drifting buoys in the southern Atlantic. Dokl. Earth Sci. Sect. (a translation of Dokl. Akad. Nauk SSSR), 287(1-6):191-194.

Experience during GARP suggests that random, or even 'intuitive,' initial placement of satellite-tracked drifting buoys is very sub-optimal, and that, in order to maximize the information returned, placement must be based on at least a rough picture of current dynamics. A procedure for thus placing the buoys is described for the Southern Ocean. Res. Inst. of the Arctic and Antarctic, Leningrad, USSR. (fcs)

88:4370 Zedel, L.J. and J.A. Church, 1987. Real-time screen-

ing techniques for Doppler current profiler data. J. atmos, ocean. Technol., 4(4):572-581.

Indicators based on measures of acoustic signal quality do not provide a mean reduction in confidence intervals. A combination of velocity quality screening criteria can reduce the confidence intervals of velocity estimates made with a 150 kHz profiler by as much as 25 percent. After screening, both components of horizontal currents are about as accurate, almost independent of depth, to at least 240 m. Data screening also removes a depth- dependent bias from velocity profiles. For the indicators tested, we recommend threshold values for our system configuration; these values can serve as guidelines to suitable settings in other applications. Dept. of Oceanogr., Univ. of British Colum- bia, Vancouver, BC V6T 1W5, Canada.

A40. Area studies, surveys

88:4371 Rochford, D.J., 1987. Monitoring of Great Barrier

Reef waters; some oceanographic requirements. CSIRO mar. Labs Rept, 184:31pp.

88:4372 Sekine, Yoshihiko and Yasushi Matsuda, 1987.

Hydrographic structure around the Tosa-bae, the

bump off Shikoku south of Japan, in November 1985. Mer, Tokyo, 25(3): 137-146. (In Japanese, English abstract.) Inst. of Geosci. and As- tronomy, Natl. Defense Acad., Yokosuka, 239 Japan.

88:4373 Titov, V.B., 1987. Variability of water temperature in

the active layer of the Black Sea as indicated by multiyear measurements. Oceanology (a translation of Okeanologiia), 27(2): 153-157.

The annual (depth 8 m) and biennial (depth 20 m) cycles of hourly change in water temperature measured from a stabilized buoy on the Black Sea shelf are analyzed, yielding estimates of the contributions of seasonal, synoptic, and mesoscale fluctuations to the total variability of the temperature field. A qualitative physical mechanism for the development of synoptic fluctuations in the temperature field is identified. Southern Div., Shirshov Inst. of Oceanol., Acad. of Sci., Gelendzhik, USSR.

88:4374 Viehoff, Thomas, 1987. Determination of mesoscale

variability of sea surface temperature and attenuation in the North Atlantic from satellite measurements. Ber. Inst. Meeresk. Christian- Albrechts-Univ., 162:192pp. (In German, English abstract.)

Horizontal mesoscale temperature and attenuation patterns in the region of the North Atlantic Current are analysed from AVHRR and CZCS data, focus- ing upon the summers of 1981 and 1983. Fairly substantial sections dealing with the underlying theory and methodology are followed by detailed descriptions of the temperature and attenuation distributions and their associated variance and coherence spectra. Inst. fur Meeresk., Abt. Theore- tische Ozeanogr., Dusternbrooker Weg 20, 2300 Kiel 1, FRG. (emm)

88:4375 Yanagi, Tetsuo, 1987. Seasonal variations of water

temperature and salinity in Osaka Bay. J. oceanogr. Soc. Japan, 43(4):244-250.

Seasonal variations in water temperature, salinity, and density are described for the upper, middle and lower layers of Osaka Bay, which exhibits the mixing characteristics of an estuary. A partition of the bay into three areas based on average salinity and seasonal temporal variations is described. Dept. of Ocean Engng, Ehime Univ., Matsuyama 790, Japan. (emm)

698 A. Physical Oceanograpay OLR (1988) 35 (8)

A50. General hydrography (distribution of common oceanic properties)

88:4376 Lyubimtsev, M.M., 1987. The probability structure of

the water surface temperature field of the ocean. Oceanology (a translation of Okeanologiia), 27(1):28-31.

The surface temperature field is considered as the superposition of an average determinate T and two random components T~ and T 2 associated with large-scale and small-scale turbulence, respectively. Equations are derived for the single-valued probability densities of T~ and T 2 and their solutions are analyzed. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

88:4377 Monin, A.S. and R.V. Ozmidov, 1987. Boundary

layers above seamounts. Dokl. Earth Sci. Sect. (a translation of Dokl. Akad. Nauk SSSR), 287(1- 6):208-211.

Reported here are the results of a series of hydrological measurements made above the Amp6re Seamount in September 1985 including STD sounding, an echo probe transect, temperature and salinity measurements, and two hydrophysical micro- sections. Descriptions of the thermocline and spa- tially varying thickness and turbulence characteristics of the upper mixed and bottom boundary layers are included with a more general discussion of the cruise results. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR. (emm)

88:4378 Navrotskaya, S.Ye. and V.F. Dubravin, 1987. Dis-

tribution of the subsurface salinity maximum ISSM] in the tropical Atlantic Ocean. Oceanology (a translation of Okeanologiia), 27(2):142-146.

Seasonal mean data are used to discuss the lateral distribution of the SSM in the tropical Atlantic. Calculation of the percentage of tropical water present in the SSM core shows that the SSM forms at the equator under the influence of Southern Hemi- sphere waters throughout the year. There is consid- erable seasonal variability in the SSM as a result of the current regimes. A close correlation between the topography of the SSM and the principal characteristics of the surface dynamic topography is identified. Atlantic Div., Shirshov Inst. of Oceanol., Acad. of Sci., Kaliningrad, USSR.

88:4379 Seager, Richard, S.E. Zebiak and M.A. Cane, 1988.

A model of the tropical Pacific sea surface

temperature climatology. J. geophys. Res., 93(C2): 1265-1280.

The upper ocean response is computed using a time dependent, linear, reduced gravity model, with the addition of a constant depth frictional surface layer. The full three-dimensional temperature equation and a surface heat flux parameterization that requires specification of only wind speed and total cloud cover are used to evaluate the SST. The model simulates the major features of the observed tropical Pacific SST and captures the seasonal evolution of these features. Analysis of the results demonstrates the control the ocean has over the surface heat flux from ocean to atmosphere and the crucial role that dynamics play in determining mean SST in the equatorial Pacific. The model's sensitivity to perturbations in surface heat flux, cloud cover specification, diffusivity, and mixed layer depth is discussed. NASA Goddard Inst. for Space Studies, 2880 Broadway, New York, NY 10025, USA.

88:4380 Talley, L.D. and W.B. White, 1987. Estimates of time

and space scales at 300 meters in the midlatitude North Pacific from the TRANSPAC XBT program. J. phys. Oceanogr., 17(12):2168-2188.

Temperature data from TRANSPAC XBT traces at 300 m depth were grouped in two-month bins and gridded using a surface mapping program. Mean trends and temperature variances over the midlatitude North Pacific for the 1976--84 period are described. Zonal wave number, frequency o~/k, and k/ l spectra are computed for a number of latitudes in eastern and western portions of the region and used to determine propagation of annual temperature waves throughout the region. The effective spatial resolution of the dataset is also addressed. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA. (emm)

A80. Circulation

88:4381 Coeffe, Y., S. Courtier and B. Latteux, 1987. Tidal

sea mathematical modelling: current applications and future developments. Coast. Engng, A mst., 11(5-6):479-511.

Characteristic theoretical, numerical, and algorith- mic approaches to dealing with frequency filtering of tidal processes and to solving the shallow-water equations are outlined. An illustration of current applications as well as concurrent work in peripheral areas is given and future developments are discussed. Lab. Natl. d'Hydraulique, E.D.F., B.P, 49, F-78401 Chatou, France. (emm)

OLR (1988) 35 (8) A. Physical Oceanography 699

88:4382 Crisciani, F., F. Cavallini, R. Mosetti and F.

Zanolin, 1987. Eigenvalue confinement in the problem of linear baroclinic instability for oceanic zonal flows. Nuovo Cim., 10C(4):397-407.

Analysis is performed for a baroclinic zonal flow perturbed by a monochromatic plane wave, harmonic in the latitude. Results, obtained from the a priori properties of the eigenvalue equation, yield estimates of the phase velocity and the growth rate of the perturbation. Consequently the spectrum is confined within a bounded region of the complex plane, which depends upon the zonal flux only through its extreme values and the shear maximum; the larger the wave number of the meridional structure of the perturbation, the narrower the obtained confinement. C.N.R. Istituto Talasso- grafico, Trieste, Italy.

88:4383 Cushman-Roisin, Benoit, 1987. On the role of heat

flux in the Gulf Strcam-Sargasso Sea subtropical gyre system. J. phys. Oceanogr., 17(12):2189- 2202.

In contrast with the traditional view of midlatitude circulation driven by winds in the ocean interior and regulated by friction along the western boundary, it is hypothesized that some control can be attributed to surface cooling acting primarily in a recirculation region off the western boundary current. Several arguments suggest that this mechanism and the generation of eddies are the two major reactions of the midlatitude ocean under the action of the surface winds. Dept. of Oceanogr., Florida State Univ., Tallahassee, FL 32306, USA.

88:4384 Fumes, G.K. and Martin Mork, 1987. Formulation

of a continuously stratified sea model with three-dimensional representation of the upper layer. Coast. Engng, Amst., 11(5-6):415-444.

A two-layered model is considered in which the upper layer is continuously stratified and the lower layer is homogeneous; it is driven by atmospheric forces, and bottom stress and topography are included. Linear 3-D hydrodynamical equations are used to describe the system. Taking the eddy viscosity in the upper layer as inversely proportional to the static stability, dependent variables are expanded in terms of continuous functions in the vertical. With this method it is possible to compute currents and internal displacements at any depth in the upper layer. Numerical test experiments are carried out for a cross section and a closed rectangular basin. Norsk Hydro Res. Centre, P.O. Box 4313, N-5013 Nygaardstangen, Norway.

88:4385 Greatbatch, R.J. (comment), John Marshall and

George Nurser (reply), 1987. [Discussion of] 'Steady, free circulation in a stratified quasi- geostrophlc ocean: J. phys. Oceanogr., 17(12): 2378-2381.

88:4386 Guo, Binghuo, Kui Lin and Jingming Lu, 1987.

Characteristics of circulation in the continental shelf area of the East China Sea in winter. Acta oceanol, sin. (English version), 6(Suppl, I):51-60. First Inst. of Oceanogr., State Oceanic Admin., Qingdao, People's Republic of China.

88:4387 Ierley, G.R., 1987. On the onset of inertial recir-

culation in barotropic general circulation models. J. phys. Oceanogr., 17(12):2366-2374.

A nonlinear ordinary differential equation which models the western boundary layer of quasi-geostrophic barotropic models of wind-driven circulation is discussed. For mild nonlinearity the model has two possible outflow solutions which match to a Sverdrup interior. For stronger nonlinearity, no solutions exist. In the weakly nonlinear case linear stability theory is used to resolve the problem of multiple solutions. A highly stretched regional model of the full quasi-geostrophic equations is used to investigate the disappearance of solutions of the boundary layer model. Failure of the boundary layer model is coincident with the onset of recirculation at a sufficiently large ratio of basin scale to viscous boundary-layer scale. For less extreme ratios, the onset of recirculation is deferred, hence its relation to a failure of the boundary layer model is obscured. Dept. of Earth, Atmos. and Planetary Sci., MIT, Cambridge, MA 02139, USA.

88:4388 Jamart, B.M. and Jos60zer , 1987. Comparison of

2-D and 3-D models of the steady wind-driven circulation in shallow waters. Coast. Engng, Amst., 11(5-6):393-413.

The classical theory of the steady wind-driven circulation in shallow waters described by the 3-D linear equations is generalized to include arbitrary variations of the vertical eddy viscosity. The stream function equation is compared to the corresponding equation of a 2-D model. The influence of various eddy viscosity profiles and/or bottom boundary conditions on the solution is discussed. From comparison of the equations, a parameterization of the bottom stress in terms of transport and wind stress is derived such that the 2-D model can yield

700 A. Physical Oceanography O LR (1988) 35 (8)

results identical to those of the 3-D model. Inst. de Math., Ave. des Tilleuls, 15, 4000 Liege, Belgium.

88:4389 Kawase, Mitsuhiro, 1987. Establishment of deep

ocean circulation driven by deep-water production. J. phys. Oceanogr., 17(12):2294-2317.

A linear, two-layer baroclinic model is formulated which determines upwelling internally by inclusion of a Newtonian damping term in the continuity equation. Analytical solutions for the steady state show that the coefficient of damping determines the nature of the flow. With a large damping coefficient, the deep western boundary current from the deep- water source region separates along the Equator, reaches the eastern boundary, then flows poleward in both hemispheres as an eastern boundary current. In the limit of very weak damping, the flow spins up to the Stommel-Arons state with the western boundary current crossing the Equator and with poleward flows in the interior. Numerical experiments show that the flow is first set up by a Kelvin wave along the western-equatorial-eastern boundary layers; then in the case of weak-damping, the eastern boundary current disperses as long Rossby waves to set up the poleward interior flow of the Stommel-Arons model. School of Oceanogr., Univ. of Washington, Seattle, WA 98195, USA.

88:4390 Marinone, S.G. and P. Ripa, 1988. Geostrophic flow

in the Guaymas Basin, central Gulf of California. Continent. Shelf Res., 8(2): 159-166.

Hydrographic data taken between 1939 and 1983 are used to calculate the along-gulf geostrophic transport. In addition to the traditional assumption of a deep level of no-motion for the geostrophic calculations, absolute velocities are estimated using constraints of mass conservation or minimum kinetic energy in the whole section. The three methods give similar results in the upper hundred meters. A seasonal cycle is observed for the total transport in the upper hundred meters, with a maximum in May-June and a minimum in January-February. Data from the October cruises show large variability around the seasonal hindcast. The across-gulf surface flow variation and the deep circulation show no seasonal signal. Centro de lnvestigacion Cientifica y de Educacion Superior de Ensenada, B.C., Espinoza No. 843 Ensenada, B.C., Mexico.

88:4391 Marotzke, J., P. Welander and J. Willebrand, 1988.

Instability and multiple steady states in a meridional-plane model of the thermohaline circulation. Tellus, 40A(2): 162-172.

With forcing and geometry symmetric to the Equa- tor, the symmetric solution was unstable to infini- tesimal perturbations, and an asymmetric pole- to-pole circulation was the end-result in all cases. The structure obtained for the meridional-plane stream function and for the poleward heat flux agree qualitatively with those obtained by Bryan (1986). Convective overturning caused by static instability was not essential for transition to the asymmetric steady state. The study suggests certain aspects of the ocean circulation, in particular those related to ocean climate, may be profitably explored by use of two-dimensional, zonally averaged models. Inst. fur Meeresk. an der Univ. Kiel, Dusternbrooker Weg 20, D-2300 Kiel, FRG.

88:4392 Martinsen, E.A. and Harald Engedahl, 1987. Im-

plementation and testing of a lateral boundary scheme as an open boundary condition in a barotropic ocean model. Coast. Engng, Amst., 11 (5 -6):603 -627.

The flow relaxation scheme (FRS) is tested as an open boundary condition (OBC). When one uses the FRS as a pure OBC, the FRS method degenerates to a sponge type OBC. As a sponge type OBC does not work well in all cases, we introduced local wind- induced solutions as a part of the external solutions (ES). When the tide was included in the ES, the FRS method handled the tidal input problem very well; even where noise was added to the tide in the ES, results were good. Norwegian Meteorol. Inst., Postbox 43, Blindern, 0313 Oslo 3, Norway.

88:4393 Mathew, Basil and P.M. Muraleedharan, 1987.

Circulation in the northern Arabian Sea. Indian J. mar. Sci., 16(3):196-198.

Geostrophic flow field is examined using 2 different data sets for early and late northeast monsoon. Earlier works and the present study suggest the possible occurrence of an anticyclonic eddy in the vicinity of the Murray Ridge throughout the year, though it is not clear whether other eddies found in the northern Arabian Sea are transient or perma- nent. The persistence of an anticyclonic eddy near Murray Ridge appears to be the effect of topo- graphic interaction. Naval Phys. and Oceanogr. Lab., Cochin 682 004, India.

88:4394 Oey, L.-Y., L.P. Atkinson and J.O. Blanton, 1987.

Shoreward intrusion of upper Gulf Stream water onto the U.S. southeastern continental shelf. J. phys. Oceanogr., 17(12):2318-2333.


Advective movement of upper Gulf Stream waters shoreward along a positive density gradient was studied by means of a series of hydrographic transects made during January 1986. The results help confirm previous numerical predictions and lead to the introduction of a semi-empirical model relating onshore intrusion to water stratification directly inshore of the shelf break. Model analysis gives some indication of the respective roles played by wind stress-induced Ekman transport and Gulf Stream meanders during the period of study. Finally, transient upwelling along the shelf break followed by shoreward intrusion is considered as a mechanism for nutrient transport. Dept. of Oceanogr., Old Dominion Univ., Norfolk, VA 23508, USA. (emm)

88:4395 Ragoonaden, S., V.R. Babu and J.S. Sastry, 1987.

Physico-chemical characteristics and circulation of waters in the Mauritius-Seychelles ridge zone, southwest Indian Ocean. Indian J. mar. Sci., 16(3): 184-191.

The ridge affects the zonal flow by causing divergence with a consequent increase in nutrient levels in its leeward side especially during winter. Distri- butions of physico-chemical parameters together with geostrophic flow patterns for both austral winter and summer are presented. Meteorol. Serv- ices, Vacoas, Mauritius.

88:4396 Su, Jilan and Yuqiu Pan, 1987. On the shelf

circulation north of Taiwan. Acta oceanol, sin. (English version), 6(Suppl. I): 1-20. Second Inst. of Oceanogr., State Oceanic Admin., Hangzhou, People's Republic of China.

88:4397 Vethamony, P., V.R. Babu and M.R.R. Kumar,

1987. Thermal structure and flow patterns around Seychelles group of islands (Indian Ocean) during austral autumn. Indian J. mar. Sci., 16(3):179- 183.

XBT data on properties of the thermal structure in the upper 750 m around the Seychelles are presented along with the inferred flow patterns. The topography of 20°C isotherm suggests a broad eastward flow in the north and northeasterly flow in the southern region of the islands. A divergence zone with shallow thermocline in the south is visualized as a result of shear flow between opposing zonal equatorial currents--equatorial counter current in the northern and south equatorial current in the southern parts of the islands. Relatively low thermocline gradients in the north, due to stronger mixing, indicate the probable existence of an

equatorial undercurrent. Phys. Oceanogr. Div., Natl. Inst. of Oceanogr., Dona Paula, Goa 403 004, India.

88:4398 Yuan, Yaochu, Jilan Su and Songyun Xia, 1987.

Three dimensional diagnostic calculation of circulation over the East China Sea shelf. Acta oceanol, sin. (English version), 6(Suppl. 1):36-50.

Results of a three-dimensional diagnostic calculation of ocean circulation for summer 1984 and winter 1985 show that the Taiwan Warm Current was the dominant feature. In summer it was composed of two current systems: the offshore branch derived mainly from the Kuroshio NE of Taiwan, and the inshore branch mainly from the Taiwan Strait. In winter, both branches seemed to have originated from the Kuroshio and the coastal current flowed southward to the west of a strong coastal front, while the Taiwan Warm Current flowed northward east of the front. Upwelling occurred near the Zheijang coast in summer and on the eastern side of the front in winter. Second Inst. of Oceanogr., State Oceanic Admin., Hangzhou, People's Republic of China.

A90. Currents

88:4399 Blatov, A.S. and V.I. Ul'yanova, 1986. Investigation

of the hydrodynamic stability of large-scale flows in the ocean within the framework of a multilevel quasigeostrophie model. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(11): 904-909.

The existence of four types of instability is shown in the model, which lead to the appearance of unstable wave perturbations of different spatial structure. The identified types of instability can be considered as a genetic basis for a classification of synoptic vortex formations. Univ. of Moscow, USSR.

88:4400 Borenas, K.M. and P.A. Lundberg, 1988. On the

deep-water flow through the Faroe Bank Channel. J. geophys. Res., 93(C2): 1281-1292.

A field survey comprising hydrographic observations as well as current measurements was carried out in the channel during May 1983 to estimate this flux of cold, low-saline bottom water. Transport calculations for a total of four sets of observations yielded values ranging from 1.5 to 1.9 Sverdrup. The outflow is most likely subjected to hydraulic control, and consequently, a simple model has been formulated to determine the maximum discharge through a rotating channel of parabolic cross section. The theoretically predicted magnitude of the transport was in


good agreement with the observations. Dept. of Oceanogr., Goteborg Univ., Box 4038, S-40040 Goteberg, Sweden.

88:4401 Bubnov, V.A., N.P. Kuz'mina and I.S. Podymov,

1987. Phenomenological description of an eddy observed in the Gulf Stream. Oceanology (a translation of Okeanologiia), 27(1): 16-19.

A mesoscale cyclonic eddy was observed using STD measurements; structural features are compared with those for typical eddy formations in the Gulf Stream frontal zone. It is concluded that this is a new type of eddy structure previously unobserved in the Gulf Stream frontal zone. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

88:4402 Chereskin, T.K., D. Halpern and L.A. Regier, 1987.

Comparison of shipboard acoustic Doppler current profiler and moored current measurements in the equatorial Pacific. J. atmos, ocean, Technol., 4(4):742-747.

Depth-averaged current shears computed from acoustic Doppler current profiler (ADCP) and vane vector-averaging current meter (VACM) measurements are compared at 35, 62.5, 100 and 140 m depths within 7 km of each other near 0 °, 140°W during a 12-day interval in November 1984. The agreement between the shears was excellent. The average root-mean-square difference of hourly shear values was small, ~0.21 × 10 2 s ~, and the average correlation coefficient was 0.90. Spectral estimates were equivalent to within 95% significance level and the VACM and ADCP shears were 95% statistically coherent with zero phase difference for frequencies below 0.2 cycles per hour. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA.

88:4403 Cornillon, Peter and D.R. Watts, 1987. Satellite

thermal infrared and inverted echo sounder determinations of the Gulf Stream northern edge. J. atmos, ocean. Technol., 4(4):712-723.

The northern edge of the Gulf Stream off Cape Hatteras was located from AVHRR SST maps using four objective methods based upon the maximum SST, SST gradient, and variance and skewness changes, and one subjective method. The results were compared to the location of the 15°C isotherm at 200 m as determined from inverted echo sounders. The best method overall was subjective location by an analyst, while the best objective method made use of sign changes in the skewness of the SST distribution. Grad. School of Oceanogr., Univ. of Rhode Island, Narragansett, RI 02882, USA. (emm)

88:4404 Davies, A.M., 1987. On extracting current profiles

from vertically integrated numerical models. Coast. Engng, Amst., 11(5-6):445-477.

A transformation method is presented by which current profiles can be extracted at any horizontal position and moment in time from a vertically integrated, two-dimensional, hydrodynamic numerical model. An arbitrary vertical variation of eddy viscosity incorporating a no-slip bottom boundary condition can be included. The technique assumes that the sea is homogeneous. The method is used to improve the representation of bottom stress within the two-dimensional model. Idealized calculations for a range of eddy viscosity profiles show that elevations, current profiles, and time series of current extracted are in good agreement with currents obtained from a full three-dimensional model. Inst. of Oceanogr. Sci., Bidston Observ., Birkenhead, Merseyside L43 7RA, UK.

88:4405 de Vriend, H.J. and M.J.F. Stive, 1987. Qnasi-3D

modelling of nearshore currents. Coast. Engng, Amst., 11(5-6):565-601.

Existing concepts of wave-induced nearshore current models, in the cross-shore vertical plane (2DV) and depth-integrated (2DH), are combined to a quasi-3D mathematical model. This combination is tested for reproducing correct results in 2DV and 2DH situations. The importance of various contributions to wave-induced secondary circulation in the vertical plane is investigated for realistic parameter ranges, which leads to the conclusion that both the non- breaking and the breaking fraction of a random wave field in the surf zone generate important secondary currents. Delft Hydraulics, 2600 MH Delft, Netherlands.

88:4406 Dingemans, M.W., A.C. Radder and H.J. de Vriend,

1987. Computation of the driving forces of wave-induced currents. Coast. Engng, Amst., 11(5-6):539-563.

Under the common conditions of slowly varying wave fields, the driving force per unit mass is closely proportional to the wave energy dissipation per unit area and diffraction-related terms give insignificant contributions. This result holds good for wave fields without current refraction. Examples show that formulation of the driving forces in terms of the wave dissipation yields more trustworthy results than those obtained by numerical differentiation of the radiation stress tensor. Delft Hydraulics, 2600 MH Delft, Netherlands.


88:4407 Gilmour, A.E., 1987. A preliminary rotary spectral

analysis of inertial currents off the west coast of New Zealand. N.Z. Jl mar. Freshwat. Res., 21(2):353-357.

Results from a preliminary spectral analysis of inertial currents at a depth of 1505 m are described. Rotary spectral analysis indicates that inertial currents form a significant constituent of the observed oscillatory currents recorded. Dept. of Sci. and Industrial Res., New Zealand Oceanogr. Inst., Private Bag, Kilbirnie, Wellington, New Zealand.

88:4408 Griffin, D.A., 1988. Mooring design to minimize

Savonius rotor overspeeding due to wave action. Continent. Shelf Res., 8(2): 153-158.

A theoretical formula providing an estimate of the surface wave induced overspeeding of non-vector- averaging recording current meters is derived for shallow water single meter moorings having subsurface buoyancy directly above the meter. The common practice of placing meters close to the bottom to escape wave action can result in greater overspeeding, even though wave induced currents are weaker at depth. When a variety of meters are available it is recommended that the newer vector- averaging meters be used near the bottom as well as near the surface, with non-vector-averaging meters being used only at mid-depth on moorings whose uppermost buoyancy is also at mid-depth. Dept. of Oceanogr., Univ. of British Columbia, 6270 Univ. Blvd., Vancouver, BC V6T IW5, Canada.

88:4409 Guza, R.T. (comment), D.G. Aubrey and J.H.

Trowbridge (reply), 1988. [Discussion of:] 'Kin- ematic and dynamic estimates from electromagnetic current meter data.' J. geophys. Res., 93(C2): 1337-1346.

R.T. Guza argues that the electromagnetic current meters manufactured by Marsh-McBirney, Inc. are, after all, satisfactory for surf zone applications, and criticizes the calibration procedures employed by Aubrey and Trowbridge. They in turn, while acknowledging several of Gnza's points, mention the work of others that is qualitatively consistent with their own, and call for a 'careful mix' of field and laboratory experiments to resolve the uncertainties. (fcs)

88:4410 Halper, F.B., D.W. McGrail and W.J. Merrell Jr.,

1988. Seaso~tl variability in the currents on the outer Texas-Louisiana shelf. Estuar. coast. Shelf

Sci., 26(1):33-50. AT&T Bell Lab., 600 Moun- tain Ave., Murray Hill, NJ 07974, USA.

88:4411 Heath, R.A. and A.E. Gilmour, 1987. Oceanic

exchange variability across the continental slope west coast, South Island, New Zealand. N.Z. Jl mar. Freshwat. Res., 21(2):327-336.

Current observations taken at depths between 630 and 830 m from the west coast South Island continental slope exhibit one- to four-weekly peri- odicities superimposed on the semi-diurnal tide. These variable flows at 630 m and other large, longer-timescale events have a significant onshore/ offshore component of flow which leads to a similar transport of alongshore momentum and heat. Dept. of Sci. and Industrial Res., New Zealand Oceanogr. Inst., Private Bag, Kilbirnie, Wellington, New Zealand.

88:4412 Jenkins, A.D., 1987. A Lagrangian model for wind-

and wave-induced near-surface currents. Coast. Engng, Amst., 11(5-6):513-526.

A theory of near-surface currents induced by variable wind stress and deep-sea wave fields is based upon Weber's (1983) second-order expansion of the Navier-Stokes equations in Lagrangian coordinates. The theory includes the Coriolis effect, as well as wave dissipation and momentum transfer within the current field via an eddy viscosity function. Results are described for different eddy viscosities and a number of applications are discussed. Bergen Sci. Centre IBM, Allegaten 36, N-5000 Bergen, Norway. (emm)

88:4413 Kirwan, A.D. Jr., J.K. Lewis, A.W. Indest, P.

Reinersman and I. Quintero, 1988. Observed and simulated kinematic properties of l oop Current rings. J. geophys. Res., 93(C2):1189-1198.

Two rings, shed by the Loop Current in 1980 and 1982, were observed for several months by satellite- tracked drifters to migrate across the Gulf of Mexico. Both rings impacted the Mexican continental slope at about 22.8°N, 95.5°W, then re- established and migrated slowly northward in the slope region. The paths of the centers of both rings along the slope are virtually identical. A comparison of some simulated drifter data with the observed ring data shows that the observed rings showed stronger interaction with the continental slope topography and/or circulation in midgulf, but along the slope. model ring kinematic characteristics were in ex- traordinary agreement with observations. Dept. of

704 A. Physical Oceanography OLR (I 988) 35 (8)

Oceanogr., Old Dominion Univ., Norfolk, VA 23508, USA.

88:4414 Kostyanoy, A.G. and G.I. Shapiro, 1986. Evolution

and structure of an intrathermocline eddy. Izv. .4 tmos. Ocean Phys. (a translation of Fiz..4 tmos. Okeana), 22(10):855-860.

The general structure and the time evolution of the associated density and 3-D velocity fields are considered for an intrathermocline vortex lens in a viscous rotating fluid. The universality of the dimensionless time-dependence of the lens radius is demonstrated, as well as its relative independence from the initial density and velocity fields. Exper- imental determinations of the time dependence characteristics of vortex lenses are made by two methods, yielding reasonable agreement with theoretical results. Inst. of Oceanol., Acad. of Sci., USSR. (emm)

88:4415 Kozlov, V.F. and Ye.V. Yaroshchuk, 1987. Numer-

ical model for Rayleigh instability and spin-off eddies at frontal sections. Oceanology (a translation of Okeanologiia), 27(1):6-9.

Using contour dynamics, a barotropic model is proposed for the evolution of a frontal section identified with the cyclonic shear layer. Using linear stability analysis and numerical experiments, it is shown that the unstable shear layer breaks up into a chain of eddies (the analog of eddy spin-off), whereas for finite disturbances of the edges the stable layer can undergo deformation suggesting the 'tiled' structures observed in the ocean. Far East Sci. Center, Pacific Oceanol. Inst., Acad. of Sci., Vla- divostok, USSR.

88:4416 Kozubskaya, G.I. and K.V. Konyayev, 1986. Run-

ning spectra of synoptic currents from POLY- MODE data. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(11):910-915.

It is shown on the basis of three-dimensional current field spectra in the 'POLYMODE' experiment that synoptic oscillations of the current velocity appeared three times in the form of one or two periods of zero- or first-mode Rossby waves and then were rapidly reorganized into eddy motions. Acoustical Inst., Acad. of Sci., USSR.

88:4417 Lambrakos, K.F., Dag Myrhaug and O.H. Slaattelid,

1988. Seabed current boundary layers in wave- plus-current flow conditions. J. WatWay Port

coast. Ocean Engng, Am. Soc. cir. Engrs, 114(2): 161-174.

Measurements of tidal current and wave velocity were made at 0.24, 0.61, 1.22, 1.83, and 3.66 m above a rough seafloor under a wide range of conditions. The measurements and analysis results demonstrate clearly the existence of large boundary-layer current gradients in the tidal environment. Large values of roughness and friction velocity parameters depend on the ratio of the wave- to the current-flow components as well as the upstream bottom roughness. Boundary layers in the flow near the seabed can affect the design of offshore structures such as offshore pipelines. Exxon Production Res. Co., P.O. Box 2189, Houston, TX 77001, USA.

88:4418 Moretti, Mauro, Emilio Sansone and Giancarlo

Spezie, 1987. Current measurements with a drifting ship. Boll. Oceanol. teor. appl., 5(3):207- 212. (In Italian, English abstract.) Istituto di Meteorol. e Oceanogr., I.U.N., Napoli, Italy.

88:4419 Sherwin, T.J., 1988. Measurements of current speed

using an Aanderaa RCM4 current meter in the presence of surface waves. Continent. Shelf Res., 8(2):131-144.

The Aanderaa RCM4 with Savonius rotor integrates motions that have a period significantly smaller than the recording interval, thus causing a quantifiable amplification of the observed mean speed. The minimum speed that can be recorded is 2~/7r, where ~, is the amplitude of the speed of the oscillating motion. In general, the amplification factor decreases as the ratio of mean speed over p increases. It is recommended that vector averaging current meters be used for current measurement in the upper 50-100 m of shelf sea regions that experience small tidal currents and a large oceanic swell. Unit for Coastal and Estuarine Studies, Mar. Sci. Lab., Menai Bridge, Anglesey LL59 5EY, UK.

88:4420 Song, Lina, 1987. A hydrodynamic velocity-splitting

model with a depth-varying eddy viscosity in shallow seas. Acta oceanol, sin. (English version), 6(Suppl. I): 135-150.

A second-order linear differential equation for the shallow-water vertical current profile is derived from more general 3-D boundary value equations for nonlinear tides. The equation incorporates a depth- varying eddy viscosity coefficient and allows the current velocity to be split into three parts: the gradient current, the stress current, and the gravi- tation current. Tractable expressions for water level


and bottom stress are obtained, and the model is applied with success to describe ultra-shallow-water surges in the Bohai Sea. Shandong Coll. of Oceanol., Qingdao, People's Republic of China. (emm)

88:4421 Umatani, Shin-ichiro and Toshio Yamagata, 1987.

Evolution of an isolated eddy near a coast and its relevance to the 'Kyucho.' J. oceanogr. Soc. Japan, 43(3): 197-203.

The translation speed of the adjusted eddy is estimated well by the mutual induction mechanism adapted to a rotating stratified fluid. The nonlinear Kelvin wave excited during the adjustment process is discussed in connection with the 'Kyucho, ' the sudden warming of coastal waters associated with swift currents. Div. of Ocean Hydrodynamics, Res. Inst. for Appl. Mechanics, Kyushu Univ., Kasuga 816, Japan.

88:4422 Wang, Joe and Jin Wu, 1987. Effects of near-bottom

return flows on wind-induced currents. J. phys. Oceanogr., 17(12):2263-2271.

Wind, currents, and surface waves were measured in a circulating wind-wave tank. Conditions corresponding to both coast and ocean, with and without bottom return flows respectively, were simulated. Spectra of currents exhibit a -5 /3 slope outside the frequency range of motions induced by dominant waves. For the coastal condition, Reynolds stress decreases linearly with depth, and turbulence energy decays with a z ~ trend, where z is the depth. For the oceanic condition, wind-induced drift currents are extended much further downward; a region of constant momentum flux prevails, and a uniform vertical distribution of turbulence energy exists. Below this surface region the turbulence energy decays with a z 2 trend, possibly implying a dissipative mechanism. Inst. of Oceanogr., Natl. Taiwan Univ., Taipei, Taiwan.

88:4423 Wang, Wei and Jilan Su, 1987. A harotropic model of

the Kuroshio system and eddy phenomena in the East China Sea. Acta oceanol, sin. (English version), 6(Suppl. I):21-35.

The study has simulated the branching features and flowing path of the Kuroshio itself. Also the Huanghai Warm Current and cyclonic gyre south of Jizhou Island have been reflected in model experiments. The model has predicted the possible existence of a weak cyclonic gyre and the branching relationship of the southward current along the west coast of Kyushu with the Tsushima Warm Current.

Natl. Inst. for Polar Res., Shanghai, People's Republic of China.

88:4424 Wright, D.G., 1987. Comments on 'Geostrophic

control of fluctuating barotropic flow through straits' [Toulany and Garrett, 1984]. J. phys. Oceanogr., 17(12):2375-2377.

88:4425 Yegorikhin, V.D. et al., 1987. An intrathermocline

lens of Mediterranean Water in the tropical North Atlantic. Oceanology (a translation of Okeanologiia), 27(2):121-127. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

88:4426 Yin, Xunfu, Kui Lin and Binghuo Guo, 1987. An

analysis on the current vector spectra in the southern East China Sea. A cta oceanol, sin. (English version), 6(Suppl. I):61-75.

Using current measurement data obtained from two investigations in June-July 1984 and January 1985, values of rotating spectra and ellipse elements are calculated. Results show that the semi-diurnal tidal current dominates followed by the diurnal one. The isoplethic spectra of the currents run from NW to SE, and in the longshore area, nearly parallel to the coast. Values of the spectra are much larger in the south and north portions, much smaller in the middle region, and largest north of the Taiwan Strait. Values decrease with increasing depth. There is a low frequency current with a period of 8 days. First Inst. of Oceanogr., State Oceanic Admin., Qingdao, People's Republic of China.

A l l 0 . Water masses and fronts

88:4427 Bennett, A.F. and P.F. Cummins, 1988. Tracking

fronts in solutions of the shallow-water equations. J. geophys. Res., 93(C2):1293-1301.

A front-tracking algorithm of Chern et al. (1986) is tested on the shallow-water equations, using the Parrett and Cullen (1984) and Williams and Hori (1970) initial state, consisting of smooth finite amplitude waves depending on one space dimension alone. At high resolution the solution is almost indistinguishable from that obtained with the Glimm algorithm. The solutions obtained using the front- tracking algorithm at 8 times coarser resolution are quite acceptable, indicating a very substantial gain in efficiency. Coll. of Oceanogr., Oregon State Univ., Corvallis, OR 97331, USA.


88:4428 Delcroix, Thierry, Gerard Eldin and Christian

H~nin, 1987. Upper ocean water masses and transports in the western tropical Pacific (165°E). J. phys. Oceanogr., 17(12):2248-2262.

Analyses of six hydrographic and current sections taken along the 165°E meridian are presented here. 'Typical' vertical temperature, salinity and zonal velocity profiles for January 1986 are described in detail as is the eastward equatorial jet measured in January 1985. Volume transport calculations use a definition based upon an isodensity surface to resolve the various currents. The large variability observed is addressed with respect to dynamic height and geostrophic current estimates from XBT and mean temperature-salinity curves. Groupe SUR- TROPAC, ORSTOM, B.P. A5, Noumea, New Caledonia. (emm)

88:4429 Huzzey, L.M. and J.M. Brubaker, 1988. The for-

marion of longitudinal fronts in a coastal plain estuary. J. geophys. Res., 93(C2):1329-1334.

Longitudinal estuarine fronts, aligned parallel to the axis of the estuary, are characteristic of the York River. Their time scale for genesis and decay is of the order of hours; they are usually located at the inner edge of the shoals or over the main channel. Marked intratidal differences in density and current speeds across this estuary can be correlated with changes in depth and the strength of the advective processes. Differential advection between the channel and shoal regions, when acting upon a constant longitudinal density gradient, is of sufficient magnitude to generate strong lateral density gradients, and thus fronts, at particular times within the tidal cycle. USGS, 345 Middlefield Rd., Menlo Park, CA 94025, USA.

88:4430 Wallace, D.W.R. and J.R.N. Lazier, 1988. Anthro-

pogeulc chlorofluoromethanes in newly formed Labrador Sea Water. Nature, Lond., 332(6159): 61-63.

Convection to 2000 m in the Labrador Sea during severe winters partially renews Labrador Sea Water (LSW), a water mass traceable at intermediate depth throughout the North Atlantic. Labrador Sea CFM data suggest that LSW originated at only 60% saturation with respect to contemporary atmospheric concentrations, in contrast to the 100% usually assumed. The newly formed water mass was also colder and less saline than any previously measured LSW. Monitoring of CFMs and other tracers in this region will be essential for establishing boundary

conditions for models of the North Atlantic tracer distributions. Dept. of Appl. Sci., Brookhaven Natl. Lab., Upton, NY 11973, USA.

AI20. Convergences, divergences, upwelling

88:4431 Bychkova, I.A. and S.V. Viktorov, 1987. Use of

satellite data for identification and dassification of upwemng in the Baltic Sea. Oceanology (a translation of Okeanologiia), 27(2):158-162. Le- ningrad Div., State Oceanogr. Inst., USSR.

88:4432 Wenju, Cai and G.W. Lennon, 1988. Upwemng in

the Taiwan Strait in response to wind stress, ocean circulation and topography. Estuar. coast. Shelf Sci., 26(1): 15-31. Flinders Inst. for Atmos. and Mar. Sci., Flinders Univ. of South Australia, Bedford Park, SA 5042, Australia.

AI50. Tides and sea level

88:4433 Fang, Guohong, 1987. Nonlinear effects of tidal

friction. A cta oceanoL sin. (English version), 6(Suppl. I): 105-122.

Gallagher and Munks' work (1971) on nonlinear effects of friction on tidal motion, and even on non-frictional hydraulic behavior, is extended. Two problems are addressed: (1) Fourier expansion of the quadratic friction term for cases of more than one wave, and (2) the consideration of friction's role in the propagation of primary waves and the growth of shallow water waves. Inst. of Oceanol., Acad. Sinica, Qingdao, People's Republic of China. (fcs)

88:4434 Lafuente, J.G., F.F. de Castillejo and M.J. Garcia,

1987. Results of the tidegaage network in the Strait of Gibraltar. Revta Geofis., 43(1):37-56. (In Spanish, English abstract.) Inst. Espanol de Oceanogr., Centro Costero de Fuengirola, Fuengirola, Milaga, Spain.

88:4435 Mitchum, G.T. and Roger Lukas, 1987. The lati-

tude--frequency structure of Pacific sea level variance. J. phys. Oceanogr., 17(12):2362-2365.

We report an unprecedented description of the latitudinal structure of tropical Pacific Ocean sea


level variability for time scales between 3 and 100 days. A plot of calculated sea level variance versus latitude and frequency is described and exposes a rich variety of phenomena. We find signals due to the fortnightly tide, equatorial waves, zonal current instabilities, and atmospheric forcing. TOGA Sea Level Center, Hawaii Inst. of Geophys., Univ. of Hawaii, Honolulu, HI 96822, USA.

88:4436 Pascual, J.R., 1987. The vertical and horizontal M 2

tide in the ria de Arnsa (Galicia, NW Spain). Revta Geofis., 43(1):57-64. (In Spanish, English abstract.) Inst. Espanol de Oceanogr., Av. Brasil, 31, 28020 Madrid, Spain.

88:4437 Rocha C., C.A. and A.J. Clarke, 1987. Interaction of

ocean tides through a narrow single strait and narrow multiple straits. J. phys. Oceanogr., 17(12):2203-2218.

Tidal interactions between two oceans of constant depth joined by a strait of constant depth which is narrow with respect to tidal scale are studied. Cross and along-strait sea level gradients and resultant currents produced within the strait and strait effects on the outer tides are described for varied strait widths and tidal magnitudes. The theory is applied to Atlantic/Mediterranean interactions through the Strait of Gibraltar with good results. The addition of multiple straits is shown to produce complicated coupling effects. Dept. of Oceanogr., Florida State Univ., Tallahassee, FL 32306, USA. (emm)

88:4438 Unnikrishnan, A.S., 1987. Numerical modelling

experiments in the Gironde Estuary. Study of tidal circulation and a comparison of the numerical methods used. Bull. Inst. G~ol. Bassin Aquitaine, 42:143-161. Natl. Inst. of Oceanogr., Dona Paula, Goa 403 004, India.

AI60. Waves, oscillations

88:4439 Abe, Kuniaki and Hiroshi Ishii, 1987. Distribution of

maximum water levels due to the Japan Sea tsunami on 26 May 1983. J. oceanogr. Soc. Japan, 43(3): 169-182.

Along the west coast of northeast Japan, the level reached a maximum at the coast eastward of the epicenter and decreased with distance measured from the coast nearest to the epicenter. An excitation of edge waves brought about a small increase of

levels at the southern coast. In contrast with the decrease with distance shown on the coasts of the main islands, some noticeable peaks were observed at several small islands. It is suggested that a short period component is predominant for the initial wave motion because the source region is 3000 m deep. N ippon Denta l Univ., Ni igata , 1-8 Hamauracho, Niigata 951, Japan.

88:4440 Basovich, A.Ya. et al., 1986. The effect of short trains

of intensive internal waves on wind waves. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(11):929-935.

In the case of short internal wave trains a number of previously uninvestigated features of the effect of these waves on wind waves arise, in particular, a variation of the intensity of the wind-wave anomalies along the train of internal waves, the presence of a precursor of surface anomalies, and the appearance of variation scales of the spectral density of the waves that are smaller than the period of the internal waves. These unique features are explained within the framework of a kinematic model of the effect of internal waves on wind waves. Inst. of Appl. Phys., Acad. of Sci., USSR.

88:4441 Belzons, Max, Elisabeth Guazzelli and Olivier

Parodi, 1988. Gravity waves on a rough bottom: experimental evidence of one-dimensional localization. J. Fluid Mech., 186:539-558.

The localization phenomenon is observed through very precise measurements in a wave tank. Viscous dissipation and rough-bed finite-size effects are examined. The experimental estimation of the localization lengths are compared with the theoretical predictions of Devillard et al., this issue of JFM. Finally, the resonant modes due to the disorder are directly observed for the first time. Dept. de Phys. des Systemes Desordonnes, Univ. de Provence, Centre de Saint-Jerome, F-13397 Marseille Cedex 13, France.

88:4442 Bezzabotnov, V.S., R.S. Bortkovskiy and D.F.

Timanovskiy, 1986. On the structure of the two-phase medium formed when wind waves break. Izv. A tmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(11):922-928.

The structure of the breaking crests of wind waves--whitecaps and their foam wakes--is investigated by means of remote photography. Data are obtained on the concentration of bubbles and their size distribution at the interface and at a depth of 10


cm, and the air-phase concentration in the subsurface layer is estimated. The characteristic particle velocities in the breaking waves are determined. Leningrad Hydrometeorol. Inst., Main Geophys. Observ., Leningrad, USSR.

88:4443 Bogdanov, K.T., 1987. Tidal wave propagation and

tidal level oscillations of the Persian Gulf. Oceanology (a translation of Okeanologiia), 27(1):20-23. Pacific Oceanol. Inst., Far East Sci. Center, Acad. of Sci., Vladivostok, USSR.

88:A.A.A. A . Carbonell, R. and X. Lana, 1987. Rayleigh waves

group velocities at the Indian Ocean by means of spherical surface harmonics. Revta Geofis., 43(1): 75-84. (In Spanish, English abstract.)

Surface spherical harmonic expansions are applied to a set of group velocities of Rayleigh waves with the aim of mapping such velocities. For several points belonging to different age zones of propagation media, dispersion values of group velocities, with periods from 20 to 100 s, are found. Such values are discussed in terms of some published results for the Atlantic and the Pacific ocean. Dept. de Fisica de la Terra i del Cosmos, Facultat de Fisica, Avda. Diagonal, 645, 08028 Barcelona, Spain.

88:4445 Dagnino, Ignazio, Carlo Palau and Alberto Albert,

1987. Shallow-water wind wave analysis: a re- examination of data recorded in 1951-1952-1953 at Genoa-Pra. Boll. Oceanol. teor. appl., 5(3): 221-236. (In Italian, English abstract.) Istituto di Sci. Ambientali Mar., Univ. di Genova, Italy.

88:a.a.a.6 Devillard, Pierre, Francois Dunlop and Bernard

Souillard, 1988. Localization of gravity waves on a channel with a random bottom. J. Fluid Mech., 186:521-538.

After recalling localization theory and applying it to the shallow-water case, we give the first study in the framework of the full potential theory; in particular we develop a renormalized-transfer-matrix approach to this problem. Results yield numerical estimates of the localization length, which we compare with the viscous dissipation length. This allows the prediction of which cases localization should be observable in versus hidden by dissipative mechanisms. Centre de Phys. Theorique, Ecole Polyteeh., F-91128 Palaiseau, France.

88:4447 Dippner, J .W, 1987. A swell model of the German

Bight. Coast. Engng, Amst., 11(5-6):527-538.

A numerical model is presented in which momentum transfer, by swell decaying to the mean circulation, is calculated including wave-current interaction without refraction. The model couples deep-water and shallow-water energy dissipation mechanisms such as wave attenuation and wave breaking and com- putes wave set-up, wave set-down and a longshore current. The pure wave-induced circulation and the residual circulation due to the interaction between waves and tide are calculated. Results suggest that wave-induced currents can be neglected for the calculation of transport of near-surface pollutants. Deutsches Hydrograph. Inst., Bernhard Nocht Str. 78, D-2000 Hamburg 4, FRG.

88:4448 Evans, D.V., 1988. Mechanisms for the generation of

edge waves over a sloping beach. J. Fluid Mech., 186:379-391.

Two mechanisms are described using classical linear water-wave theory. The first is an extension of the result of Yih (1984) to a class of localized bottom protrusions on a sloping beach in the presence of a longshore current; the second is a class of longshore surface-pressure distributions over a beach. In both cases, Ursell-type standing edge-wave modes can be generated in an appropriate frame of reference. Typical curves of the mode shapes are presented; in certain circumstances the dominant mode is not the lowest. School of Math., Univ. of Bristol, BS8 1TW, UK.

88:4449 Gao, Wenda, 1987. Probability analysis of typhoon

surge and typhoon storm tide. Tropic Oceanol., 6(1):73-80. (In Chinese, English abstract.) De- sign and Project Bur. of Water Transportation of Guangdong Province, People's Republic of China.

88:4450 Kirby, J.T., 1988. Current effects on resonant

reflection of surface water waves by sand bars. J. Fluid Mech., 186:501-520.

Using a multiple-scale expansion, evolution equations for the amplitudes of linear waves are derived and used to investigate the reflection of periodic wave trains with steady amplitude for both normal and oblique incidence. The presence of a current shifts resonant frequencies, by possibly significant amounts, and also enhances reflection of waves by bar fields due to the additional effect of the

O LR 0988) 35 (8) A. Physical Oceanography 709

perturbed current field. Coastal and Oceanogr. Engng Dept., Univ. of Florida, Gainesville, FL 32611, USA.

118:4451 Lavrenov, I.V. and V.V. Ryvkin, 1986. Evolution of

average parameters of gravity waves in a current that varies along its propagation direction, lzv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(10):849-854.

Using the geometrical optics approximation, a numerically averaged description of surface gravity waves in a horizontally nonuniform current is derived in the form of a nomogram representing the average heights, lengths, and periods of the waves. Comparison with field data yields satisfactory agreement. State Oceanogr. Inst., USSR. (emm)

88:4452 Liu, P.L.-F. and P.L. Boissevain, 1988. Wave

propagation between two breakwaters. J. WatWay Port coast. Ocean Engng, Am. Soc. civ. Engrs, 114(2):237-247.

A numerical model for computing wave propaga- tions between two breakwaters is presented. Each breakwater consists of one or two straight-line segments. Water depth varies in space. The numerical model is based on the parabolic wave equation approach with a boundary-fitted coordinate system. Good agreement with laboratory experimental data is observed. Engrg. Coll., Cornell Univ., Ithaca, NY 14853, USA.

88:4453 Longuet-Higgins, M.S., 1988. Lagrangian moments

and mass transport in Stokes waves. Part 2. Water of finite depth. J. Fluid Mech., 186:321- 336.

Some simple relations between the Lagrangian moments and cumulants in a steady finite-amplitude gravity wave on deep water are here generalized to water of finite depth. The first three Lagrangian moments are given in terms of the mass-transport velocity at the free surface, the potential and kinetic energy densities, and the mean-square particle velocity on the bottom. A simple method of calculation exploits certain quadratic relations between the Fourier coefficients in Stokes' series. For limiting waves, i.e. those with sharp crests, it is found that the most symmetric orbits, in the Lagrangian sense, occur not in very deep or very shallow water, but at one intermediate value of the ratio of depth to wavelength. Dept. of Appl. Math. and Theoretical

Phys., Univ. of Cambridge, Silver St., Cambridge CB3 9EW, UK.

88:4454 Malard~, J.-P., Pierre De Mey, Claire P6rigaud and

J.-F. Minster, 1987. Observation of long equatorial waves in the Pacific Ocean by Seasat altimetry. J. phys. Oceanogr., 17(12):2273-2279.

Synoptic maps of the mesoscale dynamic topography in a band between 7.5°N and 7.5°S are drawn from Seasat altimeter data. They show a set of eddies 600 km in diameter and 15-20 cm in amplitude moving westward with a velocity of about 40 km d a y ~ along 4.5°N. Their occurrence is consistent with the SST front undulations observed by Legeckis. South of the Equator the signal is less coherent, but a significant degree of symmetry with the north is evidenced. The dynamics of the wave system might also present some degree of nonlinearity, as some water seems to be carried along with the wave. GDTA/ALGOS, 18 Ave. Edouard Belin, 31055 Toulouse Cedex, France.

88:4455 Masuda, Akira, 1987. A proof and applications of the

expansion theorem for the Rossby normal modes in a closed rectangular basin. J. oceanogr. Soc. Japan, 43(4):237-243.

An expansion theorem for normal Rossby modes in a closed rectangular basin is proven and the modes are shown to be complete. The general linear versions of initial value and response problems are solved and the Green's function for instantaneous torque is derived. In addition, an analytical extension to weakly non-linear versions, and an application to numerical treatments of more general non-linear formulations, are given. Res. Inst. for Appl. Mechanics, Kyushu Univ., Kasuga 816, Japan. (emm)

811:4456 Mei, C.C., Tetsu Hara and Mamoun Naciri, 1988.

Note on Bragg scattering of water waves by parallel bars on the seabed. J. Fluid Mech., 186:147-162.

A recent theory of Bragg scattering of surface waves by sinusoidal sandbars is applied to three cases: (l) oblique incidence on a strip of infinitely long bars, (2) oblique incidence on the corner of a bar field. and (3) seabed with a mean slope. While the Bragg mechanism has been studied previously for sandbars present on many shorelines, it can be a basis for breakwaters where the soil is not strong enough to support a single massive breakwater. Dept. of Civ. Engng., MIT, Cambridge, MA 02139, USA.


88:4457 Miles, J.W., 1988. The evolution of a weakly non-

linear, weakly damped, capillary-gravity wave packet. J. Fluid Mech., 187:141-154.

Longuet-Higgins' (1976) analysis of energy transfer within a narrow spectrum of gravity waves with approximately uncorrelated phases is generalized to accommodate capillarity and weak damping, based on a generalization of Zakharov's (1968) work. The results for a symmetric normal spectrum are ex- pressed in terms of elliptic integrals and depend, after appropriate scaling, on a single similarity parameter and on the sign of the curvature of the linear dispersion relation. Inst. of Geophys. and Planetary Phys., Univ. of Calif., La Jolla, CA 92093, USA.

88:4458 Mirchina, N.R. and Ye.N. Pelinovskiy, 1987. The

dispersion enhancement of tsunami waves. Ocean- ology (a translation of Okeanologiia), 27(1):24- 27. Gorki Polytech. Inst., Inst. of Appl. Phys., Acad. of Sci., Gorki, USSR.

88:4459 Mitsudera, Humio and Kimio Hanawa, 1988. Damp-

ing of coastal trapped waves due to bottom friction in a baroclinic ocean. Continent. Shelf Res., 8(2):113-129.

In this study, bottom friction is assumed to be much smaller than the combined effects of stratification and topography. Therefore, the lowest order solution represents a free hybrid wave, while the next order solution represents wave damping. Results are summarized as follows: (1) the damping rate of the continental shelf wave family is larger than that of the internal Kelvin wave family, consistent with their vertical structure; (2) in the neighbourhood of a 'kissing' condition, the damping rates of the two adjacent modes intersect each other and are associated with a change in the properties of the wave from one family to another. Evidence for differential dissipation between shelf waves and internal Kelvin waves is also discussed. School of Math., Univ. of N.S.W., P.O. Box 1, Kensington, NSW 2033, Aus- tralia.

88:4460 Miyoshi, Hisashi, 1987. True run-up heights reached

[in Ohkuhn, Japan] by the huge tsunami of 1896. J. oceanogr. Soc. Japan, 43(3):159-168. 3-3-33, Minami-Oizumi, Nerima-ku, Tokyo 177, Japan.

88:4461 Neu, W.L. and R.P. Shaw, 1987. Tsunami filtering by

ocean topography. Ocean Phys. Engng, 12(1):1- 23.

Topographical filtering of a tsunami moving toward a run-up location is investigated here. In particular, the influences of submerged obstacles (e.g. seamounts) of length scales comparable to the characteristic wavelength of the tsunami and interactions with near-coastline topography (trench-slope-shelf and slope-shelf systems) are considered. Although significant filtering effects are seen only for shorter periods and high angles of incidence, resonance with the continental slope-shelf system is observed. Dept. of Aerospace and Ocean Engng, Virginia Poly- technic Inst. and State Univ., Blacksburg, VA 24061, USA. (emm)

88:4462 Plant, W.J., 1988. Correction to 'A two-scale model of

short wind-generated waves and scatterometry' by William J. Plant. J. geophys. Res., 93(C2):p. 1347. Dept. of the Navy, Code 8314, Naval Res. Lab., Washington, DC 20375, USA.

88:4463 Steinsaltz, David, 1987. Instability of baroclinic waves

with bottom slope. J. phys. Oceanogr., 17(12): 2343-2350,

Pedlosky's theory explaining the behavior of unstable baroclinic waves in the t-plane is modified to include a sloped bottom. The result is the same sort of nonlinear oscillatory behavior described by Pedlosky, except in the case of short wavelengths for negative shears, where the theory predicts an initial explosive growth of the wave amplitude, so that it will reach amplitudes that are very large compared with its initial scale. This suggests a possible mechanism for small-scale current fluctuations in the oceans. Yale Univ., New Haven, CT.

88:4464 Trivero, P. and C. Cappa, 1987. Sea wave spectra by

electromagnetic techniques. Nuovo Cim., 10C(4): 409-418.

Sea wave measurements have been carried out in the Sicilian Channel using a navigational radar for the lower-frequency component and a teflon-coated wire (Goubau line) for the high-frequency component. The results are discussed and the continuity of the complete spectrum is clearly proved, lstituto di Fisica Generale dell'Univ., Torino, Italy.

88:4465 Wang, Shen, Bernard Le Mehaute and C.-C. Lu,

1987. Effect of dispersion on impulsive waves. Mar. geophys. Res., 9(1):95-111.

The generation and propagation of surface waves resulting from suddenly created disturbances over


water surfaces is investigated. Initial boundary conditions defining the disturbance are given either by a velocity of the free surface, an initial elevation, or a pressure impulsively applied on the free surface. The corresponding three forms of solutions are related by a simple time derivative. Linear solutions are obtained in cases where wave motion is assumed to be nondispersive, mildly dispersive and fully dispersive, and where the motion is given by the method of stationary phase. Criteria are established to indicate each method's limit of validity. Div. of Appl. Mar. Phys., RSMAS, Univ. of Miami, FL 33149, USA.

88:4466 Weber, J.E., 1987. Wave attenuation and wave drift in

the marginal ice zone. J. phys. Oceanogr., 17(12): 2351-2361.

Surface gravity waves in a viscous rotating ocean are studied theoretically when they penetrate an area of highly concentrated brashlike ice. Results for wave attenuation and wave drift are obtained in the asymptotic limit of a thin, very viscous upper layer. The derived damping rate compares favorably with field data from the marginal ice zone. The drift velocity in the ocean exhibits a marked maximum in the viscous boundary layer. At the outer edge, it exceeds the inviscid Stokes drift. Computed values for the mean viscous drag on ice induced by wave motion show this effect may compete with the frictional effect of wind in packing the ice. The integrated horizontal mass transports in the open ocean and under ice do not match, leading to upwelling in the vicinity of the ice edge. Inst. of Geophys., Univ. of Oslo, 0315 Oslo 3, Norway.

88:4469 Yermakov, S.A., K.D. Ruvinskiy, S.G. Salashin and

G.I. Freydman, 1986. Experimental investigation of the generation of capillary-gravity ripples by strongly nonlinear waves on the surface of a deep fluid. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(10):835-842.

Laws governing the generation of capillary-gravity waves by steep surface waves are investigated for the first time. Dependence of ripple parameters at the crest on amplitude and frequency is measured. Experiments and theories to date yield dependencies different in character. The discrepancies are due to a zero approximation description of steep waves that is inadequate. Damping of strong surface waves is measured and shown to be due to the generation of ripples. Inst. of Appl. Phys., Acad. of Sci., USSR.

88:4470 Yesipov, I.B., K.A. Naugornykh, V.N. Nosov and

S.Yu. Pashin, 1986. Measurement of the probability distribution of the radii of curvature of the sea surface. Izv. A tmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(10):869-871.

Laboratory and field measurements were made of the probability distribution of the radius of curvature of sea surface. The technique employed involves the repeated measurement at a single point of individual surface wave curvatures from the intensity of reflected light pulses, yielding a probability distribution which represents the radius of curvature of the sea surface at that point. Acoustics Inst., Acad. of Sci., USSR. (emm)

88:4467 Xu, Delun, 1987. Slope of equilibrium range of

wind-wave spectrum. Acta oceanol, sin. (English version), 6(Suppl. I):86-95.

A linear model gives a slope that varies continuously from deep to shallow water. The discrepancy between these results and experimental data suggests the use of a nonlinear model which gives a slope more consistent with field and laboratory data, especially for shallow water. Shandong Coll. of Oceanol., Qingdao, People's Republic of China.

88:4468 Yang, Ganran and Lianggui Chen, 1987. Wave

characteristics and calculation of typhoon wave in Mawan Harbour [China]. Tropic Oceanol., 6(1): 66-72. (In Chinese, English abstract.) Zhong- shang Univ., People's Republic of China.

A170. Wind-wave interactions

88:4471 Akhmedov, N.I., Ya.Z. Gadzhiyev, A.I. Gumbatov

and T.M. Tatarayev, 1987. A nonstationary model of the development of the turbulent boundary layer above a sea of finite depth during the generation of surface wind waves. Oceanology (a translation of Okeanologiia), 27(1):36-39.

The nonstationary model of the atmospheric boundary layer above an infinitely deep sea is formulated for a sea of finite depth. Formulas are derived for the dynamic characteristics of the atmospheric boundary layer that describe their evolution and dependence on the degree of development of wind waves. It is shown that the surface roughness parameter decreases with a decrease in sea depth. Sci.-

712 A. Physical Oceanography OLR (I 988) 35 (8)

Industrial Space Res. Union, AzerbSSR Acad. of Sci., Baku, USSR.

88:4472 Deo, M.C. and Sampathiengar Narasimhan, 1988.

Generalized estimation of wave force spectra. J. WatWay Port coast. Ocean Engng, Am. Soc. civ. Engrs, 114(2):175-190.

A generalized approach is presented to estimate the cross-spectral densities of the multidirectional wave forces exerted on cylindrical members of inclined offshore structures. All possible interspectral com- binations of the forces can be obtained based upon the surface spectrum and rms particle velocity. Estimates of the wave force coefficients for the inclined cylindrical members placed in multidirectional waves are obtained based upon the principle of comparing the observed cross-spectral densities with their theoretical estimates; this gives the frequency-dependent estimates along different coordinate directions. A practical application of these developments is discussed. Dept. of Cir. Engng, Indian Inst. of Tech., Bombay 400 076, India.

88:4473 Makin, V.K., 1987. Wavelike momentum fluxes in

boundary layer above sea waves. Oceanology (a translation of Okeanologiia), 27(2):128-132.

A numerical model of the boundary layer above waves is based on 2-D nonlinear equations of motion of a turbulent air flow above a moving curvilinear surface. Equations for the wavelike momentum flow are written in curvilinear and Cartesian coordinates. The structure of wavelike momentum fluxes above developed wave action is studied. Results include data on the vertical distribution of mean wavelike momentum fluxes and their cospectra and phase spectra. Leningrad Div., Shirshov Inst. of Oceanol., Acad. of Sci., USSR.

88:4474 Makin, V.K. and D.V. Chalikov, 1987. Spectral

structure of the boundary layer above sea waves. Dokl. Earth Sci. Sect. (a translation of Dokl. Akad. Nauk SSSR), 287(1-6): 198-205.

The model given here is a refined version of an earlier numerical model designed by the authors to describe the dynamics of a turbulent incompressible fluid above a curvilinear surface in an arbitrary state of motion. The refined version introduces a new vertical coordinate which 'smooths' the boundaries of the upper turbulent layer, making possible a detailed study of its spectral structure. Leningrad Div., Shirshov Inst. of Oceanol., Acad. of Sci., Leningrad, USSR. (emm)

A180. Internal waves and tides

88:4475 Burenkov, V.I. and A.P. Vasil'kov, 1987. Charac-

teristics of internal waves in the upper thermo- dine near the Mascarene Ridge. Oceanology (a translation of Okeanologiia), 27(2):138-141.

Low-period internal waves observed in the upper thermocline near the Mascarene Ridge displayed spectral densities an order of magnitude higher than in the Garret-Munk model spectrum. Coherences near the frequency of the spectral maximum re- mained high for vertical separation up to 50-60 m, and fell quickly with vertical separation at other frequencies, suggesting that only short-period waves propagating as quasimonochromatic trains are unimodal. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR. (emm)

88:4476 Ivanov, V.F., 1987. Forced internal waves in the

ocean with complex distribution of the Vtlislilil frequency and of the flow velocity. Oceanology (a translation of Okeanologiia), 27(2):p.167.

Characteristics of internal waves generated by a periodic wind source are calculated from distributions of the V~tisal~t-Brunt and average flow frequencies by means of a previously proposed method (Ivanov, 1984) with the inclusion of a complex representation of the surface wave amplitude. Vertical amplitude profiles of the internal wave, velocity component, perturbed density, and pressure are presented and discussed. Inst. for Mar. Hydrophys., UkSSR Acad. of Sci., Sevastopol, USSR. (emm)

88:4477 Meng, J.C.S. and J.W. Rottman, 1988. Linear

internal waves generated by density and velocity perturbations in a linearly stratified fluid. J. Fluid Mech., 186:419-444.

A generalized theoretical analysis and finite-difference solutions of the Navier-Stokes equations of the initial-value problem are applied to obtain the linear internal wave fields; the velocity perturbations are those due to an axisyrnmetric swirl and a vortex pair. Solutions obtained correspond to the strong stratification limit. The theoretical results of the rotational perturbation cases show an oscillating non-propagating disturbance, which is absent in the density-perturbation case. The swirl-flow solution shows an oscillatory behaviour in both the angular momentum deposited in the fluid and in the torque exerted by the external gravitational force field. The vortex-flow solution shows a vertical ray pattern.


Gould Defense Systems, Inc., Ocean Systems Div., 1 Corporate Place, Middletown, RI 02840, USA.

88:4478 Serebryanyy, A.N., 1987. Internal waves above the

[Sea of Japanl shelf close to the continental slope as indicated by data from a towed distributed temperature sensor. Oceanology (a translation of Okeanologiia), 27(2):165-166. Andreyev Inst. of Acoustics, Moscow, USSR.

88:4479 Zhao, Junsheng, Shijiang Geng, Zhenxiang Wang,

Xuejun Gu and Hongliang Sun, 1987. Analysis of wave packet structure for tidally-generated internal waves in offshore areas. A cta oceanol, sin. (English version), 6(Suppl. 0:96-104.

Based on observational data, wave packet structure is studied, indicating the discontinuity of a tide- generated internal wave travelling in a single direction with four sets of wave packet and three noise ranges in between. A comparison of models shows that the physical implications of our two-layer model are consistent with those of soliton theory, i.e., both models reflect that, in the propagation direction of the wave, the shear effect of tide- generated internal waves is proportional to its amplitude. First Inst. of Oceanogr., State Oceanic Admin., Qingdao, People's Republic of China.

A210. Ice

88:4480 Digby-Argus, S.A., R.K. Hawkins and K.P. Singh,

1987. Microwave remote sensing of ice in Lake Melville and the Labrador Sea. IEEE Jl ocean. Engng, OE-12(3):503-517. RADARSAT Project Office, Canada Centre for Remote Sensing, Ottawa, ON K1A 0Y7, Canada.

88:4481 Eicken, H., T.C. Grenfell and B. Stonehouse, 1988.

Sea ice conditions during an early spring voyage in the eastern Weddell Sea, Antarctica. Polar Rec., 24(149):49-54. Alfred Wegener Inst. fur Polar und Meeresforschung, 2850 Bremerhaven, FRG.

88:4482 Glen, J.W., 1987. Fifty years of progress in ice

physics. J. Glaciol, Special issue(1987):52-59.

Although fifty years ago the tetrahedral hydrogen bonding of water molecules in ice had been determined, the dielectric relaxation and electrical conductivity of ice was still unknown. Over the last half

century much work has been done to investigate the electrical properties of ice and the behavior of ice under various physical conditions. Much of this data is fundamental to our understanding of cloud physics, thunderstorm electricity, and current theories of the composition of comets. Dept. of Phys., Univ. of Birmingham, BI5 2TT, UK. (hbf)

88:4483 Hanssen-Bauer, Inger and Y.T. Gjessing, 1988.

Observations and model calculations of aerodynamic drag on sea ice in the Fram Strait. Tellus, 40A(2): 151-161.

Wind and temperature profiles in the constant flux layer obtained by tethersonde were used to compute the total aerodynamic drag on an area of 60% pack ice. Eddy correlation measurements in the local constant flux layers over ice floes were used to estimate the skin drag of an area of 100% ice cover. A drag partition model is proposed for computing the total drag over an area of pack ice as a function of ice concentration, mean freeboard and length of the ice floes, and typical roughness lengths of ice and sea surfaces. The model predicts maximum form drag at 73% ice concentration for floes of the type observed. Dept. of Geophys., Univ. of Bergen, N-5007 Bergen, Norway.

88:4484 Lewis, E.L., 1987. Fifty years of progress in under-

standing sea ice. J. Glaciol., Special issue(1987): 48-51.

Practical motivations for research on sea ice are discussed and an historical outline given of work carried out from 1936-86. Advances in understanding the physical properties of sea ice and atmosphere-ice-ocean energy exchanges are listed. These factors, together with an increasing ability to formulate changing ice-thickness distributions, have led to sophisticated models of ice movement having a useful predictive capability. Inst. of Ocean Sci., Sidney, BC V8L 4B2, Canada.

88:4485 Martin, Seelye and Paul Becker, 1988. Ice floe

collisions and their relation to ice deformation in the Bering Sea during February 1983. J. geophys. Res., 93(C2): 1303-1315.

Four radar-tracked buoys, equipped with triaxial accelerometers and located initially in compact ice floes at distances > I00 km from the ice edge (and >300 m from each other), were used to study ice deformation in relation to floe collisions in the Bering Sea. The aceelerometer records revealed two major collisions correlated with large-scale deformation and a host of smaller collisions associated


with sea swells. School of Oceanogr., Univ. of Washington, Seattle, WA 98195, USA. (emm)

88:4486 Motoi, Tatsuo, Nobuo Ono and Masaaki Wakat-

suchi, 1987. A mechanism for the formation of the Weddell Polynya in 1974. J. phys. Oceanogr., 17(12):2241-2247.

We propose that a high-salinity mixed layer in summer resulted in formation of the Weddell Polynya in 1974. Results from a 1-D convective mixed-layer model show that the high salinity allows deep convection driven by surface cooling alone, and the resulting upward transfer of heat and salt prohibits sea-ice formation throughout the winter, subject to the freshwater input less than 0.4 m y r ~. The occurrence of the deep convection during the 1974 polynya formation is confirmed by summer data from 1975, showing the deep water to be colder, fresher and richer in oxygen than in 1974. The upward heat flux through the deep convection resulted in formation of the Weddell Polynya in 1974. Maizuru Mar. Observ., Japan Meteorol. Agcy., Maizuru, 624 Japan.

88:4487 Murthy, H.A. and Simon Haykin, 1987. Bayesian

classification of surface-based ice--xadar images. IEEE JI ocean. Engng, OE-12(3):493-502. Indian Inst. of Tech., Madras 600 036, India.

88:4488 Robin, G. de Q. and Charles Swithinbank, 1987.

Fifty years of progress in understanding ice sheets. J. Glaciol., Special issue(1987):33-47.

Fifty years ago the ice sheets of Greenland and Antarctica were viewed as static relicts of a glacial age; today they are considered dynamic features in equilibrium with global climatic factors which have been subject to major changes in past centuries. Prior to the 1957-1958 IGY, progress in glaciology was largely limited to results of various polar expeditions. Since that time, however, technological advances in data acquisition--satellite imagery and altimetry, radio echo sounding, borehole sampling, and ice temperature and ice movement measurements--and model studies have resulted in a rapidly expanding body of knowledge on the volume, distribution, mass balance, flow, and deformation of glacial ice. Scott Polar Res. Inst., Univ. of Cam- bridge, CB2 I ER, UK. (hbf)

88:4489 Slotten, H.R. and C.R. Stearns, 1987. Observations

of the dynamics and kinematics of the atmospheric surface layer on the Ross Ice Shelf,

Antarctica. J. Climate appt Met., 26(12):1731- 1743.

The values of geostrophic departure angle obtained using surface data from a 6-station array just south of Ross Island are in good agreement with previous findings. A tendency of the geostrophic departure angle to increase with increasing wind speed over open ice has been confirmed in the region far to the south of the island's influence; near the south side, this relation does not apply. It is postulated that the forcing of Ross Island on the dynamics of the lowest atmospheric layers is responsible for this difference. On the assumption of a linear decrease of friction with height, the height for zero friction increases toward the south of Ross Island. Tentative evidence of higher pressure immediately south of the island supports the theory that cold stable air advected northward by the predominant southerly flow is piling up on the south side of Ross Island. Dept. of Meteorol., Univ. of Wisconsin, Madison, WI 53706, USA.

A240. Optical properties 88:4490

Stavn, R.H., 1988. Lambert-Beer law in ocean waters: optical properties of water and of dissolved/suspended material, optical energy budgets. Appl. Opt., 27(2):222-231.

The Lambert-Beer law and the three-parameter model of the submarine light field are used to construct an optical energy budget for any hydrosol. It is further applied to the analytical exponential decay coefficient of the light field and used to estimate the optical properties and effects of the dissolved/suspended component in upper ocean layers. Concepts of the empirical exponential decay coefficient of the light field and a constant exponential decay coefficient for molecular water are analyzed; the latter is rejected. Biol. Dept., Univ. of North Carolina, Greensboro, NC 27412, USA.

A260. Acoustics

88:4491 Abdullaev, S.S., B.A. Niyazov and P.K. Khabibul-

laev, 1987. Modeling of the spatial correlation and intensity of low-frequency surface noise in a shallow sea. Sov. Phys. Acoust. (a translation of Akust. Zh.), 33(1): 1-3.

An asymptotic method is proposed for calculating the spatial correlation function and intensity of the

OLR (I 988) 35 (8) A. Physical Oceanography 715

sound field generated by surface noise in an ocean in finite depth. The method takes into account the reflection of sound from the surface and the bottom. Inst. of Nuclear Phys., Acad. of Sci., Uzbek SSR, USSR.

88:4492 Andreev, M.Yu., 1987. Sound scattering by distant

regions of the bottom in horizontal sensing of the ocean. Sov. Phys. Acoust. (a translation of Akust. Zh.), 33(1):55-56. N.N. Andreev Acoustic Inst., Acad. of Sci., USSR.

88:4493 Artel'nyi, V.V. and M.A. Raevskii, 1987. Multiple

scattering of low-frequency sound waves by ocean turbulence. Sov. Phys. Acoust. (a translation of Akust. Zh.), 33(1):4-7.

The attenuation of the coherent components and energy and the transformation of the mode and angular spectra of a monochromatic sound wave are analyzed on the basis of the equations for the moments of the normal-mode amplitudes. Inst. of Appl. Phys., Acad. of Sci., USSR.

88:4494 Baggeroer, A.B., W.A. Kuperman and Henrik

Schmidt, 1988. Matched field processing: source localization in correlated noise as an optimum parameter estimation problem. J. acoust. Soc. Am., 83(2):571-587. MIT, Cambridge, MA 02139, USA.

88:4495 Buckingham, M.J., 1988. Spherically symmetrical

acoustic propagation across a fluid/fluid boundary. J. acoust. Soc. Am., 83(2):566-570. Dept. of Ocean Engng, MIT, Cambridge, MA 02139, USA.

88:4496 Gulin, O.I~., 1987. Numerical simulation of low-

frequency acoustic noise in a layered ocean. Sov. Phys. Acoust. (a translation of Akust. Zh.), 33(1):68-70. Pacific Ocean Oceanol. Inst., Far Eastern Sci. Center, Acad. of Sci., USSR.

88:4497 IannieUo, J.P., 1988. High-resolution multipath time

delay estimation for broad-band random signals. IEEE Trans. Acoust. Speech Signal Process., 36(3):320-327. New London Lab., Naval Un- derwater Systems Center, New London, CT 06320, USA.

88:4498 Komissarova, N.N., 1987. Noise field generated by

surface sources in a coastal wedge. Sov. Phys. Acoust. (a translation of Akust. Zh.), 33(1):25-28. N.N. Andreev Acoustics Inst., Acad. of Sci., USSR.

88:4499 Kovalev, A.N., E.A. Rivelis and S.L. l~del'shtein,

1987. Influence of the parameters of an underwater acoustic waveguide on the mode attenuation coefficients. Soy. Phys. Acoust. (a translation of Akust. Zh.), 33(1):81-83. Computing Center, M.A. Suslov State Univ., Rostov-on-Don, USSR.

88:4500 Kudryashov, V.M., 1987. Sound field in a wavegulde

with a sloping bottom. Soy. Phys. Acoust. (a translation of Akust. Zh.), 33(1):32-34. N.N. Andreev Acoustic Inst., Acad. of Sci., USSR.

88:4501 Lewis, J.K. and W.W. Denner, 1988. Arctic ambient

noise in the Beaufort Sea: seasonal relationships to sea ice kinematics. J. acoust. Soc. Am., 83(2):549-565. Sci. Applications Internatl. Corp., 1304 Deacon, College Station, TX 77840, USA.

88:4502 Mercer, J.A., 1988. Gcoacoustic parameters and the

depth-dependent Green's function for a silty sediment at 100 Hz in shallow water. J. acoust. Soc. Am., 83(2):611-616.

Acoustic data for transmissions at 100 Hz, in a simple shallow-water environment with a horizontally stratified silty sediment, are simulated using a fast-field method of solving the Helmholtz equation. The derivative of the artificial data with respect to the sediment model parameters is determined numerically and used to represent the data kernel of the linearized inverse problem. This allows computation of the model parameter resolution matrix which provides a formal evaluation of the ability to predict the model parameters from the data. Results for this particular environment and acoustic frequency suggest that the water-sediment sound-speed ratio is the only geoacoustic parameter that can be reliably inferred; it is also the only sediment parameter that need be determined to predict long-range propagation. Appl. Phys. Lab., Univ. of Washington, Seattle, WA 98105, USA.

88:4503 Ostashev, V.E., 1987. Equation for acoustic and

gravity waves in a stratified moving medium. Soy.


Phys. Acoust. (a translation of Akust. Zh.), 33(1):95-96. Inst. of Phys. of the Atmos., Acad. of Sci., USSR.

88:4504 Ostashev, V.Ye., 1986. Wavegulde propagation of a

high-frequency acoustic field in a stratified moving medium near an impedance boundary. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(11):936-941. Inst. of the Phys. of the Atmos., Acad. of Sci., USSR.

88:4505 Ransford, G.A. and J.W. loup, 1987. Locating and

determining the orientation of underwater research equipment: acoustic range and range rate data. IEEE Jl ocean. Engng, OE-12(3):524-533.

A formulation is presented for evaluating the performance of acoustic systems to determine the location and orientation of underwater research apparatus. The variables to describe position are referenced to a surface ship, and represent the straight-line distance from the stern of the ship to a point on the apparatus, the angular distance down from the sea surface and the angular distance from the direction of motion of the ship. A simple model for the sound velocity variation with depth is included in the range data analysis, while the Doppler data are shown not to need that further complication. An error model is applied to repre- sentative geometries. Performance requirements are derived. Sverdrup Tech., NSTL, MS 39529, USA.

88:4506 Sen, M.K., L.N. Frazer and S. Mallick, 1988.

Analysis of multipath sound propagation in the ocean near 49°N, 128°W. J. acoust. Soc. Am., 83(2):588-597.

Downslope sound propagation data for a shallow source and a deep receiver are examined. Different propagation paths could be identified in different bathymetric regions viz., shelf, slope, and deep ocean. A ridge at a range of 79 km shadowed some of the propagating rays; ray tracing from the apex of the ridge was used to calculate travel time curves for some of the diffracted arrivals; however, these were difficult to identify in the data. Data collected in the range of 1-52 km were modeled by computing synthetic sonograms using a reflectivity technique modified to remove phase from the vertical wave- functions. These synthetics were used to constrain the velocity, velocity gradient, sediment thickness, and the absorption coefficient in the upper part of the sediment. Hawaii Inst. of Geophys., 2525 Correa Rd., Honolulu, HI 96822, USA.

88:4507 Sheng, Jinyu and A.E. Hay, 1988. An examination of

the spherical scatterer approximation in aqueous suspensions of sand. J. acoust. Soc. Am., 83(2): 598-610. Dept. of Phys., Memorial Univ. of Newfoundland, St. John's, NF AIB 3X7, Can- ada.

88:4508 Stein, P.J., 1988. Interpretation of a few ice event

transients. J. acoust. Soc. Am., 83(2):617-622. Atlantic Appl. Res. Corp., 4 A St., Burlington, MA 01803, USA.

88:4509 Voronovich, A.G., 1987. The small-slope approxi-

mation in the theory of sound scattering by an uneven free surface. Dokl. Earth Sci. Sect. (a translation of Dokl. Akad. Nauk SSSR), 287(1- 6): 186-190. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

A290. Physical processes, properties (dif- fusion, turbulence, etc.)

88:4510 Avdeyeva, I.Yu. and V.S. Maderich, 1987. Ener-

getics of turbulent patches in a stably stratified ocean. Oceanology (a translation of Okeano- logiia), 27(2): 133-137. Inst. of Hydromechanics, UkSSR Acad. of Sci., Kiev, USSR.

88:4511 Cavazzoni, S. and F. Crosera, 1987. Turbulent

structures dependent on tidal currents in the bottom boundary layer of the Venice Lagoon. Nuovo Cim., 10C(4):419-431. ISDGM-CNR, S. Polo 1364, 30125 Venezia, Italy.

88:4512 Fedorov, K.N., 1987. Thickness of layers and

exchange coefficients in layer-by-layer convection in the ocean. DokL Earth Sci. Sect. (a translation of Dokl. Akad. Nauk SSSR), 287(1-6):205-208.

A parameterization scheme is proposed which makes possible the prediction, given the general thermohaline properties of the inversion layer, of the important parametric features of the layered structure formed through layer-by-layer convection. These include heat and salt exchange coefficients, convective layer thickness, and the critical Rayleigh number giving the perturbation threshold for initi- ation of the convective process from a smooth vertical temperature distribution in the inversion


layer. Shirshov Inst. Of Oceanol., Acad. of Sci., Moscow, USSR. (emm)

88:4513 Goodrich, D.M., W.C. Boicourt, Peter Hamilton and

D.W. Pritchard, 1987. Wind-induced destratification in Chesapeake Bay. J. phys. Oceanogr., 17(12):2232-2240.

Multiyear continuous observations of velocity and salinity in the bay indicate that wind-induced destratification occurs frequently from early fall through midspring over large areas of the estuary. Storm-driven breakdown of summer stratification occurred near the autumnal equinox in two separate years. Surface cooling reduces the vertical temperature gradient in the days prior to the mixing event. Large internal velocity shear precedes mixing events, suggesting a mechanism involving the generation of dynamic instability across the pycnocline. Destrat- ification fundamentally alters the response of the velocity field to subsequent wind forcing; in stratified conditions, response is depth-dependent while after mixing a depth-independent response is observed. NOAA Office of Climatic and Atmos. Res., Rockville, MD 20852, USA.

88:4514 Klein, Holger, 1987. Benthic storms, vortices, and

particle dispersion in the deep west European basin. Dt. hydrogr. Z., 40(3):87-102.

From September 1983-May 1986, twenty benthic storms with velocities up to 27 cm/s and duration between 3 and 25 days were observed in a region centered at 47°20"N and 20°W. All storms between September 1983 and September 1984 occurred in connection with deep reaching synoptic vortices and were important mechanisms for dispersion of tracers, which are released at the seabed, and enable particles to pass the interface between the well- mixed bottom boundary layer and stratified interior of the deep sea. Eddies trap the particles and facilitate horizontal and vertical transports within the eddy. By means of its shear, each vortex deforms a parcel of contaminated water to thin sheets, making small-scale mixing processes work effec- tively. Deutsches Hydrographisches Inst., Bernhard Nocht Strasse 78, 2000 Hamburg 4, FRG.

88:4515 Kopelevich, O.V. and A.S. Monin, 1986. On the

mixing of waters in strong currents. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 22(11):899-903.

Marine hydro-optical methods are described for studying water mixing zones in strong sea and river currents, including methods for estimating the

horizontal mixing coefficients. They are illustrated for the unique example of the mixing of the dense white waters of the upper Amazon with the less dense black waters of its main northern tributary, the Negro River. The mixing coefficient is of the order of 106 cm2/sec, just as in many ocean currents. Inst. of Oceanol., Acad. of Sci., USSR.

88:4516 Marmorino, G.O. and D. Greenewalt, 1988. Infer-

Hng the nature of microstructure signals. J. geophys. Res., 93(C2): 1219-1225.

Further study is done of Holloway and Gargett's (1987) suggestion that it is possible to distinguish salt-fingering microstructure signals from those induced by turbulence by using the kurtosis (the relative flatness) of the scalar probability distribution, Support for their result comes from an examination of towed measurements of conductivity gradient fluctuations from turbulent and salt finger patches in the Sargasso Sea; however, when data are examined from presumably salt finger interfaces in the thermohaline staircase east of Barbados, data segments are found having both the suppressed kurtosis values expected of salt fingering and the high values associated with turbulence. Ocean Dynamics Branch, Acoustics Div., Naval Res. Lab., Washington, DC 20375, USA.

88:4517 McDougall, T.J., 1987. The vertical motion of

submesoscale coherent vortices across neutral surfaces. J. phys. Oceanogr., 17(12):2334-2342.

While it has been recognized that submesoscale coherent vortices (SCVs) make an important con- tribution to lateral property fluxes in the ocean, their vertical motion across neutral surfaces is examined here. These vertical fluxes of heat and salt can be either down- or up-gradient corresponding to either a positive or a negative vertical diffusivity. The magnitude of the effective diffusivity for salt is different from that for heat. Formulae are derived for estimating the mean vertical velocity of SCVs through neutral surfaces. CSIRO Div. of Oceanogr., Hobart, Tas., Australia.

88:4518 Miner, E.W., O.M. Griffin and R.A. Skop, 1987.

Bubble motions in seawater. Ocean Phys. Engng, 12(1):25-46.

A method is presented for calculating the evolution and transport of bubbles in the wake of a surface ship. Results compare reasonably well with the limited experimental data which are available. Suggestions for further research are given. Lab. for


Computational Phys. and Fluid Dynamics, Naval Res. Lab., Washington, DC 20375-5000, USA. (emm)

88:4519 Nabatov, V.N. and R.V. Ozmidov, 1987. Study of

turbulence in the ocean in the benthic boundary layer. Oceanology (a translation of Okeanologiia), 27(1): 1-5.

To explain the properties of the turbulent benthic layer, a model is proposed that is based on the equation for turbulent energy balance in a density- stratified flow. According to the model, the thickness of the turbulent layer is inversely proportional to the Vais~tla frequency and directly proportional to the frictional velocity, in good agreement with the experimental data. Estimates are also given for the parameters of coherent eddy structures in the benthic boundary layer. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

88:4520 Peters, H., M.C. Gregg and J.M. Toole, 1988. On the

parameterization of equatorial turbulence. J. geophys. Res., 93(C2): 1199-1218.

Prof,_'les of currents, density, and microstructure were obtained on and near the Pacific equator at 140°W. During a 4~/2-day time series, the shear zone above the core of the undercurrent had very low mean Richardson numbers, between IA and ~/2. Average turbulent dissipation rates were high and varied by a factor of 100 between early afternoon and night. The signal reached to 90 m, well into the stratified zone. Eddy coefficients were low at high Ri, and gradually increased as Ri decreased. Appl. Phys. Lab., Coll. of Ocean and Fish. Sci., Univ. of Washington, Seattle, WA 98105, USA.

88:4521 Shapiro, G.I., 1987. Toward a theory of quasi-

geostrophic motions of finite amplitude in a viscous stratified ocean. Oceanology (a translation of Okeanologiia), 27(1): 10-15.

It is demonstrated that under certain conditions, finite amplitude geostrophic motions in a viscous stratified rotating fluid are described by solutions of a generalized geostrophic potential vorticity equation. This leads to calculations of the 3-D velocity field, time behavior and rate of viscous degeneracy of intrathermoclinic eddies and to a classification of geostrophic motions in viscous stratified media. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR. (emm)

88:4522 West, J.R. and K. Shiono, 1988. Vertical turbulent

mixing processes on ebb tides in partially mixed estuaries. Estuar. coast. Shelf Sci., 26(1):51-66.

The objectives of this study were to determine the vertical transport of momentum and solute for stable flows. Attention was restricted to partially mixed conditions for shallow ebb tide flows which have flow depths of less than 5 m, Under these conditions the turbulence field is dominated by bed-generated rather than internal-wave-generated turbulent kinetic energy. These effects are tentatively explained by the concept of turbulent fluctuations being replaced by wavelike fluctuations in stable conditions. Results for momentum and solute lengths help substantiate previously published values. Dept, of Cir. Engng, Univ. of Birmingham, Birmingham, UK.

88:4523 Wolanski, Eric, 1988. Island wakes in shallow waters.

J. geophys. Res., 93(C2):1335-1336.

Field, laboratory, and numerical results suggest that the free shear layer behind flow separation points and the internal circulation generated by rotation in the eddy are important processes in island wakes in shallow coastal waters. Australian Inst. of Mar. Sci., P.M.B. 3, Townsville M.C., Qld. 4810, Australia.

88:4524 Yanagi, Tetsuo, 1987. Classification of 'siome,'

streaks and fronts. J. oceanogr. Soc. Japan, 43(3): 149-158.

'Siome' is a line of convergence on the sea surface. It is proposed that siome should be classified into 'streak' (the convergence within the same water mass) and 'front' (the convergence between two different water masses). Streaks and fronts are further classified on the basis of mechanisms of generation. Dept. of Ocean Engng, Ehime Univ., Bunkyo 3, Matsuyama 790, Japan.

A300. Fluid mechanics

88:4525 CederlOf, Ulf, 1988. Free-surface effects on spin-up.

J. Fluid Mech., 187:395-407.

The effects of a free surface on the spin-up of a homogeneous fluid are analyzed using cylindrical geometry. The spin-up process is strongly modified as the rotational Froude number (F) becomes large. The dynamic effect of the free surface causes delayed response outside a sidewall boundary layer; the timescale in the slowly decaying core is larger

OLR (1988) 35 (8) 719

than the usual spin-up time by a factor of order F. A set of laboratory experiments were carried out in order to test the theory. An interesting deviation was observed at smaller F, consisting of an anticyclonic vortex at the centre. This phenomenon might be explained by Lagrangian mean motion resulting from inertial oscillations. Dept. of Oceanogr., Univ. of Gothenburg, Box 4038, 400 40 Gothenburg, Sweden.

88:4526 Crisciani, Fulvio, 1987. The time rate of change of the

total angular momentum of quasi-geostrophic, barotropic flows in bounded basins. Boll. Oceanol. teor. appl., 5(3):251-254. C.N.R., Istituto Speri- mentale Talassografico, Trieste, Italy.

88:4527 Turcotte, D.L., 1988. Fractals in fluid mechanics. A.

Rev. Fluid Mech., 20:5-16.

The author provides a general survey of the role of fractals in various aspects of fluid mechanics and related disciplines, underlining the unifying notion of scale invariance which in fact predates any explicit consideration of fractals in fluid mechanics (and elsewhere). While acknowledging the present lack of mathematical rigor underlying the fractal approach, he emphasizes its potential for providing fresh perspectives and as an organizing concept. Dept. of Geol. Sci., Cornell Univ., Ithaca, NY 14853, USA. (emm)

88:4528 Vincent, A.P. and D.A. Yuen, 1988. The onset of

plume dynamics in the spectral space. Phys. Fluids, 31(2):225-227.

Time-dependent convection for infinite Prandtl number fluids has been investigated hitherto in the physical domain. Dynamics of plumelike structures resulting from boundary-layer instabilities can be interpreted in the spectral domain as having both direct and inverse cascades of energy taking place. In the physical domain only a small part of the

spectrum is discernible, but the rest of the spectrum is needed for properly describing the nonlinear process. Only a relatively few modes, fewer than ten, are actually required for describing the essential features associated with the onset of plume dynamics. Minnesota Supercomputer Inst., Univ. of Min- nesota, Minneapolis, MN 55455, USA.

A330. Books, collections (general)

88:4529 Dyke, P.P.G. (ed.), 1987. Special issue.

JONSMOD'86. Selected papers from the third JONSMOD workshop, Delft, The Netherlands, May 1986. Coast. Engng, Amst., 11(5-6):392-627; 9 papers.

This collection from members of the Joint North Sea Modelling Group 'records the latest developments in numerical models of shallow seas, but emphasizes smaller length scales where the concern is more with surface waves and less with Coriolis acceleration.' Dept. of Math. and Statistics, Plymouth Polytechnic, Plymouth, Devon. PL4 8AA, UK. (fcs)

A340. Miscellaneous

88:4530 Nakamura, Shigehisa, 1987. Possible subsurface

source of an acoustic tsunami precursor. J. oceanogr. Soc. Japan, 43(4):228-236.

A model is introduced to show that focused caustics can be a possible source of a boom; in this model, the fault line that includes the epicenter of an earthquake at the sea bed was assumed to be the sound source. Some of the acoustic rays radiated from the source form an acoustic caustic between the sea surface and the axis of the sound channel. Thus caustics can be a subsurface source of an acoustic tsunami precursor. Shirahama Oceanogr. Observ., Disaster Prevention Res. Inst., Kyoto Univ., Katada-Hatasaki, Shirahama, Wakayama 649-22, Japan.

B. MARINE METEOROLOGY

B10. Apparatus and methods

88:4531 Michael, Kelvin, 1988. On the measurement of

relative humidity in a marine environment. Boundary-layer Met., 42(4):403-409.

A Vaisala HMP 26 UT humidity sensor was successfully used to monitor the near-surface relative humidity at John Brewer Reef, Australia, for one year. The sensor was supplemented with a poly- tetrafluoroethane filter, and shielded from radiation and spray. This permitted the unattended meas-

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