Oceanographic Literature Review

(1989) 36 (9)

The citations are those received in the editorial office during the period 1-30 June, 1989. 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

AI0. Apparatus and methods

89:4959 Bisagni, J.J., 1989. Wet tropospheric range correc-

tions for satellite altimeter-derlved dynamic to- pographies in the western North Atlantic. J. geophys. Res., 94(C3):3247-3254. Bldg. 679, Naval Underwater Syst. Ctr., Newport, RI 02841, USA.

89:4960 Denner, W.W. (workshop chairman), 1989. Special

issue on Arctic Ocean science. IEEE J1 ocean. Engng, 14(2):125-220; 11 papers.

Polar regions are gaining in importance because of the role they play in climate, their natural resources, and their strategic uses. However their darkness, ice, and remoteness pose special problems for research- ers. The several papers here were originally pre- sented at a workshop on polar instrumentation held jointly by the IEEE and the Marine Technology

Society. Several papers cover remote sensing of sea ice parameters, and several more instrumentation for physical oceanography, including discussions of the Autonomous Ocean Profiler and the Polar Floats Program. Other topics include sea ice stress/strain measurement, radiosondes, a portable sound source and hand deployed sonobuoys, and a cable-lowered instrument frame. (fcs)

89:4961 Echert, D.C. et al., 1989. The aa~ommmms ocean

profiler: a cmrent-drivea ~ sensor platform. IEEE Jl ocean. Engng~ 14(2):195-202.

The AOP is an instrument platform for measuring profiles of physical, thermodynamic, and biological properties in the ocean. The profiler employs a hydrodynamic lift device to 'fly' the instrument package up and down the water column along a taut vertical cable; power requirements are low. By using satellite retrieval networks, the system can supply near real-time data at very high vertical resolution.

762 A. Physical Oceanography OLR (1989) 36 (9)

Because only a single set of sensors is required to cover the vertical range desired, the system is low cost and, for many applications, expendable. Flow Res., Inc., 21414 68th Ave. So., Kent, WA 98032, USA.

89:4962 Horsley, L.E., 1989. Modification and deployment

techniques for hand-deployed Arctic long-life sonolmoys. IEEE Jl ocean. Engng, 14(2):211-220. NORDA, Arctic Acoust. Branch, Stennis Space Ctr., MS 39529-5004, USA.

g9:4963 Krauss, W., J. Dengg and H.-H. Hinrichsen, 1989.

The response of drtftln~ buoys to currents and wind. J. geophys. Res., 94(C3):3201-3210.

Two buoy types were tested with respect to their drift performance under drogued and undrogued conditions and forces acting on the buoys were measured directly. Quadratic drag laws were con- firmed for the drag in water and the combined drag of wind and waves. Correlations between drift and wind speed in the Atlantic suggest that the finear law is a better approximation under realistic conditions. According to these measurements the described buoy-drogue system with a windowshade drogue in 100-m depth is a good current-measuring device. Slippage is negligible for wind speeds < 15 m/s and is < 2 em/s under gale conditions. Undrogued buoys are strongly affected by wind and cannot be used for the analysis of currents without correction, even under light winds. Inst. fur Meereskunde an der Univ. Kiel, Dusternbrooker Weg 20, D-2300 Kiel 1, FRG.

89:4964 Manley, T.O., J.-C. Gascard and W.B. Owens, 1989.

The Polar Floats Program. IEEE Jl ocean. Engng, 14(2):186-194.

The program, an adaptation of mid-latitude SOFAR float technology into the polar regions, will be used to monitor subsurface circulation patterns over large spatial and temporal scales as well as to track mesoscale features in near real-time. It comprises three major components that are now under devel- opment and will be used during the Coordinated Eastern Arctic Research Experiment: the 80 Hz float transducer, sea-ice deployable listening stations using ARGOS data telemetry, and the software needed for real-time tracking. In concert with the French, floats will be deployed in Fram Strait, the Eurasian Basin of the Arctic Ocean, and within mesoseale eddies at the marginal ice zone. Near real-time positions of these floats will be used to adapt sampling patterns of other measurements in

order to follow these features and monitor their evolution in the open ocean, marginal ice zone, and beneath the more interior pack ice. Lamont-Doherty Geol. Observ., Palisades, NY 10964, USA.

89:4965 McPhee, M.G., 1989. A rigid, eabk~.lowered in-

strument frame for mcasmtag turledence and internal waves in the Arctic. IEEE JI ocean. Engag, 14(2):203-207.

For the 1985 Arctic Internal Wave Experiment (AIWEX), four instrument clusters, each measuring temperature, conductivity, and three orthogonal components of current velocity, were mounted on a 5.5-m-long rigid frame which was lowered by cable to depths as much as 70 m below the ice/ocean interface. The frame was used for both turbulent boundary layer studies in the near-surface mixed layer, and for high-frequency internal wave studies in the Arctic halocline. Deployment of an improved version of the internal wave frame is planned for the Fram Strait region in spring 1989. McPhee Res. Co., 1410 Old Naehes Hwy., Naches, WA 98937, USA.

89:4966 Morison, J.H., 1989. Physical oceanography instru-

mentation for the polar regions: a review. IEEE Jl ocean. Engng, 14(2):173-185.

Over the past 15 years, instrumentation for high- latitude physical oceanography has improved dra- matically. Hydrographic buoys have been developed that make long-term measurements of water tem- perature and conductivity as they drift through remote regions. Other instruments have been devel- oped to take advantage of the unique platform the ice provides. Systems are being developed to telem- eter data from bottom-moored instruments through the ice and to monitor SOFAR drifters in ice- covered areas. The development of measurement systems for physical oceanography in polar regions is summarized here and selected instruments are described. Polar Sci. Ctr., Coll. of Ocean and Fish. Sci., Univ. of Washington, Seattle, WA 98105, USA.

A S 0 . G e n e r a l h y d r o g r a p h y (dis t r ibut ion of c o m m o n oceanic proper t ies)

89:4967 Oort, A.H. et al., 1989. New estimates of the available

potential energy lAPEl in the World Ocean. J. geophys. Res., 94(C3):3187-3200.

The computed amounts of zonal mean and transient eddy APE and the amount of kinetic energy present in the oceans are at least 1 order of magnitude smaller than those in the atmosphere. The computed

OLR(1989)36(9) A. Physical Oceanography 763

estimates were obtained by extrapolation from the corresponding values measured at the ocean surface. The fact that relatively large density variations are found only in the upper few hundred meters of the oceans, and the greater stability of the oceans, are the basic reasons for the generally small values of the potential and kinetic energy in the oceans compared with those in the atmosphere. GFD Lab., NOAA, Princeton Univ., P.O. Box 308, Princeton, NJ 08542, USA.

A80. Circulation

89:4968 Druffel, E.R.M., 1989. Decade time scale variability

of ventilation in the North Atlantic: high-pre- cision measurements of bomb radiocarbon in banded corals. J. geophys. Res~ 94(C3):3271- 3285.

The striking dissimilarities between the post-1950 records at Bermuda and the Florida Straits illustrate the different mixing processes in the upper ocean at each site. Convective overturn associated with 18°-water formation during late winter in the northern Sargasso Sea facilitates storage of bomb radiocarbon at depth, which accounts for the damping of the A~4C signal at Bermuda during the 1960s. The rate of water mass renewal in the Sargasso Sea was high during 1963-1964, decreased during the late 1960s, and remained low during most of the 1970s. The ~4C-derived record of water mass renewal precedes by about four years that derived from isopycnal salinity in the Sargasso Sea, illus- trating that the coral ~4C record is controlled to a large extent by changes in ocean circulation rather than by atmospheric exchange of CO e. Dept. of Chem., WHOI, Woods Hole, MA 02543, USA.

89:4969 Hsiung, Jane, R.E. Newell and Thomas Houghthy,

1989. The annual cycle of oceanic heat storage and oceanic meridional heat transport [1949- 1960]. Q. Ji R. met. Soc, 115(485):1-28.

There is a large annual cycle in heat storage change at almost all latitudes with the largest amplitude in latitudes where the western boundary currents dominate. There is also a considerable annual cycle in heat transport estimates. Heat transport in the Atlantic is northward, except in January when there is significant southward transport; the largest north- ward transport is at 5°N during March. In the Pacific, northward transport dominates north of 20°N with a maximum in July-September. South of 20°N, there is significant southward transport in

July through September. Overall, the largest north- ward transport in the Pacific is in March at 10°N. Heat transport in the Indian Ocean is mostly southward with a maximum in May at 20°S except for a small northward transport in January-Feb- ruary north of 5°S. Dept. of Earth, Atmos. and Planetary Sci., MIT, Cambridge, MA 02139, USA.

89:4970 Rudels, Bert et al., 1989. Greenland Sea eonveetioa in

the winter of 1987-1988. J. geophys. Res~ 94(C3): 3223-3227.

During February 1988 a layer of almost uniform temperature and salinity between 100 and 1250 m depth was observed in the central Greenland Sea. This feature, indicative of previous deep convection, is explained in terms of a conceptual penetrative convection model. Norsk Polar Inst., Postboks 157, 1330-Oslo Lufthavn, Norway.

89:4971 Takematsu, M. and T. Kita, 1989. Some aspects of

thermally induced circulat~n in a rotating basin. Dynam. Atmos. Oceans, 13(1-2):149-164.

A laminar convective circulation in a rotating cylinder with a sloping bottom is studied experi- mentally. Flow is induced by impressing a uniform temperature change on the basin sidewall which is originally in thermal equilibrium with the working fluid. The resulting thermal motion is observed until its flow structure no longer changes appreciably. The well-developed thermal circulation exhibits an ob- vious 'east-west' asymmetry (with the up-slope direction designated 'north'), with an intensified boundary current along a portion of the sidewall. In the cooling (ATe0) case the current intensification due to the bottom slope occurs on the 'eastern' side of the basin, while in the heating (AT>0) case it occurs on the opposite ('western') side. Res. Inst. for Appl. Mech., Kyushu Univ., Kasuga 816, Japan.

A90. Currents

89:4972 Johns, Elizabeth, E.R. Watts and H.T. Rossby, 1989.

A test of geostrophy in the Gulf Stream. J. geophys. Res~ 94(O):3211-3222.

Two detailed sections of density and absolute velocity were taken across the Gulf Stream to accurately test geostrophy in a strong current. Each was completed within 48 h, using one ship to make closely spaced CTD measurements and a second to simultaneously take Pegasus absolute velocity pro- files to the ocean bottom. The Gulf Stream path and

764 A. Physical Oceanography OLR (1989) 36 (9)

curvature were also surveyed. The geostrophic method (properly referenced) underestimated ob- served velocities by 10-25 cm s -~ in the core of the current where speeds exceeded 150 cm s -~. We can account for the supergeostrophic currents effectively by including the centripetal acceleration (from the path curvature) in the momentum equation. In this case differences in the current core decrease to less than 5-10 cm s -j, well within the uncertainties of the method. Deep variability, attributed to topographic Rossby waves, introduces more than 10 Sv uncer- tainty in defining the total volume transport of the Gulf Stream. AOML, NOAA, 4301 Rickenbacker Cswy, Miami, FL 33149, USA.

89:4973 Kjerfve, BjOrn and Carmen Medeiros, 1989. Current

vanes for me~mu'ing tidal currents in estuaries. Estuar. coast. Shelf Sci, 28(1):87-93. Mar. Sci. Program, Univ. of South Carolina, Columbia, SC 29208, USA.

89:4974 Pares-Sierra, Alejandro and J.J. O'Brien, 1989. The

seasonal and interannnal variability of the Cali- fornia Current system: a numerical model. J. geophys. Res., 94(C3):3159-3180.

A reduced gravity model that incorporates the geometry of western North America was used to study the dynamics of the California Current system. The main objective was to analyze the low-frequency variability of the California Current system in terms of its contributions from remote and local forcing. Away from the coast, the basic (steady) state of the model is determined by the predominantly negative wind curl through a Sverdrup balance. Most of the interannual variability in sea level height at the coast is due to disturbances of equatorial origin that propagate into the region in the form of coastally trapped Kelvin waves. For the annual frequency variability, however, both local and remotely forced variability contribute to the total variance. Scripps Inst. of Oceanogr., La JoUa, CA 92093, USA,

89:4975 Picaut, Jo~l, S.P. Hayes and M.J. McPhaden, 1989.

Use of the ~ appmximntion to estimate time-varying zonal era'rents at the Equator. J. geophys. Res, 94(C3):3228-3236.

Statistical analyses indicate that for time scales longer than 30-50 days, the observed and geo- strophicaily estimated zonal velocities are similar, thus low-frequency equatorial current oscillations are reasonably well represented by the geostrophic

approximation. However, the mean currents are poorly resolved with the array. In the eastern Pacific the mean zonal speed difference over the 10-month comparison period is 25 cm s -~ at 25 m, increasing to 60 cm s J at 125 m. At 165°E mean differences in the upper 250 m are typically 50 cm s J over a 4-month record. The principal reason for these large mean differences is that the meridional scale of the mean currents is smaller than the spacing of the moorings; meridional spacing of about 1 o latitude would be optimum. Groupe SURTROPAC, ORSTOM, B.P. A5, Noumea, New Caledonia.

89:4976 Rikiishi, Kunio and Hiroshi Sato, 1989. Sea surface

inclination due to the effect of the Coriolis force on an ocean current. J. geophys. Res., 94(C3): 3237-3246.

A unique data set of simultaneous observations of the ocean current and absolute sea surface slope in the Tsugaru Strait, Japan, has been analyzed in order to examine the effect of Coriolis force on an ocean current. The mean surface slope across the strait was compared dynamically with the mean current along the strait; both are in good geostrophic balance. In the subtidal frequency range, the time variation in current velocity was followed by variation in sea surface inclination such that both are generally in geostrophic balance. In the tidal frequency range, the dynamical relation between current velocity and inclination shows good agree- ment with theory. Dept. of Earth Sci., Hirosaki Univ., Hirosaki 236, Japan.

89:4977 Stramma, Lothar and T.J. MUller, 1989. Some

observations of the Azores Current IACI and the North Equatorial Cm'rent INECI. J. geophys. Res., 94(C3):3181-3186.

Associated with the AC are strong horizontal thermohaline gradients that can be located easily with temperature data alone, thus making satellite IR imagery and XBT profiles suitable for observing it. During winter, the surface expression of the AC is often found to the north of the strongest subsurface gradients. In contrast, the NEC has relatively weak horizontal temperature and salinity gradients, re- quiring density information in order to identify it, and there is no clear surface manifestation. Both currents, though, transport 0(8 Sv) in the upper 800 m of the ocean near 27°W, with the largest velocities in the upper 400 m. Inst. fur Meereskunde an der Univ. Kiel, Dusternbrooker Weg 20, 2300 Kiel, FRG.

OLR (1989) 36 (9) A. Physical Oceanography 765

A120. Convergences, divergences, up- welling

89:4978 Narimousa, S. and T. Maxworthy, 1989. Application

of a laboratory model to the interpretation of satemte and field observations of coastal npwell- ing. Dynam. Atmos. Oceans, 13(1-2):1-46.

Experiments were run on the effects of asymmetric ridges (similar to Mendocino escarpment) and a perturbed coastline (similar to that near Point Conception) on the upwelling; overall results were similar to symmetric cases previously reported. In general, the model suggests that the large, standing features (waves) that extend far offshore and which are seen repeatedly in satellite images near major capes and ridges are produced as the result of interaction of the upwelling system with the coastal irregularities themselves. In the absence of any major coastal protuberances the standing features are absent also, and instead a uniform upwelled front and associated smaller scale, frontal, baroclinic eddies develop. When such eddy fields interact with the upwelling system, geostrophic jets transport the upweiled water far offshore in the form of mean- dering filaments, as seen in (IR) images. Dept. of Mech. Engng, Univ. of Southern California, Los Angeles, CA 90089-1453, USA.

A150. Tides and sea level

89:4979 Bartsch-Winkler, Susan and D.K. Lynch, 1988.

Catalog of woddwide tidal bore occm~nees and characteristics. Circ. U.S. geol. Surv~ 1022:17pp.

Tidal bores are solitary, moving water waves up to 6 m in height that form upstream in estuaries with semidiurnal tide ranges > 4 m. They propagate up tidal estuaries a greater distance than the width of the estuary, but most occur within 100 km upstream of the river mouth. Bores are known to have occurred in at least 67 localities in 16 countries at all latitudes, including every continent except Antarc- tica. Parts of Argentina, Canada, Central America, China, Mozambique, Madagascar, northern Europe, North and South Korea, the U.K. and the U.S.S.R. probably have additional undiscovered or unre- ported tidal bores. Several methods were used to compile the catalog; field measurements of the Turnagain Arm estuarine tidal bores are also described. Thule Scientific, 22914 Portage Cir. Dr., Topanga, CA 90290, USA.

A160. Waves, oscillations

89:4980 Feng, Z.C. and P.R. Sethna, 1989. Symmetry-

breaking bilurcations in resonant surface waves. J. Fluid Mech, 199:495-518.

Surface waves in a nearly square container subjected to vertical oscillations are studied. Results are based on the analysis of a derived set of normal form equations, which represent perturbations of systems with 1:1 internal resonance and D 4 symmetry. Bifurcation analysis shows that the system is capable of periodic and quasi-periodic standing as well as travelling waves; parameter values at which chaotic behaviour is to be expected are identified. The theoretical results are verified experimentally. Dept. of Aerospace Engng and Mech., Univ. of Minnesota, Minneapolis, MN 55455, USA.

89:4981 Lee, S.-J., G.T. Yates and T.Y. Wu, 1989. Exper-

iments and analyses of upstream-advancing soli- tary waves generated by moving distm4mnces. J. Fluid Mech, 199:569-593.

The phenomenon of forced generation of nonlinear waves by disturbances moving steadily with a transcritical velocity through a layer of shallow water is investigated. The plane motion considered here is modelled by the generalized Boussinesq equations and the forced Korteweg-de Vries equa- tion, both of which admit two types of forcing agencies in the form of an external surface pressure and a bottom topography. Numerical results are obtained using both theoretical models for the two types of forcings. Results illustrate that within a transcritical speed range, a succession of solitary waves are generated, periodically and indefinitely, to form a procession advancing upstream of the disturbance, while a train of weakly nonlinear and weakly dispersive waves develops downstream of an ever elongating stretch of a uniformly depressed water surface immediately behind the disturbance. Engng Sei., California Inst. of Tech., Pasadena, CA 91125, USA.

89:.4962 Leykin, I.A. and A.S. Rozenberg, 1987. Mensm-ing

the high-frequency sgeetr~a for eeson waves from a dh'f~flng ~hip. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):886- 889.

Measurements are given for the high-frequency (up to 8-10 l-Iz) region of wave spectra for combined wind-driven waves and wind speeds of 6-8 m/s. Absolute values for the spectral density are 1.5-2

766 A. Physical Oceanography OLR (1989) 36 (9)

times less than for the equilibrium Phillips spectrum. Inst. of Oceanol., Acad. of Sci., USSR.

89:4983 Miles, John, 1989. Edge waves on a gently sloping

beach. J. Fluid Mech, 199:125-131. Inst. of Geophys. and Planetary Phys., Univ. of Cali- fornia, La Jolla, CA 92093, USA.

89:4984 Musman, Steven, 1989. Sea height wave form in

¢qmttor~ waves and its interlffetation. J. geophys. Res., 94(C3):3303-3309.

In a previous paper a variation in sea slope of 1.6_+ 0.6 cm per degree of latitude between 2°N and 4°N in Scasat altimeter data was associated with the passage of two temperature crests. This work has been extended to include variations in sea height with arbitrary phase in the wave. A mean wave pattern was found with maximum amplitude of 5 cm near 6°N. Fluctuating velocities in geostrophic equilibrium with the mean wave height are com- bined with a mean zonal flow to derive streamlines in a coordinate system moving westward with the phase velocity of the mean wave. One streamline shows the trochoidal form of the temperature front at about the appropriate latitude. Flow immediately north of this streamline exhibits clockwise gyres near each trough. I suggest that this is the basic pattern of the observed form and motions in the waves. Off. of Charting and Geodetic Serv., NOS, NOAA, Rock- ville, MD 20852, USA.

89:4~5 Simonelli, F. and J.P. Gollub, 1989. Surface wave

mode interactions: effects of symmetry and degenen~. J. Fluid Mech, 199:471-494.

We have investigated the dynamics of the interaction of two modes that are degenerate in a square layer, but non-degenerate in a rectangular one. Novel experimental techniques allowed both stable and unstable fixed points (sinks, sources, and saddles) to be determined, and the nature of the bifurcation sequences to be clearly established. In most of the dynamical regimes, multiple attractors and repellers were found, including both pure and mixed modes. Symmetry of the fluid cell has dramatic effects on the dynamics; the fully degenerate case (square ceil) yields no time-dependent patterns, and is qualita- tively understood in terms of third-order amplitude equations whose basic structure follows from sym- metry arguments. In a slightly rectangular cell, where the two modes are slightly separated, mode competition produces both periodic and chaotic states organized around unstable pure and mixed-

state fixed points. Phys. Dept., Haverford Coll., Haverford, PA 19041, USA.

AI70. Wind-wave interactions

89:4986 Anisimova, Ye.P. et al., 1987. Experimental study of

flow above rigid wave pcoflles. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):916-919.

The structure of a wave flux incident on three successive rigid wavy profiles of trochoidal form was studied with a focus on the air flow structure above the second wave. The experimental conditions were designed to facilitate boundary layer measurements behind the crest, and a two-component mechanotron anemometer was used to obtain unambiguous sensor readings in regions of complex flow geometries where the intensity of current pulsations exceeds the average speed. Moscow Univ., USSR. (emm)

ALSO. Internal waves and tides

89:4987 Belobrov, A.A., N.A. Panteleyev and A.A. Slepy-

shev, 1987. Modnll~ion effects in the propagation of internal waves. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):923- 925.

Following previous studies describing steady-state amplitude modulation of internal waves, the authors consider periodic modulation regimes of short periodic internal waves occurring in the presence of a low-frequency energy beating wave. Mar. Hydro- phys. Inst., Ukrainian Acad. of Sci., USSR. (emm)

89:49~ Grigor'yev, P.L., A.S. Tibilov and V.A. Yakovlev,

1987. Internal wave scattering by a weakly ~ m ~ m a m ~ d the ~km~ty fle~ in a t t b ~ l y e r ~ d the oee~ . Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):890-893.

Scattering causes saturation of the spectrum for an incident internal wave by high spatio-temporal frequencies. Because of the interference of various modes, the flow field for a scattered internal wave is concentrated in narrow zones characterized by velocity gradients that are large in comparison with the initial ones.

OLR (1989) 36 (9) A. Physical Oceanography 767

89:4989 Korchagin, N.N. and V.P. Maslov, 1987. Propaga-

t im of Internal waves in a stepwise stratified liquid. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):920-922.

The propagation of linear gravity waves in a stepwise-stratified vertically unbounded liquid is considered here, with special consideration of the effect of small-scale inhomogeneities in water den- sity introduced by waves passing through the liquid. Inst. of Oceanol., Acad. of Sei., USSR. (emm)

89:4990 McPhee, M.G. and L.H. Kanta, 1989. Generation of

internal waves by sea ice. J. geophys. Res, 94(C3):3287-3302.

We investigate the downward flux of momentum and energy by internal waves in an ice-covered ocean, with an idealized model comprising a mixed layer overlying a deep, uniformly stratified layer. A buoyancy jump separates the mixed layer from the pycnocline. Model calculations show that plausible values for the peak wave number of the idealized spectrum and roughness variance can account for (1) decreased ice velocity relative to the wind, (2) decreased heat exchange coefficient between the ice and ocean, and O) lack of mixed-layer deepening, all of which were observed. 1410 Old Naches Hwy., Naches, WA 98937, USA.

89:4991 Renouard, D.P. and Xuizhang Zhang, 1989. Baro-

clinic wave generation by barotxopic waves pass- ing over a shelf. Dynam. Atmos. Oceans, 13(1- 2):123-148. Inst. de Mecanique de Grenoble, B.P. 68, 38402 Saint-Martin d'Heres Cedex, France.

89:4992 Sabinin, K.D., A.A. Nazarov and A.N. Serikov,

1987. Study of high-amplitude internal waves near steep bottom rises. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):879- 885.

Vertical motions of the thermocline, fluctuations in acoustic scattering layers, and observations behind swift current bands at the surface of the ocean near the Seychelles are reported. Soliton-like deepenings of the thermocline were observed, propagating with speeds greatly exceeding that of the corresponding linear internal waves and reaching heights ~ 100 m. The form of the solitary waves, their high propa- gation speed, and the unvarying nature of swift currents accompanying these bands indicates that they are solitons. The field observed near the

Seychelles arises from the superposition of ordinary internal waves and solitons that originate with the nonlinear breakup of the internal tides. Acoust. Inst., USSR.

A210. Ice

89:4993 Carsey, Frank, 1989. Review and status of remote

sensing of sea ice. IEEE Jl ocean. Engng, 14(2): 127-138.

The status of obtaining geophysical observations through the interpretation of satellite data over sea ice is discussed. The community working in this area has grown in size and sophistication over the last decade, the connection between microscopic prop- erties of ice and its microwave behavior is now being understood, and accurate satellite-derived data can now be obtained. Areas of ongoing, as well as needed work are outlined, especially in the under- standing of first-year and old-ice microwave prop- erties. The efficient advance of remote sensing will require more focus on in-situ studies. JPL, California Inst. of Tech., 4800 Oak Grove Dr., Pasadena, CA 91109, USA.

89:4994 Dionne, J.-C., 1989. An estimate of shore ice action in

a Spara~ tidal marsh, St. Lawrence Estuary, Qu~4~ec, Canada. J. coast. Res., 5(2):281-293. Dept. of Gcogr., Univ. Laval, Quebec, PQ G1K 7P4, Canada.

89:4995 Duckworth, Roger and P.H. Westermann, 1989.

Stress and strain instru~nts developed for field measurements of ice. 1EEE Jl ocean. Engngo 14(2): 159-165.

A delta strainmeter developed for slow creep loading of ice at Tarsiut Island in the Beaufort Sea has since been used to record surface strain on a surging glacier on Svalbard with data transmission by satellite. Ice stress cannot be derived from the strain rate when ice loads vary rapidly or when fracturing occurs. A thin disc sensor has been produced with a high axial stiffness and thermal stability; good contact between the sensor and the ice mass is essential. The methods used in a range of field conditions are described. A data set showing stresses of up to 600 kPa recorded in first-year ice near a Beaufort Sea structure is presented. BP Res. Ctr., Chertsey Rd., Sunbury-on-Thames, Middlesex TWI6 7LN, UK.

768 A. Physical Oceanography OLR (1989) 36 (9)

89:4996 Hawkins, J.D. and Matthew Lybanon, 1989.

GEOSAT altimeter sea-ice mapping. IEEE Jl ocean. Engng, 14(2):139-148.

This paper details efforts to use GEOSAT data to refine an ice index that is applicable to widely varying ice conditions. Sea-ice mapping require- ments, the present Navy ice-index operational utilization, and ongoing and future work are de- scribed. Remote Sensing Branch, NORDA, Stennis Space Ctr., MS 39529-5004, USA.

89:4997 Winebreuner, D.P. et al., 1989. Sea-ice character-

ization measurements needed for testing of microwave remote sensing models. IEEE J1 ocean. Engng, 14(2):149-158. Coll. of Ocean and Fish. Sci., Univ. of Washington, Seattle, WA 98105, USA.

A260. Acoustics

89:4998 Chapman, D.M.F., 1989. A simple estimate of

propagation loss fluctuations due to modal inter- ference. J. acoust. Soc. Am, 85(3):1097-1106. Inst. of Sound and Vibration Res., The Univer- sity, Southampton SO9 5NH, UK.

89:4999 Collins, M.D., 1989. A nearfield asymptotic analysis

for underwater acoustics. J. acoust. Soc. Am, 85(3):1107-1114. NORDA, Stennis Space Ctr., MS 39529, USA.

89:5000 de Heering, Philippe, 1989. An impact sound source

nsoful for Arctic remote sensing. IEEE J1 ocean. Engng, 14(2):166-172. Canadian Astronautics Ltd., 1050 Morrison Dr., Ottawa, ON K2H 8K7, Canada.

89:5001 Hay, A.E. and A.S. Schaafsma, 1989. Resonamae

scattcling in saspensions. J. acoust. Soc. Am, 85(3): 1124-1138. Delft Hydraulics, P.O. Box 177, 2600 MH Delft, Netherlands.

89:5002 Kotulski, Z., 1989. [Aconsticl wave propagation in a

randomly stratified medhm. J. Sound Vibr, 128(2): 195-208. Inst. of Fund. Tech. Res., Polish Acad. of Sci., Warsaw 00-049, Poland.

89:5003 Plumpton, N.G. and C.T. Tindle, 1989. Saddle point

analysis of the reflected acoustic field. J. acoust. Soc. Am, 85(3):1115-1123. Phys. Dept., Univ. of Auckland, New Zealand.

89:5004 Prosperetti, A., L.A. Crum and H.C. Pumphrey,

1989. The umierwater noise of rain. J. geophys. Res., 94(C3):3255-3259. Dept. of Mech. Engng, Johns Hopkins Univ., Baltimore, MD 21218, USA.

89:5005 Rohr, Jim, Ray Glass and Brett Castile, 1989. Effect

of I~ l lon lo legn la r film~ oni t he a a d e r l y ~ ocean ambient-noise field. J. acoust. Soc. Am, 85(3): 1148-1157.

A series of tests has unequivocally established that the presence of a monomolecular film on the sea surface results in a pronounced reduction of ambient noise beneath the film. This reduction was observed to begin around 2 kHz, continue to at least 20 kHz, and was evident to some degree throughout sea states 11/2 to 6. A predictive model is developed that is generally consistent with the film's observed behavior, and several possible mechanisms are speculated through which the film could affect the underlying ambient-noise field. Naval Ocean Syst. Ctr., San Diego, CA 92152, USA.

89:5006 Smith, G.B. et al., 1989. A nonlinear matdted-field

processor for detection and localhmtion of a quiet soorce in a noisy shallow-water environment. J. acoust. Soc. Am, 85(3): 1158-1166. Dept. of Phys. and Engng, Xavier Univ., New Orleans, LA 70125, USA.

89:5007 Ward, P.D., 1989. Letter. A novel method of f indi~

normal modes in shallow water. J. Sound Vibr~ 128(2):349-354. Inst. of Sound and Vibration Rcs., Univ. of Southampton, Highfield, South- ampton SO9 5NH, England.

89:5008 Yang, T.C., 1989. Low-frequency transmtmion loss in

the Arctic SOFAR clmnnel for shallow sources and receivers. J. acoust. Soc. Am, 85(3):1139- 1147. Naval Res. Lab., Washington, DC 20375, USA.

OLR (1989) 36 (9) A. Physical Oceanography 769

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

89:5009 Fernando, H.J.S., D.L. Boyer and R. Chen, 1989.

Turbulent thermal convection in rotatin~ and stratified fluids. Dynam. Atmos. Oceans, 13(1- 2):95-121.

During the past two decades, numerous laboratory experiments have been performed to understand the influence of rotation and stratification on turbulence induced by thermal convection. A brief overview of these studies and their geophysical implications are presented and some potential future research areas are identified. Some preliminary observations of laboratory studies in progress on entrainment and mixing in rotating and stratified fluids are also outlined. Dept. of Mech. and Aerospace Engng, Arizona State Univ., Tempe, AZ 85287, USA.

89:5010 Gavrilin, B.L. and M.M. Domanov, 1987. A mech-

anism for salt lransfer in a stratified fluid. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):875-878. Inst. of Oceanol., Acad. of Sci., USSR.

89:5011 Kozlov, O.V., G.M. Reznik and T.E. Soomere, 1987.

Weak turlmlence on the fl-plane in a two-layer ocean. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):869-874.

The kinetic equation for slightly linear Rossby waves in a two-layer ocean is derived. It is shown that the spectrum of any steady zonal flow is a solution of the kinetic equation and is stable. The equation describ- ing the evolution of the wave spectrum against the zonal flow background is derived, along with the entropy equation for such a system. The spectrum equal to the sum of the zonal flow spectrum and the isotropic equilibrium spectrum for two-dimensional turbulence is also the thermodynamic equilibrium and stable. Inst. of Oceanol., Acad. of Sci, USSR.

89:5012 Rasenat, S., F.H. Busse and I. Rehberg, 1989. A

theoretical and experimental study of donble- layer omveetion. J. Fluid Mech, 199:519-540.

The onset of thermal convection in a double layer of two superimposed immiscible fluids heated from below is investigated. The onset of steady convection in the two layers may occur in the form of either viscously or thermally coupled motions. In addition to the oscillatory interfacial instability, which de- pends on a non-vanishing distortion of the interface,

a second oscillatory instability corresponds to a cyclic variation between viscous and thermal coup- ling. Conditions for the onset of this instability are outlined and its connections with the other modes of the system are demonstrated in bifurcation dia- grams. In the experiments the shadowgraph method is used for the visualization of the onset of convec- tion and for *.he measurement of its wavelength. Inst. of Phys., Univ. of Bayreuth, D-8580 Bayreuth, FRG.

89:5013 Waling, GOsta and Lena Lundberg, 1988. On the

distrilmtion of geeslmphk flow in a stratified surface layer. Rept oceanogr. Inst. GOteborgs Uni% 48:23pp.

We consider the drainage of a light surface layer from a semienclosed deep basin. The flow is geostrophically controlled and occurs in the frontal region where the isopycnals bend upward to meet the surface. Frontal structure information is needed for the calculation of the flow of heat, salt and chemical constituents which are not well mixed within the surface layer. A general formula for the distribution of the flow with respect to density is derived, and some useful qualitative properties are demonstrated which may be helpful for modelling purposes. Dept. of Oceanogr., Univ. of Gothenburg, Box 4038, S-400 40 Gothenburg, Sweden.

M(H). Fluid mechanics

89:5014 Baines, P.G. (ed.), 1989. Special issue. Laboratory

experiments in geophysical fluid dynamics: cur- rent progress and new horizons. Dynam. Atmos. Oceans, 13(1-2):164pp; 6 papers.

Numerical modelling of fluid dynamics has been very fruitful, but doesn't have the advantage (and certainty) of working with a real fluid. However, flow visualization and recording techniques can now give data outputs and detail comparable to models. This issue focuses on laboratory contributions (present and future) to geophysical fluid dynamics. Topics include lab experiments that demonstrate, replicate or duplicate coastal upwelling, lift forces on obstacles in flows, convective oceans, thermal convection in rotating, stratified fluids, baroclinic wave generation by barotropic waves and thermal circulation in rotating basins. (fcs)

89:5015 Condie, S.A., 1989. A laboratory model of a convee-

tively driven ocean. Dynam. A tmos. Oceans, 13(1-2):77-93.

770 OLR (1989) 36 (9)

Many large-scale flows in the ocean are driven by an imposed horizontal density gradient and the result- ing circulation is strongly influenced by the Earth's rotation. In a laboratory model buoyancy driven boundary currents produced by heating and cooling were unstable and the resulting eddy structures eventually dominated the system. A broad mean flow, perpendicular to the side walls, developed in the central region of the cavity. The resultant steady-state flow had a barotropic component consisting of two large-scale gyres of cyclonic and anticyclonic senses. Measurements of the time-scales for the establishment of stratification point to the existence of two dynamical density adjustment modes. Dept. of Oceanogr., Old Dominion Univ., Norfolk, VA 23529, USA.

89:5016 Dobritsyn, A.A. and Yu.B. Sedov, 1987. Collapse of

geostrolgaic eddies. Izv. Atmos. Ocean Phys. (a translation of Fiz. Atmos. Okeana), 23(11):852- 858.

In contrast to the collapse of logarithmic eddies, the collapse of geostrophic eddies is non-uniform and finite. The contour dynamics method is used to demonstrate that the collapse of three-point eddies is stable with reference to both the circular initial form of the eddy and the collapse conditions. Eddy pairs can be studied in the concluding stage of collapse of eddies of finite size. Inst. of Atmos. Phys., USSR.

89:5017 Marshall, J.S. and P.M. Naghdi, 1989. A thermo-

dynamical theory of turlmlence. 1. Basic devel-

olmmnts. Phil. Trans. R. Soc., (A)327(1595):415- 448.

The authors offer a 'manageable' theory of turbu- lence based on a continuum model and designed to encompass a wide range of experimental results and observations, particularly those surrounding a wide- ly studied class of 'large' eddies which carry most of the energy associated with turbulent fluctuations. A complete theory of viscous turbulent flow is devel- oped, but the inviscid case is also discussed. In addition to the usual thermochemical effects, the theoretical results account for a variety of mechan- ical and energetic aspects of turbulent flows. Dept. of Mech. Engng, Univ. of California, Berkeley, CA 94720, USA. (emm)

89:5018 Marshall, J.S. and P.M. Naghdi, 1989. A thermo-

d y n m e a l theory of turbulence, II. Determination of constitutive coefficients and iflustrative ex- amples. Phil. Trans. R. Soc., (A)327(1595):449- 475.

In part 1 of this paper a theory was developed for viscous turbulent flow. Part 2, presented here, is concerned with the determination of constitutive response coefficients from a simplified version of the basic turbulence theory. The difficulty of this task makes the present results tentative; however, most of the relevant coefficients are determined, or at least their functional forms estimated, and the results are used in conjunction with macroscopic equations of motion to examine a number of simple solutions. Dept. of Mech. Engng, Univ. of California, Berkeley, CA 94720, USA. (emm)

B. MARINEMETEOROLOGY

BI0. Apparatus and methods

89:.5019 Wright, P.B., 1989. Homogenized long-peltod South-

era Oscillation indices. Int. J. Climatol~ 9(1):33- 54.

A long-term (100 yr or longer) index of the Southern Oscillation is necessary for a number of applications,

but pre-1950 data are limited. In this paper, long-term SST, rainfall, and pressure data indices are compared, and corrections are made. Gaps are filled using substitutions from 1950-1979 index regressions. The resulting indices are given: monthly SST for 1872-1985, monthly rainfall for 1893-1983, and seasonal pressure for 1851-1984; extreme years (in terms of SST and rainfall) are indicated. 69 Talfourd Ave., Reading R96 2BP, UK. (gsb)