Physical oceanography

Oceanographic Literature Review (1985) 32 (7)

The citations are those received in the editorial office during the period 1-30 April, 1985. 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 85:3311

Bertoglio, J.-P. and Jean Mathieu, 1984. A stochastic sul~grid model for huge eddy simulation: general formulation. C. r. Acad. Sci~ Paris, (S~r. II)299(12):751-754. (In French, English abstract.) Lab. de Mecan. des Fluides, Ecole Centrale de Lyon, B.P. 163, 69131 EcuUy Codex, France.

85:3312 Bertoglio, J.-P. and Jean Mathieu, 1984. A stochastic

subgrid model for large eddy simulation: generation of a stochastic process. C. r. Acad. Sci, Paris, (S~r. II)299(13):835-838. (In French, English abstract.)

A Markovian random forcing is proposed for backscatter modelling, and a stochastic process for spectral simulation of non-isotropic homogeneous fields is presented. Statistical quantities are shown to

be in agreement with the properties required for a subgrid model. Lab. de Mec. des Fluides, Ecole Centrale de Lyon, B.P. no 163, 69131 Ecully Cedex, France.

85:3313 Davydov, L.M. and A.V. Maksimov, 1984. A

one-dimensional mathematical model of water dynamics and tnmsport of dissolved matter in estuaries. Meteorologiya Gidrol, 10:100-106. (In Russian, English abstract.)

The model takes into account the effect of spatial inhomogeneity of the density field upon transport and mixing dynamics. The method permits calculation with large time steps, and the simple algorithm facilitates computer use.

85:3314 Harger, R.O., 1984. A fundamental model and

efficient Inference for SAR ocean imaaery. IEEE J! ocean. Engng, OE-9(4):266-276.

49g \ . P!r,'-,lc:t] ()ccal+ograph,, OI.,R (1985) 32 (7i

Employing a synthetic aperature radar imaging model based on fundamental models of nonlinear hydrodynamics, electromagnetic scattering from a two-scale surface, and SAR imaging of a time- variant scene, the optimal estimates of the parameters of a sinusoidal long gravity wave and the short gravity wave ensemble are found in an efficient recursive form. Their performance is evaluated, generally by numerical simulation, in a 1-D stationary version. An application is made to Seasat- SAR complex imagery. Elect. Engrg. Dept., Univ. of Maryland, College Park, MD 20742, USA.

85:3315 Jackson, F.C., W.T. Walton and P.L. Baker, 1985.

Aircraft and satellite measurement of ocean wave directional spectra using scanning-beam microwave radars. J. geophys. Res., 90(C1):987-1004.

A microwave radar technique for remotely meas- uring the vector wave number spectrum of the ocean surface is described. The technique, which employs short-pulse, noncoherent radars in a conical scan mode near vertical incidence, is shown to be suitable for both aircraft and satellite application and has been validated at 10 km aircraft altitude, where excellent agreement between buoy and radar-in- ferred absolute wave height spectra was found. Lab. for Oceans, NASA Goddard Space Flight Center, Greenbelt, MD, USA.

85:3316 Jackson, F.C., W.T. Walton and C.Y. Peng, 1985. A

comparison of in-situ and airborne radar observations of ocean wave directionality. J. geophys. Res., 90(C1): 1005-1018.

The directional spectrum of a fully arisen ~ 3 m sea as measured by an experimental airborne radar (ROWS) is compared to reference pitch-roll buoy data and to the classical SWOP (stereo wave observation project) spectrum for fully developed conditions. The ROWS spectrum is in excellent agreement with the buoy spectrum. A comparison of the ROWS and SWOP spectra shows them to be very similar, in detailed shape as well as in terms of the gross spreading characteristics. Both spectra exhibit bimodal structures which accord with the Phillips resonance mechanism, supporting Phillips' contention that the SWOP modes were indeed resonance modes, not statistical artifacts. NASA Goddard Space Flight Center, Greenbelt, MD, USA.

85:3317 Keller, W.C., W.J. Plant and D.E. Weissman, 1985.

The dependence of X band microwave sea return on atmospheric stability and sea state. J. geophys. Res., 90(C1): 1019-1029.

The data reveal that cross sections increase with decreasing ratio of height to Obukhov length in unstable atmospheric conditions. In near-neutrally stratified atmospheric conditions, X band cross sections at constant and relatively low wind speeds increase with long-wave slope, while modulation transfer functions decrease with long-wave slope. No clear dependence of either parameter on wave slope was observed in highly unstable conditions. Impli- cations are discussed. Naval Res. Lab., Washington, DC, USA.

85:3318 Lyzenga, D.R., R.A. Shuchman, J.D. Lyden and

C.L. Rufenach, 1985. SAR [Synthetic ApeNure Radar] imaging of waves in water and ice: evidence for velocity bunching. J. geophys. Res., 90(C!): 1031-1036.

SAR images collected over the Arctic marginal ice zone show gravity wave patterns in both open water and ice. Diffuse wave patterns are visible in the water at near range (small incidence angles), while more distinct wave patterns are visible in the ice across the entire swath. Wave patterns in the ice appear as bright lines rather than sinusoidal intensity variations and the images show a periodic displacement of the ice/water boundary, apparently due to Doppler shift effects associated with the gravity wave orbital motions. These observations are interpreted as evidence for the velocity bunching effect and also illustrate the effects of random scatterer motions in open water. Radar Div., Envi- ron. Res. Inst. of Michigan, Ann Arbor, MI, USA.

85:3319 Nakajima, Hideo, 1984. Some remarks on the

spectrum of rapid-chanlging random data in the ocean. J. oceanogr. Soc. Japan, 40(5):367-370.

The spectral characteristics calculated for rapidly varying data, including 'saw-tooth' and stepwise changing, are discussed. It is shown that the spectra for these time series have frequency dependencies in the range of -2 to -4. Fac. of Engng, Hiroshima Univ., Shitami, Saijo-cho, Higashi-hiroshima 724, Japan. (wbo)

85:3320 Scivier, M.S. (comment) and R.O. Harger (reply),

1984. Comments on 'A sea surface height esti- mator using synthetic aperture radar complex imagery.' (/EEE J. Ocean/c gn~lneerh~ voi. OE-8, no. 2, pp. 71-78, Apr. 1983.) IEEE Jl ocean. Engng, OE-9(4):281-283. King's Coll. (KQC), Univ. of London, Strand, London WC2R 2LS, UK.

OLR 0985) 32 (7) A. Physical Oceanography 499

85:3321 Young, I.R., W. Rosenthal and F. Ziemer, 1985. A

three-dimensional analysis of marine radar images for the determination of ocean wave directionality and surface currents. J. geophys. Res~ 90(C1): 1049-1059.

In the absence of a surface current the spectral energy in the 3-D wave number frequency space will lie on a shell defined by the dispersion relationship. Any deviation from the expected dispersion relationship can be interpreted as being due to a current-induced Doppler shift of the wave frequency. A comparison of the radar-determined spectra and derived surface currents with ground truth data indicates that the radar system and analysis technique produce results consistent with conventional instrumentation. Inst. fur Meeres. der Univ., Hamburg, FRG.

A40. Area studies, surveys

85:3322 Hirai, Mitsuyuki, 1984. Analysis of hydrographic

conditions in the northeastern Sea of Japan using infrared images obtained by NOAA--6 satellite. Bull. T6hoku reg. Fish. Res. Lab., 46:27-38. (In Japanese, English abstract.)

NOAA-6 satellite data from October 1981 were analyzed for water mass fluctuations. Standard deviations between locations identified by horizontal temperature distributions and those derived from remote sensing were within 15 miles, suggesting that infrared images are valid for analysis of short- and long-term fluctuations. (lit)

85:3323 Mizuno, Keisuke, 1984. Notes on the hydrographic

variability in the vicinity of the east coast of Japan. Bull. Trhoku reg. Fish. Res. Lab., 46:61- 80. (In Japanese, English abstract.)

Monthly 100-m temperature maps compiled over a 17-yr period were analyzed for statistical characteristics of hydrographic variability. Seasonal variability was found in the Tsugaru Warm Current area; the first Oyashio intrusion showed weak seasonal variability. The path of the Kuroshio Extension showed no significant seasonal variability. Application to fisheries forecasts is discussed. (lit)

85:3324 Toole, J.M., 1985. Near equatorial CTD observations

at 85°W in October 1982. J. geophys. Res, 90(C1):929-933.

With respect to data from November 1981, virtually the entire section exhibited downward displacements in the upper kilometer of the water column. Ob- served displacements at the depth of the mean thermocline were large (~150 m) and relatively symmetric about the Equator; displacements about 1 km depth were near zero. This stratification change appears to have been produced by a zonal convergence of mass at temperatures above 15°C, with divergence below. Analysis revealed significant contributions from modes 1 and 2 with meridional structure consistent with Kelvin waves. The observations thus support current theories that relate El Nifio onset in the eastern Pacific to anomalous wind forcing in the west. WHOI, Woods Hole, MA 02543, USA.

A50. General hydrography (distribution of c o m m o n oceanic properties)

85:3325 Huyer, Adriana, 1984. Hydrographic observations

along the CODE [Coastal Ocean Dynamics Experiment] central line off northern California, 1981. J. phys. Oceanogr., 14(10):1647-1658.

The section consisted of nine stations between 1 and 46 km from the shore in water depths between 40 and 1700 m; shelf-break was at 150 m. During April-August, winds were strong and favorable for upwelling. Isotherms, isohalines and isopycnals in the upper 200 m sloped persistently upward toward the coast, peaking at the most inshore station. Variations in wind strength caused surface layer changes over the entire shelf; stronger winds were associated with lower temperatures and higher salinities. Shelf waters were considerably warmer and less saline in winter, when the wind direction and speed were highly variable; isotherms, isohalines and isopycnals were nearly level. Coll. of Oceanogr., Oregon State Univ., Corvallis, OR 97331, USA.

85:3326 Martin, P.J., 1985. Simulation of the mixed layer at

OWS [Ocean Weather Stations] November and Papa with several models. J. geophys. Res., 90(C1):903-916.

The 1-D mixed-layer models of MeUor-Yamada, Niiler, and Garwood were used to simulate changes in the mixed layer at the weather stations in 1961 using simple forcing. If model constants were readjusted at each site, reasonable results were obtained. Sensitivity to external model parameters was investigated. Turbidity, which affected the vertical distribution of solar heating, and ambient

500 A, Physical Oceanograph) OLR (1985) 32 (7)

thermal diffusivity were found to be sensitive parameters. NORDA, Natl. Space Tech. Lab., Mississippi, USA. (wbo)

85:3327 Petrov, V.M. and I.E. Frolov, 1984. The mechanism

of formation of the warm interlayer of waters in the pycnocline layer of Arctic seas. Meteorologiya Gidrol., 1 ! :110-111. (In Russian.)

ASO. Circulation

85:3328 Adamec, David and R.L. Elsberry, 1984. The use of

mean atmospheric forcing in an ocean mixed- layer model. J. phys. Oceanogr., 14(10):1670- 1676.

Model simulations are sensitive to length of the averaging window applied to the atmospheric forcing; both detail and trends in the mixed-layer depth and temperature deviate more from the control with increasing length of the averaging window. The cases which use forcing calculated from averages of actual observations better simulate the detail and trend in mixed-layer depth for 30-day windows than cases which use forcing based on the average of the calculated fluxes. By contrast, the latter leads to better predictions of SST detail and trend than does the use of average observations to compute averaging forcing. Dept. of Meteorol., Naval Postgrad. Sch., Monterey, CA 93943, USA.

85:3329 Adamec, David and R.W. Garwood Jr., 1985. The

simulated response of an upper-ocean density front to local atmospheric forcing. J. geophys. Res., 90(C1):917-928.

Four simulations with different atmospheric forcing are used to examine the transient response of an upper-ocean density front using an embedded mixed-layer ocean circulation numerical model. Results are compared with observations taken south of Sicily in the Maltese front. Using observed forcing, the model is consistent with most of the observed response except that it predicts too much mixed-layer deepening and no increased along-front flow. The additional experiments investigate the effects of a change in wind direction and the inclusion of surface buoyancy forcing. Inclusion of diurnal forcing produces a markedly better simulation. Dept. of Meteorol., Naval Postgrad. School, Monterey, CA 93943, USA. (wbo)

85:3330 Lewis, J.K. and R.O. Reid, 1985. Local wind forcing

of a coastal sea at subinertial frequencies. J. geophys. Res., 90(C1):935-944.

An analytical, normal mode, two-layer model is linear and is developed in frequency space; theoretical development indicated the requirement of a frictional parameter in both barotropic and baroclinic modes to balance wind stress at lower frequencies. Experimentation showed both frictional effects were required throughout the subinertial frequency range. With appropriate frictional parameters, the model predicts the response of the Texas coastal region to local wind forcing quite well. Underprediction of current energy levels under certain summer conditions most likely indicates the presence of nonlocally generated shelf wave phenomena. The author is with Science Applications, Inc.

85:3331 McCreary, J.P. Jr., 1985. Modeling equatorial ocean

circulation. A. Rev. Fluid Mech., 17:359-409.

Interest in equatorial circulation has grown tre- mendously in recent years due to observations of a surprising variety of phenomena in the area (of particular note, the presence of vertically propagating Rossby-gravity waves) and the realization that equatorial SST anomalies influence global climate (as in the 1982-83 El Nifao). Reviewed here are the models, ranging in complexity from simple, linear, surface layer models to sophisticated, nonlinear continuously stratified models, developed to study these phenomena. As simple linear models are capable of singling out important dynamic processes, some linear solutions are presented in detail. Un- forced solutions, solutions forced by switched-on wind and those forced by periodic winds are discussed; linear and nonlinear solutions are compared. A final section examines current research on E1 Nifao phenomena. Nova Univ. Oceanogr. Center, Dania, Florida 33004, USA. (msg)

85:3332 Richez, C., G. Philander and M. Cr~pon, 1984.

Oceanic response to coastal winds with shear. Oceanologica Acta, 7(4):409-416.

The response of a stratified ocean to a wind blowing over a patch and parallel to a coast is examined. In the f-plane case, the upwelling and jet occurring at the coast rather quickly acquire stable values, because they are arrested by Kelvin wave fronts generated at the wind discontinuity, while the downwelling and the double jet occurring at the wind discontinuity continue to increase with time.

OLR (1985) 32 (7) A. Physical Oceanography 501

The fl effect suppresses the coastal motion via radiation of westward propagating Rossby waves for eastern coasts; the downwelling eventually reaches a constant value which extends westward at the speed of long baroclinic Rossby waves and occupies a large oceanic surface. This phenomenon could trigger the El Ni~o. L.A. 175 CNRS, Lab. d'Oceanogr. Phys., Mus. Natl. Hist. Nat., Paris, France.

85:3333 Roden, G.I. and B.A. Taft, 1985. Effect of the

Emperor Seamonnts on the mesoscale thermohaline structure during the summer of 1982. J. geophys. Res., 90(C1):839-855.

Data show that the Emperor Seamount Chain deflects the oncoming flow of the Kuroshio Exten- sion and gives rise to secondary perturbations of small horizontal extent but large vertical amplitude. In general there was uplifting near the seamounts and vertical displacement on their flanks; details varied for each seamount. In one case the perturbations appear to be those of a stratified Taylor column and in another, that of a meander or eddy associated with the Kuroshio Extension. Detailed hydrographic analyses and calculations of geopo- tential flow are given. School of Oceanogr., Univ. of Washington, Seattle, WA, USA. (wbo)

85:3334 Thouvenin, B. and J.-C. Salomon, 1984. Three-

dimensional model of circulation and dispersion in a tidal coastal area. Oceanologica Acta, 7(4):417- 429. (In French, English abstract.)

The model described here accounts for real bottom topography and variations of the free surface. It was applied to flat bottom schematic basins, a real channel and density currents associated with a salty wall; results were compared to theoretical solutions and results from other models. Lab. d'Oceanogr. Phys., ERA 766, Univ. de Bretagne Occidentale, 6, ave. Victor-Le Gorgeu, 29283 Brest Cedex, France. (msg)

A90. Currents

85:3335 Baranov, E.I., 1984. A quasi-stationary anticyclonic

eddy and its role in the formation of the Newfoundland energy-active zone. Meteoroiogiya Gidrol., 10:87-93. (In Russian, English abstract.)

Based on data from 14 surveys, the size, multiyear position, and multiyear maximum heat output of the large-scale warm anticyclonic eddy are discussed. (msg)

85:3336 Ishizaki, Hiroshi and Masahiro Endoh, 1984. Deep

flow on the continental slope off Omaezaki, in the northern part of the cold water region associated with the Kuroshio meander. Pap. Met. Geophys., Tokyo, 35(2):49-62.

Presented are the results of 136 days of direct measurements of the deep flow (30, 100, 310, 1000 m above the bottom) on the shelf off central Japan. Mean flow was SE at 30 m and southward at 100 m, in contrast to the W-SW flow at 100 m observed in a prior study. The degree of coherency of temporal variations of the flow field between depths is discussed. Meteorol. Res. Inst., Tsukuba, Japan. (msg)

85:3337 Larsen, J.C. and T.B. Sanford, 1985. Florida Current

volume transports from voltage measurements. Science, 227(4684):302-304.

Simultaneous measurements of velocity-profile derived volume transport and the motionally induced voltage difference between Florida and the Grand Bahama have a correlation of 0.97. The calibration factor is 25+_0.7 Sv/volt; root-mean-square discrepancy is 0.7 Sv. Induced voltage is about half the open circuit value, implying that conductance of the sediments and lithosphere approximates that of the water column. NOAA, PMEL, Seattle, WA 98115, USA.

85.'3338 Lee, T.N., F.A. Schott and Rainer Zantopp, 1985.

Florida Current: low-frequency variability as observed with moored current meters during April 1982 to June 1983. Science, 227(4684):298-302.

Transport estimates, using a constant shear extrap- olation to the surface, from 5 subsurface moorings deployed across the Florida Straits at 27°N are in good agreement with simultaneous measurements using acoustically tracked profilers and submarine cable electro-magnetic measurements. The temporal spectrum for variations in the transport shows no gap between seasonal and weekly time scales and has a slope of about -1.5. Higher frequency variations (periods ~40 days) have significant coherence with local meridional wind stress, suggesting that they are due to atmospheric forcing. RSMAS, Univ. of Miami, FL 33149, USA. (wbo)

85:3339 Maul, G.A., Frank Chew, Mark Bushnell and D.A.

Mayer, 1985. Sea level variation as an indicator of Florida Current volume transport: comparisons with direct measurements. Science, 227(4684): 304-307.

502 A. Physical Oceanography OLR (1985) 32 (7~

Sea level measurements from tide gauges and bottom pressure gauges on both sides of the Straits of Florida were analyzed with concurrent direct volume transports. Measurements on the eastern side of the strait were not significantly correlated with the direct measurements; those on the Florida coast were significantly correlated with both the direct volume measurements and with the submarine cable observations. These results suggest that a combination of easily obtained observations are sufficient to mon- itor the daily volume transport fluctuations of the Florida Current. NOAA, AOML, Miami, FL 33149, USA. (wbo)

85:3340 Molinari, R.L. et al., 1985. Subtropical Atlantic

climate studies: introduction. Science, 227(4684): 292-295.

An introduction for a series of reports on the results of a 2-year intensive monitoring of the Florida Current gives an overview of the design criteria for the experiment and a brief description of the times and types of measurements taken. A brief summary of some of the important results is also presented. NOAA, AOML, Miami, FL 33149, USA. (wbo)

85:3341 Molinari, R.L., W.D. Wilson and Kevin Leaman,

1985. Volume and heat transports of the Florida Current: April 1982 through August 1983. Sci- ence, 227(4684):295-297.

Vertical profiles of velocities and temperatures taken on 9 cruises across the Straits of Florida at 27°N using an acoustically tracked profiler (Pegasus) are used to es t imate mean annual volume (30.5_+1 × 106 m 3 s ~) and heat (1.2_+0.1 × 10 ~5 watts) fluxes in the Florida Current. Combining these values with historical midbasin data, a total meridional heat flux through a section at 27°N is calculated that agrees with previous values. Varia- tions in these fluxes through the Florida Straits are characterized by high values in the late spring and early summer and low values in the late fall and early winter. NOAA, AOML, Miami, FL 33149, USA. (who)

85:3342 Salusti, Ettore and Rosalia Santoleri, 1984. A yon

wake in the Ligurian Sea. Boll. Oceanol. teor. appl., 2(4):275-280.

Eddies and meanders observed in the Ligurian Sea are analyzed via hydrological observations and satellite imagery. An hypothesis on their generation, i.e. through turbulent interaction between the two main currents flowing northward from the east and

west sides of the Corsica Island, is discussed. A v o n K~lrmfin wake can be at the origin of many--but not a l l - -of the observed irregularities of these marine currents. INFN, Dipt. di Fis., Univ. La Sapienza, Roma, Italy.

85:3343 Schott, Friedrich and Rainer Zantopp, 1985. Florida

Current: seasonal and interannual variability. Science, 227(4684):308-311.

Using historical sea level differences from both sides of the Florida Straits, from the Caribbean, and from the subtropical Atlantic together with wind field data, the existence and possible causes of annual and interannual variations in the Florida Current are investigated. The seasonal cycle appears to be locally forced, either upstream in the Caribbean or downstream over topography. The interannual variations in transport are only of the order of l x l06 m 3 s and are correlated with sea level differences across the Caribbean and the subtropical Atlantic and not with variations in the interior Sverdrup flow deduced from changes in the large scale wind stress curl. RSMAS, Univ. of Miami, FL 33149, USA. (wbo)

85:3344 Takeuchi, Kensuke, 1984. Numerical study of the

Subtropical Front and the Subtropical Counter- current. J. oceanogr. Soc. Japan, 40(5):371-381.

That the Subtropical Front occurs in the North Pacific and North Atlantic suggests that it and the Subtropical Countercurrent are not the consequence of oceanic topography, geometry, or wind stress distribution. A highly idealized model is developed, depicting the North Pacific as a flat-bottomed rectangle driven by wind stress and heat exchange through the sea surface. Results demonstrate the feasibility of the model and suggest that the formation of the Subtropical Front is due to wind-driven gyre circulation and differential heating; a detailed mechanism of formation remains unknown. Two factors previously thought important to formation were found to be nonessential: the presence of a small trough of wind stress curl in the lower latitudes of the Subtropical Gyre, and the meridional Ekman convergence. Dept. of Geophys- ics, Hokkaido Univ., Sapporo 060, Japan. (msg)

85:3345 Yasuda, Hidekazu, 1984. Longitudinal dispersion of

matter due to the shear effect of steady and oscillatory currents. J. Fluid Mech., 148:383-403.

A theoretical study of an idealized 2-D case reveals the process whereby dispersion reaches a stationary stage after the release of the dispersing substance as


an instantaneous line source in steady and in oscillatory currents. The relation between the stationary dispersion coefficients in steady and oscillatory currents is also given analytically. A clear definition of the vertical average of the variance is required for analysis of the dispersion during the initial stage; introduction of a new vertical average aids in understanding the problem of the negative dispersion coefficient obtained by the usual vertical average. Govt. Indust. Res. Inst., Chugoku 15000, Hiromachi, Kure 737-01, Japan.

AllO. Water masses and fronts

85:3346 Armi, Laurence and Walter Zenk, 1984. Large lenses

of highly saline Mediterranean Water. J. phys. Oceanogr., 14(10): 1560-1576.

Isolated compact anticyclonic salt lenses with highly anomalous T and S were found in the Canary Basin centered at ~1100 m; vertical extent is up to 900 m and radii ~ 5 0 km. Eddy velocities were up to 29 cm/s. Finestructure with vertical scales of ~20 m and less, possibly due to intrusive decay, appears at the outer edges of the lenses; the centers are free of such structure. The probability of finding a salt lens at any station in the Canary Basin is fairly high. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA.

85:3347 Garvine, R.W., 1984. Propagating long waves on

oceanic density fronts: an analytic model. J. phys. Oceanogr., 14(10): 1590-1599.

The model is barotropic but has ageostrophic dynamics, based on Stommel's model of the Gulf Stream with uniform potential vorticity and order one Rossby number. Inviscid dynamics are assumed apart from a narrow dissipative zone adjacent to the surface front; the latter exerts a bulk effect on the larger inviscid zone, especially in generating small cross-stream flow in the basic state. For zero cross-flow resulting waves are stable, have downstream phase speeds that are slow compared to the current speed and that increase with frequency, and have anomalous dispersion. For finite cross-flow waves grow slowly in the downstream direction when flow is out of the current and decay when flow is into the current. Corresponding net growth or decay in the wave kinetic energy is produced by action of the cross-correlation wave Reynolds stress against the lateral shear of the basic state current. Coll. of Mar. Stud., Univ. of Delaware, Newark, DE 19716, USA.

A120. Convergences, divergences, upwelling

85:3348 Kelly J., Rolando and Jos~ Blanco G., 1984.

Upwelling process off Punta Nngurne, Chile (Lat. 36°S), March 1983. Investigaci6npesq., Santiago, 31:89-94. (In Spanish, English abstract.)

Upwelling of Equatorial Subsurface Waters (low in oxygen and high in salinity) from depths of 150-200 m is described. Using a 2-layer stratified ocean model, a vertical velocity of 0.016 cm/s and a horizontal extension of 12.7 km were obtained. The upwelling more closely resembled upwelling processes observed off the Oregon coast than those described off Peru. (msg)

A150. Tides and sea level

85:3349 Brundrit, G.B., 1984. Monthly mean sea level

variability along the west coast of southern Africa. S. Afr. J. mar. Sci., 2:195-203.

The first principal component, accounting for >55% of the variability in monthly mean sea level, was a near uniform rise and fall everywhere along the west coast of southern Africa. Its spectrum showed a strong interannual trend well correlated with long- term trends of temperature anomaly over the entire SE Atlantic; a high-frequency term could not be resolved at a time period of one month. The second principal component showed the contrasting response of the northern and southern sites on a seasonal scale and could be correlated with seasonal wind data. Dept. of Phys. Oceanogr., Univ. of Cape Town, Private Bag, Rondebosch 7700, South Africa.

85:3350 Fais, Silvana, Ferruccio Mosetti, Nicol6 Purga and

Antonio Miehelato, 1984. Cyclic comlmnents of the sea level fluctuations. The case of Trieste. Boll. OceanoL teor. appl~ 2(4):333-349. Osserv. Geofis. Sperimentale, Trieste, Italy.

85:3351 Mayer, D.A., K.D. Leaman and T.N. Lee, 1984.

Tidal motions in the Florida Current. J. phys. Oceanogr., 14(10): 1551-1559.

Sea level and the north component of the depth- averaged tidal velocity in the Straits of Florida are linearly related. A I-D model predicts barotropic tidal currents across the straits near 27°N, inde- pendent of the choice of a sea-level reference site between Key West and Patrick Air Force Base. The

504 A. Physical Oceanography OLR (1985) 32 (7)

predicted diurnal tidal current is dominant and can account for more than 80% of the predicted tidal energy. Twice a year the model yields a maximum amplitude of 12 cm/s corresponding to a tidal transport of 5.1 × 106 m3/s (5.1 Sv). NOAA, AOML, Miami, FL 33149, USA.

85:3352 Moody, J.A. et al., 1984. Atlas of tidal elevation and

current observations on the northeast American continental shelf and slope. Bull. U.S. geol. Surv., 1611 : 122pp.

This atlas is a compilation of tidal constants for current and pressure made at 216 locations on the North American continental shelf from Cape Hat- teras to the Laurentian Channel. It is the first compilation of tidal elevation over this region for constituents other than M2 and of tidal currents at depths other than at the surface. Includes 21 plates (several foldouts) mostly of coamplitude and cophase lines for the various tides. USGS, Woods Hole, MA 02543, USA.

85:3353 Platzman, G.W., 1984. Normal modes of the World

Ocean. Part IlL A procedure for tidal synthesis. J. phys. Oceanogr., 14(10):1521-1531.

In preceding parts of this study a set of normal modes was constructed as a basis for synthesizing diurnal and semidiurnal solutions of Laplace's tidal equations. Here a procedure by which such solutions can be computed as eigenfunction expansions is described. Since the calculated normal modes are nondissipative, it is necessary to incorporate dissipation into the synthesis procedure; this is done by a variational treatment of the tidal equations. Dept. of Geophys. Sci., Univ. of Chicago, IL 60637, USA.

85:3354 Platzman, G.W., 1984. Normal modes of the World

Ocean. Part IV. Synthesis of diurnal and semidiurnal tides. J. phys. Oceanogr., 14(10):1532- 1550.

Tides of second and third degree are synthesized from 60 normal modes with periods ranging 8-96 hr. Diurnal tides, especially second degree, can be represented by remarkably few modes. Semidiurnals are spectrally more heterogeneous, and more resonant, than diurnals, but some specific features can be attributed to individual modes. The observed tendency for the total tide to be predominantly semidiurnal in the Atlantic but mixed diurnal and semidiurnal in many parts of the Pacific and Indian Oceans is discussed. Dept. of Geophys. Sci., Univ. of Chicago, IL 60637, USA

85:3355 Prandle, D., 1985. Classification of tidal response in

estuaries from chonnei geometry. Geophys. Jl R. astr. Soc., 80(1):209-221.

Numerical and analytical techniques, combined to interpret the tidal response of estuaries with expo- nentially varying widths and depths, led to a new basic classification system for tidal responses. The theory is applied to ten major estuaries; response variations are examined as to different tidal frequencies, changes in the friction factor and the presence of tidal barriers. Results indicate that the large tides in the Bay of Fundy and the Bristol Channel result more from 'their overall shapes...than from a specific resonant length.' Inst. of Oceanogr. Sci., Bidston Observ., Birkenhead, Merseyside L43 7RA, UK. (msg)

85:3356 Wilson, R.E., K.-C. Wong and Ronald Filadelfo,

1985. Low frequency sea level variability in the vicinity of the East River [New York City] tidal strait. J. geophys. Res., 90(C1):954-960. SUNY, Stony Brook, NY, USA.

AI60. Waves, oscillations

85:3357 Akylas, T.R., 1984. On the excitation of nonlinear

water waves by a moving pressure distribution oscillating at resonant frequency. Phys. Fluids, 27(12):2803-2807.

A theoretical study is made of the free-surface flow induced by a traveling oscillatory pressure distribution acting at the surface of water of finite depth. Depending on the relative values of the water depth and the frequency and speed of the applied pressure, the solution of the linearized water-wave problem may be singular, owing to a resonance phenomenon. An asymptotic analysis shows that, close to resonant conditions, the finite-amplitude response is bounded, and it is governed by a forced nonlinear Schrodinger equation. Under certain circumstances, the generated wave disturbance may not reach a steady state; in particular, for deep water, a steady state is never attained. Dept. of Mech. Engrg., MIT, Cambridge, MA 02139, USA.

85:3358 Atanassov, V., W. Rosenthal and F. Ziemer, 1985.

Removal of ambigalty of two--dllmelaslonal power spectra obtaiued by processi~ ship radar imnges of ocean waves. J. geophys. Res., 90(C1)'1061- 1067.

OLR (I 985) 32 (7) A. Physical Oceanography 505

The usual spatial power spectra of ocean wave images taken from PPI of a ship radar show an ambiguity in the wave propagation direction. A simple numerical procedure is suggested to remove this ambiguity using the data from two consecutive turns of the radar antenna as well as the wave dispersion law. Results obtained show a good agreement with the ground truth. Inst. of Elec- tronics, Sofia, Bulgaria.

85:3359 Bates, J.R., 1984. An efficient semi-Lngrangian and

alternating direction implicit method for inte- grating the shallow water equations. Mort. Weath. Rev., 112(10):2033-2047.

The grid-point method is more efficient than a previous semi-Lagranglan scheme and is simpler than the semi-implicit scheme, involving only the solution of linear tridiagonal systems of equations rather than a Helmholz equation. Theoretical properties are examined for the E-grid. The scheme is unconditionally stable for advection and for simple Rossby waves and has a very lenient stability criterion for gravity-inertia waves. Though two-level in time, it gives second-order accuracy for both types of wave solution; no splitting errors occur in either case. Irish Meteorol. Serv., Dublin, Ireland.

85:3360 Crawford, W.R., 1984. Energy flux and generation of

diurnal shelf waves along Vancouver Island. J. phys. Oceanogr., 14(10): 1600-1607.

The energy flux of strong diurnal-period currents due to a tidally driven shelf wave superimposed upon a Kelvin wave is investigated here. Both the Kelvin wave and the first-mode shelf wave transport energy NW in the direction of phase propagation, but when the two waves are superimposed the combined energy flux vectors form meanders and gyres over the shelf; the pattern repeats in the alongshore direction every wavelength of the shelf wave. Near Southern Vancouver Island these waves combine to form a gyre in which the nearshore side carries energy SE toward Juan de Fuca Strait. Kinetic energy flows up-strait until it is dissipated in narrow tidal channels. Decrease in energy flux together with the convergence toward the strait of flux vectors of the combined waves suggests the shelf wave originates at the entrance to Juan de Fuca Strait. Inst. of Ocean Sci., Sidney, BC V8L 4B2, Canada.

85:3361 Crawford, W.R. and R.E. Thomson, 1984. Diurnal-

period continental shelf waves along Vancouver Island: a comparison of observations with theo-

reticai models. J. phys. Oceanogr., 14(10):1629- 1646.

Current and sea level data taken off Vancouver Island (May 1979-September 1980) are dominated by shelf waves of diurnal period. Current meter results are compared to theoretical solutions for a combination of free shelf waves and barotropic Kelvin waves over uniform alongshore topography using Brink's scheme. There is good agreement except for the seasonal variations in observed wavelengths. Inclusion of a mean alongshore current with cross-shelf shear improves the comparisons, suggesting that this variation is due to :)oppler shifting of the wave frequency. For the observations near irregular bottom topography, the comparison deteriorates, as expected. Inst. of Ocean Sci., Sidney, BC V8L 4B2, Canada. (wbo)

85:3362 Efimov, V.V. and Yu.P. Solov'ev, 1984. Low-

frequency oscillations of sea level and group structure of wind waves. Fiz. Atmosf. Okeana, 20(10):985-994. (In Russian, English abstract.)

85:3363 Holman, R.A. and A.H. Sallenger Jr., 1985. Setup

and swash on a natural beach. J. geophys. Res., 90(C1):945-953.

Under incident waves varying from 0.4 to 4.0 m significant wave height, setup, swash height, and total runup varied linearly with the surf zone similarity parameter. For low Irribaren numbers the swash height in the incident frequency band be- comes saturated but not for high Irribaren numbers. Sch. of Oceanogr., Oregon State Univ., Corvallis, OR, USA.

85:3364 Houghton, I., 1984. A long time-series verification of

hindcasts from the [U.K.] Meteorological Office wave model archive. Met. Mag., Lond., 113(1348):317-329.

Wave height data hindcast from the British Mete- orological Office fine-mesh wave model are compared with measurements at three stations in the west of Great Britain. The model agreed reasonably well with the results. Intercomparison time series, error statistics, model deficiencies, and data needs for better verification are discussed. Coventry, Lanchester Polytechnic, UK. (wbo)

85:3365 Larraza, A. and S. Putterman, 1984. Theory of

non-propagating surface-wave solitons. J. Fluid Mech., 148:443-449.

506 A. Ph)'~,ica] ()ccanogra[3il) OLR (1985) 32 17t

An incompressible inviscid fluid contained in a channel in a gravitational field admits soliton-like disturbances (recently discovered by Wu, Keolian and Rudnick) where the velocity potential depends upon all three coordinates as well as time, yet its centre of mass can be at rest. Calculations are carried out with the multiple-scales approach: consequences of mass conservation and radiation are discussed. Phys. Dept., Univ. of Calif., Los Angeles. CA 90024, USA.

85:3366 Longuet-Higgins, M.S., 1984. New integral relations

for gravity waves of finite amplitude. J. Fluid Mech., 149:205-215.

Some new exact relations are derived between integral properties of a progressive irrotational gravity wave of finite amplitude in deep water. The Eulerian-mean angular momentum is equal to the Lagrangian kinetic energy density minus the potential energy density times twice the phase speed divided by the gravitational acceleration. A similar form is found for the differential relationship between changes in the angular momentum and changes in the phase speed. It is shown that the previous result in which the level of action is nearly equal to the crest level for limited wave steepness is probably a numerical coincidence. Dept. of Appl. Math. and Theoret. Phys., Silver St., Cambridge, UK. (wbo)

85:3367 Miles, John, 1984. On damped resonant interactions.

J. phys. Oceanogr., 14(10): 1677-1678.

The evolution equations for a triad of weakly damped, resonantly interacting waves are isomor- phic to the corresponding equations for undamped waves (and therefore may be integrated in terms of elliptic functions) if the damping coefficient is the same for each member of the triad. This condition is satisfied for topographic Rossby waves for which dissipation is through a turbulent Ekman layer and the wavelengths are small compared with the Rossby radius of deformation. Inst. of Geophys. and Planet. Phys., Univ. of Calif., La Jolla, CA 92093, USA.

85:3368 Miles, J.W., 1984. Paran~trically excited solitary

waves. J. Fluid Mech., 148:451-460.

A modulated cross-wave of slowly varying complex amplitude is induced in a long channel and is subjected to a vertical oscillation. The complex amplitude satisfies a cubic Schr0dinger equation, generalized to incorporate weak damping and the parametric excitation. A solution is obtained that

describes the standing solitary wave observed by Wu, Keolian and Rudnick (1984). The corresponding cnoidal waves (of which the solitary wave is a limiting case) are considered in an appendix. Inst. of Geophys. and Planet. Phys., Univ. of Calif., La Jolla, CA 92093, USA.

85:3369 Oh, im Sang and C.E. Grosch, 1985. Numerical study

of finite amplitude wave refraction. J. WatWay Port coast. Ocean Engng, Am. Soc. cir. Engrs, 111(1):78-95.

Refraction of monochromatic waves is considered in examining finite amplitude effects using Stokes wave theory assuming a locally flat bottom exists. Ray trajectories and refraction coefficients (obtained by using the first and third order wave theory including and excluding energy dissipation) are compared for various topographies. Results from various bottoms of constant slope are summarized at the depth near the wave breaking point. Third order theory including energy dissipation seems to produce significant differences in the final results of the refraction calculation. Dept. of Oceanogr., Univ. of Hawaii, Honolulu, HI 96822, USA.

85:3370 Papa, Lorenzo, 1984. A wave refraction investigation

in the northern Ligurian Sea. Boll. Oceanol. teor. appl., 2(4):267-274. Dipt. di Fis., Univ. di Genova, Italy.

85:3371 Pennell, S.A. and C.H. Su, 1984. A seventeenth-order

series expansion for the solitary wave. J. Fluid Mech., 149:431-443.

Solitary waves are investigated numerically using a series in sech 2 t/zx to describe the wave profile. For amplitudes up to half the undisturbed fluid depth, the 17-term partial sum gives profiles and wave- parameter values with at least two-digit accuracy. For waves of larger amplitude (Pad6 approximants used to accelerate convergence) the computed values of the wave parameters agree with those obtained by Longuet-Higgins and Fenton (1974), but differ from those of Williams (1981), Witting (1981) and Hunter and Vanden-Broeek (1983). Possible explanations of this discrepancy are discussed. Dept. of Math., Univ. of Lowell, MA 01854, USA.

85:3372 Roskes, G.J., 1984. Nonlinear slowly varying standing

waves on deep water. Phys. Fluids, 27(12):p.2966.

The existence of nonlinear slowly varying standing waves on deep water is discussed from the point of


view of wealdy nonlinear slowly varying multiphase interactions. Dept. of Math., Queens Coll., Flushing, NY 11367, USA.

85:3373 Simon, M.J. and F. Ursell, 1984. Uniqueness in

Iinearized two-dimensional water-wave problems. J. Fluid Mech., 148:137-154.

A geometrical condition sufficient for uniqueness in 2-D time-periodic linear water-wave problems is derived, and some examples are given. The paper provides a review of current knowledge on the topic of uniqueness, and gives a simple form of John's (1950) proof. Recent progress, in which uniqueness can be demonstrated for surface-piercing bodies that do not satisfy John's geometrical criterion, is described. While the new technique proves uniqueness for a large class of problems involving floating, submerged, and multiple-body systems, it still does not constitute a general proof of uniqueness for all configurations. Dept. of Math., Univ. of Manches- ter, UK.

85:3374 Svendsen, I.A. and P.A. Madsen, 1984. A turbulent

bore on a beach. J. Fluid Mech., 148:73-96.

A theoretical model is developed giving a moder- ately detailed description of the flow in a turbulent bore, the velocity profiles, shear stresses, energy dissipation, etc. An analysis of flow conditions at the toe of the turbulent front indicates significant differences from the usual description based on finite-amplitude shallow-water equations; the present model gives a closer description of actual physical conditions. Numerical results are presented that illustrate how the model works, and test its validity on an example with known properties. ISVA, Tech. Univ. of Denmark, Bldg. 115, DK- 2800, Lyngby, Denmark.

85:3375 Takeda, Hiroshi, 1984. Topographically trapped

waves over the continental shelf and slope. J. oceanogr. Soc. Japan, 40(5):349-366.

Eigenvalues and ray theory are employed to char- acterize topographically trapped subinertial waves; three different cases of S(x) (the slope parameter) are considered. When S(x) decreases monotonically away from the coast, waves are trapped near the coast. Where S(x) has a maximum, waves can be trapped near the maximum as well as near the coast. Where S(x) has a negative region (i.e., a trench), waves are trapped in that region propagating with the coast to their left in the Northern Hemisphere (and vice versa in the southern), in addition to the

waves trapped near the coast. The second case is the typical one; model results show trapped waves over the continental slope as well as over the shelf. Dept. of Appl. Physics, Univ. of Tokyo, Bunkyo-ku, Tokyo 113, Japan. (sir)

85:3376 Thomas, K.V. and M. Baba, 1983. Wave climate off

Valiathura, Trivandrum [India]. Mahasagar, 16(4):415-421. Centre for Earth Sci. Stud., Reg. Centre, Cochin 682018, India.

85:3377 Vaysband, V.B., 1984. Estimating the relative max-

immn of a wind wave spectrum of a shallow sea. Meteorologiya Gidrol., 10:94-99. (In Russian, English abstract.)

The relationship between the 'frequency of wave energy spectral density maximum and the mean frequency of waves' is studied. The ratio of these quantities is non-constant and depends on bottom steepness, water depth and wave steepness. Exam- ples are offered. (sir)

85:3378 Weissman, M.A., S.S. AtaktUrk and K.B. Katsaros,

1984. Detection of breaking events in a wind- generated wave field. J. phys. Oceanogr., 14(10): 1608-1619.

Measurements were made of the surface elevation of a fetch-limited wave field (fetch 7 km, wind speed about 6 m s-~). Good high frequency response was attained by the use of a very thin, bare wire probe of diameter 0.13 ram. Breaking waves were detected based on the energy in the 18-32 Hz frequency band. The temporal intermittency of wave breaking (fraction of time spent in breaking regions) was only 1.2%; however, the fraction of high-frequency (5-50 Hz) energy in those regions was 12%. It is argued that the spatial intermittency and the spatial energy fraction should have the same values. The mean crest height of the breaking waves was lower by a factor of 4 than expected from theoretical consid- erations. Microscience, Inc., Federal Way, WA 98003, USA.

85:3379 Yamamoto, Tokuo and Shigeo Takahashi, 1985.

Wave damping by soil motion. J. WatWay Port coast. Ocean Engng, Am. Soc. civ. Engrs, 111(1): 62-77. RSMAS, Univ. of Miami, FL 33149, USA.

508 A. Physical Oceanograph3 OLR (1985) 32 (7)

A170. Wind-wave interactions

85:3380 AI-Zanaidi, M.A. and W.H. Hui, 1984. Turbulent

airflow over water waves: a numerical study. J. Fluid Mech., 148:225-246.

Turbulent airflow over a Stokes surface wave train of small amplitude is studied numerically using the two equation closure model of Saffman and Wilcox (1974), including an explicitly calculated viscous sublayer near the water wave surface. The energy transfer from wind to waves depends on the flow being hydraulically rough, transitional, or smooth. An approximate formula for the wave growth rate is found which is in good agreement with most data from field and laboratory experiments. Dept. of Math., Univ. of Kuwait. (wbo)

85:3381 Baldy, Serge and Maurice Bourguel, 1985. Meas-

urements of bubbles in a stationary field of breaking waves by a laser-based single-particle scattering technique. J. geophys. Res., 90(C1): 1037-1047.

An original numerical processing of the scattered intensities, taking advantage of the low particle (bubble) velocities, allowed the concentration probability densities to be determined. Other information, such as the crossing frequency, arrival time interval, or estimated speed distributions, also is available. The investigations were carried out in the immediate vicinity of breaking waves generated by the wind flow or by the cumulative effects of the wind and a wavemaker. High bubble concentrations, no peaked distributions, and important modifica- tions of these distributions with wave age were observed. Bubble speed and additional arrival time information allowed further notice of high fluid- estimated velocities and characterization of bubble clusters in the vicinity of breaking waves. Inst. de Mecan. Statis. de la Turbulence, Marseille, France.

85:3382 Bouws, E., H. GOnther, W. Rosenthal and C.L.

Vincent, 1985. Similarity of the wind wave spectrum in finite depth water. I. Spectral form. J. geophys. Res., 90(C1):975-986.

A self-similar spectral shape (TMA spectrum) to describe wind waves in water of finite depth is presented. The parametric spectral form is depth dependent and an extension of the deep water JONSWAP spectrum. About 2800 spectra selected from three data sets (TEXEL storm, MARSEN, ARSLOE) are investigated to show its general validity. The behavior of the spectrum in frequency

and wave number space is discussed. Royal Neth- erlands Meteorol. Inst. (KNMI), De Bilt, Nether- lands.

AI80. Internal waves and tides

85:3383 Artale, V., D. Levi, E. Salusti and F. Zirilli, 1984. On

the generation of internal solitary marine waves. Nuovo Cim., (C)7(3):365-377.

A nonlinear model of solitary internal wave generation is discussed. When a large surface wave passes over a submarine mountain or crosses a strait, packets of internal waves often can be detected. The phenomenon can be schematized, in an approximate but realistic way, by using the solutions of an inhomogeneous KdV equation. The forcing term depends on the air-sea surface elevation and on the bottom topography. The model is applied to tidal currents flowing through the Straits of Gibraltar. Dipt. di Fis. dell'Univ, la Sapienza, Roma, Italy.

85:3384 Helfrich, K.R., W.K. Melville and J.W. Miles, 1984.

On interfaciai solitary waves over slowly varying topography. J. Fluid Mech., 149:305-317.

Equations are formulated to include cubic nonlinearity, which dominates quadratic nonlinearity in some parametric neighborhood of equal layer depths. Numerical solutions are obtained for either a single solitary wave or a rank-ordered pair of such waves incident in a monotonic transition between two regions of constant depth. Solutions are used to investigate the change of polarity of incident waves as they pass through a 'turning point' of approximately equal layer depths. Results exhibit significant differences from those reported by Knick- erbocker and Newell (1980); in particular, more than one wave of reversed polarity may emerge. Ralph M. Parsons Lab., MIT, Cambridge, MA 02139, USA.

85:3385 Kuzaaetsov, A.S., A.N. Paramonov and Yu.A. Stepa-

nyants, 1984. Investigation of solitary internal waves in the tropical zone of the west Atlantic. Fiz. Atmosf. Okeana, 20(10):975-984. (In Rus- sian, English abstract.)

Internal wave trains and solitary internal waves (amplitudes up to 85 m) were observed in deep water. Surface manifestations of such large internal waves comprise 'well-developed foamy ripples' propagating in concert with the internal wave. (sir)

OLR 0985) 32 (7) A. Physical Oceanography 509

A210. Ice

85:3386 Colony, R. and A.S. Thorudike, 1985. Sea ice motion

as a drunkard's walk. J. geophys. Res., 90(C1): 965-974.

Observations of sea ice displacement over short periods of time are used to deduce some statistics of ice motion over long periods of time. The trajectory of a piece of ice is followed, starting at a randomly selected time and location and ending when the ice either melts or leaves the Arctic Basin. Trajectories are also followed backward to the time and location of formation. Statistical properties considered are the age and remaining lifetime of ice in various locations and the probability that ice presently occupying a particular location was originally created or will ultimately melt in certain regions. Possible applications are to the distribution of pollutants by sea ice and the design of experiments involving drifting measurement platforms. Polar Sci. Center, Univ. of Washington, Seattle, WA, USA.

85:3387 Hanley, T.O.'D, 1984. A field study of rough

shore-fast sea ice. J. Glaciol., 30(105):230-234.

During December 1973 the initial smooth ice cover on the Chukchi Sea near Barrow, Alaska, broke away from the shore during a period of strong wind and was replaced by a cover of broken, rafted ice which remained for the rest of the winter. Cores were examined for salinity, density, and temperature gradient. Despite large deviations, probably due to the irregularity of the ice cover, thickness and salinity followed the patterns seen by other observ- ers. Campion Coll., Univ. of Regina, SK $4S 0A2, Canada.

85:3389 Keys, J.R. and K.L. Williams, 1984. Rates and

mechanisms of iceberg ablation in the D'Urviile Sea, Southern Ocean. J. Glaciol., 30(105):218- 222.

Wave action causes ablation in a narrow zone around an iceberg's waterline, up to 0.3 m per day, in water of - I ° C with waves up to 0.4 m high. Subsequent subaerial calving of ice from iceberg sides takes place. Submarine melting is an order of magnitude slower than wave action but acts over the largest part of an iceberg. Ablation rates derived elsewhere are in reasonable agreement with those measured here. Drifting icebergs trail a plume of mixed, slightly cooled and diluted sea-water in their wake. P.O. Box 221, Wellington, New Zealand.

85:3390 Killworth, P.D. and Nathan Paldor, 1985. A model of

sea-ice front instabilities. J. geophys. Res., 90(C1):883-888.

Linear instability of an infinite ice front overlying a passive ocean is demonstrated for the case where ice concentration satisfies a simple condition far from the front. Long wave analytical estimates are confirmed numerically for an ice dispersivity that is not too small, but a very large dispersivity stabilizes the front. Inclusion of cross-frontal wind stress merely alters the mean state and does not affect the instability process. Dept. of Appl. Math. and Theoret. Phys., Univ. of Cambridge, UK.

85:3391 Koci, B.R. and K.C. Kuivinen, 1984. The PICO

[Polar Ice Coring Office] lightweight coring auger. J. Glaciol., 30(105):244-245. Polar Ice Coring Office, Univ. of Nebraska, Lincoln, NE 68588-0200, USA.

85:3388 Home, E.P.W., 1985. Ice--induced vertical circulation

in an [Canadian] Arctic fiord. J. geophys. Res., 90(C1): 1078-1086.

CTD and nutrient data taken in South Cape Fiord next to a glacier face show strong evidence of upwelling and a region of downwelling was found 0.5-5 km from the ice. Intruding layers with thicknesses consistent with lab measurements were found near the ice. A phytoplankton bloom was found in the fiord, and an upweUing velocity of 2.5 × 10 ~ m s -~ is calculated by assuming that all the nitrogen required is upwelled from the deep water within l0 -2 m of the glacier. Mechanisms to drive the downwelling are discussed. Bedford Inst. of Oceanogr., Dartmouth, NS, Canada.

85:3392 Lingle, C.S. and J.A. Clark, 1985. A numerical model

of interactions between a marine ice sheet and the solid earth: application to a West Antarctic ice stream. J. geophys. Res., 90(C1):1100-1114.

Feedback interactions between an ice stream and deformation of the underlying earth due to ice loading are simulated and applied to ice stream E, West Antarctica, using a time-dependent numerical model. During rising Holocene sea level, retreat of the grounding line resulting from thinning of the ice stream began slowly at 15,000 yrBP and accelerated after 13,000 yrBP. By 8000 yrBP feedback effects delayed the retreat by ~ 1000 years relative to retreat over a rigid bed. Uplift of the seafloor eventually halted retreat, and between 3000 yrBP and the

510 A. Physica[ Oceanography OLR ( 1985~ 32 (7)

present, following the end of eustatic rise of sealevel, a 20 km re-advance of the grounding line occurred. Coop. Inst. for Res. in Environ. Sci., Univ. of Colorado, NOAA, Boulder, CO, USA. (hbf)

85:3393 Potter, J.R., J.G. Paren and J. Loynes, 1984.

Glaeiological and oceanographic calculations of the mass balance and oxygen isotope ratio of a melting ice shelf. J. Glaciol., 30(105):161-170.

An investigation and modelling of the ice extent, accumulation pattern, and variation in oxygen isotope ratio on George VI Ice Shelf show that average thickening can be no more than 1 m a t and that the present accumulation over the catchment is approximately equal to the ice melt. It is concluded that there is 'no strong evidence for a secular climatic change in the Antarctic Peninsula over the last few millennia.' British Antarctic Survey, NERC, High Cross, Madingley Rd., Cambridge CB3 0ET, UK. (hbf)

85:3394 Ross, Becky, 1984. A model investigation of inter-

annual sea-ice variability in the Beaufort Sea. J. Glaciol., 30(105):223-226.

Correspondence between the modeled and observed fluctuations of ice-covered area is quite good. Ice anomalies are persistent throughout the August- May period; however, because the thickness anomalies undergo large fluctuations during July and August, only a small amount of summertime pre- dictability can be derived from the thickness data. Findings are consistent with the observational results of Rogers (1978), who found that summertime temperatures and wind directions accounted for much of the variability of Beaufort Sea ice during August and September. Dept. of Atmos. Sci., Univ. of Illinois, Urbana, IL 61801, USA.

85:3395 Shaw, R.P. and R.R. Rumer, 1984. Interaction of

Stokes edge waves with near-shore ice formation. J. Glaciol., 30(105):227-229.

The effect of a well-fragmented ice suspension on the classical Stokes edge wave is discussed and the possibility that ice-cusp formation (and, thereafter, ice mounds or volcanoes) can be initiated by edge waves is examined. Results indicate a negligible effect of a well-fragmented floating ice field on the Stokes dispersion equation for typical wave periods, but do indicate that the presence of a standing Stokes edge wave may lead to the initiation of ice-field cusps as ice formation occurs in the near-shore zone. Dept. of Civil Engrg., SUNY, Buffalo, NY 14260, USA.

85:3396 Smedstad, O.M. and L.P. Roed, 1985. A coupled

ice-ocean model of ice breakup and banding in the marginal ice zone. J. geophys. Res., 90(C1): 876-882.

The model consists of a nonlinear sea ice model and a two-layer (reduced gravity) ocean model. De- pendence of the upwelling response on wind stress direction is discussed. Results confirm earlier analytical work. It is shown that there exist directions for which there is no upwelling, while other directions give maximum upwelling. The ice and ocean are coupled directly through the stress at the ice-ocean interface. When the ice edge is almost stationary the ice tends to break up a few tenths of kilometers inside of the ice edge. Mesoscale Air-Sea Interaction Gr., Florida State Univ., Tallahassee, FU USA.

85:3397 Swift, C.T., L.S. Fedor and R.O. Ramseier, 1985. An

algorithm to measure sea ice concentration with microwave radiometers. J. geophys. Res., 90(C I ): 1087-1099.

An algorithm which uses two microwave radiometer channels to estimate quantitative fractions of first- year and multiyear sea ice types was applied to data obtained from satellite sensors, and the data trends used to refine values of the emissivities. Test results were in reasonable agreement with visual observations, where mixtures of first-year sea ice and multiyear sea ice were known to coexist. However, on a synoptic basis the satellite estimates differ from visual and radar means of classifying ice that has survived at least one melt season (old ice). A possible explanation for the discrepancy is that the emissivity of sea ice changes over time periods longer than one melt season. Dept. of Elect. and Computer Engrg., Univ. of Mass., Amherst, MA, USA.

85:3398 Wadhams, Peter, A.S. McLaren and Ruth Wein-

traub, 1985. Ice thickness distribution in Davis Strait in February from submarine sonar profiles. J. geophys. Res., 90(C1):1069-1077.

Within 50-100 km of the ice edge there is a marginal ice zone (MIZ) where the mean draft is 0.25-0.51 m, most of the ice is undeformed, and there are many leads but few ridges, all ,(6.1 m in draft. The interior zone is composed mainly of first-year ice with a mean draft of 0.77-1.66 m, increasing slightly from NE to SW. Level ice is less common than in the MIZ, as are leads; ridging is more common. Ice draft and keel draft distributions followed a negative exponential distribution at depths beyond 3 ~, m.


and the distribution of lead widths followed a power law with exponent -2.29. Scott Polar Res. Inst., Univ. of Cambridge, UK.

A260. Acoustics

85:3399 Adekola, S.A, 1984. On the complete solution to the

Diriclllet problem of echosonde synthesis. Acustica, 56(2): 105-113. Dept. of Elect. Engrg., Univ. of Lagos, Akoka, Yaba, Nigeria.

85:3400 Bolotin, Yu.I., 1984. A solution of a three-dimen-

sional problem in the theory of cylindrical piezoceramic transducers. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):260-263. Dal'- standart Sci.-Indust. Union, USSR.

85:3401 Burov, V.A., O.V. Dmitriev and A.V. Sidorov, 1984.

Optimal signal processing in plane waveguides. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):267-269. M.V. Lomonosov State Univ., Moscow, USSR.

85:3402 Chahine, G.L., V.E. Johnson Jr., W.T. Lindenmuth

and G.S. Frederick, 1985. The use of serf- resonating cavitating water jets for underwater sound generation. J. acoust. Soc. Am., 77(1): 113- 126.

The system is based on matching the natural frequency of a submerged jet with that of a resonant chamber through a feedback mechanism. It is observed that the efficiency of STRATOJETs (self- resonating cavitating jets) is more than two orders of magnitude higher than that of a conventional cavitatingjet. The knowledge developed in this study allows for selection of the amplitude and frequency of the emitted noise by proper dimensioning of the assembly and correct choice of the functioning conditions. Tracor Hydronautics, Inc., 7210 Pindell School Rd., Laurel, MD 20707, USA.

85:3403 Dyubchenko, M.E., 1984. Influence of axisymmetric

vibrational modes on the sensitivity and direc- tivity patterns of a plezoceramic sphere. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):286-288. Polytech. Inst., Odessa, USSR.

85:3404 Ivanova, G.K., 1984. Space-frequency dependence of

a sound field in layered media. Sov. Phys. Acoust. (a translation of Akust. Zh.), 30(4):293-296.

Using a normal mode expansion, the space (range)- frequency dependence of the acoustic energy for a broadband source is examined. The interference maxima (maximum energy) for a two mode vertical profile are calculated for a deeply submerged source. Inst. of Appl. Physics, Acad. of Sci., USSR. (wbo)

85:3405 Kalyuzhnyi, A.Ya., L.G. Krasnyi and V.V. Kriz-

hanovskii, 1984. Spatial processing of acoustic signals in a plane-parallel waveguide. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):296- 300.

85:3406 Lapin, A.D., 1984. Excitation of a surface wave on an

inhomogeueons boundary. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):332-333. N.N. Andreev Acoustics Inst., Acad. of Sci., USSR.

85:3407 Lyubavin, L.Ya., 1984. Imbedding method in the

acoustics of variable--density media. Sov. Phys. Acoust. (a translation of Akust. Zh.), 30(4):333- 334. Pacific Ocean Oceanol. Inst., Far-Eastern Sci. Center, Acad. of Sci., USSR.

85:3408 Metlov, L.S., 1984. Lateral waves in a three-layer

liquid system. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):303-305. Ukranian Br. of the All-Union Sci.-Res. Inst. of Mining Geomech. and Mine Survey., USSR.

85:3409 Pace, N.G., Z.K.S. Al-Hamdani and P.D. Thorne,

1985. The range dependence of normal incidence acoustic backscatter from a rough surface. J. acoust. Soc. Am., 77(1):101-112. Sch. of Phys., Univ. of Bath, Claverton Down, Bath BA2 7AY, UK.

85:3410 Roden, G.I., 1984. Mesoscale sound speed fronts in

the central and western North Pacific and in the Emperor Seamounts region. J. phys. Oceanogr., 14(10):1659-1669.

In the flat-bottomed central Pacific where currents are weak, the main sound speed fronts occur near water mass boundaries. In the western Pacific, where topography is rugged and currents strong, fronts are encountered throughout. Vertical oscillations of the sonocline are large and give rise to deep and at times quasi-regularly spaced (~400 kin) sound speed fronts. In the vicinity of the Emperor Seamounts a variety of sound speed fronts is observed. Frontal

512 A. Ph~ sical Oceanography, OLR (1985) 32 (7)

deflections are observed over some seamounts. A Taylor-column-like feature occurs over Suiko Sea- mount. Conspicuous sound speed domes occur near Jingu and Kanmu seamounts (diameter ~ 150 km; displacement 300 m). The largest perturbations occur within 100 km of the seamounts. Sch. of Oceanogr., WB-10, Univ. of Washington, Seattle, WA 98195, USA.

85:3411 Sockell, Michael, Ioannis Besieris, Werner Kohler

and Herbert Freese, 1985. A Markov process model of ocean sediments. J. acoust. Soc. Am., 77(1):74-82.

Monochromatic plane-wave illumination of a randomly stratified, laterally homogeneous sediment layer is considered. The deposition process creating the stochastic layering is assumed to be a continuous parameter, finite state Markov chain. A Riccati equation for the plane-wave reflection coefficient is formulated and first-order partial differential equations for relevant probability density functions are subsequently obtained and solved numerically for a two-material turbidite model. Virginia Polytech. Inst., Blacksburg, VA 24061, USA.

85:3412 Spiesberger, J.L., 1985. Ocean acoustic tomography:

travel time biases. J. acoust. $oc. Am., 77(1):83- 100. Dept. of Ocean Engrg., WHOI, Woods Hole, MA 02543, USA.

85:3413 Yavor, M.I., 1984. Asymptotic calculation of sound

fields in the ocean in the presence of a deep waveguide and a near-surface waveguide. Soy. Phys. Acoust. (a translation of Akust. Zh.), 30(4):327-331.

Procedures for calculating acoustic wave propagation for range-dependent sound speeds with vertical profiles with near-surface or deep sound channel minimums are given using asymptotic formulas of the normal-mode vertical decomposition. It is proposed that this procedure, valid for frequency ranges from I0 Hz to 1 kHz, is an efficient algorithm as it requires a limited number of modes to be computed. A.A. Zhdanov State Univ., Leningrad, USSR. (wbo)

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

85:3414 Biesheuvel, A. and L. van Wijngaarden, 1984.

Two-phase flow equations for a dilute dispersion

of gas bubbles in liquid. J. Fluid Mech., 148:301- 318. Tech. Univ. Twente, Enschede, Nether- lands.

85:3415 Cushman-Roisin, Benoit, 1985. Conditions for inter-

face surfacing, upper bounds on extent of ventilation, and formation of bottom lenses above topography. J. geophys. Res., 90(C1):889-894.

It is shown how a simple 1-D reduced-gravity model can lead to surfacing criteria and upper bounds on the extent of the ventilation area created by the separation of two newly formed fronts. First a no-surfacing theorem is established under restrictive conditions. Then, by relaxing conditions one by one, wind, coast, and topography effects are investigated and front properties derived. Mesoscale Air-Sea Interaction Group., Florida State Univ., Tallahassee, FL, USA.

85:3416 Lange, P.A. and Heinrich Htthnerfuss, 1984. Hori-

zontal surface tension gradients induced in monolayers by gravity water wave action. J. phys. Oceanogr., 14(10): 1620-1628.

The films (oleyl alcohol, palmitic acid methyl ester and cetyl trimethyl ammonium bromide) can sustain unexpectedly large surface tension variations of the order 12-14 (×10 -3) N m -~ and were found to experience a relaxation with time (order of 1500 s) and with position on the wave (phase shift). The relaxation and phase shift are attributed to a reordering of the film molecules and the subsequent modification of the mutual interaction between the film molecules and the water molecules of the underlying water layer. Bundesanstalt fur Wasser- bau, Wedeler Landstr. 157, 2000 Hamburg 56, FRG.

85:3417 McDougall, T.J., 1984. The relative roles of dtapycual

and isopyenal mixing on subsurface water mass conversion. J. phys. Oceanogr., 14(10): 1577-1589.

Conservation equations for the rate of change (Lagrangian derivative) of potential temperature on a neutral (isopycnal) surface in the presence of both isopycnal and diapycnal (across isopycnal) turbulent mixing and double-diffusive convection are derived by eliminating the diapycnal advection term between the heat and salt conservation equations. Cast in this form, the diapycnal mixing term is proportional to the eddy diffusivity multiplied by the curvature of the O-S curve rather than the usual form in which it is proportional to vertical derivatives. For O-S values typical of the central waters of the World Ocean, diapycnal mixing would be a small fraction of that


previously calculated. It is suggested that future studies of subsurface water mass conversion be studied using these equations. CSIRO, Hobart, Tasmania 7001, Australia. (wbo)

85:3418 Newell, T.A., 1984. Characteristics of a double-

diffusive interface at high density stability ratios. J. Fluid Mech., 149:385-401.

Using a transient experiment technique, a transition from boundary-layer to core-region-dominated transport has been observed. Interface growth can occur through a series of steps owing to a sharp transition to a region with large interface growth rates. Hysteresis occurs within the large density stability ratio region. Finally, the property-transport flux ratio increases as an interface switches from boundary- to core-dominated transports. Dept. of Mech. and Indust. Engrg., Univ. of Illinois, 1206 West Green St., Urbana, IL 61801, USA.

85:3419 Nikolaev, Yu.V., A.P. Makshtas and B.V. Ivanov,

1984. Physical processes in the marginal zones of drifting sea ice. Meteorologiya Gidrol., 11:73-80. (In Russian, English abstract.)

Heat fluxes are estimated for typical spring air-sea interactions in the marginal ice zone, and hydrological and atmospheric boundary layer characteristics in the near-ice zone are analyzed. Ice-water boundary layer formation mechanisms are discussed. (slr)

85:3420 Nokes, R.I., A.J. McNulty and I.R. Wood, 1984.

Turbulent dispersion from a steady two--dimensional horizontal source. J. Fluid Mech, 149:147- 159. Dept. of Civil Engrg., Univ. of Canterbury, Christchurch, New Zealand.

85:3421 Pogorzelski, S., B. Linde and A. Sliwinski, 1984.

Capillary wave attenuation on a water surface coated with monolayers of oil--derivative sub- stances. Acoust. Lefts, 8(1):5-9.

Ultrasonic pulse reflection was used to measure capillary wave attenuation by surface monolayers. Attenuation is determined by the surface elasticity modulus; very low values of the latter may result in much greater attenuation than predicted by classical theory for a totally immobile surface. At low surface pressures, surface viscosity may play an important role. (sir)

85:3422 Ruddick, B.R., 1985. Momentum transport in ther-

~ e s ~ J. geophys. Res~ 90(C1): 895-902.

A simple model for momentum transport in an actively convecting thermohaline staircase shows that the average dissipation and viscosity are controlled by the interfaces. Model results are combined with a mechanistic argument for momentum transport across the interfaces by convection- driven internal waves. The average eddy viscosity for the staircase is about 40 times the buoyancy flux divided by the square of the buoyancy frequency; the turbulent Prandtl number is constant and equal to -40. The model predictions imply eddy viscosities of about 10 -3 m2/s. Dept. of Oceanogr., Dalhousie Univ., Halifax, NS, Canada.

85:3423 Stommel, Henry and Laurence Armi, 1984. A

hydraulic-inertial model of thermal convection. C. r. Acad. Sci, Paris, (Str. II)299(14):937-942. (In French, English abstract.)

Most conceptual models of forced buoyancy-convection involve hypothetical diffusive processes; the simple convection model described here is governed by the Bernoulli equation and involves a critical hydraulic control point. The process by which vertical upwelling into the mixed layer occurs resembles that of a natural carburetor. WHOI, Woods Hole, MA 02543, USA.

A300. Fluid mechanics

85:3424 George, W.K., P.D. Beuther and R.E.A. Arndt,

1984. Pressure spectra in turbulent free shear flows. J. Fluid Mech., 148:155-191. SUNY, Amherst, NY 14260, USA.

85:3425 Hyde, R.A., 1984. On the serf-interaction of a

geostrophic current and its inertia-gravity normal modes. J. atmos. Sci., 41(19):2882-2900.

Computed numerically are 1) the normal modes associated with a zonal current, 2) the nonlinear wave forcing produced by the normal modes, and 3) the equilibria of the zonal current forced by the waves. Behavior displayed by the normal modes and the equilibria is not radically different from that of other barotropic models. The concept of wave-mean interaction formulated here is briefly contrasted with that in the theories of adjustment, noninteraction and initialization; results here indicate that modi-

514 OLR 11985)32 (7)

fication of certain classical notions may be desirable if the inertia-gravity component is to be included in the dynamics. Nat. Sci. Dept., Plymouth Coll., NH 03264, USA.

85:3426 Itsweire, E.C. and C.W. Van Atta, 1984. An exper-

imental investigation of coherent substructures associated with turbulent spots in a laminar boundary layer. J. Fluid Mech., 148:319-348. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA.

85:3427 Janowitz, G.S., 1984. Lee waves in three--dimensional

stratified flow. J. Fluid Mech., 148:97-108.

The effect of a shallow isolated topography on an initially uniform flow in the x-direction is considered. The Green-function solution is without swirl and thus the effect can be described in terms of a stream function. The vertical displacement field is in agreement with the limited versions of Crapper (1959). The Gaussian curvature of the zero-frequency dispersion surface is obtained analytically. For topographies far downstream that are even functions of x and y, the details of the topography affect the displacement field only in the vicinity of the x-axis; elsewhere, the amplitude of the displacement is proportional to the net volume of the topography. Dept. of Mar. and Atmos. Sci., North Carolina State Univ., Raleigh, NC 27650, USA.

85:3428 Ryskin, G. and L.G. Leal, 1984. Numerical solution

of free-boundary problems in fluid mechanics. Part 1. The finite-difference technique. J. Fluid Mech., 148:1-17.

A numerical technique based on a finite-difference solution of the equations of motion on an orthogonal

curvilinear coordinate system, which is also constructed numerically and always adjusted so as to fil the current boundary shape, is described. The overall solution is achieved via a global iterative process, with the condition of balance between total normal stress and the capillary pressure at the free boundary being used to drive the boundary shape to its ultimate equilibrium position. Dept. of Chem. Engrg., Northwestern Univ., Evanston, IL 60201, USA.


of free--boundary problems in fluid mechanics. Part 2. Buoyancy-driven motion of a gas bubble through a quiescent liquid. J. Fluid Mech., 148:19-35. Dept. of Chem. Engrg., Northwestern Univ., Evanston, IL 60201, USA.


of free-boundary problems in fluid mechanics. Part 3. Bubble deformation in an axisymmetric straining flow. J. Fluid Mech., 148:37-43. Dept. of Chem. Engrg., Northwestern Univ., Evanston. IL 60201, USA.

85:3431 Spall, J.R. and H.G. Wood Ill, 1984. An analysis of

the stability of the compressible Ekman boundary layer. Phys. Fluids, 27(12):2808-2813. Aerother- modynam. Branch, NASA Langley Res. Center, Hampton, VA 23665, USA.

85:3432 Vongvisessomjai, Suphat, 1985. Regime of oscillatory

flow. J. WatWay Port coast. Ocean Engng, Am. Soc. cir. Engrs, 111(1):96-110. Div. of Water Res. Engrg., Asian Inst. of Tech., P.O. Box 2754, Bangkok, Thailand.

B. MARINE METEOROLOGY

B10. Apparatus and methods

85:3433 Gollvik, Stefan, 1984. On the convergence of non-

linear normal mode initialization methods. Tel~us, (A)36(5):409-416.

Non-linear, normal mode initialization schemes are studied in a low order fl-plane, shallow water model in which Machenhauer's initialization scheme may diverge due to both linear advective terms and non-linear effects. Using more general methods to find non-linearily balanced states, convergence may

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