Oceanographic Literature Review (1987) 34 (10) The citations are those received in the editorial office during the period 1-31 July, 1987. 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 87:5304 Beal, R.C. /guest editor), 1987. Measuring ocean waves from space. Proceedings of the symposium (held at The Johns Hopkins University Applied Physics Laboratory. April 15 17, 1986). Johns Hopkins APL tech. Dig., 8(1):1-147:24 papers. High resolution synthetic aperture radar (SAR) data collected in late 1984 during NASA's second Shuttle Imaging Radar experiment (SIR-B) provided exten- sive ocean wave imagery from space. In addition, for the first time, estimates of the directional energy spectrum from simultaneous measurements by newly developed aircraft radar sensors were available for comparison with SAR imagery. A symposium was organized to evaluate these developments and 'to re-examine the scientific and operational motivation for measuring ocean waves from space, to review the SIR-B results, and to explore the benefits of a global wave-monitoring capability.' These papers are ar- ranged accordingly, treating motivation, measure- ments, and implications, preceded by an introduc- tory overview. (hbf) 87:5305 Kuznetsov, V.N. and A.V. Nosov, 1986. A laser- based wave recorder system. Oceanology (a translation of Okeanologiia), 26(3):392-394. Results of full-scale tests of an optical system for measuring sea surface slopes are presented; the system measures the total duration of light pulses reflected by the surface at fixed angles. Test results are consistent with data available in the literature. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR. 87:5306 Lagerloef, G.S.E. (comment) and M.A. Srokosz (reply), 1987. IDiscussionl 'On the joint distri- bution of surface elevations and slopes for a
Transcript
Oceanographic Literature Review
(1987) 34 (10)
The citations are those received in the editorial office during the period 1-31 July, 1987. 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.
waves from space. Proceedings of the symposium (held at The Johns Hopkins University Applied Physics Laboratory. April 15 17, 1986). Johns Hopkins APL tech. Dig., 8(1):1-147:24 papers.
High resolution synthetic aperture radar (SAR) data collected in late 1984 during NASA's second Shuttle Imaging Radar experiment (SIR-B) provided exten- sive ocean wave imagery from space. In addition, for the first time, estimates of the directional energy spectrum from simultaneous measurements by newly developed aircraft radar sensors were available for comparison with SAR imagery. A symposium was organized to evaluate these developments and 'to re-examine the scientific and operational motivation for measuring ocean waves from space, to review the SIR-B results, and to explore the benefits of a global
wave-monitoring capability.' These papers are ar- ranged accordingly, treating motivation, measure- ments, and implications, preceded by an introduc- tory overview. (hbf)
87:5305 Kuznetsov, V.N. and A.V. Nosov, 1986. A laser-
based wave recorder system. Oceanology (a translation of Okeanologiia), 26(3):392-394.
Results of full-scale tests of an optical system for measuring sea surface slopes are presented; the system measures the total duration of light pulses reflected by the surface at fixed angles. Test results are consistent with data available in the literature. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.
87:5306 Lagerloef, G.S.E. (comment) and M.A. Srokosz
(reply), 1987. IDiscussionl 'On the joint distri- bution of surface elevations and slopes for a
~,0(I A. Physical Oceanography ( ) I R ~ I~g71 34 t ltl)
nonlinear random sea, with an application for radar altimetry.' J. geophys. Res., 92(C3):2985- 2990.
87:5307 Mackas, D.L., K.L. Denman and A.F. Bennett,
1987. Least squares multiple tracer analysis of water mass composition. J. geophys. Res., 92(C 3 ): 2907 -2918.
We present an inverse method that uses measure- ments of the concentration of several tracer variables to find the mixture of source water types that best describes (in a weighted least squares sense) the composition of the water sample. The method is particularly valuable in regions involving strong mixing among a relatively large number of source water types. In contrast to conventional TS analysis, more water types can be considered, the assumption of mixing along isopycnals is unnecessary, and sensitivity to errors in individual tracer measure- ments is reduced by averaging the influence of a larger number of tracers, We demonstrate the method using data from two oceanographic regions. Inst. of Ocean Sci., P,O. Box 6000, Sidney, BC V8L 4B2, Canada.
87:5308 Schluessel, P., H.-Y. Shin, W.J. Emery and H.
Grassl, 1987. Comparison of satellite-derived sea surface temperatures with in-situ skin measure- ments. J. geophys. Res., 92(C3):2859-2874.
SSTs computed from sensor systems on the NOAA polar-orbiting satellites are compared with surface skin temperatures (from an infrared radiometer mounted on a ship) and subsurface temperature measurements. Three split window retrieval methods using channels 4 and 5 of the NOAA 7 advanced very high resolution radiometer (AVHRR) sensor were investigated. These methods were (1) using AVHRR alone, (2) using AVHRR with atmospheric temperature and water vapor profiles from the TIROS operational vertical sounder, and (3) using AVHRR and data from the high-resolution infrared sounder (HIRS). The importance of scan angle correction is discussed, and the improvement of SST retrievals using sensor combinations is demonstrat- ed. The improved SST accuracy by AVHRR plus HIRS is due to additional correction for the atmospheric water vapor and temperature structures, made possible with some of the H1RS channels. Significant differences between ship skin and sub- surface temperatures were observed, with the mean deviation being 0.2C ° for a range of temperature differences between -0.25 and 0.6C °. Inst. fur Meereskunde, Dusternbrooker Weg 20, 2300 Kiel, FRG.
87:5309 Verron, Jacques, 1986. Use of open boundary con-
ditions for the numerical simulation of an ocean box model. Oceanologica Acta, 9(4):415-423. (In French, English abstract.)
An original feature of the model is the use of open boundary conditions on the fluid boundaries. Its efficiency is demonstrated in several cases of flow generated over submarine topography. The bound- ary permeability appears to be good even when strong non-linear perturbations are passing through. Inst. de Mecanique de Genoble, BP 68, 38402 Saint Martin d'Heres Cedex, France.
A40. Area studies, surveys
87:5310 Chiswell, S.M., D.R. Watts and Mark Wimbush,
1987. Inverted echo sounder observations of variability in the eastern equatorial Pacific during the 1982--1983 El Nifio. Deep-Sea Res., 34(3A): 313-327.
Meridional and zonal baroclinic variability was investigated in a ~1000-km region around the Galapagos Islands with an array of three inverted echo sounders. The resulting dynamic height time series show two principal maxima separated by several months, in good agreement with available CTD observations. Autospectra, dispersion char- acteristics and symmetry properties reveal that the first baroclinic mode wave field contains five regimes: (1) at long time scales (~114 days), westward-propagating Rossby waves: (2) in the 38- to 16-day band, a barotropic instability mode with westward phase and group velocity: (3) near 12 days. eastward-propagating Kelvin waves: (4) from 10 to 4 days, clearly defined eastward-propagating Rossby- gravity waves: and (5) in the 6- to 2-day band, inertia-gravity waves of locally resonant second and possibly higher meridional modes. Graduate School of Oceanogr., Univ. of Rhode Island, Narragansett, RI 02882, USA.
87:5311 Greig, M.A., K.R. Ridgway, D.J. Vaudrey and J.S.
Godfrey, 1986. M/V Anro Australia sections: thermal profiles in the eastern Indian Ocean, May 1983 to July 1984. CSIRO mar. Labs Rept. 174:29pp.
The methods used to monitor the temperature profile between the central coast of Western Aus- tralia and Sunda Strait are described: in addition maps showing the position of each profile, the steric height, and the SST are presented together with a
)1 R ¢ I~,',- ~ 34 ( IO~ A. Phys ica l O c e a n o g r a p h y ~(11
vertical temperature section for each voyage. Div. of Oceanogr., CSIRO Mar. Lab., GPO Box 1538, Hobart, Tas. 7001, Australia.
87:5312 Meshal, A.H., 1987. Hydrography of a hypersaline
coastal lagoon in the Red Sea. Estuar. coast. Shelf Sci.. 24(2):167-175. Unesco Reg. Office, P.O. Box 3945 Doha, Qatar.
87:5313 Ouellet, Y. and P. Dupuis, 1986. ]Effects of the
diversion of the Eastmain River (James Bay, Canada) on the estuarine hydrodynamics.] Naturaliste can., 113(4):369-381. (In French, English abstract.) Dept. de genie civil, Univ. Laval, PQ G IK 7P4, Canada.
87:5314 Sakai, Kazuhiko, Shigeo Nakamura and Hideo
Nakamura, 1986. Oceanographic conditions ob- served around Sesoko Island [Japan] from Jan- uary to May, 1986. Galaxea, 5(2):299-300. Sesoko Mar. Sci. Center, Univ. of the Ryukyus, Sesoko, Motobu-cho, Okinawa 905-02, Japan.
bispectrum for a simple non-Gaussian Markov process are derived here. It can be shown by inverse modeling that this process yields a satisfactory approximation to the spectra and the real part of the bispectra of SST-anomaly data. Moreover, the analysis indicates that the imaginary part of the bispectrum cannot be represented in terms of a single-variable model. Climate Dynamics Lab., Inst. of Geophys, and Planetary Phys.. UCLA, Los Angeles, CA 90024, USA.
87:5317 Piterbarg, L.I., 1986. Seasonal features of the
formation of ocean surface temperature anoma- lies. Soy. Met. ltydrol. (a translation of Meteo- rolog~va Gidrol.), 6:46-50.
A one-dimensional stochastic model of the upper quasi-homogeneous layer is used to calculate the annual course of variance, asymmetry, and excess of ocean surface temperature anomalies. The increased intensity of anomaly formation in the spring and summer seasons is verified. Orb)
AS0. General hydrography (distribution of common oceanic proper t ies)
87:5315 D~mgu). J.R. and G. Meyers. 1987. Observed and
modelled topography of the 20°C isotherm in the tropical Pacific. Oeeanologiea A eta, 10( 1 ):41-48.
Variability in depth of the 20°C isotherm observed h\ XBT 1979-83 is documented at selected locations where interannual signals are large. The observed variability is compared to the pycnocline height generated in the Florida State University tropical ocean model, forced by estimates of the observed field of trade winds. The model and observations show good agreement along the Equator and in the western Pacific. Discrepancies are found in the extra-equatorial central Pacific. ORSTOM, II :REMER. B.P. no. 337, 29273 Brest Cedex, France.
87:5316 Mt~ller, Detlev, 1987. Bispectra of sea-surface tem-
perature anomalies. J. phys. Oeeanogr., 17( 1 ):26- 36.
Observed SST anomalies exhibit significant triple- correlations and bispectra. Features of this type are not covered by the standard Ornstein Uhlenbeck (OU) concept of SST fluctuations. The spectrum and
A80. Circulation
87:5318 Barros, VR. and C.M. Krepper, 1977. [A stationary
model of circulation in Golfo Nuevo, Argentina.J Acta oceanogr. Argent., 1(2):11-30. (In Spanish, English abstract.) Centro Nacional Patagonico, Puerto Madr),n, Prov. del Chubut, Argentina.
87:5319 Bormans, Myriam, Chris Garrett and K.R. Thomp-
son, 1986. Seasonal variability of the surface inflow through the Strait of Gibraltar. Ocean- ologica Acta, 9(4):403-414.
Using historical sea level, wind stress, temperature and salinity data as well as idealized models and simple physical arguments it was determined that seasonal changes do not reflect: (1) a purely barotropic flow required by mass conservation: (2) a month-by-month adjustment of a two-layer salt- conserving flow: or (3) a baroclinic flow hydrau- lically controlled at the sill and driven by density changes of inflowing water without changes in interface depth. It is suggested that exchange through the strait is submaximal and that the interface depth changes over the course of the year. Dept. of Oceanogr., Dalhousie Univ., Halifax, NS B3H 4J I, Canada.
802 A. Physical Oceanography ~)1 R I I'~ST~ 3.1 110)
87:5320 Chao, S.-Y., 1987. Wind-driven motion near inner
shelf fronts. J. geophys. Res.. 92(C4):3849-3860.
This work generalizes previous studies to the three- dimensional realm by use of a primitive-equation general circulation model. The model light-water pool is initially driven by injecting light water near the surface and withdrawing heavier water from below along one coastal wall of a cyclic channel; in some of the experiments the boundary forcing is uniform alongshore while in others the alongshore extent of buoyant discharge is restricted to a narrow outlet. Line source and point source experiments are compared to better understand the three-dimen- sionality of the flow. Center for Environ. and Estuarine Studies, Univ. of Maryland, P.O. Box 775, Cambridge, MD 21613, USA.
87:5321 Harvey. J.G. and A. Theodorou, 1986. The circu-
lation of Norwegian Sea overflow water in the eastern North Atlantic. Oceanologica Acta, 9(4): 393-402.
Neutral surfaces are defined from historical hydro- graphic data on which the spreading of Iceland- Scotland overflow water may be examined. Over 40% of the water flowing through the Charlie-Gibbs fracture zone at ~2400 m has the original overflow water characteristics. Geostrophic calculations with a reference level of no motion selected on the basis of the water mass analysis are used to derive quantitative circulation patterns of all deep water below the reference level and of the original overflow water. School of Environ. Sci., Univ. of East Anglia, Norwich NR4 7TJ, UK.
87:5322 Hearn, C.J., J.R. Hunter and M.L. Heron, 1987. The
effects of a deep channel on the wind-induced flushing of a shallow bay or harbor. J. geophys. Res.. 92(C4):3913-3924.
Wind-driven circulation in a shallow bay or harbor is greatly influenced by bathymetry; wind-induced flushing time can be significantly reduced by a deep channel dredged along the prevailing wind direction. In Koombana Bay (southwest Australia), there exists such a naw~t ion channel. Its effective flushing of the bay is studied by current meter and drogue deployments, surface transport measurements, and simulations with idealized long-basin models and 2- and 3-D numerical models. Centre for Environ. Fluid Dynamics, Univ. of Western Australia, Ned- lands 6009, W.A., Australia.
87:5323 Hopkins, T.S. and D.A. Dieterle, 1987. Analysis of
the baroclinic circulation of the New York Bight with a 3-D diagnostic model. Continent. Shelf Res., 7(3):237-265. SACLANT ASW Res. Cen- tre, La Spezia, APO New York, NY 09019, USA.
87:5324 Kessler, W.S. and B.A. Taft, 1987. Dynamic heights
and zonal geostrophic transports in the central tropical Pacific during 1979-84. J. phys. Oceanogr., 17( I ): 97-122.
Dynamic height is calculated from XBT and surface salinity data in the central Pacific using a mean T/S relation in the usual way below the thermocline but assuming isohaline water in the upper layer where the temperatures are isothermal. This scheme pro- duces a better estimate of dynamic height and significant improvements near the Equator where small pressure gradients imply large geostrophic currents, During the 1982-83 El Niflo water of very low surface salinity was observed spanning the equator; this event is attributed both to extreme local rainfall and anomalous advection from the western Pacific. Geostrophic transports of the major surface currents are estimated for the period January 1979 through December 1984. The North and South Equatorial countercurrents are found to have the largest annual fluctuations, and the vertical dis- placements of the thermocline associated with these fluctuations are qualitatively consistent with local Ekman pumping, School of Oceanogr., Univ. of Washington, Seattle, WA 98195. USA.
87:5325 Kinder, T.H. and Gregorio Parrilla, 1987. Yes, some
of the Mediterranean outflow does come from great depth. J. geophys. Res., 92(C3):2901-2906.
In 1973 Stommel et al. predicted that the Western Mediterranean Deep Water (WMDW) contributes directly to the Mediterranean outflow through the Strait of Gibraltar. Hydrographic data obtained in November 1985 showed unambiguous evidence of WMDW west of the major Gibraltar sill, thus confirming the prediction. Naval Ocean Res. and Develop. Activity, Natl. Space Tech. Lab., MS 39529, USA.
87:5326 Maderich, V.S. and V.O. Efroimson, 1986. A simple
model of a sea with a strait. Oceanology (a translation of Okeanologiia), 26(3):300-304.
A two-layer integral model of the evolution of a sea's area-averaged characteristics (layer temperature and salinity, upper layer thickness) with a hydraulic
()1 I,~ ~ ~,)~7~ 34 i Il~) A. Phys ica l O c e a n o g r a p h y 803
model of a strait is proposed. Calculations for the Black Sea with various salt balance values are given and the case of the Mediterranean Sea is discussed. Inst. of Hydromechanics, UkSSR Acad. of Sci., Kiev. USSR.
87:5327 Manley, T.O.. J.Z. Villanueva, J.C. Gascard, P.F.
Jeannin, K.L. Hunkins and J. Van Leer, 1987. Mesoscale oceanographic processes beneath the ice of Fram Strait. Science, 236(4800):432-434.
87:5328 Ostlund, H.G., GOran Possnert and J,H. Swift, 1987,
Ventilation rate of the deep Arctic Ocean from carbon 14 data. J. geophys. Res., 92(C4):3769- 3777.
Application of mass balances of ~O, tritium and salt, plus ~C data, shows that the deep Eurasian Basin exchanges water with the subarctic Atlantic on a time scale of 10-100 years, while the deep Canada Basin has an exchange time scale of ~700 years. Only small fractions, ~10-15% of the deep waters, originate from the shelves. The deep Canada Basin cannot consist of fossil water from glacial time or from the latest cool climate spell just 100 to 300 years ago. RSMAS, Univ. of Miami, FL 33149, USA.
87:5329 Philander, S.G.H., W.J. Hurlin and R.C. Pacanow-
ski, 1987. Initial conditions for a general circu- lation model of tropical oceans. J. phys. Oceanogr, 17( 1 ): 147-157.
A general circulation model of the tropical Pacific, which realistically simulates El Niho of 1982 83, has been used to determine how different initial con- ditions affect the model. Given arbitrary initial conditions the model takes almost a year to return to a state in which currents and density gradients are in
equilibrium with the winds. Errors in the absolute value of the temperature persist far longer, indicating that accurate density data are essential initial conditions. If the correct density field is specified initially, but no information is provided about currents, then the model recovers the currents within an inertial period, except for the eastern equatorial region, which is affected by equatorial Kelvin waves. Currents associated with these waves are relatively modest and do not affect the density field signif- icantly. Because of the large zonal scale of the thermal field in the tropical Pacific, three or four high resolution meridional density sections appear adequate for the initialization of the model. GFD Lab, /NOAA, Princeton Univ., Princeton, NJ 08542, USA.
87:5330 Prandle, D., 1987. Response of the N.W. European
shelf sea at subtidal frequencies. Continent. Shelf Res., 7(3):267-284.
Studies involving subtidal circulation in these seas have sometimes suggested 'anomalous' flow com- ponents of unknown origin e.g. Jefferies et al. (1982). This study assesses how low-frequency barotropic forcing extant in the adjoining ocean might influence shelf circulation and hence contribute to such flow anomalies: a linearized 2-D numerical model is used to examine the shelf response. Inst. of Oceanogr. Sci., Bidston Observ., Birkenhead, Merseyside L43 7RA, UK.
87:5331 Stigebrandt, Anders, 1987. Computations of the flow
of dense water into the Baltic Sea from hydro- graphical measurements in the Arkona Basin. Tellus, 39A: 170-177.
This flow creates a pool of dense water whose leakage is assumed to be controlled by the vertical stratification in the basin together with the rotation of the Earth. For each instance of known strati- fication the accompanying leakage is computed from 182 historical vertical hydrographic profiles taken over 25 years. The profile salinity surplus and profile potential energy completely determine the flows of volume and buoyancy (salt excess). Dept. of Oceanogr., Univ. of Gothenburg, Box 4038, S-40040 Gothenburg, Sweden.
AgO. Currents
87:5332 Aagaard, K., A. Foldvik and S.R. Hillman, 1987.
The West Spitsbergen Current: disposition and
804 A. Physical O c e a n o g r a p h y ~)1 R 119~7t 34 1 IO)
water mass transformation. J. geophys. Res., 92(C4):3778-3784.
The current, which provides the principal contri- bution to the Arctic Ocean of salt and heat, and a variety of anthropogenic tracers, has a complex circulation. North of 79°N, the current contains two separate warm cores that follow different isobaths. The western core follows the western flank of the Yermak Plateau: at least part of this flow detaches from the plateau, probably to contribute to recir- culation in Fram Strait. The inshore branch follows the shelf break into the Arctic Ocean. This inshore branch provides the primary focus in this paper. During the transit of inshore waters past NW Spitsbergen, the core properties change primarily through vertical heat flux, which during ice-free conditions in winter is estimated to be of the order of 200 W m" from the core layer alone. With some freshening within the Arctic Ocean, this process is responsible for fully transforming the original Atlantic Water into Arctic Intermediate Water within about 600 km of Fram Strait. NOAA Pacific Mar. Environ. Lab., Seattle, WA 98115, USA.
87:5333 Barth, J.A, and K.H. Brink, 1987. Shipboard acoustic
Doppler profiler velocity observations near Point Conception: spring 1983. J. geophys. Res.. 92(C4):3925-3943.
Doppler log current data (April 1983) is used to describe spatial flow structures and their variability as a function of time and wind stress. Data accuracy and descriptive aspects of the flow field are dis- cussed, and time series of spatially averaged currents are treated, followed by a quantitative discussion of the relation between directly measured velocity and the hydrographic fields. WHOI, Woods Hole, MA 02543, USA.
87:5334 Btatov, A.S., N.S. Rapil 'bekova and V.I. UFyanova,
1986. A three-layer quasigeostrophic model of hydrodynamically unstable flow for use in study- ing the conditions of eddy formation in the oceans. Oceanology (a translation of Okeano- logiia), 26(3):290-293.
Stability diagrams are constructed for a velocity profile that models open ocean conditions, and eddy formation is evaluated from examples in the Poly- gon-70 data. The eddies identified could not have been formed by baroclinic instability but seem to be a superposition of planetary waves generated in the Canary current region. Moscow Univ., Computer Center, Acad. of Sci., Moscow, USSR.
87:5335 Choi, S.-W. and Y.Q. Kang, 1987. Empirical or-
thogonal function analysis of coastal water tem- peratures in the Tsushima Current region. Bull. Korean Fish, Sot., 20(2):89-94. Dept. of Oceanogr., Natl. Fish. Univ., Pusan, 608 Korea.
87:5336 Filyushkin, B.N., 1986. Lateral variability of thermal
structure of the active layer of the ocean during passage of synoptic eddies. Oceanology' (a trans- lation of Okeanologiia), 26(3):294-299.
Temperature survey data from the 1977-78 POLY- MODE experiment are used to map active layer variabilities for upper homogeneous layer thickness and temperature, seasonal thermoclinic lower boundary, and thermal gradient size: analysis re- veals qualitative correlation among these quantities which enables synoptic eddy identification from upper-ocean temperature surveys. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.
and satellite altimetry. Nature. Lond., 326(6112): p,524. Inst. of Ocean Sci., Sidney, BC, VSL 4B2, Canada.
87:5338 Hamann, llse and B.A. Taft, 1987. On the Kuroshio
Extension near the Emperor Seamounts. J. geophys. Res., 92(C4):3827-3839.
In June-July 1982 and November 1983, studies were made of the Kuroshio Extension's vertical structure along 167°E and the current path as it approached the Emperor Seamounts: moored current meter records from three locations were obtained. Dis- cussed are the results of the current meter data and geostrophic transport calculations: comparisons are made with the data from the more extensive mooring array deployed along 152°E (Schmitz et al,, 1982: Niiler et M., 1985). School of Oceanogr., Univ. of Washington, Seattle, WA 98195, USA.
87:5339 H~nin, C. and P. Hisard, 1987. The North Equatorial
Countercurrent [NECC] observed during the Programme Francais Ocean Climat dans rAtlan- tique Equatorial Experiment in the Atlantic Ocean, July 1982 to August 1984. J. geophys. Res., 92(C4):3751-3758.
Observations from FOCAL cruises in 1982 and 1984 have confirmed that in the central Atlantic the NECC has a well-defined seasonal regime with a very reduced flux during spring. The main core of
I )l R i /~>,- ~ 34 I lq~ A. Phys ica l O c e a n o g r a p h y 805
the NECC always lies between 4 ° and 6°N. Obser- vations have also shown that a long-term change of N ECC may occur and contribute to the devel- opment of an El Niflo type event in the eastern Atlantic. Office de la Recherche Sci. et Tech. Outre-Mer. Noumea, New Caledonia.
87:5340 Hughes, R.L., 1987. The role of the higher shelf
modes in coastal hydraulics. J. mar. Res., 45(I): 33-58.
A simple barotropic model is used to establish the basic nature of the hydraulics of the various shelf modes in coastal flows. There is a major difference in behavior between flows with an even number of subcrilical modes and those with an odd number of subcritical modes. It is suggested that a poleward- flowing western boundary current exhibiting an odd number of subcritical shelf modes loses contact with the coast at that latitude at which the flow becomes critical to the next higher shelf mode. The East Australian Current and the East Cape Current are discussed as examples of this behavior. CSIRO, Div. Atmos. Res., Private Bag 1, Mordialloc, Vic., 3195, Australia.
87:5341 ,Iohannessen, O.M., J.A. Johannessen, E. Svendsen,
R.A. Shuchman, W.J. Campbell and E. Josber- ger. 1987. Ice-edge eddies in the Fram Strait marginal ice zone. Science. 236(4800):427-429.
Five prominent ice-edge eddies in Fram Strait on the scale of 3040 km were observed over deep water within 77°N to 79°N and 5°W to 3°E. The use of remote sensing, a satellite-tracked buoy, and in-situ oceanographic measurements showed the presence of eddies with orbital speeds of 30--40 cm/s and lifetimes of at least 20 days. Ice ablation meas- urements made within one of these ice-edge eddies indicate that melting, which proceeded at rates of 20~40 cm/d, is an important process in determining tile ice-edge position. These studies give new insight on the formation, propagation, and dissipation of ice-edge eddies. ~ 1987 by AAAS. Geophy. Inst., Univ. of Bergen, Norway.
87:5342 Kao, T.W., 1987. The Gulf Stream and its frontal
structure: a quantitative representation. J. p&,s. Oceanogr.. 17(1): 123-133.
A model of the Gulf Stream cross-sectional density and current structure is presented, using the com- plete dynamical and mass-conservation equations. Ihe model postulates a forcing, at the interior ocean boundary, by a cross-stream ageostrophic circulation
with inflow of light water in the upper ocean and a return flow at greater depths; the model Gulf Stream is found to develop after initial geostrophic ad- justment of several inertial periods. Dept. of Civil Engng, Catholic Univ., Washington, DC 20064, USA.
87:5343 K~ise, R.H. and Walter Zenk, 1987. Reconstructed
Mediterranean salt lens trajectories. J. phys'. OceanoRr,, 17(l): 158-163.
The existence of energetic anticyclonic mid-depth vortices of Mediterranean Water (meddles) ques- tions the validity of a conventional advective- diffusive balance in the eastern Atlantic subtropical gyre. A mesoscale experiment in the Azores Madeira region reveals a link of these meddies to large-scale subsurface meanders. Meddles may have strong surface vorticity, indicative of a generation process involving the Azores Current a deep reaching near-surface jet. Inst. fur Meereskunde an der Univ. Kiel, 2300 Kiel 1, FRG.
87:5344 Mc('reary, J.P. Jr., P.K. Kundu and S.-Y. Chao,
1987. On the dynamics of the California Current system. J. mar. Res., 45(I): 1-32.
The dynamics of the California Current System are studied using two models, one with a shelf and one without. Both models are viscid and linearized and solutions are forced by' steady and annually periodic winds with and without curl and by an idealized wind field representation. The focus of the study was to determine what drives the Davidson Current against the wind, and what generates the equator- ward flow in a region of positive wind curl. Many of the results have a general applicability as well. Nova Univ. Oceanogr. Center, 8000 North Ocean Drive, Dania, FL 33004, USA.
87:5345 Metso, A., G.S. Wells, D.J. Vaudrey and G.R.
Cresswell, 1986. Satellite-tracked buoy data Inear Australial, July 1982 to September 1984. CS1RO mar. Labs Rept, 180:50pp.
Track, speed, and SST data were recorded by buoys released near Australia. information on the currents on the North West Shelf, the South Equatorial Current, the Leeuwin Current, and the East Austra- lian Current is presented. Div. of Oceanogr., CSIRO Mar. lab., GPO Box 1538, Hobart, Tas., 7001, ~' u s l r a , ILa.
806 A. Physical Oceanography ()1 R 11987) 34 (10)
87:5346 Orli6, Mirko, Milivoj Kuzmie and Zoran Vueak,
1986. Wind-curl currents in the northern Adriatic and formulation of bottom friction. Oceanologica Acta, 9(4):425-43 I.
Wind and current data show that the characteristic winter wind induces downwind currents over the whole water column. Results of the numerical model show it is possible to approximate the empirical results if the wind curl, besides the bottom slope, is taken into account, and the alongshore dynamics can be reasonably well approximated by the balance of surface and bottom stresses. For this area, the quadratic law for bottom friction is not superior to the linear one. Geophys. Inst., Univ. of Zagreb, Yugoslavia.
87:5347 Park, Y.-H. and S.-I. Kim, 1987. A numerical model
study on tide-induced residual currents around Chejudo Island [Korea[. J. oceanol. Soc. Korea, 22(I):9-18. Dept. of Oceanogr., Cheju Natl. Univ., Aradong, Cheju, Korea.
87:5348 Razzhivin, V.A., 1986. Structure of oceanic synoptic
eddies. Soy. Met. Hydrol. (a translation of Meteorologiya Gidrol.), 5:88-90.
Oceanic eddy structure is examined from obser- vations of currents and distribution of hydrological characteristics in the Kamchatka Current zone of the NW Pacific. Results confirm the probable spiral structure of deep ocean synoptic eddies. (jrb)
87:5349 Richardson, P,L. and G. Reverdin, 1987. Seasonal
cycle of velocity in the Atlantic North Equatorial Countercurrent as measured by surface drifters, current meters, and ship drifts. J, geophys. Res,, 92(C4):3691-3708.
This report describes the general circulation and seasonal variation of currents in the region, con- centrating on the North Equatorial Countercurrent (NECC) and using data from SEQUAL and FOCAL plus historical ship drifts. The horizontal transport of the NECC and vertical transport out of the near- surface layer are estimated. Velocity time series in the NECC are presented: a 23-yr series from ship drifts, a 2 ~ - y r series from drifters, and a 20-month series from current meters: interannual variations, seasonal variations and higher frequencies are discussed and similarities with numerical model predictions are presented. WHOI, Woods Hole, MA 02543, USA.
87:5350 Richman, J.G., R.A. de Szoeke and R.E, Davis,
1987. Measurements of near-surface shear in the ocean. J. geophys. Res., 92(C3):2851-2858.
A string of vector-measuring current meters was deployed off southern California at 34°N 121 °30"W in November 1981 and allowed to drift for ~ 7 days: measurements were given at depths of 2.5, 5.5, 8.5, I 1.5, 14.5, 25 and 63 m. Comparatively strong shears are found in the upper 8 m, of the order of 10 : s comparable to certain shear magnitudes based on the applied wind stress, and weaker shear or none at all between 8-15 m. Currents averaged over the length of the deployment show a consistent turning to the right with depth, in agreement with Ekman theory. Coll. of Oceanogr.. Oregon State Univ., Corvallis, OR 97331, USA.
87:5351 Rossby, T., 1987. On the energetics of the Gulf
Stream at 73W. J. mar. Res.. 45(I):59-82.
Decomposing the velocity and temperature obser- vations into mean and fluctuating fields in two coordinate systems, geographic (or Eulerian) and 'stream' coordinates, showed that at least "/~ of the eddy kinetic and potential energy is caused by the meandering of a well defined baroclinic front with a structure that is nearly independent of space and time. More than 95% of the kinetic energy of the front can be accounted for by a barotropic and baroclinic mode with near equipartition between the two. Grad. School of Oceanogr., Univ. of Rhode Island, Narragansett, RI 02882, USA.
87:5352 Seung, Y.-H., 1987. A buoyancy flux-driven cyclonic
gyre in the Labrador Sea. J. pt~vs. Oceanogr., 17(l): 134-146.
The generation mechanism for a wintertime cyclonic gyre in the western Labrador Sea is studied by using simple theoretical models. Atmospheric cooling, which occurs during outbreaks of cold, dry conti- nental air, can be localized by air modification induced by oceanic heat and water vapor transport. The resulting scale of cooling is comparable to the cross-shore scale of the observed gyre. Density structure of the underlying water mass is then altered by this localized cooling and also by horizontal mixing. The observed gyre may be generated when the new density structure adjusts itself to geostrophic equilibrium. Dept. of Oceanogr., lnha Univ., Incheon 160, Korea.
( ) 1 R I I L~ , 7) 34 f l O~ A. Physical O c e a n o g r a p h y 807
87:5353 Yamagata, Toshio and S.-I. Umatani, 1987. The
capture of current meander by coastal geometry with possible application to the Kuroshio Current. Tellus, 39A: 161-169.
The problem of the bimodal behavior of the Kuroshio is discussed by use of the KdV equation with forcing and dissipation. A localized, large meander of the ocean current is produced by coastal step-like geometry when the upstream current is faster than the long Rossby wave speed, Even if the forcing due to coastal geometry is weak, the dynamical system has a chance to jump from a small meander state to a large meander state because of multiple equilibria. This transition is accomplished by capturing a large, propagating disturbance. Model results are qualitatively consistent with observations. Div. of Ocean Hydrodynamics, Res. Inst. for Appl. Mechanics, Kyushu Univ., Kasuga 816, Japan.
87:5354 Yoon, J.-H. and Ichiro Yasuda, 1987. Dynamics of
the Kuroshio large meander: two-layer model. J. phys. Oceanogr., 17(1):66-81.
A simple two-layered in/outflow model is studied to explain the peculiarity of the Kuroshio path. The geometry south of Japan with a length scale L and the characteristic velocity U of the Kuroshio give an important parameter 3 ' = 2~rV~/~/L. The Kuroshio can take two kinds of paths for a given value of 7 (multiple equilibria), one straight, the other mean- dering. The selection of a path in a multiple equilibrium state depends upon the history of the parameter 3' (the hysteresis phenomenon). The combined effect of horizontal viscosity along the coast and the inclination of the coastline are essential factors which control the Kuroshio path as well as "~. The effect of stratification is remarkable in such time-dependent phenomena as eddy sheddings and the 'trigger meander.' Baroclinic energy con- versions take place in these phenomena. Geophys. Inst.. Univ. of Tokyo, Bunkyo-ku, Tokyo, Japan.
A l l 0 . Water masses and fronts
87:5355 Emery, W.J. and J. Meincke, 1986. Global water
masses: summary and review. Oceanologica Acta, 9(4):383-391.
Using published material, the temperature-salinity characteristics of the world's water masses are
defined for the upper, intermediate and deep/abyss- al regions of the World Ocean, The global distri- butions and boundaries of these water masses are mapped along with indications of their formation regions. Representative temperature-salinity rela- tionships are presented for each of the three major oceans. Dept. of Oceanogr., Univ. of British Co- lumbia, Vancouver, BC, V6T I W5, Canada.
87:5356 Krepper, C.M., 1977. IDiffusion of low salinity water
from the Magellan Strait into the continental shelf waters of Argentina.[ A cta oceanogr. Argent., 1(2):49-66. (In Spanish, English abstract.) Cen- tro Nacional Patagonico, Puerto Madryn, Prov. del Chubut, Argentina.
87:5357 Lutjeharms, J.R.E. and L.H. McQuaid, 1986.
Changes in the structure of thermal ocean fronts south of Africa over a three-month period. S. Afr. J. Sci., 82(9):470-476.
Measurements have been made on the thermal structure of the upper ocean layers between South Africa and Antarctica. The location of five frontal systems in the area and their temporal evolution are shown over a period of two months during the summer of 1979-80. The growth of step-like frontal morphologies with the onset of summer is confirmed. Results suggest that the changeover in the thermal structure from a winter to a fully developed summer regime may occur over a relatively short period. Natl. Res. Inst. for Oceanol., CSIR, P.O. Box 320, Stellenbosch 7600, South Africa.
87:5358 Schlitzer, Reiner, 1987. Renewal rates of East
Atlantic Deep Water estimated by inversion of ~4C data. J. geophys. Res., 92(C3):2953-2969.
Renewal of the deep water of the East Atlantic and its large-scale internal circulation are studied on the basis of distributions of potential temperature, silicate ECO:, and '~C. An isopycnal multibox model including advection, mixing, and sources and sinks is set up and described. ~C data are valuable in determining absolute flow rates. Model results confirm the importance of the Romanche Fracture Zone for renewal; eastward flows through the Romanche Fracture Zone were between 2.6 and 5.1 Sv. Flows through the Vema Fracture Zone amount to at most 20% of the Romanche Fracture Zone inflow. Contributions of Antarctic Bottom Water at the southern end (Walvis Ridge), and Iceland Scotland Overflow Water at the northern end, are small. Dept. of Earth, Atmos., and Planetary Sci., MIT, Cambridge, MA 02139, USA.
808 A. Physical Oceanography ()1 R I 1'*~7134 t l0)
87:5359 Schlosser, Peter, Wolfgang Roether and Gerd
Rohardt, 1987. Helium-3 balance of the upper layers of the northwestern Weddell Sea. Deep-Sea Res., 34(3A):365-377.
A He balance for the winter mixed layer is proposed, which suggests the rate of entrainment of Warm Deep Water into the Winter Water is between 15 and 35 m y '. The vertical eddy diffusivity within the pycnocline above the Warm Deep Water core is approximately 5 x 10" m: s ~, Estimates are based on summer observations: of the assumptions re- quired, that of quasi-stationarity of the gas transfer across the pycnocline appears most critical, but other assumptions require further study as well. Inst. fur Umweltphysik der Univ. Heidelberg, lm Neuen- heimer Feld 366, 6900 Heidelberg, FRG.
87:5360 Whitehead, J.A., 1987. On the ratio of the mixing
coefficients of heat and salt of Antarctic Bottom Water in the North Atlantic. J. geophys. Res., 92(C3): 2981-2984,
AABW values of vertical eddy salt diffusivity and heat diffusivity were previously estimated (White- head and Worthington, 1982) from both current meter results and geostrophic calculations. The ratios of the diffusivities have one impossible value of 0.858 for water colder than I.I°C potential temperature for the geostrophic results. However, a small interpolation error in their Tables 5 and 6 was uncovered. The corrected ratio is 1.01, which is possible, although very close to 1, and one other ratio is 0.98. Thus geostrophic calculations cannot be ruled out, but they lead to ratios very close to I. Dept. of Physical Oceanogr., WHOI, Woods Hole, MA 02543, USA.
A150. Tides and sea level
87:5361 Abraham, G., H. Gerritsen and G.J.H. Lindijer,
Tidally induced residual circulations are produced by tidal oscillations advecting vorticity over bottom topographic features. In areas with a pronounced small-scale bottom topography, tidally induced circulations of a given horizontal length scale can be significantly affected by bottom topography of a smaller length scale. On the basis of a comparison of 1.5 km and 10 km grid computations of the tidal flow in the Southern Bight of the North Sea, for areas with a pronounced small-scale bottom topog- raphy, a significant production of vorticity at the 10
km scale was induced by that part of the bottom topography which in the 10 km grid computations is of subgrid size. Delft Hydraulics, P.O, Box 177, 2600 MH, Delft, Netherlands.
87:5362 Bongers, Thomas and Klaus Wyrtki, 1987. Sea level
at Tahiti--a minimum of variability. J. phys. Oceanogr., 17(l): 164-168.
Tahiti lies close to an amphidromic point with respect to the major semidiurnal tides; it is rarely affected by strong atmospheric disturbances, and the standard deviations of daily and monthly mean sea level are the lowest for nearby stations with a representative record length. Low-frequency vari- ability of sea level is smallest when compared with nearby stations; only the 1982-83 El Niflo event is clearly apparent in the data. Tahiti displays the lowest variability of sea level on all time scales considered, which makes it an ideal location for the calibration of satellite altimeter measurements. Dept. of Oceanogr., Univ. of Hawaii, Honolulu, HI 96822, USA.
87:5363 Godin, Gabriel, 1987. Drift of the node of the
semidiurnal tide in Northumberland Strait. Con- tinent. Shelf Rev., 7(3):225-235.
Northumberland Strait M, tide varies between the winter and the summer months. This implies that the semidiurnal node, assumed to exist in the northern extremity of the strait, is displaced over the seasons. Sets of observations in the immediate vicinity of the node contain such a weakened and irregular semi- diurnal signal that there is no possibility' of resolving from them the components that make up the semidiurnal band. When handling and interpreting field data, it is preferable to conceive of a zone of minimum semidiurnal activity in the northern extremity of the strait, which is displaced by ice and storms, by cycles of neap and spring tides in the Gulf of Saint Lawrence and by short lived weather events, rather than assume the existence of a fixed point of no vertical motion. 2936 Aries Mews, Mississauga, ON, L5N 2N2, Canada.
87:5364 Lupachev, Yu,V.. 1986. Rise of mean water level at
the mouth of a river due to a tidal wave. Soy. Met. HydroL (a translation of Meteorolog(va Gidrol.), 6:81-83.
Observations of the water level at the mouth of the Mezen River confirm the effect of Stokes stress on the tidal wave penetration. This nonlinear effect is the basis for the 'tidal inflation' typical of tidal river mouths.
()1 I~, (I tlYTp34 l lt)l A. Physical O c e a n o g r a p h y 809
87:5365 Weisberg, R.H., D. Halpern, T.Y. Tang and S.M.
Hwang, 1987. M, tidal currents in the eastern equatorial Pacific Ocean. J. geophys. Res., 92(C4):3821-3826.
Current meter measurements recorded over the water column at 10 depths ranging from 20 to 3027 m near 0 °. I10°W are analyzed for the M tidal current over a 10-month sampling interval. A kinematic description is given by month and depth, followed by a decomposition into a barotropic mode and three baroclinic modes. The barotropic tide was dominant, and its hodograph was stable over the 10 months sampled. The baroclinic tide was random, isotropic, and without mode preference. Dept. of Mar. Sci., Univ. of South Florida, St. Petersburg, FL 33701, USA.
AI60. Waves, oscillations
87:5366 Blennerhassett, P.J.F.T. Smith 1981. Shorl-scale
waves on wind-driven water ('cat's paws'). Proc. R. Sot., Lond.. tA)410(1838):1-17.
Wind-generated water waves are considered from the viewpoint of linear stability theory applied to the flow of one fluid over another. Most attention is given to short waves, driven predominantly by a combination of the local shear stresses, the viscous forces and the surface tension, whereas gravity, the local curvature and other properties of the general velocity profiles play relatively little part. Although the corresponding rnain fluid motions near the interface are dominated by viscous dissipation, pressures induced by viscous motions diminish at the interface and allow inertial forces to exert a controlling influence there, bringing in the shear stresses above. Wave features seem to tie in with th~)se observed in "cat's paws" on wind-driven stretches of water. School of Math., Univ. of New South Wales. P.O. Box 1, Kensington, NSW 2033, Australia.
87:5367 ('avaleri, Luigi and Stefano Zecchetto, 1987. Reyn-
olds stresses under wind waves. J. geophys. Res., 92(C4):3894-3904.
lhis paper describes a series of wave measurements concerning water particle kinematics. Attention is focused on the phase relationship between surface elevation and the velocity components. Large phase shifts with respect to the expected values are found under active wave conditions, while swell behavior
closely follows the linear theory. The reliability of the measurements is analyzed in detail; possible physical reasons for the findings are indicated. Istituto per 1o Studio della Dinamica delle Grandi Masse, Consiglio Nazionale delle Ricerche, Venice. Italy,
87:5368 Engevik, L., 1987. A new approximate solution to the
Recent measurements of wave kinematics, showing that the horizontal velocity under the trough is in absolute value greater than the velocity under the crest, cannot be explained by the Stokes theories normally used by the offshore industry. This has led to a reconsideration of the surface wave problem. By applying a Green function technique a solution is obtained which reflects these recent experimental results on solutions to the surface wave problem: however, this new solution gives a better fit to the measurements than do the approximate solutions obtained from the Stokes higher order theories. Deep water waves are discussed, but the method of solution can just as well be applied to the finite water depth case. Dept. of Math., Univ. of Bergen, Norway.
87:5369 Ewing, J.A., M.S. Longuet-Higgins and M.A.
Srokosz, 1987. Measurements of the vertical acceleration in wind waves. J. phys. Oceanogr,, 17(1):3-11.
Recent theoretical studies of the accelerations in regular gravity waves of finite steepness have shown striking differences between the Eulerian and the Lagrangian accelerations (those measured by fixed instruments or freely floating instruments, respec- tively). Here attention is directed to field obser- vations of accelerations in random seas: two sets of data are analyzed. The Eulerian accelerations are notably asymmetric, with maximum downwards accelerations exceeding -1.6g. The Lagrangian ac- celeration histograms are narrower and more sym- metric. As might be expected, the acceleration variance is highly sensitive to the high-frequency cutoff, in both types of data. Inst. of Oceanogr. Sci., Wormley, Surrey GU8 5UB, UK.
87:5370 Grimshaw, R., 1987. Resonant forcing of barotropic
coastally trapped waves. J. phys. Oceanogr., 17(1 ):53-65.
The interaction of a longshore current with a longshore topographic feature is investigated in the
810 A. Physical O c e a n o g r a p h y ( ) I R 11997! 34 I II~l
barotropic case. Near resonance, when a long-wave speed is close to zero, there is enhanced generation of upstream and downstream coastally trapped waves. An evolution equation of the KdV-type describes the resonant behavior, and numerical solutions are discussed for a range of parameters describing the forcing terms, the detuning term and dissipation. The analogous situation of resonant generation due to wind stress is developed in an appendix. School of Math., Univ. of New South Wales, Kensington, NSW 2033, Australia.
87:5371 Hatori, Tokutaro, 1986. Reflection waves from the
continental coast for the 1983 Japan Sea tsunami. Bull. Earthq. Res. Inst., Univ. Tokyo, 61(1- 2):329-338. (In Japanese, English abstract.)
The tsunami hit not only the Japanese coast but also the Sikhote-Alin, U,S.S.R., and Korean coasts. The duration time was long because the Japan Sea is nearly closed and the tsunami reflections from the continental coast were repeated for two days. The maximum wave occurred three hours after the earthquake at many Japanese tidal stations. The correlation of the reflected arrival times and occur- rence of the maximum wave crest on 17 tide-gauge records, and the behavior of the relected wave rays were investigated. Results suggest future tsunami warnings should take into account the effect of reflected waves.
87:5372 Ht~hnerfuss, Heinrich, Wolfgang Walter, P.A. Lange
and Werner Alpers, 1987. Attenuation of wind waves by monomoleeular sea slicks and the Marangoni effect. J. geophys. Res., 92(C4):3961- 3963.
Previous observations of wind wave damping by monomolecular surface films (slicks) have shown a pronounced energy detraction (dip) in the short gravity wave range of the wind wave spectra. In this work, wind wave tunnel experiments with mechan- ically generated water waves have supplied exper- imental evidence which clearly shows that this dip is predominantly caused by the film-induced Maran- goni effect. Inst. fur Organische Chemie der Univ. Hamburg, Hamburg, FRG.
solitary Rossby waves. Oceanology (a translation of Okeanologiia), 26(3):284-289.
Intense synoptic eddies, with large fluid particle orbital velocities compared with 'forward' motion velocity, are modeled as strongly linear solitary
Rossby waves in a continuously stratified ocean with constant Brunt-V~iisal~t frequency. The problem solution is expanded in a power series: only the zero and first approximations are considered. All-Union Sci. Res. Inst. of the Fishing Industry and Oceanogr.. Moscow, USSR.
87:5374 Kobayashi, Nobuhisa, A.K. Otta and Indrajut Roy.
1987. Wave reflection and run-up on rough slopes, J. WatWay Port coast. Ocean Engng, Am. Soc. civ. Engrs, 113(3):282-298.
A numerical flow model is developed to predict flow characteristics on rough slopes for specified, nor- mally incident wave trains. The finite-amplitude shallow-water equations, including effects of bottom friction, are solved numerically in the time domain using an explicit dissipative Lax-Wendroff finite- difference method. The reflected wave at the toe of the slope is computed approximately from the receding characteristics originating on the slope. Wave run-up is predicted from the computed movement of the instantaneous waterline on the slope. The model is in agreement with available data on wave run-up and reflection coefficients, although more extensive calibration and verification are required. Dept. of Civ. Engng, Univ. of Delaware, Newark, DE 19716, USA.
87:5375 Kuznetsov, S.Yu. and N.S. Speranskiy, 1986. Disper-
sional character of secondary waves in the surf zone. Oceanology (a translation of Okeanologiia), 26(3):315-317,
The mechanism of secondary wave generation during passage of surface gravitational waves over a system consisting of an underwater bar and an inner trough is discussed. Field data confirm the hypoth- esis that the secondary waves are of dispersional nature. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.
87:5376 Legeckis, Richard and Gilles Reverdin, 1987. Long
waves in the equatorial Atlantic Ocean during 1983. J. geophys. Re~., 92(C3):2835-2842.
The undulations of the SST front during June and July of 1983 are described. On the basis of these observations the wave speed, length, and amplitude are estimated. The trajectories of several FOCAL buoys are shown to be influenced by the position of the SST front. An attempt is also made to resolve the 0.8°C bias (satellite SST lower) found between the National Environmental Satellite, Data. and Infor- mation Service operational global 100-kin SST maps
I ~t R ~ l',~b 71 34 I Itl) A. Physical O c e a n o g r a p h y 811
and the FOCAL drifting buoy measurements at 2 m as described by Reverdin et al. (1984). NOAA, Natl. Environ. Satellite, Data, and lnfo. Service, Wash- ington, DC 20233. USA.
representations in a shallow lake. Ocean Engng. 14(1):39-50. NOAA, Great Lakes ERL, 2300 Washtenaw Ave., Ann Arbor, MI 48104, USA.
87:5378 Longuet-Higgins, M.S,, 1987. A stochastic model of
sea-surface roughness. I. Wave crests. Proc. R. Sot., Lond., (A)410(1838):19-34,
A two-scale model of sea-surface roughness takes into account the randomness of both long and short waves. The model includes long-wave-short-wave interactions, dissipation of short-wave energy by breaking, and regeneration by the wind. This leads to an integral equation for short-wave steepness, which is solved by iteration. The effects of wind speed and of long-wave steepness upon the distri- bution of roughness at the long-wave crests are calculated and discussed along with the effect of a band-width parameter for the long-wave spectrum. Dept. of Applied Math. and Theoretical Phys., Silver St., Cambridge CB3 9EW, UK.
87:5379 Mathiesen, Martin, 1987. Wave refraction by a
current whirl. J. geophys. Res., 92(C4):3905-3912.
A computer model for the computation of refraction of ocean directional wave spectra has been devel- oped. The model is applied to wave propagation through a circular current whirl. Both refraction diagrams and computed directional wave spectra are presented. Wave heights are computed for points outside the whirl; relative changes in wave heights are within +_20%. The computations reveal two areas of crossing seas on the lee side of the whirl. Between these areas is an area of reduced wave heights and nearly unidirectional waves. Norwegian Hydrotech. Lab., N-7034 Trondheim, Norway.
87:5380 McPhaden, M.J. and A.E. Gill, 1987. Topographic
scattering of equatorial Kelvin waves. J. phys. Oceanogr., 17(1):82-96.
A linear, reduced-gravity model with two active layers above a deep, resting layer is developed to study the scattering of baroclinic equatorial Kelvin waves from finite-amplitude meridional submarine ridges. The equatorial long-wave approximation is made, restricting the class of motions considered to
nondispersive Kelvin and Rossby waves in each of two internal modes; thus, coastal and topographi- cally trapped phenomena are filtered out, but variability far from the ridge is accurately modeled. NOAA/Pacific Mar, Environ. Lab., Seattle, WA 98115, USA.
87:5381 Pos, J.D. and F.A. Kilner, 1987. Breakwater gap
wave diffraction: an experimental and numerical study. J. WatWay Port coast. Ocean Engng, Am. Soc. cir. Engrs, 113(1):1-21. Natl. Res. Inst. for Oceanol., CSIR, Stellenbosch, South Africa.
87:5382 Rahman, Matiur, 1987. A design method of pre-
dicting second order wave diffraction caused by large offshore structures. Ocean Engng, 14(I): I- l& Dept. of Appl. Math., Tech. Univ. of Nova Scotia, P.O. Box 1000, Halifax, NS B3J 2X4, Canada.
87:5383 Resio, D.T,, 1987. Shallow-water waves. 1. Theory. J.
War Way Port coast. Ocean Engng, Am. Soc. civ. Engrs, 113(3):264-281.
Based on geometric scaling laws inherent in the Boltzmann integral for nonlinear wave-wave inter- actions, a theoretical framework for equilibrium spectra in water of arbitrary depth is developed. A theoretical consequence of this formulation is that a strong, constant flux of wave energy exists through the equilibrium range of the spectrum, analogous to the Komolgorov range in a turbulence spectrum. One conclusion is that the equilibrium range of a wind wave spectrum should be a depth-independent constant in terms of a representation of the spectral action density, rather than energy density. Of particular interest is the apparent existence of a natural limit to the evolution of the frequency of the spectral peak into lower frequencies. Offshore and Coastal Tech., Inc., 911 Clay St., Vicksburg, MS 39180, USA.
87:5384 Seymour, R.J. and David Castel, 1987. Sea level
changes associated with Hurricane Gloria. Ocean Engng, 14(1):79-81.
Gloria was a fast-moving, intense hurricane that grazed the North Carolina coastline in September, 1985. The resulting storm surge was measured remotely using a telephone-linked wave data system as well as a local tide gage. The surge was hindcast using a model developed for shore-parallel storm tracks; agreement with measurement was quite satisfactory. The data suggest extremely rapid rise
812 A. Physical Oceanography ()1 R (1987) 34 (Itl)
times for the peak surge of hurricanes moving at high speed along the coast. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA.
A170. Wind-wave interactions
87:5385 Papadimitrakis, Y.A., E.Y. Hsu and R.L. Street,
1987. Characteristics of mechanically-generated waves. J, WatWay Port coast. Ocean Engng, Am. Soc. cir. Engrs, 113(1):39-59.
The structure of a mechanically-generated sinus- oidal, water-wave train of fixed frequency is exam- ined under the influence of wind. Results for seven wind speeds in the range of 140M00 cm/s, and 1 Hz, 2.54 cm (nominal) amplitude, mechanically-gener- ated waves showed that: (1) the amplitude of the forced and free-traveling second harmonics com- pares favorably with existing theories: and (2) the nonlinearities of the primary wave, the interaction between short gravity waves and the primary wave, and the advection effects of wind drift are mainly responsible for the deviation of the measured phase speeds from the linear theory. NASA, Goddard Space Flight Center, Code 671, Greenbelt, MD 20771, USA.
AI80. Internal waves and tides
87:5386 Craig, P.D., 1987. Solutions for internal tidal gen-
eration over coastal topography. J. mar. Res., 45(1):83-105.
Internal tides may be described by a hyperbolic equation which, for the case of constant buoyancy frequency, has constant coefficients. The equation is solved by establishing a set of linear algebraic equations in the modal amplitudes. The capability of the solution technique is demonstrated by simulating the barotropic generation of internal waves over linear near-critical topography, when the solution exhibits high shears and discontinuous behavior at the critical slope, The structure of the waves is determined by the ratio, a, of the bottom slope to characteristic slope. The magnitude of the waves may be estimated by considering the ratio of the baroclinic to the topographic length scales which, for linear slopes, is also given by a. For supercritical slopes, the offshore energy flux varies approximately linearly with c~, while for subcritical slopes it varies as c(. Univ. of Western Australia, Nedlands, WA, 6009, Australia.
A210. Ice
87:5387 Buckley, R.G. and H.J. Trodahl, 1987. Scattering
and absorption of visible light by sea ice. Nature, Lond,, 326(6116):867-869.
The scattering and absorption of sunlight falling on the sea-ice cover exerts a strong influence over the weather of the Southern Hemisphere and over the growth of microbial communities in the water column and within the ice itself, in-situ measure- ments of the diffusive transport of light in the sea ice of McMurdo Sound, Antarctica, permit the reso- lution of depth dependence of the scattering and allow identification of an isotropic top layer, an anisotropic bulk layer and a strongly absorbing algal layer. The anisotropic scattering exerts a strong influence on the radiation field in and under the ice. Phys. and Engng Lab., Dept. of Sci. and Industrial Res., Private Bag, Lower Hutt, New Zealand.
87:5388 Comiso, J.C. and A.L. Gordon, 1987. Recurring
polynyas over the Cosmonaut Sea and the Maud Rise. J. geophys. Res,, 92(C3):2819-2833.
This paper examines two remarkable deep ocean polynyas observed in the Antarctic region during winter 1980: a recurring polynya at ~43°E 66°S (the Cosmonaut polynya), and a polynya at ~ 2 ° E 64°S (the Maud Rise polynya). The relationship of size and location of both polynyas to oceanographic and meteorological data is presented via alternate day time series using ice concentration maps from Nimbus 7 SMMR: it is proposed that both polynyas are products of deep-reaching convection which introduces warmer deep water into the surface layer. Polynya survival and termination are modeled and discussed. Lab. for Oceans, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
87:5389 Gow, A.J. and W.B. Tucker il l , 1987. Physical
properties of sea ice discharged from Fram Strait. Science, 236(4800):436-439.
It is estimated that 84% of the ice exiting the Arctic Basin through Fram Strait during June and July 1984 was multiyear ice and that a large percentage of this ice is ridged or otherwise deformed. While freeboard and thickness data, together with salinity measurements on cores, usually sufficed to distin- guish between first and multiyear floes, preliminary identification could usually be made on the basis of snow cover measurements, with snow cover being much thicker on muhiyear ice. Cores from the top half meter of multiyear floes were generally much harder and more transparent than cores from
I ) I |~, , I'~,, ; ! 34 ~ I1!) A . P h y s i c a l O c e a n o g r a p h y 8 1 3
87:5390 Hiikkinen, Sirpa, 1987. Feedback between ice flow,
barotropic flow, and baroclinic flow in the pres- ence of bottom topography. J. geophys. Res., 92( C4 ): 3807 -3820.
Results show that the satellite observed mesoscale activity of the ice edge does not necessarily reflect the mesoscale baroclinic activity in the ocean. A two-layer ocean model coupled to an ice model is constructed to simulate an ice-ocean system with a ~arying bottom topography, in the absence of wind forcing, the ice cover reflects the externally driven barotropic ocean response, especially topographi- cally forced Taylor columns by forming ice stream- ers or meanders, some of which propagate down- stream, creating an image of eddy propagation even though there is no baroclinic structure underneath. During downwelling favorable winds the Ekman flow toward the open ocean will enhance ice edge meandering due to barotropic flow. During up- welling faw)rable winds, the ice edge stays rather compact, including the case when a strong baro- clinic, cyclonic vortex is developing beneath an ice meander supported by the Taylor column in the ocean. Natl. Res. Council NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
87:5391 Kozo, I.L., W.,l. Stringer and L.J. Torgerson, 1987.
Mesoscale nov'casting of sea ice movement through the Bering Strait with a description of major driving forces. Mon. Weath. Rev., 115(I): 193-207.
Surface atmospheric pressure data from a triangular station network are used to calculate hypothetical geostrophic wind velocities. Net daily Strait ice movement derived from visible and IR NOAA satellite imagery (1974-84) are used to develop an empirical 12-11 advance forecast sea ice movement model with all-weather capabilities. A necessary outgrowth of this study has been the identification and classification of three modes of ice movement and two modes of ice immobilization according to their major driving forces. US Naval Acad., An- napolis, MD 21402, USA.
87:5392 Manley, T.O., 1987. Effects of sub-ice mesoscale
features within the marginal ice zone of Fram Strait. J. geophys. Res., 92(C4):3944-3960.
CTD measurements taken during the M1ZEX '83 East field program, in which four sub-ice mesoscale features (an anticyclonic eddy over the Yermak Plateau and three features located in deep water along the ice edge of the East Greenland Current) were observed, are used to describe the water properties and flow characteristics of Fram Strait, and mesoscale eddies in the region. Calculations of the features' heat, mass and salt fluxes show that the heat transported by the ice edge eddies was signif- icant in comparison with a depth comparable flux of the East Greenland Current, while mass and salt fluxes were ~ 7 times less. Lamont-Doherty Geolog. Observ., Palisades, NY 10964, USA.
87:5393 Shuchman, R.A. et al., 1987. Remote sensing of the
Fram Strait marginal ice zone. Science, 236(4800):429-43 I.
Sequential remote sensing images played a key role in elucidating the complex interactions of the atmosphere, ocean, and sea ice. Analysis of a subset of these images covering a 1-week period provided quantitative data on the mesoscale ice morphology, including ice edge positions, ice concentrations, floe size distribution, and ice kinematics and showed that, under light to moderate wind conditions, the morphology of the marginal ice zone reflects the underlying ocean circulation. High-resolution radar observations showed the location and size of ocean eddies near the ice edge. Ice kinematics from sequential radar images revealed an ocean eddy beneath the interior pack ice, verified by in-situ oceanographic measuremen'ts. ¢ 1987 by AAAS. Environ. Res. Inst. of Michigan, Ann Arbor, MI 48107, USA.
A240. Optical properties
87:5394 Kopelevich, O.V., 1986. An approach to World Ocean
zonation in terms of optical parameters. Ocean- o[ogv (a translation of Okeanologiia), 26(3):310- 314.
The proposed method analyzes the physical factors governing large-scale distribution of optical prop- erties. The parameters describing these properties are given (excluding polarization) and the equations for calculating the parameters using available data are presented. Shirshov Inst. of Oceanol., Acad. of Sci., Moscow, USSR.
814 A. Physical Oceanography ( ) IR (19S7) 34 t 101
87:5395 Yang, Y.-R., 1987. Optical properties of seawater in
Sagami Bay, Japan. Bull. Korean Fish. Soc., 20(2):119-125. (In Korean, English abstract.) Dept. of Fish. Tech., Natl. Fish. Univ., Nam-gu, Pusan, 608 Korea.
A260. Acoustics
87:5396 Adair, R.G. (comment) and J.H. Wilson (reply),
1987. [Discussion of] the infrasonic noise theory of isakovich and Kur'yanov and its modification by Wilson. J. acoust. Soc. Am., 81(4):1192-1195.
87:5397 Buckingham, M.J. and S.A.S. Jones, 1987. A new
shallow-ocean technique for determining the critical angle of the seabed from the vertical directionality of the ambient noise in the water column. J. aeoust, Soc. Am., 81(4):938-946.
In the absence of interference from local shipping, the vertical directionality of ambient noise in the shallow ocean overlying a fast, fluid sediment is a stable feature of the noise field; it is controlled primarily by the bottom reflectivity, which is a time invariant property of the channel. The noise field shows a peak symmetrically placed around the horizontal whose angular width is twice the critical grazing angle of the bottom. By measuring the noise power distribution in the vertical, the critical angle of the seabed can be determined and hence the compressional sound speed in the bottom sediment deduced. Dept. of Ocean Engng, MIT, Cambridge, MA 02139, USA.
87:5398 Dyer, Ira, P.H. Dahl, A.B. Baggeroer and P.N.
Mikhalevsky, 1987. Ocean dynamics and acoustic fluctuations in the Fram Strait marginal ice zone. Science, 236(4800):435-436.
by AAAS. Dept. of Ocean Engng, MIT, Cambridge, MA 02139, USA.
87:5399 Howe, B.M., P.F. Worcester and R.C. Spindel, 1987.
Ocean acoustic tomography: mesoseale velocity. J. geophys. Res.. 92(C4):3785-3805.
Travel times of acoustic pulses transmitted in opposite directions over a 300-km distance in mid-ocean have been used to measure the fields of sound speed and absolute water velocity with mesoscale resolution. Transceivers on two moorings (west of Bermuda, August and September 1983) sent and received signals every 2 hours for 21 days. Ray paths in opposite directions were nearly reciprocal; effects due to internal waves and mean currents were small. The principal results are (1) range-averaged sound speed perturbation decreased over the 21 days, corresponding to a temperature decrease, (2) the field determined from XBT measurements at the start of the experiment agrees with the field deter- mined using the acoustic data within estimated errors of _+ 1.6 m s ~, and (3) during the 21 days the range-averaged barotropic velocity mode increased by a factor of 3, while the baroclinic mode decreased by a factor of 2. Scripps Inst. of Oceanogr., La Jolla. CA 92093, USA.
Lu, 87:5400
I.T. and L.B. Felsen, 1987. Adiabatic transforms for spectral analysis and synthesis of weakly range-dependent shallow ocean Green's functions. J. acoust, Soc. Am., 81(4):897-911. Dept. of Elect. Engng and Computer Sci., Weber Res. Inst,, Polytech. Univ., Route 110, Farmingdale, NY 11735, USA.
87:5401 Mazar, R. and L.B. Felsen, 1987. High-frequency
coherence functions propagated along ray paths in the inhomogeneous background of a weakly random medium. I. Formulation and evaluation of the second moment. J. acoust. Soc. Am,, 81(4):925-937. Dept. of Elect. Engng and Com- puter Sci., Polytech. Univ., Farmingdale, NY 11735, USA.
87:5402 Motamedi, M.E. and R.M. White (guest editors),
1987. Special issue on acoustic sensors. IEEE Trans. Ultrasonics, Ferroelect., Freq. Ctrl, 34(2): 156pp: 21 papers.
The papers cover recent advances in acoustic sensors and are classified by measurand sensed, after the scheme described in the first paper: biolog cal/chemical, electric, mechanical, and therm;
~)1 R I 1~)~;7~ 34 I IO~ A, Physical O c e a n o g r a p h y 815
Subjects include the shift of the center frequency of an ultrasonic resonator: the ultrasonic delay line oscillator: acoustic attenuation, wave reflection, and timing measurement in sensors; timing measure- ments on transmitted and reflected waves in robotic sensors: importance of the phase of the wave reflection coefficient; and use of the sound emitted by the object under study. (jrb)
87:5403 Westwood. E.K. and P.J. Vidmar, 1987. Eigenray
finding and time series simulation in a layered- bottom ocean. J. acoust. Soc. Am., 81(4):912-924. Appl. Res. Lab., Univ. of Texas, Austin, TX 78713-8029, USA.
87:5404 Wunsch, Carl, 1987. Acoustic tomography by Ham-
iltonian methods including the adiabatic approx- imation. Revs Geophys., 25(1):41-53.
Long-range acoustic propagation for ocean tomog- raphy is elegantly described by invoking a Hamil- tonian formulation. Cycling between the upper and lower ocean that is characteristic of oceanic sound propagation is treatable as a libration phenomenon. The tomographic two-point boundary value problem leads, in an analogy to the old Bohr quantum mechanics, to quantization of the action, although the more naturally quantized variable is the canon- ical angle. In the adiabatic approximation the range dependent bias problem in tomography can be fully understood and accounted for as long as the source and the receiver remain axial, Dept. of Earth, Atmos.. and Planetary Sci., MIT, Cambridge, MA 02139, USA.
87:5405 Baldy, S. and M. Bourguel, 1987. Bubbles between
the wave trough and wave crest levels. J. geophys. Res., 92(C3):2919-2929.
In order to estimate ocean-atmosphere mass transfer fluxes controlled by aerosol generation the inter- facial bubble population must be known; the authors use a laser-based single-particle technique to investigate this zone for different breaking wave fields generated in a wind-water simulation facility. The main population characteristics common to the fields investigated are a roughly invariant size distribution with a spectrum slope of ~ - 2 ; concen- trations rapidly increasing upward, following ap- proximately an exponential law; and clustered
distributions at the different measurement levels. Inst. de Mecanique Statistique de la Turbulence, Case 903, 13288 Marseille, Cedex 9, France.
87:5406 Booth, D.A., 1987. Some consequences of a flood tide
front in Loch Creran [Scotlandl. Estuar. coast. Shelf Sci., 24(3):363-375.
Loch Creran is a small sea loch with two basins connected by a shallow narrows. A sharp front forms just inside the narrows during flood tides producing a simple mechanism for flushing the top brackish layer of the inner basin. The mechanism is shown to be consistent with temperature and velocity data. Conservation equations are used with salinity data to estimate mixing and entrainment rates and thus the energy used. A bottom drag coefficient for the narrows is estimated from the tidal signals of velocity and pressure gradient, and the turbulent kinetic energy entering the inner loch is calculated, so that a value for the flux Richardson number can be given. Inst. Maurice-Lamontagne, C.P. 1000, Mont-Joli, PQ, G5H 3Z4, Canada.
87:5407 Jiang, Ganxing, 1985. Some studies on the calculation
method of the density flow in shallow waters. Taiwan Strait, 4(1):1-7. (In Chinese, English abstract.)
Density flow is expressed in terms of the geostrophic current velocity and a variable shallow-water friction depth. The direction of density flow is not perpen- dicular to the density gradient, but instead makes an angle dependent on the gradient and the depth, highlighting the importance of bottom friction to current flow in shoals. Third Inst. of Oceanogr., NBO, Xiamen, People's Republic of China. (fcs)
87:5408 Joyce, T.M. and K.G. Speer, 1987. Modeling the
large-scale influence of geothermal sources on abyssal flow. J. geophys. Res., 92(C3):2843-2850.
An approximate temperature perturbation equation for a continuously stratified deep ocean layer on an equatorial ]3 plane is presented. A vertically inte- grated flow is allowed, forced by uniform upwelling. Solutions with truncated vertical structure are presented, forced by a representation of localized geothermal heat sources. Solutions exhibit a range of behavior from passive advection to /3 plume, de- pending on the ratio of barotropic flow speed to long Rossby wave phase speed. The forced vertical structure is dispersed, which can result in positive and negative temperature anomalies both upstream
816 A. Phys ica l O c e a n o g r a p h y ( )1. R I I q~ 7) 34 ( I O)
and downstream of the source. The ability of localized sources to influence upstream conditions is enhanced in equatorial regions compared with higher latitudes, where the background flow is better able to advect the temperature perturbations down- stream. Depending on the strength of the temper- ature anomaly at the source, there may or may not be a large-scale reversal of the total flow field. Thus the correlations between temperature, geostrophic shear, and a passive tracer such as He can be positive, negative, or zero away from the geothermal source. WHOI, Woods Hole, MA 02543, USA.
87:5409 Nof, Doron, 1987. The bifurcation of outflows. J.
phys. Oceanogr., 17(1):37-52.
The behavior of outflows resulting from channels cutting through broad continents and emptying into wedgelike oceans, or channels cutting in wedgelike continents and emptying into broad oceans, is examined analytically. The model is nonlinear and inviscid, and the vertical structure is approximated by two layers: the upper layer is active and the lower is passive. When the outflow results from a channel cutting through a broad continent and emptying into a wedgelike ocean, there are two possibilities. If the wedge opening is less than 90 ° , the outflow deflects to the right: if larger than 90 ° , the outflow deflects to the left. In contrast, when the channel is cutting through a deltalike continent and emptying into a broad ocean, the outflow bifurcates. Possible appli- cation of this theory to the two outflow modes observed near the Tsugaru Strait is mentioned. Dept. of Oceanogr., Florida State Univ., Tallahassee, FL 32306, USA.
87:5410 Washburn, Libe and R.H. K2ise, 1987. Double
diffusion and the distribution of the deusitv ratio in the Mediterranean waterfront southeast of the Azores. J. phys. Oceanogr., 17(1):12-25.
This paper examines the distribution of the saltwater density ratio (R.) in an experimental region SE of the Azores which may be readily estimated at least to vertical scales. Laboratory and theoretical investi- gations indicate that double diffusive fluxes become large with decreasing R ; mapping of R both vertically and horizontally may, therefore, indicate where these fluxes are likely to be important and how water masses might evolve under their influ- ence. Center for Earth Sci., Univ. of Southern Calif., Los Angeles, CA 90089, USA.
87:5411 Wolanski, Eric and JOrg lmberger, 1987. Friction-
controlled selective withdrawal near inlets. Estuar. coast. Shelf Sci., 24(3):327-333.
A simple analytical model is used to show that, without buoyancy effects, the flow toward an inlet in shallow water exhibits a selective withdrawal ap- pearance if the seafloor is shelving toward deeper water offshore. This prediction is confirmed by field experiments in Koombana Bay, Australia, and by a Hele-Shaw cell simulation. Australian Inst. of Mar. Sci., PMB No. 3, Townsville, M.C., QId. 4810, Australia.
A300. Fluid mechanics
87:5412 Babiano, Armando, Claude Basdevant, Pascal Le
Roy and Robert Sadourny, 1987. Single-paNicle dispersion, Lagrangian structure function and Lagrangian energy spectrum in two-dimensional incompressible turbulence. J. mar. Res., 45(1 ): 107-131,
The domain of validity of the classical asymptotic estimates is extended: in particular the asymptotic behavior of the single-particle dispersion at small times remains valid throughout the whole self-similar range when the Lagrangian energy spectrum is steeper than ~ ~. Straightforward estimates of the Lagranglan integral time scale and the diffusion coefficient at large times, based on energy and enstrophy, are proposed: to some extent, they remain valid locally, which allows an analysis of their spatial variability within a single turbulent field. Finally, the detrimental effect of artificial numerical diffusion on the numerical simulation of Lagrangian statistics is highlighted and discussed. Lab. de Meteorol. Dynamique du CNRS, Ecole Normale Superieure, 24, rue Lhomond, 75231 Paris Cedex 05, France.
P.C. Gallacher and Peter Mt~ller (reply), 1987. [Discussion of[ 'Wind direction and equilibrium mixed-layer depth: general theory.' J. phys. Oceanogr., 17(I): 169-172.
Discussion of the paper by Garwood et al. centers on the importance and interpretation of three factors applied to the mixed layer: (l) the Richardson number value, (2) the estimated size of the integral length scale, and (3) the importance of rotation. (fcs)
87:5414 Friedlander, Susan, 1987. Internal waves in a rotating
stratified spherical shell: asymptotic solutions.
()1 R t 19~,7~ 341 I~11 817
Geophys. Jl R. astr. Soc., 89(2):637-655, Dept. of Math., Statistics and Computer Sci., Univ. of Illinois, Chicago, IL 60680, USA.
87:5415 Pedlosky, Joseph and L.M. Polvani, 1987. Wave-
wave interaction of unstable baroclinic waves. J. armor. Sci., 44(3):631-647.
Two slightly unstable baroclinic waves in the two-layer Phillips model interact with each other as well as the mean flow, A theory for small dissipation rates is developed to examine the role of wave-wave interaction in the dynamics of vacillation and aperiodicity in unstable systems. The form of the dissipation mechanism as well as the overall dissi- pation timescale determines the nature of the dynamics. Dissipation proportional to potential vorticity expunges amplitude vacillation due to wave-mean flow interaction. Wave-wave interaction can yield amplitude vacillation. As dissipation is decreased, solutions evolve from steady waves to periodic vacillation until finally chaotic behavior is obtained. This occurs in a range of relative growth rates of the two waves which depends on the strength
of the wave-wave and wave-mean flow interactions. WHOI, Woods Hole, MA 02543, USA.
and their role in atmospheric transport and chemistry models. Revs Geophys., 25(1):71-100.
The extensive literature comparing transport algo- rithms is reviewed, and several conclusions can be made. The judicious use of simple finite difference schemes provides a minimum level of accuracy that is suitable for many atmospheric applications (sig- nificant improvements in accuracy can be obtained at great expense). Spectral and pseudospectral techniques consistently provide the highest degree of accuracy, but expense and difficulties assuring positive mixing ratios are serious drawbacks. Schemes which consider fluid slabs bounded by grid points (volume schemes) provide accurate positive definite results. The computer memory requirements of the volume schemes can be excessive. Atmos. Chem. and Dynamics Branch. NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
B. MARINE METEOROLOGY
BI0. Apparatus and methods
87:5417 gnting, I.G., 1987. On the application of lattice
statistics to ]CO_,] bubble trapping in ice. Tellus, 39B( 1-2): 100-113.
[he use of the percolation model from lattice statistics to represent the distribution of trapping times for air bubbles in polar ice is discussed. A number of relevant techniques and results from the statistical mechanics of phase transitions are re- viewed in order to propose suitable approaches for performing a more refined lattice statistics analysis of bubble trapping. CSIRO, Div. of Atmos. Res., Private Bag 1, Mordialloc, Vic 3195, Australia,
87:5418 Fraedrich, Klaus, 1987. El Nifio iterations. Beitr.
Phys. 4 tmos., 60( 1 ):22-33.
An empirical (quadratic) temperature iteration is deduced from observed annual E1 Niflo/Southern Oscillation intensities with the thermal inertia or ocean surface layer depth representing the external or bifurcation parameter, This leads to the concept of an iterative climate system, the dynamics of which are analysed. (1) The structural analysis of the system emphasizes a basin of attraction and em- bedded intervals, from which the time evolution of the system cannot escape. (2) Further details of the time evolution reveal the known features of period doubling. (3) Stochastic forcing diffuses the itera- tions and enhances the parameter domain of irreg- ularity with increasing noise level: but the main stability properties with the attractor basin and
