996 A. Physical Oceanography OLR (1986) 33 (12)

Two hypothetical basal melting scenarios are com- pared: (1) zero melting everywhere and (2) melting sufficient to balance any large-scale patterns of ice-shelf thickening that would otherwise occur. As a result of the temperature-dependent flow law, sim- ulated ice-shelf velocities for the second scenario are reduced by up to 20% below those of the first. Results support the hypothesis that melting patterns presently maintain ice thickness in steady state and conform to patterns of oceanic circulation presently thought to ventilate the sub-ice cavity. Differences between the simulated and observed velocities are too large in the extreme southeastern quarter of the ice shelf to permit verification of either basal melting scenario. Dept. of the Geophys. Sci., Univ. of Chicago, IL 60637, USA.

86:6798 StOssel, Achim, 1985. Thermodynamic calculations of

ice production in the northern Baltic proper. Dr. hydrogr. Z., 38(6):261-284. Eichenstrasse 46, 2000 Hamburg 20, FRG.

86:6799 Sturman, A.P. and M.R. Anderson, 1986. On the

sea-ice regime of the Ross Sea, Antarctica. J. Glaciol., 32(110):54-59.

A study of the sea-ice regime using ESMR passive microwave data and supporting information, shows air flow has a dominant influence on sea-ice distribution and movement, with oceanic circulation playing a more minor role. Broad areas of ice convergence and divergence were identified by assimilating the rather limited oceanic and atmos- pheric information with observed sea-ice variations. In spite of some basic physical similarities of the Weddell and Ross seas, it is apparent that the major differences in their sea-ice regimes are due to the differing roles of oceanic and atmospheric circu- lation in each area. Dept. of Geogr., Univ. of Birmingham, BI5 2TT, UK.

86:6800 Thorndike, A.S., 1986. Diffusion of sea ice. J.

geophys. Res., 91(C6):7691-7696.

The field of motion of sea ice is such that a Lagranglan element will be progressively deformed. The Lagrangian element spreads out at a rate determined by the mean field (usually more impor- tant), and by the random field, which gradually mixes the element with the surrounding ice. A mechanism for this mixing is discussed. The simplest mode of deformation for sea ice may be a finite shear displacement along a single crack. If the ice deforms in this way, the result will be a complete reshuffling of the ice pack. In terms of the relative

diffusion of pairs of points, the model predictions have a weak resemblance to actual ice behavior. Dept. of Phys., Univ. of Puget Sound, 1500 North Warner, Tacoma, WA 98416, USA.

A240. Optical properties 86:6801

Burenkov, V.I., A.P. Vasilkov and L.A. Stephantzev, 1986. Mesoscale variability of the ocean spectral reflectance. Okeanologiia, 26(2):212-218. (In Russian, English abstract.)

86:6802 Spinrad, R.W., 1986. A calibration diagram of specific

[light] beam attenuation. J. geophys. Res., 91(C6):7761-7764. Sea Tech, Inc., Corvallis, OR, USA.

86:6803 Yang, Y.-R. and Tsutomu Morinaga, 1986. Optical

properties of seawater in Tokyo Bay. Bull. Korean Fish. Soc., 19(3):234-240. (In Korean, English abstract.) Dept. of Fishing Tech., Natl. Fish. Univ. of Pusan, Nam-gu, Pusan 608, Korea.

A260. Acoustics 86:6804

Floyd, E.R., 1986. The existence of caustics and cusps in a rigorous ray tracing representation. J. acoust. Soc. Am., 79(6):1741-1747. Arctic Submarine Lab., NOSC, San Diego, CA 92152-5000, USA.

86:6805 Frazer, L.N., 1986. Applications of multifold Kirch-

hoff-Helmimltz path integrals to sound propa- gation in the ocean. Part I. Theory. J. acoust. Soc. Am., 79(6):1748-1759. Inst. of Geophys., Univ. of Hawaii, Honolulu, HI 96822, USA.

86:6806 Gulin, O.E. and V.I. Klyatskin, 1986. On resonance

structure of acoustical field spectral components in the ocean excited by atmospheric pressure. Fiz. Atmosf. Okeana, 22(3):282-291. (In Russian, English abstract.)

86:6807 Hang, Ruheng, Long Men and Xiecheng Wang,

1985. Measuring transmission loss of underwater sound with a telemetry sonobuoy. Tropic

OLR (1986) 33 (12) A. Physical Oceanography 997

Oceanol., 4(4):68-76. (In Chinese, English ab- stract.) Inst. of Acoustics, Acad. Sin., People's Republic of China.

86:6808 Knobles, D.P. and P.J. Vidmar, 1986. Simulation of

bottom interacting waveforms. J. acoust. Soc. Am., 79(6): 1760-1766. Appl. Res. Lab., Univ. of Texas, Austin, TX 78713-8029, USA.

86:68097 Kuperman, W.A. and Henrik Schmidt, 1986. Rough

surface elastic wave scattering in a horizontally stratified ocean. J. acoust. Soc. Am., 79(6): 1767- 1777. Naval Res. Lab., Washington, DC 20375- 5000, USA.

86:6810 McCammon, D.F. and S.T. McDaniel, 1986. Surface

velocity, shadowing, multiple scattering, and curvature on a sinusoid. J. acoust. Soc. Am., 79(6):1778-1785. Appl. Res. Lab., Pennsylvania State Univ., P.O. Box 30, State College, PA 16804, USA.

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

86:6811 Bagryantsev, N.V. and V.V. Guretsky, 1986. On the

heat transport in the Antarctic zone of the Southern Ocean. Meteorologiya Gidrol., 1:62-69. (In Russian, English abstract.)

Mechanisms and estimates of heat transport in the Southern Ocean are analysed. Mean advective heat flux in the Weddell Gyre was calculated to be negligible when compared with the standard error estimate; synoptic eddies and intense narrow cur- rents not accounted for in standard heat transport calculations may carry heat into the gyre. (sir)

86:6812 E, Xuequan and E.J. Hopfinger, 1986. On mixing

across an interface in stably stratified fluid. J. Fluid Mech., 166:227-244. Inst. of Mech., Chi- nese Acad. of Sci., Beijing, People's Republic of China.

86:6813 Kalkwijk, J.P.T., 1985. Dispersion of matter at sea

under homogeneous conditions. Dt. hydrogr. Z., 38(6):245-260.

In this paper the dispersion of a solute at sea is examined by means of a horizontal 2-D approach.

The velocity field is horizontally homogeneous and characterized by a velocity ellipse with axes of arbitrary magnitude. Stratification is absent. Be- cause of the tidal motion the dispersion tensor is time dependent. It is particularly shown that the initial behavior of the concentration is very variable and depends on the moment of release and on the dispersion transverse to the mean velocity. Delft Univ. of Tech., Dept. of Civ. Engng., P.O. Box 5048, NL-2600 GA Delft, Netherlands.

86:6814 Knobloch, Edgar, D.R. Moore, Juri Toomre and

N.O. Weiss, 1986. Transitions to chaos in two--dimensional double-diffusive convection. J. Fluid Mech., 166:409-448. Dept. of Phys., Univ. of Calif., Berkeley, CA 94720, USA.

86:6815 Sanderson, Brian, Karen Perry and Tom Pedersen,

1986. Vertical diffusion in meromictic Powell Lake, British Columbia. J. geophys. Res., 91(C6): 7647-7655.

Powell Lake is a meromictic former fjord containing trapped seawater. Near the bottom of the lake the vertical diffusivity is about 4 times that of the molecular diffusivity of salt. On this basis, ions with different molecular diffusion coefficients will be lost from the bottom of the lake at different rates, which partially explains differences observed in the ratios of concentrations of ions in saline bottom water from ratios characteristic of seawater. The observed increase in temperature with depth results from the geothermal heat flux through the lake's bottom. Dept. of Phys., Memorial Univ., St. John's, NF AIB 3X7, Canada.

A300. Fluid mechanics

86:6816 Batchaev, A.M. and M.V. Kurgansky, 1986. On the

instability of periodic shear flow of weakly stratified fluid. Fiz. Atmosf. Okeana, 22(1):3-9. (In Russian, English abstract.)

86:6817 Chen, Changsheng and Zenghao Qin, 1985. On the

geostrophic adjustment process of oceanic mo- tions. Scientia sin., (B)28(10): 1093-1109.

For the barotropic ocean, the horizontal scale constrains the linear geostrophic adjustment; the unbalanced energy dispersive mechanism acting