766 A. Physical Oceanography OLR(1979)26(12)

Stationary waves in a stratified shallow sea with an absence of external flow are investigated. A detailed, numerical analysis of internal wave propagation in the Arkona Basin (Baltic Sea) is performed; local Richardson numbers are calculated and it is shown that 'Ri < 1/4 can occur for solitary waves which may cause organization of some turbulent regions.' Institute of Mechanical Problems of the U.S.S.R. Academy of Sciences, prospect Vernadskogo 101, 117526 Moscow, U.S,S.R. (izs)

79:5902 Lundberg, Peter, 1979. Nonhydrostatic waves in

canals of varying depth. Rept oceanogr. Inst. G~teborgs Univ., 32:25 pp.

The phenomenon of standing waves in enclosed basins, which do not satisfy the shallow-water criterion and are thus influenced by nonhydrostatic effects, is investigated by inclusion of the effects of vertical accelerations in the analysis. Oceanografiska Institutionen, G6teborgs Universitet, Box 4038, 400 40 G6teborg, Sweden. (izs)

79:5903 Olbers, D. J. and Klaus Herterich, 1979. The spectral

energy transfer from surface waves to internal waves. J. Fluid Mech., 92(2): 34%379.

Internal wave generation b~ resonantly interacting surface waves is investigated with a 3-1aver stability frequency model within the framework of spectral scattering theory. Spectral transfer is shown to be negligible for the oceanic main thermocline but ma~ be of significant importance for waves trapped in the seasonal thermocline. Includes appendices on wave- wave interaction coupling coefficients and internal wave eigenfunctions, lnstitut ffir Meereskunde, Universitat Kiel, Kiel, F.R.G. (izs)

79:5904 Stiassnie, M. and G. Dagan, 1979. Partial reflexion of

water waves by non-uniform adverse currents. J. FluidMech., 92(1): 119-129.

Linearized wave propagation on a non-uniform slowly varying current in deep water is investigated via a Schr6dinger ordinary differential equation solved by the WKB method to precisely determine the dependence of the reflexion degree upon current velocity distribution. It is analytically shown that upon encountering an adverse current barrier, part of the wave energy is transmitted and part reflected. Coastal and Marine Engineering Research Institute, Technion, Haifa, Israel. (izs)

79:5905 Wubber, Chresten, 1979. Die zweidimensionalen

Seiches der Ostsee. [The two-dimensional seiches in the Baltic.] Ber. Inst. Meeresk. Christian- Albrechts-Univ., 64: ca. 100 pp. Includes ca. 40

Baltic Sea oscillation charts, institut fiir Meereskunde Abt. Theoretische Ozeanographie. 23 Kiel Diisternbrooker Weg 20, F.R.G.

15. Internal waves and tides

79:5906 Dore, B. D. and M. A. AI-Zanaidi, 1979. On second-

ary vorticity in internal waves. Q. appl. Math.. 37(I): 35-50.

The generation of secondary vorticity by internal wave processes is investigated for two semi-infinite. homogeneous, immiscible fluids of different density, for a continuously-stratified fluid of great depth, and for a continuously-stratified fluid of finite depth. University of Reading, England. (rio)

79:5907 Mahanti, N. C., 1979. Small-amplitude internal waves

due to an oscillatory pressure. Q, appl. Math., 37( 1 ): 92-97.

The initial-value problem of waves in superposed fluids due to an axisymmetrical oscillatory pressure is solved by the method of integral transforms. The wave integral representing interracial displacement is evaluated in an asymptotic form that remains uniformly valid through the transition zone. I.I.T.. Hauz Khas, New Delhi 110029, India.

17. Underwater acoustics

79:5908 Bannister, R. W., R. N. Denham, K. M. Guthrie,

D. G. Browning and A. J. Perrone, 1979. Vari- ability of low-frequency ambient sea noise. J, ac oust. Soc. Am., 65(5): 1156-1163.

Variability of wind- and shipping-generated noise as related to receiver depth, wind speed and frequency was investigated in the South Fiji Basin (northeast of New Zealand). Standard deviation was not receiver- depth dependent; wind noise had low standard deviations (less than 0.1 dB) and was frequency independent; shipping noise depended on the detailed line structure and had variable standard deviations. Defence Scientific Establishment, HMNZ Dockyard, Auckland 9, New Zealand. (izs)

79:5909 Fisher, F. H., 1979. Sound absorption in sea

water by a third chemical relaxation. J. acoust. Soc. Am.. 65(5): 1327-1329.

In addition to sound absorption effects caused by boric acid and magnesium sulfate, a chemical relaxation process at 3 kHz has been identified via