OLR (1990) 37 (12) A. Physical Oceanography 1079

estimates from hydrographic data. Dept. of Phys. Oceanogr., WHOI, Woods Hole, MA 02543, USA.

90:6878 Servain, Jacques, Mare S~va and Pierre Rual, 1990.

Climatology comparison and long-term variations of sea surface temperature over the tropical Atlantic Ocean. J. geophys. Res~ 95(C6):9421- 943 I.

The first climatology uses merchant ship meas- urements taken between 1911 and 1972. The second uses 1964-1984 data and is generally warmer by a few tenths of degrees. Part of the difference is due to changes in the temperature measurement techniques with time. Using a simple technique to eliminate spurious bias, the analysis allows isolation of the long-term trend of SST anomalies in the tropical Atlantic. South of the thermal equator, a warming trend occurs principally during boreal summers and extends to the present with an increasing range when calculated over the past 26-yr. In the north, such a warming is more questionable between the 1940s and 1970s. It is more evident during the past 26-yr, but with a temperature range less than half of that for the southern basin. Three spatially limited areas with a cooling trend are suggested. Ctr. ORSTOM, IFREMER, BP 70, 29280 Plouzane, France.

variations of the Kuroshio axis. J. oceanogr. Soc. Japan, 45(5):310-320. Kanagawa Prefectural Fish. Experimental Sta., Jyogashima, Miura, Kanagawa, 238-02, Japan.

90:6881 Larouche, Pierre and J.-M.M. Dubois, 1990. Dy-

namlcal evaluation of the surface circulation using remote sensing of drifting ice floes. J. geophys. Res. 95(C6):9755-9764.

This method leads to a good approximation of the surface circulation in a region where ice floes are free drifting; on the other hand, sole use of the floe drift over time to evaluate the currents leads to results that are far from the measured values. Tests made using various air and ice drag coefficients, and wind speeds and directions for different drift distances show that the error associated with these parameters is small. Although the values obtained using the numerical data involved considerably more effort and expense, the results were not significantly better than those found using photographic prod- ucts. A good approximation of the surface circu- lation can thus be made using a simple digitization of the floe positions on photographic products. Oceanogr. Phys., Inst. Maurice-Lamontagne, C.P. 1000, Mont-Joli, PQ G5H 3Z4, Canada.

A80. Circulation

90:6879 Cummings, P.F., Greg Holloway and A.E. Gargett,

1990. Sensitivity of the GFDL ocean general circulation model to a parameterization of vertical diffusion. J. phys. Oceanogr, 20(6):817-830.

A case with constant diffusivity is compared with a case in which the diffusivity is inversely proportional to the local Brunt-V~is~ila frequency. The stability- dependent parameterization of vertical diffusivity yields a poleward heat flux similar to that of a small, constant diffusivity; however, it also increases the mean temperature in the deep ocean by about 0.8 C ~ and the strength of the meridional circulation by over 40%. In addition, the stabili ty-dependent diffusivity increases stratification in the deep ocean. It may be possible to calibrate the rate of deep-water formation of general circulation models, without affecting the poleward heat transport, by varying the magnitude of the vertical diffusivity below the thermocline. Inst. of Ocean Sci., 9860 W. Saanich Rd., Sidney, BC V8L 4B2, Canada.

90:6880 Iwata, Shizuo and Masaji Matsuyama, 1989. Surface

circulation in Sagami Bay: the response to

90:6882 Power, S.B., R.H.J. Grimshaw and J.H. Middleton,

1990. Large-scale, low-frequency barotropie cir- culation on continental margins. J. phys. Oceanogr, 20(5):769-785.

Analytic solutions are obtained for forced, baro- tropic circulation at subinertial frequencies over a bilinear continental margin (~helf and slope), in situations where bottom friction is important. Three different alongshore forces are considered: wind- stress, offshore oceanic pressure gradients and offshore currents. Results are compared to earlier 'steady' and unilinear models. Special attention is paid to differences between wind and offshore driven responses, and to dependence of solutions on forcing frequency, friction, and bathymetry. Climate Res. Group, Dept. of Meteorol., McGill Univ., Montreal, Canada.

90:6883 Signell, R:P. et al., 1990. Effect of wave-current

interaction on wind-driven circulation in narrow, shallow embayments. J. geophys. Res~ 95(C6): 9671-9678.

In the model, a constant wind stress is applied in the along-channel direction to a channel with a constant cross-sectional profile. Wind-induced flushing is