Results of recent theoretical studies are used as a basis for a new two-parameter system of estuarine classification. The classes are delineated by the magnitudes of the relative stratification and circulation parameters associated with changes in the salt balance mechanism. The theoretical results depend on a knowledge of the eddy coefficients of viscosity and diffusivity. Tentative relationships between these coefficients and the bulk parameters of tidal current, river flow, and geomorphology, which are obtained from experimental data, may be used to determine the salinity and net current distributions in partially mixed and well-mixed coastal plain estuaries. l Contribution No.

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Data from 20 satellite‐tracked drifting buoys deployed in the eastern equatorial Pacific Ocean during the summer of 1979 were used to investigate the nature, effects, and energetics of currents associated with cusp‐shaped long waves observed in satellite IR imagery of the sea surface during all except El Nino years. It is shown that the long waves are associated with a vigorous pattern of mesoscale eddies lying primarily between the equator and 7°N. The spatial structure of the eddy kinetic energy closely resembles the eigenfunctions obtained from Philander's (1978) investigation of barotropic instability of that part of the South Equatorial Current lying north of the equator. Computation of the energy exchange between the eddies and the mean field suggests an e folding time of about two weeks for the eddies and a braking effect on the mean flow comparable to a change of surface wind stress of a few tenths of a dyne per square centimeter. The eddies also effect an equatorward transport of heat that amounts to about two thirds of the poleward heat transport of the divergent Ekman transport in the near‐surface waters.

Data from satellite-tracked drifting buoys and VOS/XBT profiles for the years 1979-95 were used to evaluate the seasonal cycle of how major oceanic processes redistribute heat in the cold tongue region of the tropical Pacific. The most active processes for the annual cycle are local heat storage and heat export by entrainment of upwelling and by mean meridional advection. Heat export by zonal advection, however, is not negligible, and meridional eddy heat fluxes associated with tropical instability waves effect a negative feedback that offsets a considerable fraction of that produced by the mean meridional advection. All of these processes mimic the essentially one cycle per year of the surface wind stress, as do those of the depths of both the bottom of the surface mixed layer and the thermocline. Because it is associated with poleward Ekman transports, upwelling, and baroclinic adjustment near the equator, the zonal wind stress component appears to be the more important. The meridional wind stress, while weaker in the annual mean, has a larger annual variation and, therefore, has equal influence on the annual variation of the scalar stress and perhaps the mixed layer thickness. The Monin-Obukov length is found to underestimate the mixed layer thickness considerably. Finally, the authors produce the first estimates of the seasonal cycle of eddy heat flux convergence, which plays a significant role in the evolution of the cold tongue, and show that the eddy heat flux convergence can be quantitatively modeled as eddy diffusion with a diffusivity derived from single-particle buoy statistics.