The Abyssal Ocean. The deep distribution of oceanic variables 
(temperature, salinity, current, etc.), and planktonic and sedimentary 
particles appears to be determined by upwelling and turbulent fluxes. 
The most urgent need is for observational studies of the turbulent 
mixing processes. <A thorough, well-planned effort to study the turbu- 
lent microstructure of the main thermocline would provide insight on 
the general circulation of the oceans, global weather and climatic 
fluctuations as well. It is intolerable that direct measurements of 
turbulent fluxes at depth are not being attempted. In our judgment 
this is within present-day technological capability but might require 
substantial engineering. A few pioneering studies made with sensors 
mounted on submarines and lowered by wire from surface vessels have 
shown fascinating microstructure. These studies provide a good basis 
for future development. Submarines are essential to the study of 
water under ice sheets. This cold water, of high salinity and density, 
eventually becomes the water at the greatest depths. The development 
of the bottom water remains largely unknown. 
Distinction between various modes and types of internal waves and 
what is ineptly referred to as turbulence has to be clarified. Perhaps, 
most. random variation of temperature currents can be associated 
with internal, gravity-inertial and planetary waves. Distribution of 
energy among different modes, frequencies, and directions needs dis- 
entanglement. The existence of an equatorial, internal wave trap be- 
tween 30° S. and 30° N. lends interest to a geographical study of these 
distributions. Nonlinear interactions among these modes (including 
“general circulation” as zero frequency mode) and the irregular sea 
bottom need to be studied theoretically and experimentally. It is 
here that a solution to the problem of dynamic oceanography may be 
sought. We must cease to be surprised at irregularity of oscillations 
whenever appropriate observations are made. Irregularity is ex- 
pected as a consequence of the fact that 10° ergs sec? of energy are 
dissipated in the ocean, and this calls for r.m.s. (root mean square) 
shear of 107 sec". 
Buoy Programs. During the past few years several draft plans 
have been submitted to international bodies for oceanwide observa- 
tional programs employing dozens of ships extending over several 
years—purportedly to study variability of oceanic circulation. To 
us they have seemed ill-designed from the point of view of sampling, 
because we believe it would be better to study smaller scales and higher 
frequencies first, even though these do not provide busywork for fleets 
of oceanographic vessels. In fact instrumented buoys seem better 
adapted to variability studies, although ships will, of course, be nec- 
essary to service them. 
To date, use of moored buoys has been largely limited to efforts of 
individuals who, lacking the resources, logistic support, and necessary 
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