46
Russ E. Davis
The capabilities of the emerging global ocean observing system have been
widely described (see Koblinsky and Smith, 2001) and results from the more mature
elements have already had important impacts on ocean science. Baker (1981) gives
a wonderfully comprehensive, if dated, review of ocean observing instruments while
Gould (2005) tells the story of subsurface floats from start to the present. McPhaden
et al. (1998) describes the development of the tropical Pacific’s Tropical Ocean Global
Atmosphere (TOGA) observing system and McPhaden discusses it in this volume.
To complement these, I focus on some of the ideas, people, and institutions that I
think made progress possible. There are three themes: innovation, collaboration and
teams, and luck.
THE PIONEERS
My introduction to oceanography in 1965 was great luck. A summer-program poster
led me from engineering school to a laboratory in the Woods Hole Oceanographic
Institution (WHOI) Smith Building working with Stuart Turner on how internal waves
break. Fortune made the breaking process (through unstable nonlinear resonant interactions: Davis and Acrivos, 1967a) fascinating and understandable. More fortune
led a fellow graduate student at Stanford to knock a screwdriver into a stratified wave
tank, generating strange little eddies that were eventually identified as deep-water
solitary internal waves (Davis and Acrivos, 1967b).
As I was being introduced to oceanography, development of today’s ocean
observing system was already in progress. In 1955 John Swallow had introduced the
neutrally buoyant subsurface float to measure middepth currents. Until then, surface
buoys tracked from ships and current meters lowered from anchored ships could
measure only the strongest shallow flows, not the deep currents that were believed to
be very weak. Swallow realized that aluminum pressure cases could be built to have
density and compressibility that would allow them to equilibrate at a level of neutral
buoyancy. If they could be tracked for days, very accurate measurements of deep
currents would be possible. Swallow, a tall man of quiet manner and gentle humor
working at Britain’s National Institute of Oceanography, constructed the first floats
from scaffolding tubing using caustic soda to thin the walls and attached surplus Royal
Navy 10-kHz sound sources so that submerged floats could be located at ranges of a
few kilometers from an accompanying ship using direction finding. Within 6 months
Swallow completed design, construction, and field-testing of the first floats (Swallow,
1955) and two remarkable discoveries followed quickly.
Independently, Henry Stommel (1955) advocated determining deep currents by
tracking neutrally buoyant floats using long-range acoustics in the SOFAR channel.
In 1955 the float advocates met and agreed to test Stommel’s (1957) idea, based on
geostrophic shear and dynamical theory, of a deep equatorward countercurrent under
the Gulf Stream. In an archetype of observational hypothesis testing, Swallow and
Worthington (1957) confirmed the existence of this current, with speeds in excess of
Russ E. Davis
The capabilities of the emerging global ocean observing system have been
widely described (see Koblinsky and Smith, 2001) and results from the more mature
elements have already had important impacts on ocean science. Baker (1981) gives
a wonderfully comprehensive, if dated, review of ocean observing instruments while
Gould (2005) tells the story of subsurface floats from start to the present. McPhaden
et al. (1998) describes the development of the tropical Pacific’s Tropical Ocean Global
Atmosphere (TOGA) observing system and McPhaden discusses it in this volume.
To complement these, I focus on some of the ideas, people, and institutions that I
think made progress possible. There are three themes: innovation, collaboration and
teams, and luck.
THE PIONEERS
My introduction to oceanography in 1965 was great luck. A summer-program poster
led me from engineering school to a laboratory in the Woods Hole Oceanographic
Institution (WHOI) Smith Building working with Stuart Turner on how internal waves
break. Fortune made the breaking process (through unstable nonlinear resonant interactions: Davis and Acrivos, 1967a) fascinating and understandable. More fortune
led a fellow graduate student at Stanford to knock a screwdriver into a stratified wave
tank, generating strange little eddies that were eventually identified as deep-water
solitary internal waves (Davis and Acrivos, 1967b).
As I was being introduced to oceanography, development of today’s ocean
observing system was already in progress. In 1955 John Swallow had introduced the
neutrally buoyant subsurface float to measure middepth currents. Until then, surface
buoys tracked from ships and current meters lowered from anchored ships could
measure only the strongest shallow flows, not the deep currents that were believed to
be very weak. Swallow realized that aluminum pressure cases could be built to have
density and compressibility that would allow them to equilibrate at a level of neutral
buoyancy. If they could be tracked for days, very accurate measurements of deep
currents would be possible. Swallow, a tall man of quiet manner and gentle humor
working at Britain’s National Institute of Oceanography, constructed the first floats
from scaffolding tubing using caustic soda to thin the walls and attached surplus Royal
Navy 10-kHz sound sources so that submerged floats could be located at ranges of a
few kilometers from an accompanying ship using direction finding. Within 6 months
Swallow completed design, construction, and field-testing of the first floats (Swallow,
1955) and two remarkable discoveries followed quickly.
Independently, Henry Stommel (1955) advocated determining deep currents by
tracking neutrally buoyant floats using long-range acoustics in the SOFAR channel.
In 1955 the float advocates met and agreed to test Stommel’s (1957) idea, based on
geostrophic shear and dynamical theory, of a deep equatorward countercurrent under
the Gulf Stream. In an archetype of observational hypothesis testing, Swallow and
Worthington (1957) confirmed the existence of this current, with speeds in excess of