World Ocean Circulation Experiment
183
Numerical modelling of the ocean had advanced greatly since the pioneering
efforts of K. Bryan, G. Veronis, and a few others. But the slow, small computers of
that era, combined with the very small deformation radius in the ocean conspired to
prevent ocean models from being run in a high enough Reynolds number regime so
as to become unsteady.
Between the limited observations and the sticky ocean models, the conventional picture of the ocean circulation was that of a laminar steady state. To this
day, oceanographic textbooks still render the ocean circulation through pictures of
large-scale scalar properties (e.g., temperature, salinity, oxygen) contoured and discussed as though the system is essentially steady and flowing only on the largest
spatial scales—a geologist’s view of the ocean. An analogy would be an atmospheric
physics textbook that recognized only the mean, climate, state and failed to notice the
presence of weather.
The results of MODE-1 and its troubled successor POLYMODE (see Collins
and Heinmiller, 1989, for an account) showed that the ocean was likely an essentially turbulent fluid. Whether the turbulence had important dynamical and kinematic roles was unclear, but theory, and analogies with the atmosphere, suggested
strongly than one could not simply assume it to be an annoying source of observational
noise.
A parallel development, independent of oceanography, was the growing interest
and concern about rising CO 2 levels. Several people, but notably Roger Revelle, were
calling attention to the possibility of major climate change and insisting that the
scientific community had to learn more about the implications. An indicator of the
growing concern was the appointment of the so-called Charney Committee of the
National Research Council in the summer of 1979 to examine the question. Three
oceanographers (H. Stommel, D. J. Baker, and myself) were on the Committee, whose
report (National Research Council, 1979) made a best-guess at the range into which
global mean temperatures would be expected to rise. But a general theme of the
brief report was the inability to be very definite about anything, particularly about
inferences concerning the oceanic response, its uptake of carbon, and its thermal
memory.
2
Yet another relevant circumstance was the end of the so-called First GARP
Global Experiment (FGGE), renamed, for the public, as the Global Weather Experiment. This program had been put together by the international meteorological community [Global Atmospheric Research Program (GARP)] to address the first of two
overall goals—to improve weather forecasts. The organization of FGGE had left some
2 Remarkably, the Charney Committee’s estimate of the probable range for the expected increase in global
mean temperature has hardly changed in the intervening decades. Much more is now known about the
climate system than was true in 1979, and the continued agreement is largely fortuitous. Unhappily,
some critics have interpreted this coincidence as implying that the ongoing scientific efforts to better
understand climate change have been a waste of government money. This criticism is addressed by the
Committee on Metrics for Global Change Research (2005).
183
Numerical modelling of the ocean had advanced greatly since the pioneering
efforts of K. Bryan, G. Veronis, and a few others. But the slow, small computers of
that era, combined with the very small deformation radius in the ocean conspired to
prevent ocean models from being run in a high enough Reynolds number regime so
as to become unsteady.
Between the limited observations and the sticky ocean models, the conventional picture of the ocean circulation was that of a laminar steady state. To this
day, oceanographic textbooks still render the ocean circulation through pictures of
large-scale scalar properties (e.g., temperature, salinity, oxygen) contoured and discussed as though the system is essentially steady and flowing only on the largest
spatial scales—a geologist’s view of the ocean. An analogy would be an atmospheric
physics textbook that recognized only the mean, climate, state and failed to notice the
presence of weather.
The results of MODE-1 and its troubled successor POLYMODE (see Collins
and Heinmiller, 1989, for an account) showed that the ocean was likely an essentially turbulent fluid. Whether the turbulence had important dynamical and kinematic roles was unclear, but theory, and analogies with the atmosphere, suggested
strongly than one could not simply assume it to be an annoying source of observational
noise.
A parallel development, independent of oceanography, was the growing interest
and concern about rising CO 2 levels. Several people, but notably Roger Revelle, were
calling attention to the possibility of major climate change and insisting that the
scientific community had to learn more about the implications. An indicator of the
growing concern was the appointment of the so-called Charney Committee of the
National Research Council in the summer of 1979 to examine the question. Three
oceanographers (H. Stommel, D. J. Baker, and myself) were on the Committee, whose
report (National Research Council, 1979) made a best-guess at the range into which
global mean temperatures would be expected to rise. But a general theme of the
brief report was the inability to be very definite about anything, particularly about
inferences concerning the oceanic response, its uptake of carbon, and its thermal
memory.
2
Yet another relevant circumstance was the end of the so-called First GARP
Global Experiment (FGGE), renamed, for the public, as the Global Weather Experiment. This program had been put together by the international meteorological community [Global Atmospheric Research Program (GARP)] to address the first of two
overall goals—to improve weather forecasts. The organization of FGGE had left some
2 Remarkably, the Charney Committee’s estimate of the probable range for the expected increase in global
mean temperature has hardly changed in the intervening decades. Much more is now known about the
climate system than was true in 1979, and the continued agreement is largely fortuitous. Unhappily,
some critics have interpreted this coincidence as implying that the ongoing scientific efforts to better
understand climate change have been a waste of government money. This criticism is addressed by the
Committee on Metrics for Global Change Research (2005).