8
Chapter 1: The Development of Climate Research
semble of data. The highly nonlinear nature of the ßuid dynamics equations
and of the physical processes describing the atmosphere make the interpretation of model results not much easier than investigating the real atmosphere.
Sometimes, the subtleties of the interplay at work create a situation not much
better than Dove or Redfield faced. The atmosphere is being forced by the
sun in a very regular way, the seasonal march of the sun, but the response
of the climate system spans many scales. Intuition is a very powerful tool to
find out the relations between the various components that are masked by
the chaotic behaviour of the system, but very often it is necessary to have
powerful statistical methods to guide that intuition towards more fruitful directions. In summary, climate research seems therefore to be dominated by
three main components whose careful and balanced combination is required
to obtain a good scientific result: dynamical theory, numerical experimentation and statistical analysis.
1.2.1 Dynamical Theory
The theory of the atmospheric and oceanic circulation related to the climate
problem is based on utilizing basic concepts of hydrodynamics and thermodynamics. It has proven to be an undispensable tool to understand climate.
The impact of the baroclinic instability paper by Charney in 1949 can
be hardly overestimated. Pedlosky (1990) gives a very vivid analysis of the
importance of that paper for the development of meteorology and oceanography. The theory of baroclinic instability has allowed us to put the process of
cyclone formation on scientifically firmer ground and it has offered an entirely
new interpretative framework, opening the ground to the zonal mean-eddy
paradign that has dominated the atmospheric sciences for the following 30
years. The theory of baroclinic instability has also allowed an energetically
consistent treatment of the cyclone formation and evolution process.
Sverdrup (1947) paper was the first work to recognize the role of the wind
stress in generating vorticity into the interior of the ocean. The famous relation between the curl of the wind stress and the ßow in the ocean interior was
formulated for the first time in this work. A related result, though developed
in a quite independent way, is the paper on the Gulf Stream boundary intensification by Stommel (1948), in which the crucial role of ß, the gradient of
the planetary vorticity, is recognized as causing the asymmetry in response
to winds between the east and the west coasts of the oceans.
Stommel recognized that the Gulf Stream was generated by a mechanism
similar to the generation of boundary layer in ßow problems, smoothly joining Sverdrup solution away from the boundary. Afterward, Munk, Groves
and Carrier (1950) generalized these models to include nonlinear effects. A
beautiful discussion of the intellectual story of the formulation of the theories
of the large scale ocean circulation can be found in Veronis (1981).
Chapter 1: The Development of Climate Research
semble of data. The highly nonlinear nature of the ßuid dynamics equations
and of the physical processes describing the atmosphere make the interpretation of model results not much easier than investigating the real atmosphere.
Sometimes, the subtleties of the interplay at work create a situation not much
better than Dove or Redfield faced. The atmosphere is being forced by the
sun in a very regular way, the seasonal march of the sun, but the response
of the climate system spans many scales. Intuition is a very powerful tool to
find out the relations between the various components that are masked by
the chaotic behaviour of the system, but very often it is necessary to have
powerful statistical methods to guide that intuition towards more fruitful directions. In summary, climate research seems therefore to be dominated by
three main components whose careful and balanced combination is required
to obtain a good scientific result: dynamical theory, numerical experimentation and statistical analysis.
1.2.1 Dynamical Theory
The theory of the atmospheric and oceanic circulation related to the climate
problem is based on utilizing basic concepts of hydrodynamics and thermodynamics. It has proven to be an undispensable tool to understand climate.
The impact of the baroclinic instability paper by Charney in 1949 can
be hardly overestimated. Pedlosky (1990) gives a very vivid analysis of the
importance of that paper for the development of meteorology and oceanography. The theory of baroclinic instability has allowed us to put the process of
cyclone formation on scientifically firmer ground and it has offered an entirely
new interpretative framework, opening the ground to the zonal mean-eddy
paradign that has dominated the atmospheric sciences for the following 30
years. The theory of baroclinic instability has also allowed an energetically
consistent treatment of the cyclone formation and evolution process.
Sverdrup (1947) paper was the first work to recognize the role of the wind
stress in generating vorticity into the interior of the ocean. The famous relation between the curl of the wind stress and the ßow in the ocean interior was
formulated for the first time in this work. A related result, though developed
in a quite independent way, is the paper on the Gulf Stream boundary intensification by Stommel (1948), in which the crucial role of ß, the gradient of
the planetary vorticity, is recognized as causing the asymmetry in response
to winds between the east and the west coasts of the oceans.
Stommel recognized that the Gulf Stream was generated by a mechanism
similar to the generation of boundary layer in ßow problems, smoothly joining Sverdrup solution away from the boundary. Afterward, Munk, Groves
and Carrier (1950) generalized these models to include nonlinear effects. A
beautiful discussion of the intellectual story of the formulation of the theories
of the large scale ocean circulation can be found in Veronis (1981).