Chapter 9
A History of
Thermocline Theory
JOSEPH PEDLOSKY
INTRODUCTION
The focus of my attention in this essay is to give the reader some insight into the development of the theoretical ideas concerning the thermocline from the very personal
point of view of someone involved in that development. It is not a review paper of the
full scientific history of the subject or a detailed scientific discussion of the problem.
Rather, I want to present the more personal side of the history of the attempt to reach
an understanding of the phenomenon of the thermocline. In that special sense this is
a personal memoir of my involvement in that quest and I hope to capture the flavor of
that experience for others. It culminated for me in the development of the theory of the
Ventilated Thermocline, a theory that evolved in collaboration with Henry Stommel
and Jim Luyten and so the story is one person’s view of what was a collegial effort.
The presence of the thermocline, the region of rapid increase of density with
depth in the first one or two kilometers of the subtropical oceans, has been recognized
for a long time. Yet looking back at the older literature it is hard to find a reference to the
problem of the thermocline, that is, in explaining the maintenance of this sharp density
gradient or its cause. The thermocline itself is bowl-shaped in the meridional plane
and contains fairly entirely the wind-driven currents of the major subtropical gyres
Joseph Pedlosky, Senior Scientist, Woods Hole Oceanographic Institution.
139
A History of
Thermocline Theory
JOSEPH PEDLOSKY
INTRODUCTION
The focus of my attention in this essay is to give the reader some insight into the development of the theoretical ideas concerning the thermocline from the very personal
point of view of someone involved in that development. It is not a review paper of the
full scientific history of the subject or a detailed scientific discussion of the problem.
Rather, I want to present the more personal side of the history of the attempt to reach
an understanding of the phenomenon of the thermocline. In that special sense this is
a personal memoir of my involvement in that quest and I hope to capture the flavor of
that experience for others. It culminated for me in the development of the theory of the
Ventilated Thermocline, a theory that evolved in collaboration with Henry Stommel
and Jim Luyten and so the story is one person’s view of what was a collegial effort.
The presence of the thermocline, the region of rapid increase of density with
depth in the first one or two kilometers of the subtropical oceans, has been recognized
for a long time. Yet looking back at the older literature it is hard to find a reference to the
problem of the thermocline, that is, in explaining the maintenance of this sharp density
gradient or its cause. The thermocline itself is bowl-shaped in the meridional plane
and contains fairly entirely the wind-driven currents of the major subtropical gyres
Joseph Pedlosky, Senior Scientist, Woods Hole Oceanographic Institution.
139