US and Europe. Information flows along the lines
indicated and the picture would make a sensible
cartoon for a public discussion of volume and fluctuations of information traffic. The picture has the
great virtue of extreme simplicity. But if one looks
at one indicator of the routes of information flow
on modern computer links (Fig. 2.1.3b, see Plate
2.1.3b, p. 76), one’s understanding of the situation, and consequent policy decisions, are likely to
be quite different.
Gradually it has become clear that climate is
a global phenomenon. Nonetheless, in parallel
with the listing above of historical failure of some
simplifying hypotheses, there exist today a number
of hypotheses that are often invoked in discussions
of the ocean observation problem. They include:
¥ Things many (some?) people ‘know’ now:
¥ There is a global conveyor belt whose
strength controls the climate state through
thousands of years.
¥ Only the upper ocean is relevant to ‘climate’.
¥ Coarse resolution ocean models can be run
for 1000; years with climate forecast skill.
¥ The strength of the oceanic heat transport is
controlled by the surface density gradient
alone.
2.1 Global Problems and Global Observations
53
Wunsch
Fig. 2.1.2 Map (de Jode, 1593) showing the interesting fauna and non-existent landscape (an entire mountain range)
on the coast of New Guinea and Australia placed there by mapmakers who felt compelled to show something where
nothing was known. Modern scientists would leave blank such unexplored areas; sometimes these blanks are
reinterpreted to imply that nothing of interest lies there – an equally unfounded hypothesis.