LECTURE 2: INTRODUCTION

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LECTURE 2 INTRODUCTION
1.1 Where are the tropics and what makes them
special? 1.2 The amount of energy received by
the earth 1.3 Moisture in the tropics 1.4 Basic
equations and scalings
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1.1 Where are the tropics and what makes them
special?
Arbitrary definitions for where they
are Geography Tropics are the region of the
earth bounded by the tropic of Cancer (23.5oN)
and the tropic of Capricorn (23.5oS). These are
the latitudes where the sun reaches the zenith
just once a year at the summer solstices. Equal
Halves The region between 30N and 30S would
divide the earth into two equal halves. Defined
this way, the tropics would be the source of all
the angular momentum of the atmosphere and
most of the heat. But this is not
meteorologically sensible. Processes Riehl
(1979) chose to define the meteorological
tropics as those parts of the world where
atmospheric processes differ significantly from
those in higher latitudes (see next slides).
Riehl (1979) Climate and Weather in the
Tropics, Academic Press.
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Figure 1.1
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Land and ocean contrasts

Figure 1.2 Markedly non-uniform distribution
of land and ocean areas in the tropics may be
expected to have a large influence on the
meteorology there
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Annual Mean Rainfall

Figure 1.3
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Mean Meridional Circulations

Figure 1.4
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1.2 The amount of energy received by the earth
Solar Radiation Received at TOA

Figure 1.5
Outgoing radiation
Solar absorbed
Northward transport of energy
Northward transport by atmosphere
Figure 1.6
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1.2 The amount of energy received by the earth


Figure 1.7
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1.2 The amount of energy received by the earth


Figure 1.8(a)
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1.2 The amount of energy received by the earth


Figure 1.8(b)
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1.3 Moisture in the tropics


Figure 1.9
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1.3 Moisture in the tropics


Figure 1.10
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1.3 Moisture in the tropics


Figure 1.11
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1.3 Moisture in the tropics
Figure 1.12(a)


Figure 1.12(b)
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1.4 Basic equations and scalings
Adiabatic, Frictionless Equations in Pressure
Coordinates


where