文档介绍：Chapter 3
The vertical structure of the
atmosphere
In this chapter we discuss the observed vertical distribution of temperature,
water vapor and greenhouse gases in the atmosphere. The observed temper-
ature distribution pared to the radiative equilibrium profile discussed
in Chapter 2. We go on to calculate the implied distribution of pressure and
density assuming the atmosphere to be in hydrostatic balance pare
with observations. We discover that the atmosphere does not have a distinct
top. Rather, the density and pressure decay with height by a factor of e every
7 8km.
−
Vertical distribution of temperature and
‘Greenhouse gases’
Typical temperature profile
Temperature varies greatly both vertically and horizontally throughout the
atmosphere (as well as temporally). However, despite horizontal variations,
the vertical structure of temperature is qualitatively similar everywhere, and
so it is meaningful to think of (and to attempt to explain) a “typical” tem-
perature profile. (We look at horizontal variations in Chapter 5.) A typical
temperature profile (characteristic of 40◦N in December) up to about 100 km
is shown in .
The profile is not governed by a simple law and is plicated.
59
60CHAPTER 3. THE VERTICAL STRUCTURE OF THE ATMOSPHERE
Figure : Vertical temperature profile for the ‘US standard atmosphere’ at 40◦N
in December.
. VERTICAL DISTRIBUTION OF TEMPERATURE AND ‘GREENHOUSE GASES’61
Note, however, that the (mass-weighted) mean temperature is close to 255 K,
the emission puted in the last chapter (remember almost all
the mass of the atmosphere is in the bottom 10 km). The heating effect of
solar radiation can be readily seen: there are 3 ‘hot spots’ corresponding
to regions where solar radiation is absorbed at different wavelengths in the
thermosphere, the stratopause and the troposphere. These maxima separate
the atmosphere neatly into different layers.
Atmospheric layers
Coming down from the top