394
NEWELL AND MILLER
crude measurements of a trace substance, ozone, and was substantiated
by '8°w measurements.??
In the lower stratosphere there is cooling where the air is warm
at middle latitudes and heating where it is cold at low latitudes; this
leads to a destruction of available potential energy. The loss must be
made up from the available potential energy of the eddies, which in turn
comes from kinetic energy. The ultimate source of this kinetic energy
must be outside the stratosphere. A survey of the energy generated
layer by layer indicates that the driving energy for the lower stratosphere must come from the troposphere.
.
Above 25 km and up to about 50 km, there is cooling in the cold
higher latitudes in the winter and maximum warming near the summer
pole. This heating configuration obviously again implies a generation
of available potential energy, and here the heat-engine region effectively
stretches from pole to pole. Above this, as has been discussed elsewhere,
there is an additional refrigeration that receives its driving
energy from the 25- to 50-km region. For the higher level systems, it
appears that in winter large-scale eddies are of most importance in
the momentum budget and, by inference, the heat budget of middle and
high latitudes, whereas in summer and at low latitudes the observations
are not-yet sufficient to decide the relative importance of mean and
eddy motions. °''®
Approximate numerical values of the generation of zonal available
potential energy, together with the zonal available potential energy and
kinetic energy layer by layer, are shown in Table 1.
A more detailed picture of the conversion of zonal available
potential energy to eddy available potential energy is shown in Fig. 1.
This is based on our International Geophysical Year (IGY) stratospheric
data'® matched to the wind and temperature data analyzed by Buch?®
and Peixoto.'* The large negative regions in the troposphere represent
Table 1— DISTRIBUTION OF GENERATION OF ZONAL AVAILABLE
POTENTIAL ENERGY, G,, ZONAL AVAILABLE POTENTIAL
ENERGY, Az, AND KINETIC ENERGY OF ZONAL FLOW, K,,
WITH HEIGHT FOR ZONE FROM 20 TO 60°N, WINTER*
Layer, km
G,, ergs/cm?/sec
A,, ergs/cm?
K,, ergs/em?
10
15
20
25
to
to
to
to
15
20
25
30
~—2.9
—117
1.9
4.4
11
60
0.3
0.8
x
x
x
x
108
108
108
108
460
120
6.5
8.5
x
x
x
x
108
108
108
108
30
40
50
60
70
to
to
to
to
to
40
50
60
70
80
6.9
2.7
0.29
—0.65
—0.15
3.1
11
0.07
0.9
1.1
x
x
x
x
x
108
105
105
105
104
22
153
71
24
6.1
x
x
x
x
x
108
105
105
105
105
*Details of the computational procedure can be found in Ref. 9.