The Winds 
Winds are produced by the balancing of the earth’s heat 
budget. This is a delicate process which works somewhat 
as follows: 
The earth continually receives heat from the sun; it also | 
radiates heat away from its surface. Just as much heat must 
be radiated away into space as is received from the sun, 
otherwise the temperature on the earth would be continually 
rising or falling. But here is the catch: most of the sun’s heat 
falls on the earth in the tropics, but the heat is radiated away 
more or less equally all over the earth. Therefore there must 
be a transfer of heat from the tropics to the polar regions. 
This actually takes place. The outward manifestation is the 
world-wide system of winds (and ocean currents). 
In general it can be said that the winds of the world are 
distributed geographically according to latitude as shown 
in the chart and accompanying table. Although local condi- 
tions often change wind directions completely, there are cer- 
tain prevailing winds at different latitudes. 
LOCAL WINDS 
A more accurate knowledge of the winds at any locality 
may be obtained from a study of the wind roses on a pilot 
chart. 
Along the coasts other local winds arise, owing their exist- 
ence to local inequalities in the heating of land and sea dur- 
ing the day, or of cooling during the night. During the day 
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