__________________________________________________________ Radio Wave Propagation
Figure 2-10. Layers of the Earth's Atmosphere
2-46. The troposphere is the portion of the earth's atmosphere that extends
from the surface of the earth to a height of about 3.7 miles (6 km) at the
North Pole or the South Pole, and 11.2 miles (18 km) at the equator. Virtually
all weather phenomena take place in the troposphere. The temperature in
this region decreases rapidly with altitude, clouds form, and there may be
much turbulence because of variations in temperature, density, and pressure.
These conditions have a great effect on the propagation of radio waves, as
explained later in this chapter.
2-47. The stratosphere is located between the troposphere and the
ionosphere. The temperature throughout this region is considered to be
almost constant and there is little water vapor present. The stratosphere has
relatively little effect on radio waves because it is a relatively calm region
with little or no temperature changes.