Page 220 - PPL-engelsk 2025
P. 220
Meteorology
At night, cloud cover acts like a blanket over
the Earth, trapping warmth.
On clear nights, the heat radiates out into
space, causing the Earth to cool down.
The energy for our weather on Earth comes
from the sun.
The sun's rays are shortwave radiation and pass through the atmosphere
without much heat absorption.
About 2% of incoming radiation is converted into heat in the troposphere.
3.3.2.4 The Greenhouse Effect
When the sun's shortwave radiation reaches Earth, it warms the surface, which
then emits longwave radiation.
Approximately 80% of this
outgoing radiation is
captured by water vapor
and carbon dioxide in the
air.
The heated atmosphere
then sends radiation back
toward Earth.
This is called atmospheric
counter radiation.
The entire phenomenon is referred to as the greenhouse effect.
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 220
