Page 250 - PPL-engelsk 2025
P. 250
Meteorology
From the subtropical
high pressure, warm air
masses move towards
the temperate low-
pressure areas, where
they meet the cold polar
air.
These winds are
deflected eastward and
become the westerlies.
At the meeting point between the cold polar air masses and the warm
subtropical air masses, a front is created. This front is called the polar front.
3.4.2.3 The Polar front
Tropical air, due to its high temperature, has a large volume and reaches up to
15–18 km in height before it meets the tropopause.
Polar air, on the other hand, is cold and contracted, reaching only 8–10 km in
height.
Where the cold polar air from the Arctic meets the warmer air from lower
latitudes, a boundary is formed.
This boundary is called the polar front.
Strong winds and unstable weather can occur in the polar front because warm
and cold air meets, creating a significant temperature difference.
The polar front is not static; it can vary in both position and strength depending
on the season and specific meteorological conditions.
In winter months, the polar front is generally closer to the equator, while in
summer months, it can move further north.
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 250
