Page 229 - PPL-engelsk 2025

Meteorology

3.3.5.3 Isobars

To draw a map of the pressure systems in an area, QFF needs to be found for

several measurement points. Lines are drawn through points with the same

QFF.

These lines, connecting points

with the same pressure, are

called isobars.

For example, the isobar 1020

can be seen here.

This means the pressure along

the entire line is 1020 hPa.

3.3.5.4 Surface maps

The maps on which isobars are drawn are called surface maps.

The surface map is the bottom part of the diagram (see the next page) with

high-pressure areas (red circles with H) and low-pressure areas (blue circle

with L). Here we see the pressure system from above and from the side.

The upper part illustrates a cross-section (the part with the red oval) seen from

the front.

On the lower part, the
surface map, a cross-

section through the

pressure system from A

to B is added (the

dashed line in the red

square at the bottom of

the diagram).

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 229