Page 247 - PPL BEG-engelsk
P. 247

Meteorology

                3.4.1.1     The global wind system and high-pressure and low-pressure belts


                The  winds  we  experience  in  Denmark  are  part  of  a  large  wind  system  that

                covers the entire Earth.

                This is called the global wind system.





                At the equator, there is the greatest solar radiation. Here, warm air masses are
                formed, which rise upwards.





                At the poles, there is the least
                solar  radiation.  Here,  air

                masses sink.


                In both areas, the surrounding

                air masses are set in motion.


                This  creates  4  global  high-
                pressure  belts  and  3  global

                low-pressure  belts,  as  shown

                in the figure.





                Over the Equator, where the sun is directly overhead, a  large  thermal  low-
                pressure belt forms around the Earth.


                This is called the equatorial low-pressure belt.


                On both sides of the equatorial low-pressure belt, there are two zones of high
                pressure.


                These are called subtropical high-pressure belts.


                At the poles, we have the coldest areas on Earth. Thermal high-pressure forms

                here, which we call polar high pressure.

                In the temperate zones between the polar highs and the subtropical highs, we

                find low-pressure zones.


                These zones are called the temperate low-pressure belts.

           Flight Theory PPL(A)(UL)/LAPL             Henning Andersen, Midtjysk Flyveskole© marts 2026     247
   242   243   244   245   246   247   248   249   250   251   252