Subtropical Anticyclones
Terminology
Anticyclone - high pressure cells
“Subtropic”- areas located between Tropic of Cancer & 40°N & between Tropic of Capricorn & 40°S
Ridge - bulge next to high-pressure cell
Inversion layer - layer of air where temperature increases with increasing altitude
Location of main HP Cells
Location of high-pressure cells
● SA lies between latitudes 22°S & 35°S
● Position means climate dominate belt of subtropical highs circle Earth 30°S
● Southern Africa, 3 cells high pressure or anticyclones, form part belt of subtropical highs
○ South Atlantic High-pressure cells lies further south in summer
○ South Indian High-pressure cell lies further south & east in Summer
○ Kalahari cells exists over interior & dominates weather conditions in SA Summer higher up
in atmosphere & weaker but in winter stronger & lower
Positions three cells change with season & position of overhead sun
, General characteristics of high-pressure cells
● Subtropical highs caused air subsiding from tropical & mid-latitude cells
● Anticyclones bring descending, dry, warming air resulting clear skies & sunshine
● At surface, anticyclone in SOuthern hemisphere has winds blowing round high in anticlockwise
direction
Kalahari High-pressure cell
During Winter
● Colder, stable, subsiding air causes pressure cells strengthen makes them move closer to ground
● Inversion layer low & traps moisture, not move into interior
● No winter rain
Terminology
Anticyclone - high pressure cells
“Subtropic”- areas located between Tropic of Cancer & 40°N & between Tropic of Capricorn & 40°S
Ridge - bulge next to high-pressure cell
Inversion layer - layer of air where temperature increases with increasing altitude
Location of main HP Cells
Location of high-pressure cells
● SA lies between latitudes 22°S & 35°S
● Position means climate dominate belt of subtropical highs circle Earth 30°S
● Southern Africa, 3 cells high pressure or anticyclones, form part belt of subtropical highs
○ South Atlantic High-pressure cells lies further south in summer
○ South Indian High-pressure cell lies further south & east in Summer
○ Kalahari cells exists over interior & dominates weather conditions in SA Summer higher up
in atmosphere & weaker but in winter stronger & lower
Positions three cells change with season & position of overhead sun
, General characteristics of high-pressure cells
● Subtropical highs caused air subsiding from tropical & mid-latitude cells
● Anticyclones bring descending, dry, warming air resulting clear skies & sunshine
● At surface, anticyclone in SOuthern hemisphere has winds blowing round high in anticlockwise
direction
Kalahari High-pressure cell
During Winter
● Colder, stable, subsiding air causes pressure cells strengthen makes them move closer to ground
● Inversion layer low & traps moisture, not move into interior
● No winter rain
