South Atlantic High Pressure
Anticyclonic air circulation around SA and its influence on weather and climate
South Atlantic High Pressure
Situated in the Atlantic Ocean, causes southwesterly winds to blow towards the land.
- Causes southwesterly winds to blow towards the land off the cold Atlantic Ocean.
- Originates from subsiding air and the air circulates in an anticlockwise direction.
- It brings cool, dry, stable air to the west coast.
South Indian High Pressure
Situated east of Durban in the Indian Ocean, causes northwesterly winds to blow towards the land.
Location of high-pressure cells that affect South Africa
Subtropical anticyclones and associated weather conditions
General characteristics of high pressure cells
- atmospheric circulation over Southern Africa is greatly influenced by the Subtripcal high pressure belt (30oS).
- This pressure belt is made up of three anticyclones
- South Atlantic High Pressure
- South Indian High Pressure
- Kalahari High Pressure
Kalahari High Pressure
- High pressures, also calles anticyclones are associated with descending air. They result in clear skies and no rain.
- Air circulation is anticlockwise around anticyclones in the Southern Hemisphere.
- The anticyclones move north in the Sou in winter.
- During summer, these cells are weaker due to warm surface air rising whereas in winter, the cells are stronger due to cooler air sinking.
Situated over the interior of South Africa