Anticyclones Flashcards
Adiabatic
Temperature change due to change in height and pressure
Adiabatic warming
An increase in temperature associated with sinking Air as it is compressed at lower altitude repressions increase
Adiabatic cooling
A decrease in temperature associated with rising air as it expands at higher altitudes where pressure is decreased
Anticyclonic circulation
Airflow around a high pressure centre that is clockwise in the northern hemisphere and anti clockwise in the Southern Hemisphere
Berg wind
A local wind that blows down the escarpment from the plateau to the coast bringing hot, dry weather
Black southeaster
When the southeaster wind is accompanied by a cut-off low, as occasionally happens in the spring and autumn months, this can cause heavy rains to fall over the western cape; the laingsburg flood in 1981 is an example of this
Cape doctor
A south Easter which blows away polluted air and and has a cooling effect on Cape Town
Coastal low
Small low pressure system that develops on the coast and moves from west to east
Continental climate
A climate characterized by a great annual variation in the temperature due to the lack of significant bodies of water
Cut-off low
Cut off lows are formed when a low pressure system becomes isolated from the main low pressure system, usually cause by a ridging South Atlantic High Pressure and a blocking South Indian High Pressure
Inversion layer
A layer of air where temperature increases with increasing altitude
Jet stream
A band of very strong westerly winds high in the atmosphere above 9000m which which partly controls the development of MLCs
Line thunderstorms
Convective storms that form along the moisture front
Maritime position
A climate characterized by a relatively narrow annual temperature range due to the presence of significant bodies of water nearby
Moisture front
The boundary between two air masses of different humidity; extending from northwest to south east through the interior of South Africa.
