Geography Grade 12: Mid-Latitude Cyclones

Vocabulary based on Grade 12 Geography Grade 12 Term 1 Week 1 Lesson 1 materials regarding mid-latitude cyclones and their impacts.

Mid-latitude cyclones

Weather systems that move from west to east and significantly impact the Western Cape.

Westerlies

The global air circulation pattern associated with the movement of mid-latitude cyclones.

Warm Front

A front where the air behind it is warm and moves over the cooler air.

Cold Front

A front where the air behind it is cold, which ridges underneath the warm air and lifts it.

Cold Front Weather Change: Temperature

A characteristic drop in temperature as the front moves over an area.

Cold Front Weather Change: Wind

The wind direction changes from NW (Northwest) to SW (Southwest).

Cold Front Weather Change: Air Pressure

There is a characteristic increase in air pressure as the front passes.

Positive Agricultural Impact

Provides rain for agriculture, increases yield and income, and causes the water table to rise.

Negative Human Impact

Cold conditions and flooding can cause loss of life, stock losses, damage to crops, and costly repairs.

Positive Environmental Impact

Rain from the cyclone sustains natural vegetation and animals.

Negative Environmental Impact

Flooding causes erosion, loss of topsoil, and eroded material silts up rivers and dams.

Tourist Attraction

Snow associated with mid-latitude cyclones can serve as a positive impact for tourism.

Isobar values

Typical measurements found on a mid-latitude cyclone diagram such as $1008\,hPa$ and $1004\,hPa$.

Warm sector

The area in a mid-latitude cyclone typically represented by the color red.

Cold sector

The area in a mid-latitude cyclone typically represented by the color blue.

Circulation pattern

The air movement in these systems follows a clockwise circulation.

Aircraft takeoff/landing rule

Planes must take off and land AGAINST the wind, which is affected by the wind direction changes before and after a cold front.

Synoptic weather map winter indicators

Includes specific indicators like the presence of mid-latitude cyclones moving across Southern Africa.