SA Climate

Question 1

WHAT IS THE FIRST FACTOR INFLUENCING SA CLIMATE?

Answer 1

SURROUNDING OCEANS

• cold Benguela current
• warm Agulhas/Mozambique current

Question 2

WHAT IS THE SECOND FACTOR INFLUENCING SA CLIMATE?

Answer 2

THE PLATEAU

• high altitude=lower temps
• steeper escarpment prevents moist air coming into interior=drier

Question 3

WHAT IS THE THIRD FACTOR INFLUENCING SA CLIMATE?

Answer 3

SUB-TROPICAL ANTICYCLONES

-SA situated in the sub tropical high pressure zone->air sinks which results in higher temps

Question 4

WHAT ARE THE CHARACTERISTICS OF THE SOUTH ATLANTIC HIGH?

Answer 4

• west of SA
• air moves anticlockwise around it
• causes SW wind(cold dry) to blow onto western parts of SA

Question 5

WHAT ARE THE CHARACTERISTICS OF THE SOUTH INDIAN HIGH?

Answer 5

• east of SA
• moves from coast in summer towards west in winter
• NE winds(warm moist) blow on Eastern parts of SA

Question 6

WHAT ARE THE CHARACTERISTICS OF THE KALAHARI HIGH?

Answer 6

• dominates air flow over the land
• summer heat lowers air pressure->low pressure seen in summer
• dry, warm air->rare precipitation
• descending air causes permanent temp over SA

Question 7

WHAT HAPPENS TO KALAHARI HIGH IN WINTER?

Answer 7

column of cold air descends strongly, causing inversion layer to drop below the escarpment. This prevents moist, maritime air(SIHP) from coming over continent. SA interior has dry winter.

Question 8

WHAT HAPPENS TO KALAHARI HIGH IN SUMMER?

Answer 8

Increased heating causes inversion layer to rise ->allowing moist maritime air to penetrate over escarpment, allowing precip. Most rain falls on escarpment and decreases from E to W(W driest)

Question 9

WHAT ARE LINE THUNDERSTORMS?

Answer 9

Large scale convergence on the moisture front.
Cold, dense air from Atlantic ocean moves beneath less dense warmer air. Forces warm air up-> cumulonimbus clouds form-> thunderstorms develop. Moves east along moisture front
SUMMER

Question 10

WHAT ARE COASTAL LOWS?

Answer 10

Weak low pressure cell.
1000km wide in lower layer of atmos.
wind blows from land to sea->warm strong berg winds in front of the low and cool onshore flow behind.
form off the west coast(cloudy conditions possible.

Question 11

WHAT DIRECTION DOES WIND BLOW?

Answer 11

High pressure to low pressure

Question 12

WHAT IS A BERG WIND?

Answer 12

warm dry off shore winds descend from high lying areas, mainly in winter. Very dry, hot days in other seasons.
-raise temp by as much as 10

Question 13

Why are berg winds most likely to occur in winter

Answer 13

Kalahari high dominant over the land.

Strong pressure gradient between inland and coastal regions