1. What else affects temperature (AND rainfall)?
OCEAN CURRENTS

2. South Africa’s Ocean Currents
Agulhas Current:
Warm
East coast
Benguela Current:
Cold
West coast
Agulhas Current
South Africa
Benguela Current

3. 3. Where is this location. Cape Point. Where approx. 1
3. Where is this location? Cape Point. Where approx. 1.2km to the east, the two currents meet each other.

4. Global Ocean Currents
4. What do you notice? Cold always on west of continents, warm always on east – i.e. NOT only relevant for SA. Currents from poles are cold vs currents from tropics are warm.

5. Warm vs. Cold Currents
Cool currents come from cold polar areas to the equator. Warm currents flow from hot equatorial areas to the poles. This aims to balance out differences in temperature.
POLE
EQUATOR
5. Origin influences whether hot or cold current. This is in order to balance out the variations in latitudinal temperature – so that poles don’t keep on getting colder and tropics don’t keep on getting hotter.
POLE

6. Fish Hoek? Muizenberg? Camps Bay?
More likely to swim at Muizenberg and Fish Hoek – they are closer to the warm Agulhas ocean current.
Camps Bay?

7. Effects on Temperature
Winds blow over the ocean onto land.
Benguela:
cold wind
cools west coast
Agulhas:
warm wind
warms east coast
7. Wind warms or cools the land depending on adjacent current.
Warm wind:
Cool wind:

8. Winds can carry water onto the land.
Effects on Rainfall
Winds can carry water onto the land.
Low pressure (not a lot of air molecules)
More space for water droplets to fit in
High pressure (packed full with air molecules)
Less space for water droplets to fit in
WARM AIR
COOL AIR

9. dry weather on west coast wet weather on east coast
Effects on Rainfall
Benguela:
less water vapour
dry weather on west coast
Agulhas:
more water vapour
wet weather on east coast
The cool Benguela is dense with air molecules – so less water vapour and brings dry weather to west coast, and vice versa with warm Agulhas bringing wet weather.
Warm, humid wind:
Cool, dry wind:

10. Class Exercise
Write down how ocean currents will affect the temperature and rainfall of the following cities:
a. Durban
b. Port Nolloth
c. East London
d. Cape Town
e. Kimberley (be careful!)
Kimberley
Port Nolloth
Durban
East London
Cape Town