Undoqo_Sisibindi_Summary_Notes_ISIXHOSA.pdf

Grade 11 Geography Study Notes (CAPS) – Xhariep, Free State

Compiled for March Common Test

1.1 Earth's Energy Balance

Key Concepts:

• Insolation = Incoming solar radiation (heat from the Sun reaching Earth).
• Some energy is absorbed by the surface, some is reflected back into space.
• Albedo Effect = The percentage of sunlight reflected (ice has high albedo, oceans have low albedo).
• Greenhouse Effect = Greenhouse gases (CO₂, methane, water vapor) trap heat, keeping Earth warm.
• Global Warming = Too much greenhouse effect leads to rising temperatures.
• Heat Redistribution = Winds and ocean currents move heat from the equator to the poles.

1.2 Global Air Circulation

Key Concepts:

• Air moves because of uneven heating (hot air rises at the equator, cold air sinks at the poles).
• Hadley Cell (0°–30° latitude): Warm air rises at the equator and sinks at 30°.
• Ferrel Cell (30°–60° latitude): Moves opposite to Hadley & Polar cells.
• Polar Cell (60°–90° latitude): Cold air sinks at the poles and moves toward 60°.