The atmosphere operates as a global system transferring heat and energy — Edexcel GCSE Geography A
Verified courseTeaching note checked against the official specification.
The atmosphere operates as a global system transferring heat and energy explained
The atmosphere operates as a global system transferring heat and energy covers 2 specification points, including A.
Read the full explanation
The features of the global atmospheric… and B. How circulation cells and ocean currents…. Open a point below for its explanation and revision guidance.
a. The features of the global atmospheric circulation.
This statement asks you to identify and describe the main features of global atmospheric circulation: the three pairs of cells (Hadley, Ferrel and Polar) that operate between the equator and the poles, the surface pressure belts that result, and the prevailing winds that move air between them. Start with the energy imbalance. Intense insolation near the equator heats the surface, so air warms, becomes less dense and rises, creating low pressure. This air moves poleward at height, cools, and sinks around 30° latitude, creating subtropical high pressure. Surface air then flows back towards the equator as the trade winds. Know that the Hadley cell drives the trade winds, the Ferrel cell drives the mid-latitude westerlies and the Polar cell drives the polar easterlies.
b. How circulation cells and ocean currents transfer and redistribute heat energy across the Earth.
This statement requires you to explain how circulation cells and ocean currents move heat from where it is in surplus to where it is in deficit. Solar energy is concentrated at low latitudes, so the atmosphere and oceans carry heat poleward to balance the difference. Follow the process as a chain of agents. The Sun heats the tropical surface; warm air rises and the Hadley cell carries it towards higher latitudes at altitude; surface winds and ocean currents move warm water away from the equator. For example, the Gulf Stream carries warm water across the North Atlantic towards north-west Europe, warming the air above it. Cold water sinks and returns towards the equator at depth.
Your focus
- Label the Hadley, Ferrel and Polar cells and their latitudinal positions on a diagram.
- Explain why air rises at the equator and sinks near 30° latitude.
- Identify the prevailing surface winds associated with each cell.
Show all 6 objectives
- Explain how surplus solar energy at low latitudes is transported towards the poles.
- Describe the role of the Hadley cell and a named ocean current in transferring heat.
- Explain how transfer and redistribution reduce the temperature difference between the tropics and the poles.
The atmosphere operates as a global system transferring heat and energy exam tips
Marking Points
- Identifies three circulation cells in each hemisphere: Hadley, Ferrel and Polar.
- Links the rising air at the equator to low pressure and the sinking air near 30° to high pressure.
- States that the Hadley cell produces the trade winds and the Ferrel cell produces the mid-latitude westerlies.
- Describes the polar easterlies as the surface winds of the Polar cell, moving from high pressure at the poles equatorward towards subpolar low pressure around 60° latitude.
- Shows the sequence of processes in order: heating, rising, poleward movement, cooling, sinking and return flow at the surface.
- Explains that solar energy is in surplus at low latitudes and deficit at high latitudes, which drives the transfer.
- Describes atmospheric heat transfer by the Hadley cell, with warm air moving poleward at altitude.
- Describes ocean heat transfer by surface currents, for example the Gulf Stream carrying warm water towards north-west Europe.
- Explains redistribution as a reduction in the temperature difference between the tropics and the poles.
- Explains that cold water sinking and returning at depth completes the ocean circulation and supports heat redistribution.
Examiner Tips
- 💡Draw a simple cross-section of one hemisphere with latitude lines at 0°, 30°, 60° and 90° before answering, then label each cell and pressure belt.
- 💡Use the words rising, sinking, low pressure and high pressure consistently, and check each cause and effect link in the order it happens.
- 💡Write the names of the winds with the cell that produces them, so the link between cell and wind is explicit in your answer.
- 💡Write one sentence that names the source of heat, one that names the transfer process, and one that states the destination, then link them with because or so.
- 💡Name a specific current or cell in your answer, and state what it carries and where, rather than describing it generally.
- 💡Use the words transfer and redistribute accurately: transfer describes movement between places, and redistribute describes spreading heat more evenly.
Common Mistakes
- Treats the cells as a single loop from equator to pole; correct this by describing three separate cells in each hemisphere.
- Places high pressure at the equator; correct this by stating that the equator is a low-pressure zone where air rises.
- Assigns the westerlies to the Hadley cell; correct this by linking the westerlies to the Ferrel cell at mid-latitudes.
- Describes ocean currents as separate from the atmosphere; correct this by explaining that the atmosphere and oceans work together to move heat.
- Describes transfer only as movement of heat without stating where it moves from and to; correct this by naming the surplus and deficit areas.
- Describes the Gulf Stream as warming the whole planet; correct this by stating that it warms the air and climate of north-west Europe.