Download Wind and water - Science Museum

Atmosphere …exploring climate science
Science Museum, London
This is the transcript of an animation voice-over in the Climate Science Info Zone
exhibit.
Title: Climate system: Movement of wind and water
Voice-over: male
The climate has many interconnected components. Two of them, wind and water
transport heat and moisture around the planet.
Warm air rises at the equator and flows both north and south towards the poles,
driving colder polar air towards the equator near the surface. This is a ‘convection
cell’.
If the Earth didn’t rotate, there would be one convection cell in each hemisphere and
the prevailing winds at the surface would flow directly north and south.
But the planet’s rotation changes the direction of airflow, breaking up the circulation
into three cells in each hemisphere.
Winds that would blow straight from north to south or south to north in the tropics get
curved round, forming the easterly ‘trade winds’ between zero and 30 degrees
latitude the westerly winds between 30 and 60 degrees latitude, and the easterly
winds at the poles.
Sailors have used these prevailing winds to help them cross oceans for hundreds of
years.
Like the winds, ocean currents carry heat from the equator to the poles and the
water’s movement is also deflected by the Earth’s rotation.
This is one of many ways that different parts of the climate system influence each
other.
www.sciencemuseum.org.uk/ClimateChanging/ClimateScienceInfoZone/ExploringEa
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