Environment: understanding atmospheric and ocean flows
Environment: understanding atmospheric and ocean flows

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Environment: understanding atmospheric and ocean flows

2.2 Specific heat capacity

When energy reaches the surface of an object, the amount the object heats up is determined by its specific heat capacity. This is a measure of how much energy it takes to raise the temperature of 1 kg of a particular substance by 1 °C. A lower specific heat capacity means that it takes less energy to heat up something, and vice versa. Although the term may be unfamiliar, the concept most likely is not.

Activity 2 The effect of specific heat capacity

Timing: Allow about 5 minutes

On a very hot sunny day on a table outside in the sunshine there is a glass containing 1 kg of water (i.e. 1 litre), a 1 kg piece of cork and a 1 kg piece of iron. Ignore the effects of albedo and assume that all three items absorb the same amount of energy from the Sun. Which will be the hottest after 1 hour, and which the coolest? (Ignore all sources of heat except that received directly from the Sun.)

Interactive feature not available in single page view (see it in standard view).


You probably recognised that the 1 kg of iron would be the hottest. It does not take very much heat energy to change the temperature of the iron because it has a low specific heat capacity. The other two items are harder to place, but the cork will be cooler than the iron, and the water, which has the highest specific heat capacity, will be the coolest item on the table.

Water has an extremely high specific heat capacity and it takes a vast amount of energy to heat it. This is why virtually all car engines use water in their cooling systems.

Taking into account the combined effects of albedo and specific heat capacity, even two adjacent areas such as a beach and the sea lapping on it will heat up by different amounts on a sunny day.

Areas with lower heat capacities and lower albedos heat up more. This heat is transferred to the air above, so in these areas it will rise at a faster rate, whilst in cooler areas the air sinks. The rising and sinking air drives horizontal winds much as in Figure 4, although on a planetary scale.

Sea ice cover is also constantly moving. It is pushed by the winds and ocean currents, and drifts in the pattern shown in Figure 5.

Described image
Figure 5 The mean ice drift across the Arctic Ocean. The ice is trapped in two major circulation features, the Beaufort Gyre and the Transpolar Drift Stream. White arrows show the general movement of the ocean currents; blue arrows show the general drift of the sea ice.

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371