The Weather Notebook: Ocean Heat

Ocean Heat
Listen in RealAudio
Email your weather question

On a summer's day, you can cool down with a dip in the ocean. But you might be surprised to know just how much heat is beneath the surface. Hi I'm Bryan Yeaton and this is the Weather Notebook. To understand climate, scientists need to understand the heat storage capacity of the ocean, as Allan Coukell reports.

A cup of hot coffee holds a certain amount of heat. A cup of cold coffee also holds heat, only less. So although we don't think of it is "hot", there is a lot of heat stored in the ocean. And that has a big effect on climate.

BS: The main role of the ocean is the role it has in moving heat around the globe, and also in storing heat. It has a huge heat capacity.

Basil Stanton is an oceanographer with the National Institute of Water and Atmospheric Research in New Zealand. He says there is as much heat in the top 10 feet of the ocean as in the whole of the atmosphere. In other words, warming all the air in the world by one degree requires only as much energy as warming that that top layer of ocean.

BS: And then when you bear in mind that the ocean is four kilometers deep, on average, that gives you an idea of how much more heat can be stored in the ocean than in the atmosphere.

It takes a long time to heat your swimming pool, but only a short time warm your house - and the same is true on a planetary scale.

But the ocean has a huge influences on the temperature of the atmosphere. That means when it comes to climate change, the planet will be slow to warm up and just as slow to cool down again.

Allan Coukell reports from Auckland, New Zealand. The Weather Notebook is a production of the Mount Washington Observatory. It is supported by Subaru and the National Science Foundation. For more on climate go to our website at weathernotebook.org.