During winter, the average temperature1 in the South Pole is -60°C, but in the North Pole2 it is -30°C.
Why is there such a difference?
Three factors come together, resulting in the cold world we know as Antarctica, the icy ecosystem3:
- Height above sea level
- Atmosphere4
- Land masses
Height above sea level
The South Pole (Antarctica) is around 2,800m above sea level, unlike the North Pole (the Arctic), which is sea ice laying on the surface of the Arctic Ocean. For every kilometre (thousand metres5) that Antarctica rises up from the sea, it gets colder by around -6°C. As well as the difference in height, the North Pole is lying on top of the Arctic Ocean, and heat6 is conducted through the ice and in the narrow gaps of open water (called leads), which makes the North Pole warmer.
Atmosphere
The atmosphere above Antarctica is much thinner. Without clouds to cover it, the bright surfaces of snow and ice reflect a large percentage of sunlight. The percentage of sunlight reflected from the surface is called albedo7. In contrast, more cloud cover in the North Pole traps the heat and increases the temperature.
Land masses
If you look at a map of Antarctica, you will see that there is an ocean that circulates around it and the nearest land is some distance away. Water flows around Antarctica, getting colder and colder.
The size of land in each hemisphere also plays a role.
- In the Northern hemisphere, there are big pieces of land (like America and Europe). Land traps heat and then transfers heat into ocean currents, which, in turn, bring warmer water up to the Arctic.
- The Southern hemisphere has relatively little land – just small countries that can not trap as much heat.
- temperature: A measure of the degree of hotness or coldness of an object or substance. Temperature is measured with a thermometer calibrated in one or more temperature scales. Kelvin scale temperature is a measure of the average energy of the molecules of a body.
- North Pole: The North Pole is the northernmost point on the Earth, lying diametrically opposite the South Pole.
- ecosystem: An interacting system including the biological, physical, and chemical relationships between a community of organisms and the environment they live in.
- atmosphere: 1. The layer of gas around the Earth. 2. (atm) A non-SI unit of pressure equivalent to 101.325 kPa.
- metre: The base unit of length in the International System of Units (SI).
- heat energy (heat): Heat energy: the transfer of energy in materials from the random movement of the particles in that material. The greater the random movement of particles the more heat energy the material has. Temperature is a measure of the heat energy of a material.
Heat: the flow of energy from a warm object to a cooler object. - albedo: The proportion of solar radiation that is reflected by the Earth’s surface, typical for white surfaces (i.e. snow, ice, clouds).
