KnowHOW team explains: Much of the temperature difference between the two poles can be explained by their difference in elevation from seal level. The North Pole (with an average winter temperature of around -30 0C) lies on sea ice on the surface of the Arctic Ocean while the South Pole (at around -60 0C) is 2,800 metres above sea level on the ice sheets of the Antarctic continent.

The temperature variance due to height is about -6 0C per kilometre gain in elevation. Also, the thinner (hence colder, drier and less cloudy) atmosphere above the South Pole reflects less heat back to the surface than its northern counterpart. Much of the remainder of temperature difference can be explained by the contrasting atmospheric circulation patterns in the two hemispheres.

The continents of the northern hemisphere drive large ?planetary waves? in the atmosphere. These waves transport heat Polewards and also steer atmospheric depressions into the North Polar regions. The continents of the southern hemisphere are smaller and lower than those in the north, so the southern hemisphere planetary waves (and associated heat transport) are smaller. The high mountains of the Antarctica also block the Poleward movement of depressions. Finally, the atmosphere at the North Pole receives some heat from the underlying Arctic Ocean, although it has to penetrate two to three metres of sea ice.

The question was sent by Anisur Rahman from Siliguri