polar front

The main area of frontal weather systems in the N Pacific and N Atlantic. It forms the boundary between polar (cold) and subtropical (warmer) air masses, along which depressions or cyclones develop. The position of the front is associated with the polar jet stream, and shifts according to season. In winter it is further S (40°–50°N), and frontal activity is responsible for the cold, wet weather of N Europe. In summer it migrates N, and its location is more variable.

In meteorology, a Polar Front is the boundary between the polar cell and the Ferrel cell in each hemisphere. At this boundary a sharp gradient in temperature occurs between these two air masses, each at very different temperatures.

The polar front arises as a result of cold polar air meeting warm tropical air.

The polar front theory says that mid-latitude cyclones form on boundaries between warm and cold air. In winter, the polar front shift towards the Equator, whereas high pressure systems can dominate more in the summer.