The point in the northern hemisphere where the rotation axis of Earth touches the celestial sphere. The star Polaris, also called the Pole Star, is located very near this point, at an angular separati
on of 42 arcminutes (about 1.4 lunar diameters).
A winter fluctuation in the amplitude of a pattern characterized by low surface pressure in the Arctic and strong mid-latitude westerlies. The NAM has links with the northern polar vortex into the str
atosphere. Its pattern has a bias to the North Atlantic and its index has a large correlation with the North Atlantic Oscillation index.
A northerly foehn wind blowing down the Italian side of the Alps. The northern slopes are normally cooler than the southern slopes, and the dynamic warming is often insufficient to overcome the differ
ence of temperature. Hence a warm dry northerly wind of foehnlike character occurs less frequently than the south foehn.