A so called centre of action is a semi-permanent pressure centre that regularly appears in one particulary area on charts of mean sea level pressure. Centres of action are created by the overall general circulation of the atmosphereand have a significant role affecting the weather in surrounding areas. Some 'popular' centres of action are:
The Aleutian low, low pressure centre located at about 50°N over the Aleutian islands.
The Azores high, a subtropical anticyclone located near 30°NN in winter (i.e. south of the Azores) and 35°N in summer with a ridgethat extends towards the Iberain peninsula.
The Bermuda high, area of high pressure located over the western North Atlantic Ocean and can also be taken as a westward extension of the Azores high.
The Islandic low (Iceland low), low-pressure located over the Denmark Strait between Iceland and Greenland.