These pressure systems are characterized by high pressure centers, or lines surrounded by lower pressures. Centers of high pressure are called ‘highs’ or anticyclones. There being the highest pressure at the centre, the pressure gradient is directed from the centre towards the outer margin.
Therefore, in a “high’, the winds blow spiraling towards the outer margin. In an anticyclone the direction of flow is clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere.
Since in this pressure system the direction of wind movement is just the reverse of cyclonic circulation, it is called ‘anticyclone’. When the isobars are elliptical rather than circular, the system is called a ridge or a wedge of high pressure.
Like cyclones, the anticyclones also differ from one another in respect of their size, shape and other characteristics. However, the anticyclones are never as intense as the cyclones, but they are generally larger in size than the cyclones. The isobars are usually more symmetrical and are almost circular.