What are enclosed areas of high pressure marked by roughly circular isobars or height contours called

Answer: Anticyclones

Explanation: Anticyclone is an opposite of cyclone. Anticyclone is a meteorology concept, in which the air moves in descending order and causing a barometric pressure increase at the portion of Earth's surface contacted.

However, from central area of high pressure, the descending air tends to flow outwards in varying direction, and is deflected by the rotation of the earth, resulting to a spiral movement.

Anticyclone rotates clockwise in the northern hemisphere, while it rotates anti-clockwise in the southern hemisphere.