The wind around a surface low pressure in the Northern Hemisphere blows __. a. counterclockwise perpendicular to isobars. b. clockwise perpendicular to isotherms.

a. counterclockwise perpendicular to isobars

Explanation:

Due to the Coriolis force that shifts the air in such a way that it follows the pressure contours thereby making the air or wind blow in a counter-clockwise direction in the Northern Hemisphere around low pressure and move out around high pressure in a clockwise direction.

Hence, it can be concluded that The wind around a surface with low pressure in the Northern Hemisphere blows "counterclockwise perpendicular to isobars."