A current carrying power line carries current from west to east. The direction of magnetic field at a short distance, above it, is

Direction of magnetic field for a current carrying conductor as per direction rule like right hand grip rule/ Maxwell corkscrew rule/ Ampere's swimming rule at a point above the conductor is from north to south.

The direction of magnetic field around a straight current carrying wire is given by the direction of curling of fingers of right hand when thumb points towards the direction of current as shown in the figure.

Clearly the magnetic field above the wire carrying current west to east is from north to south.