Question

Because these are surface winds, another force acting on the air in the direction opposite to the air flow was the local ________ force. At map time, this force at Portland was acting generally toward the west.

a) Pressure gradient
b) Friction
c) Centrifugal
d) Coriolis

Answer 1

The local force opposing the wind flow described is the friction force, which interacts with the Earth's surface and the d. Coriolis force to affect wind patterns and storm rotations.

Step-by-step explanation:

The local force acting in the direction opposite to the airflow, as described in the provided context, was the local friction force. In conditions like those found at Portland, friction would generally act toward the west, opposing the direction of the wind. This friction is a result of the wind's interaction with the Earth's surface, causing a slowdown and change in direction of surface winds. It works alongside the Coriolis force, which, due to the Earth's rotation, deflects winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

These two forces combined explain the counterclockwise rotation of hurricanes in the Northern Hemisphere and the clockwise rotation in the Southern Hemisphere. For large-scale atmospheric motions like wind patterns, even though the Coriolis force is small, it has significant effects.