The Ekman spiral is a phenomenon in oceanography that describes how wind affects the movement of water in the ocean. When wind blows across the surface, it creates friction that causes the water to move. However, due to the Earth's rotation, the water moves at an angle to the wind direction, resulting in a spiral effect as you go deeper into the ocean. This spiral effect occurs because each layer of water moves more slowly than the layer above it, creating a gradual change in direction. The deeper you go, the more the water shifts to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, due to the influence of the Coriolis effect.