A closer look
If you blow on your hot soup, the liquid moves forward. If the wind blows across the ocean, the water moves sideways, because the Earth spins and fluid dynamics hates your intuition. Harald Sverdrup mapped this out in his pioneering work on oceanography, expanding on the Ekman transport theory. He proved mathematically that thanks to the Coriolis effect, the net transport of ocean water is roughly 90 degrees to the direction of the prevailing wind. So while the wind pushes forward, the vast, rotating bulk of the ocean stubbornly slides off to the right in the Northern Hemisphere, turning global navigation into a massive geometry problem.
