The coriolis effect is due to the rotation of the earth. Look up youtube videos on it, its pretty cool. If we didn't have coriolis effect then hurricane's wouldn't even form! Also it affects the trajectory of hurricanes. If you look at a path a hurricane takes it always curves quite a bit. That's also because of the coriolis affect. Imagine you're on a merry go round or on some spinning disk. You throw a ball towards the center. The ball will seem to curve away from your target because you're spinning. Now its not because the ball curved and you missed, the ball goes in a straight line but because of the spinning the target you aimed at shifted.
