The Coriolis Force (also called the Coriolis Effect)

The Coriolis Effect is named after 19th-century French engineer-mathematician Gustave-Gaspard Coriolis. In 1835 he expanded on Sir Isaac Newton’s 3 laws of motion; by describing how an inertial force acts upon things with in a rotating frame of reference. This force is to the right of the direction of body travel for counterclockwise rotation of the reference frame or to the left for clockwise rotation. 

It affects weather patterns, it affects ocean currents, and it even affects air travel. The Coriolis Effect makes things (like planes or currents of air) traveling long distances around the Earth appear to move at a curve as opposed to a straight line. This is the reason; air tends to rotate counterclockwise around large-scale low-pressure systems and clockwise around large-scale high-pressure systems in the Northern Hemisphere. In the Southern Hemisphere, the flow direction is reversed. .

Most of us can agree that the Earth is a very large round object that is rotating on its axis. We can also agree that a day is the length of time it takes the Earth to make one rotation on that axis, which is 24 hours. If this is true, then depending on latitude parts of the Earth are moving at different speeds. 

That might sound crazy, but think of it like this. If one of y’all were standing a foot to the right of the North Pole, this would make the circumference of that circle about 6 feet. It would take 24 hours for that spot to rotate back around that circle on a round rotating Earth. That’s about 0.00005 miles per hour. OK now we move and stand on the equator. The day is still 24 hours long; but the circle circumference is much bigger. At the equator the Earth's circumference is about 25,000 miles. Which would mean you’re moving about 1040 miles per hour just by standing there. So even though we are all on Earth, how far we are from the equator determines our forward speed. The farther we are from the equator, the slower we move. 

Okay how does this stop things like hurricanes from moving in a straight line? Going back to our imaginary surroundings. This time we’re moving at 70 mph down the interstate. As we move, we come up on a slower moving bus. As we pass the bus, we see an open window. Since you have a baseball in your hand, you decide to try and throw that ball through the window. You take aim, and make an extraordinary dead on throw. But in spite of that, the baseball travels to the side and misses the window. That’s because the ball is traveling not only in the direction of the window, but it is also going in the direction (and speed) of your car. And that’s the deflection we are talking about! 

Anything traveling long distances, like air currents, ocean currents, even hurricanes and airplanes, will all be deflected because of the Coriolis Effect! Uncanny but weirdly true. 

 Hope this clears some of the confusion up.