Imagine you are an astronaut looking down at Earth and its atmosphere from space. You see a small group of clouds moving from north to south. Predict where the clouds will be after they move south by clicking position A, B, or C.
Your prediction is correct.
The clouds would move to
position B.
Try again.
Remember, the clouds moved from north to south. To make your choice correct, the clouds would also need to move east to reach position C, or west to reach position A.
Click the back arrow below to
try again.
You may have noticed something was missing—Earth was not rotating! Earth rotates around its axis every day. That rotation is in a specific direction. Click the Start button to see the direction of
Earth's rotation.
This time, think about how Earth's rotation affects how the clouds appear to move. As before, the clouds will move from north to south. Given what you know about the rotation of Earth, predict where the clouds will go by clicking A, B, or C.
Your prediction is correct.
The clouds would appear to move to position A.
Try Again.
Remember, the clouds are moving from north to south. But their movement looks different when Earth is rotating at the same time. The clouds appear to move toward
position A.
Click the back arrow below to
try again.
The movement of the clouds from north to south seemed simple when Earth was not rotating. The clouds moved in a straight line toward the equator. When you watched the movement of the clouds while Earth was rotating, the clouds still moved from north to south, but Earth and its landmasses moved below the cloud. Earth’s rotation made it look like the clouds moved to the west as well as to the south. This is an example of the Coriolis effect. The Coriolis effect is the apparent change in an object's direction because of Earth’s rotation.
Now imagine clouds in the Southern Hemisphere. These clouds are moving from south to north. Based on what you know about Earth’s rotation, which pathway do you think best represents your observation of the cloud?
That’s the
correct prediction!
Just as in the Northern Hemisphere, Earth is still rotating to the right. Therefore, the clouds would appear to have moved to the left.
Try again.
The direction of Earth's rotation is the same. In the Southern Hemisphere, the rotation would make it appear that a cloud moving from south to north would also be moving to its left.
Click the back arrow below to
try again.
