Weather Observations - Pushing Down
Have you ever tried to touch the bottom of the swimming pool at the deepest part? If so, you might have noticed that the deeper you went, your ears felt funny or even hurt. It was also difficult to hold your breath for very long under the water. Now, imagine that you could and dive to the bottom of the ocean. The pressure of the ocean water above you would be so heavy that you couldn't survive.The air above us isn't as heavy as water, but it does put pressure on our bodies. Sometimes our ears even "pop" because of the change in air pressure as we travel in a car or plane.
Since air is a substance, or something that takes up space, we can observe the effect it has on us and the things around us.
The temperature of the air can be measured by a thermometer. If the air is too hot or too cold, it affects our choice of the clothes we wear and the activities we choose to do.
Try it!
Pull a balloon over the mouth of a bottle. Place the bottle in a cold place for ten minutes. How does the balloon look after being in the cold place? Then, place the bottle in a warm place for ten minutes. What happens to the balloon as the bottle becomes warm? Why?
Air moves differently as its temperature changes. Warm
air rises and cool air sinks, creating wind. The chart below was developed
by Sir Francis Beaufort of
| Observation | Estimated Wind Speed |
Smoke drifts with air |
1-3 mph |
Wind can be felt; leaves rustle |
4-7 mph |
Leaves and small twigs move; flags move |
8-12 mph |
Small branches sway; dust and paper blow |
13-18 mph |
Small trees sway |
19-24 mph |
Large branches sway |
25-31 mph |
Whole trees sway; walking is difficult |
32-38 mph |
Your challenge now will be to use the data of this chart to determine the wind speed on four separate days or four separate times of one day. Complete the data in a chart similar to the one below.
| Date | Time | Observation | Estimated Wind Speed |

