###### 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 England in 1805, to illustrate various wind speeds. It was modified from the NOAA Beaufort Wind Scale.

 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
This Sci-ber Text was developed by the Utah State Board of Education and Utah educators.