Why is it windy?

Zhao Hui Xiaoshan District Junior Academy of Sciences Primary School? Class 603? Jin Yidong

Summer is coming and the weather is getting hotter and hotter. Whenever you walk on a quiet path, in a green field, or in a green forest, a cool breeze blows, which is so beautiful. In this pleasing beauty, a cool breeze blows, which makes you feel relaxed and happy, as if the fatigue of the day has faded in this wind.

But in this cool breeze, I also have a question: Why is there wind?

In order to solve this problem, I'm going to prove it with experiments. I first took a piece of paper, stuck it on the wall, held it with my hand, took a deep breath, then let go of my hand and blew my last breath as soon as I let go. The paper didn't fall, because it was windy, and I fell as soon as I stopped blowing paper. Through this experiment, I came to a simple conclusion: because air floats in nature, its mass is very light, just like people come and go freely. Gradually, all the air began to flow, and then the wind formed.

I thought this would solve the problem, but when I entered the room, I found my electric kettle boiling water, and the water boiled and began to give off hot air. Seeing this scene, I have another guess: (www..Com) Will the evaporation of water lead to the upward flow of water vapor, thus driving some lighter gases, while some heavier objects in the sky flow downward in the opposite direction to the lighter gases?

Just as I was about to return to the water, my sister came over and said, "What's the matter? You look as if something is wrong. Come on, talk to my sister! " "I looked at my sister and thought: My sister has gone to college. I must know some of these problems. Why don't I ask my sister So, I said to my sister, "Sister, I wonder why the wind is such a problem. "When my sister heard this, she smiled and said," So you were thinking about this problem, so I'll tell you! "! It is like this: the density of warm air is relatively small and rising, so the air pressure in the area is relatively small; The density of cold air is relatively high and sinks, so the air pressure in this area is relatively high. The temperature in each area is different, and the air pressure is of course different! The air on the ground blows from a cold place to a warm place, while the air pressure at high altitude is just the opposite, blowing from a warm place to a cold place, thus generating wind. "

I finally understand why it is windy.