Traditional Culture Encyclopedia - Weather inquiry - Why doesn't the weather balloon fly away without a rope?

Why doesn't the weather balloon fly away without a rope?

The weather balloon you mentioned (borrowed from upstairs) is a fixed height balloon.

It is made of unexpanded polyester film, and the spherical skin has strong compression resistance and good gas retention. It can keep the same height in the atmosphere and drift smoothly with the airflow.

The gas in the balloon is less dense than air. The balloon will float when it is inflated, but the balloon itself has weight, and the air density will decrease with the increase of height. When buoyancy and gravity are equal, the balloon will stay at a certain height. No longer floating or falling.