Why are weather balloons partially infated before they're released into the atmosphere?

Answer 1

As you rise in elevation, the pressure around you decreases. This lower pressure would cause the balloon to expand, and burst if it was inflated to much originally. By starting it off only partly filled, it will expand to a normal size and not explode.

Answer 2

The volume of a balloon depends on the difference in pressure between the inside and outside. As the balloon rises to high altitudes, that pressure outside the balloon drops, so the difference in pressure gets higher, which means the volume of the balloon will increase.

A weather balloon that was fully inflated when released from the ground would explode when it got too high.

Answer 3

If the balloon were filled on the ground it would burst before it got very high.

As a balloon rises the exterior pressure goes down, so the gas inside the balloon expands. By putting in less gas the balloon can rise a long way before it over-stretches the skin and bursts it. The ordinary synoptic weather balloon typically gets above 100 mb, 1/10th of surface pressure, before it breaks.

Answer 4

As the weather balloons rise in the atmosphere the outside pressure decreases. This causes the gas inside the balloon to expand. If the balloon was fully inflated on the ground, then the balloon would rupture when it reached the upper atmosphere.

Answer 5

While I am not an expert in weather balloon technology, simple physics suggests an answer. Atmospheric pressure decreases as you move higher into the atmosphere. As the pressure decreases, there is less force to hold the gas inside a weather balloon in check, so to speak. This allows the gas in the balloon to push out further against the walls of the balloon, and, if it gets high enough and has enough gas inside it, it will eventually rupture. No one likes a popped weather balloon.

Answer 6

Good observation. The (Helium or Hydrogen) balloon released at sea level will contain only sufficient gas to fully inflate the balloon when it has reached its target height. Where the pressure will be much much less than at sea level.

If the balloon were filled more, then it would burst before it reached altitude,

OR it would have to be made of thicker film and would therefore not reach as high.

Answer 7

A weather balloon is filled with helium at the standard air pressure on the ground (~14 psi). As the balloon rises, the air around has relatively lower pressure compared to the helium in the balloon. When the air in the balloon can expand due to the low pressure, it does so. The balloon will expand until the point of the pop page.

The reason weather balloons are only partially inflated is to allow room for the helium in the balloon to expand.

Answer 8

The balloons expand as the external air pressure decreases as the balloon ascends.