Question

reason of use of hydrogen in Meteorological balloons

Answer 1

The balloon is usually filled with hydrogen due to lower cost, though helium can also be used. The ascent rate can be controlled by the amount of gas with which the balloon is filled.
But ...

Today helium is used instead of hydrogen, since it is inert so non-flammable which makes things a lot safer. Hydrogen can ignite very easily when mixed with the oxygen of the surrounding air. In party balloons and were people are in direct contact with the "thing" be it a balloon or even an airship helium is the safer choice.
But helium is also limited and helium prices are going up just like the fuel prices. If we ever want to see more airships in the sky we need to find a way to safely use hydrogen. The Graf Zeppelin flew many years without a single incident with hydrogen and the Hindenburg disaster was only so spectacular because the envelope was coated with the wrong paint that was close to rocket fuel. And after all, only 35 people out of 97 died. Try to get a survival rate of 60% when an airplane crashes. And most of the people who did die, did not die from the Flames they died because they jumped of the airship. If they would have stayed on board until the ship touched ground they probably would have survived. With todays technology, hydrogen might be used again for airships. The whole world talks about hydrogen today and that we should all put hydrogen in our cars if this can actually happen I believe that airships will also be able to use hydrogen again. A good start would be to use hydrogen in unmanned airships that are not flying inside or over people. Weather Balloons use hydrogen as a lifting gas today so why not use it in unmanned airships too.

Answer 2

Answer:

As hydrogen is lighter than air and even lighter than air it is used as in Meteorological balloons.