The truth about the "big fish"!

The “big fish” is a helium-filled tethered  #balloon with a volume of 60 cubic meters.

What is it for

It swims into the sky to figure out how particles and some gases distributed vertically within 1 km above the ground.

See more: 

http://english.iap.cas.cn/.../202009/t20200908_242776.html

http://english.iap.cas.cn/.../202109/t20210907_282736.html