the layer of gases surrounding the earth at a height of between 15 and 50 kilometres that is not affected by the weather and in which the temperature increases with height

The ash cloud rose 35km into the stratosphere.

During the 1980s, the amount of ozone in the stratosphere above Europe decreased by about eight percent. 20世纪80年代，欧洲上空平流层的臭氧含量降低了大约8%。