Also known as the stratospheric aerosol layer, this is the lower layer of the stratosphere consisting of predominantly sulfuric acid/water particles with an average diameter of 0. 14 μm, discovered in 1960 by Christian Junge while examining other atmospheric components. The sulphur in this layer probably comes from a stable biogenic gas released from the earth's surface, carbonyl sulfide, O=C=S, which is photolyzed and oxidised in the stratosphere. This is a more important sulphur source for the Junge Layer than reactive sulphur gases originating from the planet's surface because their lifetimes are too short to allow transportation beyond the tropopause.