Source: Science Daily
The Asian tropopause aerosol layer (ATAL) is located at twelve to 18 kilometers height above the Middle East and Asia. This accumulation of aerosols in the Asian monsoon was discovered first in 2011. Its composition and effect, however, have been unknown so far. Scientists have now found crystalline ammonium nitrate in this layer. In the AIDA cloud chamber, climate researchers have demonstrated how this substance is formed in the upper troposphere.