Nitric acid aerosols at the tropical tropopause

It is thermodynamically possible for nitric acid aerosol particles to form in the lower stratosphere and upper troposphere in tropical latitudes. This aerosol would have essentially the same composition as the polar stratospheric clouds observed in the winter polar stratosphere. Calculations have been carried out, indicating that nitric acid aerosols may form at the same altitudes as layers observed in the tropics by the SAGE satellite system.