REMOTE SOUNDING OF MINOR CONSTITUENTS IN THE STRATOSPHERE AND HETEROGENEOUS REACTIONS OF GASES AT SOLID INTERFACES

Various remote sounding techniques of minor constituents of the strato sphere may be carried out, especially during the Antarctic and Arctic winters, where heterogeneous reactions of gases at solid interfaces pl ay an important role in ozone destruction. After the El Chichon volcan ic eruption in 1982 the significant decreases in NO, NO2 and increases in HCl were not consistent with known chemistry unless CINO3 could be converted to HCl on the solid NaCl (observed to be present in the El Chichon aerosols). Recently the eruption of Mount Pinatubo in 1991 has led to a large (factor of ten) increase in stratospheric aerosol. The biggest chemical impact evident in the measurements made during the E uropean Arctic Stratospheric Ozone Experiment (EASOE) was the reductio n of NO and NO2. Given that the chemical behaviour of the solid NaCl i s most likely associated with its mechanical properties, a recently pr oposed thermodynamical model is employed to show the important role of the heterogeneous reactions with NaCl in the volcanic aerosols. These reactions might also prove to be critical in the inversion algorithms usually applied to satellite measurements.