Upper stratospheric ozone decrease events due to a positive feedback between ozone and the ozone dissociation rate
- 1Leibniz-Institute of Atmospheric Physics at the University of Rostock, Schloss-Str. 6, 18225 Ostseebad Kühlungsborn, Germany
- 2Max-Planck-Institute for Solar System Research, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany
Abstract. Ozone measurements taken with a ground based microwave instrument at Lindau (51.66° N, 10.13° E) over some years showed strong ozone decrease events within the stratopause region, particularly during the winter half-year. These events are characterized by a marked drop of the ozone mixing ratio from two to three ppmv to less than half a ppmv in extreme cases. Simultaneous water vapor measurements at the same place, also carried out by a microwave instrument, showed a strong increase of its mixing ratio and the temperature was also enhanced during these episodes. The theoretical analysis brought evidence that these events result from a positive feedback in the complex radiatively-chemical system between the ozone column density and the ozone dissociation rate.