Volcanoes ozone depletion

Lee C, Kim YJ, Tanimoto H, Bobrowski N, Platt U, Mori T, Yamamoto K, Hong CS (2005) High CIO and Ozone Depletion Observed in the Plume of Sakurajima Volcano, Japan. Geophys Res Lett 32 L21809... 

Flofmann, D., and Solomon, S. (1989) Ozone depletion through heterogeneous chemistry following the eruption of the El Chichon Volcano, J. Geophys. Res. 94, 5029-5041. 

Lee, C., Kim, Y.J., Tanimoto, H., Bobrowski, N., Platt, U., Mori, T., Yamamoto, K., Hong, C.S. High CIO and ozone depletion observed in the plume of Sakurajima volcano, Japan. Geophys. Res. Lett. 32, L21809 (2005). doi 10.1029/2005GL023785 Lehrer, E., Wagenbach, D., Platt, U. Aerosol chemical composition during tropospheric ozone depletion at Ny Alesund/Svalbard. Tellus B 49,486-495 (1997)... 

It is true that volcanoes emit vast amounts of chlorine, much more than chlorine in CFC emissions. However, only chlorine that makes it to the stratosphere depletes ozone. The chemical stability of CFCs allows them to drift to the stratosphere, where they do their damage. In contrast, chlorine ftom volcanoes is primarily in the form of HCl, a very reactive and water-soluble compound. Veiy little of the HCl emitted by volcanoes gets beyond the troposphere because it is rapidly washed out by rain and condensed steam from the eruption itself. Indeed, measurements of chlorine levels in the stratosphere showed little change after the eruption of Mt. Pinatubo in 1991. CFCs, on the other hand, are not water-soluble and are not washed out of the atmosphere by rainfall. They have long atmospheric lifetimes and eventually make it to the stratosphere. Further, the amount of chlorine in the stratosphere is about five times 1950 levels, which correlates well with CFC usage. 

---