The role of large volcanic eruptions in stratospheric ozone depletion and degradation of coniferous forests
V.V. Zuev1, N.E. Zueva1, E.S. Savelieva1, E.M. Korotkova2, A.V. Pavlinsky1
1Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
2Tomsk State University of Architecture and Construction, Tomsk, Russia
Keywords: large volcanic eruptions, volcanic aerosol, tropical stratosphere, stratospheric ozone depletion, degradation of coniferous forests
Abstract
As a result of large eruptions of tropical volcanoes, a large amount of volcanic aerosol is emitted into the stratosphere and contributes to the formation of positive temperature and negative ozone anomalies in the lower tropical stratosphere. Large eruptions with VEI ³ 5 can cause global ozone loss. A volcanic increase in the temperature of the lower tropical stratosphere leads to an increase in the stratospheric meridional temperature gradient and the subsequent strengthening of the polar vortex. Polar ozone depletion occurs under the conditions of the winter-spring strengthening of the vortex. Stratospheric ozone anomalies due to increased UV-B radiation can manifest themselves in the degradation of coniferous forests, which serve a biosphere indicator of climate change. Massive focal drying of dark coniferous forests has been observed in the mountainous regions of Southern Siberia since the mid-1990s under conditions of an increase in surface UV-B radiation as a result of ozone depletion after the eruption of Mount Pinatubo.
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