Features of the Reconstruction of Changes in Stratospheric Ozone along the Ural Meridian Using Dendrochronological Data

Abstract: An analysis of data on the density of annual rings of conifers for the periods 1979‒1993 and 1979‒2006 allows us to identify patterns in the response of trees, taking into account the processes of abnormal decrease and natural recovery of total ozone content (TOC). Reconstructions of changes in TOC over the past 300 years along the Ural meridian according to the TEMIS (Tropospheric Emission Monitoring Internet Service project) satellite monitoring of TOC and stem wood responses observed in data on the maximum density of annual rings of pine, spruce, and larch have been performed on the basis of methods of dendrochronological and spectral singular analysis, which made it possible to compare the current and past state of stratospheric ozone fields. Although changes in stratospheric ozone can play the role of a factor significantly limiting the annual growth of wood, such an approach to estimates works only under conditions of overlapping responses of trees under UVB effects in the spectral range of 280‒315 nm on stress responses from other climatic factors. Based on the results of a numerical modeling for three latitude ranges, models of maximum annual density are calculated in terms of changes in TOC and reconstructions of their past changes are given. The aridity of the climate and its cyclicity increase the stress effect of the ozonosphere on vegetation associated with an increase in UVB radiation and allow us to differentiate the responses of trees according to stressors by statistical methods. Reconstructions of TOC from April to September for the Ural meridian show that the level of TOC has not yet reached previous historical values.