%0 Journal Article
%T Lidar Observations of Aerosol Disturbances of the Stratosphere over Tomsk ( N; E) in Volcanic Activity Period 2006\!-\!2011
%A Oleg E. Bazhenov
%A Vladimir D. Burlakov
%A Sergey I. Dolgii
%A Aleksey V. Nevzorov
%J International Journal of Optics
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/786295
%X The lidar measurements (Tomsk: N; E) of the optical characteristics of the stratospheric aerosol layer (SAL) in the volcanic activity period 2006¨C2011 are summarized and analyzed. The background SAL state with minimum aerosol content, observed since 1997 under the conditions of long-term volcanically quiet period, was interrupted in October 2006 by series of explosive eruptions of volcanoes of Pacific Ring of Fire: Rabaul (October 2006, New Guinea); Okmok and Kasatochi (July-August 2008, Aleutian Islands); Redoubt (March-April 2009, Alaska); Sarychev Peak (June 2009, Kuril Islands); Grimsv£¿tn (May 2011, Iceland). A short-term and minor disturbance of the lower stratosphere was also observed in April 2010 after eruption of the Icelandic volcano Eyjafjallajokull. The developed regional empirical model of the vertical distribution of background SAL optical characteristics was used to identify the periods of elevated stratospheric aerosol content after each of the volcanic eruptions. Trends of variations in the total ozone content are also considered. 1. Introduction The optical and microstructure characteristics of the stratospheric aerosol (SA) substantially influence the radiative, dynamical, and chemical processes in the Earth¡¯s atmosphere. The natural and anthropogenic factors, which determine the state of the stratospheric aerosol layer (SAL), may have the character of a constant, gradually accumulating effect or a short-term powerful disturbance. The SA effects are most apparent after explosive volcanic eruptions, when sulfur-containing products are injected through the tropopause directly to the stratosphere, where they participate in a number of photochemical reactions to form the sulfuric acid aerosol, whose mass is several orders of magnitude larger than the mass of the background aerosol. In this case, direct measurements record considerable radiation-temperature effects [1, 2]; there are long-term declines in ozone content because heterogeneous chemical reactions on the increased surfaces of aerosol particles convert relatively inert forms of chlorine compounds to more reactive ozone-depleting species [3¨C5]. In analysis and prediction of different stratospheric changes, it is necessary to determine and identify the periods of increased SA content and to determine and predict the long-term trends of variations in the SA characteristics for different SAL states. These data make it possible to get systematic SAL observations carried out by different methods of ground-based, balloon-sonde, and satellite measurements and, in particular, with the use
%U http://www.hindawi.com/journals/ijo/2012/786295/