Summary
It is blatant volcanic eruptions affect the climatic systems occurring within the Atmosphere. The gases and explosivity of eruptions are characterised by the composition of the rock the volcano is made of, the more felsic the magma the greater the gas content thus increasing the build up of pressure causing a more violent eruption. The plate boundary determines the measure of the Volcanic Explosivity index along a convergent plate boundary eruptions are typically explosive with a VEI of 5 or higher where as Divergent plate boundaries create effusive eruptions typically rated between 1 and 4 according to the VEI.
The composition of the rock does affect the type of gases emitted as well as the concentration. The more felsic the magma, the great the content of silicate and the more gases dissolved within. The greater the concentration of different gases within the magma the greater the build up of pressure within the Volcano which contributes the characteristics of Strato-volcanic eruptions.
Halide gases aren't the main contribution to Ozone depletion due to the free radical substitution mechanism as the HCl rarely reaches the height of the Stratosphere instead condensing and falling as precipitation. It is actually the heterogeneous reactions that occur amongst the surface of Sulphuric acid aerosols increasing the rate of these reactions within the atmosphere thus causing greater depletion.
A period of global cooling is present post-eruption due to the emission of Sulphur Dioxide ejected into the Stratosphere. The SO2 reflects electromagnetic radiation produced by the Sun by processes of absorption and scattering. It was found that even infra-red radiation re-emitted by the Earth is also directed into the Exosphere and out into space. The effect of Global Cooling is a more adverse effect in comparison to Global warming in many circumstances. Yet in cases such as the Siberian traps marking the P/T boundary 250 million years ago the eruption caused global temperatures to increase and caused much of the marine species to become extinct.
Periods of global warming after an eruption are caused by the emission of Carbon Dioxide and Water vapour into the atmosphere due to the increased action of the greenhouse effect. As Ozone depletion occurs, the inability to then prevent ultraviolet radiation is insinuated to have the ability to also raise global temperatures. More energy passes into the system thus more energy is be released as heat. It is not only the penetration of electromagnetic radiation that causes global warming but also the mechanism itself. Radical Substitution is the mechanism present causing Ozone depletion. The reaction is exothermic releasing heat energy to the surroundings from the system. It is indicated to cause the Stratosphere to warm which is thought to act as an insulating layer around the Earth.
[1] http://en.wikipedia.org/wiki/Toba_catastrophe_theory
Periods of global warming after an eruption are caused by the emission of Carbon Dioxide and Water vapour into the atmosphere due to the increased action of the greenhouse effect. As Ozone depletion occurs, the inability to then prevent ultraviolet radiation is insinuated to have the ability to also raise global temperatures. More energy passes into the system thus more energy is be released as heat. It is not only the penetration of electromagnetic radiation that causes global warming but also the mechanism itself. Radical Substitution is the mechanism present causing Ozone depletion. The reaction is exothermic releasing heat energy to the surroundings from the system. It is indicated to cause the Stratosphere to warm which is thought to act as an insulating layer around the Earth.
[1] http://en.wikipedia.org/wiki/Toba_catastrophe_theory