The aerosols can stay in the stratosphere for up to three years, moved around by winds and causing significant cooling worldwide. Eventually, the droplets grow large enough to fall to Earth. Volcanoes also release large amounts of greenhouse gases such as water vapor and carbon dioxide. The amounts put into the atmosphere from a large eruption doesn't change the global amounts of these gases very much. However, there have been times during Earth history when intense volcanism has significantly increased the amount of carbon dioxide in the atmosphere and caused global warming.
Scientific American. Ozone absorbs UV radiation, and in the process ozone is changed back into an oxygen molecule and an oxygen atom. A balance exists in ozone destruction and production, so that an equilibrium concentration exists in the stratosphere.
This equilibrium has probably existed throughout much of geologic time. Recently, however, an ozone hole has been detected in the stratosphere over Antarctica, presumably due to the atmospheric build up of ozone-destroying CFCs by humans.
Ozone depletion has resulted in a greater penetration of ultraviolet radiation on the earth's surface, which is harmful to life on earth because it damages cellular DNA. The ozone effect does not appear to have a direct influence on global temperatures. Certain gases, called greenhouse gases primarily carbon dioxide and water vapor; but also methane, N 2 O, and CFCs , allow short wavelength radiation from the sun UV and visible light to penetrate through the lower atmosphere to the earth's surface.
These same gases, however, absorb long wavelength radiation infrared , which is the energy the earth reradiates back into space. The trapping of this infrared heat energy by these greenhouse gases results in global warming. Global warming has been evident since the beginning of the Industrial Revolution. Most scientists attribute global warming to the release of greenhouse gases through the burning of fossil fuels. Suspended particles, such as dust and ash, can block out the earth's sunlight, thus reducing solar radiation and lowering mean global temperatures.
The haze effect often generates exceptionally red sunsets due to the scattering of red wavelengths by submicron-size particles in the stratosphere and upper troposphere. Volcanic eruptions can enhance all three of these climate effects to variable degrees. They contribute to ozone depletion, as well as to both cooling and warming of the earth's atmosphere.
The role of volcanic eruptions on each climate effect is described below. The halide acid HCl has been shown to be effective in destroying ozone; however, the latest studies show that most volcanic HCl is confined to the troposphere below the stratosphere , where it is washed out by rain.
Thus, it never has the opportunity to react with ozone. On the other hand, satellite data after the eruptions of Mt. Pinatubo the Philippines and Mt. NASA and the National Science Foundation have funded Robock and Stenchikov to study the Pinatubo eruption in more detail, and to conduct another model comparison with the volcanic aerosol data set.
By understanding the impact of large volcanic eruptions on Earth's climate system in more detail, perhaps scientists will be in a better position to suggest measures to lessen their effects on people and natural resources. Kirchner, I. Stenchikov, H. Graf, A. Antuna, Climate model simulation of winter warming and summer cooling following the Mount Pinatubo volcanic eruption, J.
Stenchikov, Georgiy L. Both the African and Asian monsoons were weaker in the year following the Mt Pinatubo eruption in Get a Daily or Weekly round-up of all the important articles and papers selected by Carbon Brief by email. By entering your email address you agree for your data to be handled in accordance with our Privacy Policy.
Roz Pidcock GHGs and aerosols In brief: How much do volcanoes influence the climate? You have been signed up successfully.
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