Volcanoes and Their Impact On Weather and Climate
National Geographic recently reported that researchers from Arizona State University have found evidence the super volcano currently dormant in Yellowstone National Park , may erupt in the next few decades, a lot sooner than expected.
A huge volcanic eruption in Yellowstone National Park, located in the states of Wyoming, Montana and Idaho, would be absolutely devastating to the regions in and around the park, including much of the central and western United States. It would also have additional implications for the world’s weather and climate. So, how do volcanoes impact weather and climate?
Volcanoes typically impact weather very close by, especially erupting volcanoes, this according to the “Volcano World” web resource available through Oregon State University. During an eruption, thousands of ton of ash is released into the atmosphere, temporarily creating a plum of ash in the atmosphere, leading to reduced sunshine across areas downwind of the volcano. Some ash plum even totally block the sun. If the eruption is large enough, this ash can get carried thousands of miles away from its source. Along with the impacts from the ash plum, back closer to the volcano itself precipitation, lightning and thunder can and does typically occur.
Precipitation occurs because the volcanic ash, that’s thrown into the atmosphere, is great at absorbing water vapor, thus making it a very effective condensation nuclei. When enough water vapor collects on those nuclei in the atmosphere, clouds form, leading to precipitation.
Lightning and thunder occur due to the interaction of particles in the atmosphere, including the volcanic ash, as they collide and exchange charges. Eventually the energy collected in the atmosphere discharges leading to lighting and thunder.
Vog, or volcanic fog, is known to form near erupting volcanoes as well. Vog forms when sulfur dioxide, released during a volcanic eruption, combines with water vapor in the atmosphere to form sulfuric acid droplets. Enough of those droplets grouped together form volcanic fog, or a sulfuric acid cloud along or very close to the ground.
Research is still be done on how volcanic eruptions impact climate, but according to “Volcano World,” volcano eruptions can have varying effects on climate. First, volcanic eruption can spew tons of material into the atmosphere. If the material is mostly spewed in to the troposphere, the lowest part of the atmosphere and where weather occurs, it will eventually be washed out by rain. For the larger volcanic eruptions that send material well into the stratosphere, this material lingers a lot longer in this part of the atmosphere, leading to impacts on climate, with these impacts depending on particle size.
Ash particle sizes typically greater than 2 microns in diameter allow the sun’s radiation, shorter wave, high energy radiation, to easily pass through the atmosphere to reach the Earth’s surface. These particles do absorb outgoing longer wave radiation, leading to a warming atmosphere and warmer conditions at the surface. Ash particles less than 2 microns in diameter tend to absorb more of the shorter wave, high energy radiation from the sun and space, reducing the amount of the sun’s energy reaching the Earth’s surface. These particles also allow more of the longer wave radiation from the Earth’s surface to escape into space. This leads to a cooling effect at the Earth’s surface.
Over time, the volcanic ash in the atmosphere can have an impact on climate and the longer the volcanic particles stay in the atmosphere, especially in the stratosphere, the greater the potential impact on climate.
You can learn more about Yellowstone National Park and it volcanic activity, and other volcanic activity around the world by visiting the United States Geological Survey Volcano hazards Program website.