Every week WAVE 3 meteorologist Tawana Andrew breaks down what we know and what we don't about the climate and weather here in Louisville.
Bill Burton: It's time for us to take a look at the Science Behind the Forecast as I am joined by WAVE 3 meteorologist Tawana Andrew. Good morning, Tawana.
Tawana Andrew: Good morning, we're talking about something a little bit more relevant to what's happening in Iceland right now, that you would think we're talking about the cold but, no, we're heating things up a little bit more.
BB: Yeah, Iceland has got a volcano that's making a little bit of noise. So that's our topic today. Volcanoes and how they can affect weather. What do we need to know?
TA: So as volcanoes erupt, they release plumes of ash and gases into the atmosphere, and these can have significant impacts on temperatures and even precipitation globally. Volcanic eruptions that produce large amounts of sulfur dioxide into the stratosphere can actually lead to cooler temperatures not just locally, but worldwide, because sulfur dioxide blocks sunlight and actually interacts with other compounds in the atmosphere to lower temperatures at the Earth's surface. So an excellent example of this is 1991's eruption of Mount Pinatubo in the Philippines. That eruption dropped global temperatures by 1.3 degrees Fahrenheit, which doesn't seem that much, but you are talking about the entire planet seeing that temperature drop. This eruption sent about 22 million tons of sulfur dioxide into the atmosphere. That combined with the water in the atmosphere to form sulfuric acid. Those sulfuric acid droplets help to block some of that sunlight from actually reaching the Earth's surface. And that's what led to the cooler temperatures.
Now sulfur dioxide is really interesting because it helps to make things a little bit prettier, as well, after a volcanic eruption because all the dust and the sulfur dioxide that comes out of these volcanic eruptions can create more vibrant sunrises and sunsets, because they scatter the light at various wavelengths and can make these sunrises and sunsets more vivid. Something else to note is that yeah, we talked about, of course, that temperature drop with some volcanic eruptions, but others can lead to increases in temperatures. And a perfect example of this as well is what happened in Tonga in January of 2022. When that volcano erupted and shot a plume of volcanic gases, Ash, water vapor 35 miles into the sky. Yeah, it went up high. Because keep in mind, our global stratosphere only extends about 31 miles up into the atmosphere. So it went even above that. And as it erupted, it shot out 50 million tons of additional water vapor into the atmosphere since it was an underwater eruption. So all of that water, instantly went to steam and flew up all the way 35 miles high into the sky. And water vapor actually is excellent at absorbing solar radiation, and it remits it as heat. So researchers are still working on diving into the numbers to see how much of an impact is additional moisture had on that planet's temperatures but for right now things are trending on the warmer side.
BB: So much information to try to all sort out because of volcanoes. They do have such a major impact on weather worldwide, not just locally where there are erupting. Now we have a better understanding of volcanoes and how they can affect weather thanks to the latest edition of Science Behind the Forecast with WAVE 3 meteorologist Tawana Andrew. Thanks for the knowledge, Tawana.
TA: Of course.
This transcript has been lightly edited for clarity.
