Comment The Hunga Tonga-Hunga Ha’apai eruption lasted less than a day, but released the most water vapor into the atmosphere from a volcano on record. Researchers say the eruption could temporarily raise surface temperatures in the coming years and also destroy stratospheric ozone. On January 15, the undersea volcano erupted and sent a shock wave that reverberated around the world. The powerful eruption spewed aerosols, gas, steam and ash 36 miles high, possibly the highest volcanic plume in the satellite record. The explosion damaged more than 100 houses and claimed at least three lives on the island of Tonga. A new study also shows that the volcano released an unprecedented amount of water vapor, a powerful greenhouse gas that traps heat on Earth. NASA satellite data show the volcano spewed more than 146 teragrams of water – enough to fill 58,000 Olympic-sized swimming pools – into the second layer of Earth’s atmosphere, known as the stratosphere, where the ozone layer is located and just above the point airplanes fly. The study said the amount released is equivalent to 10 percent of the water already in the stratosphere. “It’s the first time this kind of injection has happened in the entire satellite era,” which includes water vapor data since 1995, said Luis Millán, the study’s lead author and an atmospheric scientist at NASA. “We’ve never seen anything like this before, so it was pretty impressive.” Volcanic eruptions eject many different types of gases and particles. Most eruptions, including Hunga Tonga, release particles that cool the Earth’s surface by reflecting sunlight back into space, but they usually dissipate after two to three years. Very few, however, shoot water vapor that high. This water vapor can stay longer in the atmosphere – five to 10 years – and trap heat at the Earth’s surface. Volcano eruption near Iceland airport sparks travel fears, risky photo shoot Millán speculates that water vapor could begin to have a warming effect on the planet’s surface temperature once the accompanying cooling particles dissipate in about three years. He is not sure how much the temperature will rise, as it depends on how the water vapor cloud develops. The team suspects that the increased warming will last for a few years, until circulation patterns in the stratosphere wash away the water vapor in the troposphere, the layer where Earth’s weather occurs. “This is just a temporary warming and then it will go back to what it was supposed to go back to,” Millán said. “It’s not going to make climate change worse.” NASA atmospheric scientist Ryan Kramer added that given the numerous factors driving temperature changes on time scales of years, the warming effect from the volcano could also be lost in the noise, depending on its size. In a shorter one On a time scale, increased water vapor could also exacerbate stratospheric ozone depletion, said Susan Strahan, an atmospheric chemist at the University of Maryland Baltimore County and NASA. Stratospheric ozone protects the Earth’s surface from harmful ultraviolet radiation. Ozone-depleting chemicals were largely phased out through the 1987 Montreal Protocol and subsequent amendments. Strahan, who was not involved in the study, explained that excess water vapor will affect many chemical reactions that control ozone concentrations in the stratosphere. NASA satellite data in July already show a drop in ozone levels compared to previous years in the location where the excess water vapor is most concentrated. He added that a full analysis should be conducted to identify the cause. “There are probably repercussions right now, but what we need [is] One model that can tell us is by what mechanism(s) the effects occurred. Meteorology and chemistry will almost certainly play roles – the question is how much, where, when?’ Strahan said in an email. Strachan also said the excess water vapor could enhance the formation of special nocturnal clouds, which appear as shimmering, ghost-like features in the night sky. They appear about 50 miles into the atmosphere, higher than the stratosphere, and are some of the rarest, driest, and highest clouds on Earth. For many people, clouds offer remarkable sky observation. However, researchers believe that any noticeable change in these clouds won’t show up until later, depending on how long it takes for water vapor to travel up into the atmosphere where the clouds form. The rare glow-in-the-dark clouds are the most vivid in 15 years Overall, Millán said excess water vapor isn’t something to worry about per se, but “something that’s just interesting that happens.” He and his colleagues are taking this opportunity to test their computer models that help us understand climate change and weather forecasting more generally. “We have these huge amounts of water vapor moving in the stratosphere, and we can test how well the models reflect their movements in the atmosphere,” Millán said. “This volcano will give a lot of work to many researchers.”
