Sydney, Australia – The catastrophic eruption of the Hunga Tonga-Hunga Ha’apai volcano on January 15, 2022, not only created a massive tsunami but also sent shockwaves around the globe, triggering a series of environmental consequences that are still being studied. A new paper published in the Journal of Climate sheds light on the extensive and unusual climate impacts of this eruption.
Ozone Hole and Unexpected Weather Patterns
According to the study, the Hunga Tonga eruption played a significant role in creating last year’s exceptionally large ozone hole and contributed to the unexpectedly wet summer of 2024. The eruption’s effects are anticipated to influence winter weather patterns for years to come.
Typically, volcanic eruptions emit sulphur dioxide, which cools the Earth’s surface by transforming into sulphate aerosols that reflect sunlight away. However, Hunga Tonga, being an underwater volcano, released minimal sulphur dioxide but expelled an enormous amount of water vapor into the atmosphere – approximately 100-150 million tonnes, equivalent to 60,000 Olympic swimming pools.
Unique Atmospheric Impact
This massive water vapor surge reached the stratosphere, a dry atmospheric layer between 15 and 40 kilometers above the Earth’s surface, where it neither forms clouds nor precipitates. Water vapor in the stratosphere contributes to ozone layer depletion and acts as a potent greenhouse gas.
“Our study highlights how this unprecedented influx of water vapor has led to significant climate anomalies,” said Martin Jucker, a lecturer in Atmospheric Dynamics at UNSW Sydney and lead author of the study. “The enhanced water vapor has facilitated chemical reactions that deplete the ozone layer, which we saw with the large ozone hole from August to December 2023.”
The researchers used climate models to simulate the future impacts of the water vapor introduced by the Hunga Tonga eruption. By comparing scenarios with and without the added water vapor, they identified significant differences attributable to the eruption. These models successfully predicted the 2023 ozone hole and the subsequent wet summer in Australia, a deviation from the expected dry conditions associated with El Niño.
In terms of global temperature changes, the study found the eruption’s impact to be minimal, around 0.015 degrees Celsius. This small effect implies that recent high global temperatures are not primarily due to the eruption.
Long-Term Regional Effects
Despite the minimal global temperature impact, the eruption is predicted to cause substantial regional climate variations. The study forecasts colder and wetter winters in northern Australia and Scandinavia, and warmer winters in North America until around 2029. These changes are linked to alterations in atmospheric wave patterns, which affect weather systems.
“This research is a crucial step in understanding the long-term climate effects of such a significant eruption,” Jucker explained. “While our models are not perfect and do not account for every variable like the El Niño–La Niña cycle, they provide valuable insights into how stratospheric water vapor can influence climate.”
Call for Further Research
The study underscores the need for further scientific exploration to understand the full extent of the Hunga Tonga eruption’s impact. It invites the scientific community to verify or challenge these findings, contributing to a more comprehensive understanding of large-scale volcanic influences on climate.
“Our findings are a starting point for more in-depth research into how massive injections of water vapor into the stratosphere can affect our climate system,” Jucker concluded. “We hope this study will inspire further investigations to either confirm or refine our predictions.”
Reference: https://www.sciencealert.com/giant-tonga-volcanic-eruption-could-disrupt-weather-for-years-to-come