Sulfur dioxide (SO2) injected into the stratosphere after volcanic eruptions is oxidized and converted to sulfate aerosols. The biggest volcanic eruption of the last 500 years, the eruption of Mount Tambora in Indonesia in April 1815 triggered the so-called “Year Without a summertime” in the following year in numerous parts of the world. Satellite measurements of the eruption at HTHH– which has actually appeared several times over the past century– revealed that its volcanic ash has actually reached an altitude of 30 kilometers deep into the stratosphere, with a total mass of only about 0.4 Tg.
Remedying for this however was something of an obstacle, as there are few southern volcanic eruptions similar to that of HTHH in the historical record. In this way, the researchers found a significant connection between the intensity of 70 chosen volcanic eruptions over the last millennium and the worldwide mean surface temperature level response in the first year after eruption.
An undersea volcano at Hunga Tonga-Hunga Haapai (HTHH) erupted strongly on 15th January 2022, which raised wide public concern about its influence on international climate. Sulfur dioxide (SO2) injected into the stratosphere after volcanic eruptions is oxidized and converted to sulfate aerosols. These aerosols remain there for one or 2 years and while there, work to minimize inbound solar radiation, leading to a short period of global cooling.
The surface temperature level returns to typical as the volcanic aerosols dissipate, therefore a single volcanic eruption is inadequate to modify the long-lasting global warming pattern, unless there are clusters of volcanic eruption that can continue through centuries as is suggested have occurred throughout the Little Ice Age in the previous millennium.
FY-4B Satellite caught the eruption of Hunga Tonga-Hunga Haapai volcano and kept an eye on the diffusion of volcanic ash clouds. Credit: National Satellite Meteorological Center of China
The biggest volcanic eruption of the last 500 years, the eruption of Mount Tambora in Indonesia in April 1815 caused the so-called “Year Without a summer season” in the following year in lots of parts of the world. There is a reduction in annual mean surface area temperature over the tropics and northern hemisphere by 0.4-0.8 ° C
. The Tambora eruption released 53-58 terrograms (Tg) of SO2. Satellite measurements of the eruption at HTHH– which has emerged numerous times over the previous century– showed that its ashes has reached an elevation of 30 kilometers deep into the stratosphere, with a total mass of just about 0.4 Tg.
One formerly reported initial estimate positioned the reduction in worldwide surface area air temperature at between 0.03 and 0.1 ° C over the next one to 2 years as a result of the HTHH eruption.
” This reported preliminary price quote may have overstated the effect as it did not take into consideration the location where the eruption took place, which changes the spatial distribution of stratospheric sulfate aerosols– a variable that can alter results significantly”, stated Tianjun Zhou of the Institute of Atmospheric Physics at the Chinese Academy of Sciences, “This is due to the fact that southern hemisphere volcanic eruption emissions are largely restricted to distributing in the same hemisphere and the tropics, with less of an effect on the northern hemisphere. This in turn causes a weaker worldwide cooling than those of northern hemispheric and tropical volcanoes”.
To reach a more precise evaluation, modelling requirements to take into consideration the latitude of the release of sulfate aerosols. Remedying for this however was something of a difficulty, as there are couple of southern volcanic eruptions similar to that of HTHH in the historical record. Luckily, climate-model simulations that use big southern volcanic eruptions in the last millennium overall offered a beneficial reference. In this method, the researchers found a substantial connection between the strength of 70 selected volcanic eruptions over the last millennium and the global mean surface area temperature level response in the first year after eruption.
They then picked 6 particularly large tropical eruptions in design simulations and scaled the surface temperature response in line with the intensity of the 1991 Mount Pinatubo eruption where 20 Tg of SO2 were ejected. The outcomes of the design simulations were discovered to be similar to real-world observations, recommending their modelling work was on the best track.
These results were then scaled down for the HTHH eruption with its dizzying injection of 0.4 Tg of SO2. The results revealed that the global mean surface temperature will reduce by just 0.004 ° C in the first year after the HTHH eruption. This is within the scope of internal variability of the environment system.
The cooling in the southern hemisphere will be stronger than in other parts of the world, with the strongest cooling of more than 0.01 ° C occurring in parts of Australia and South America. The cooling over the majority of China will be less than 0.01 ° C.
This indicates that the eruption of HTHH will not be strong enough to overwhelm the longer term international warming propensity.
The scientists did include one caveat however to these conclusions: This would be the case if the HTHH eruption is a one-time-only event. No explosive eruptions have been found at HTHH because the Jan. 15 occasion so far. However, it might end up being active again in the future as this volcano has emerged lot of times over the past 100 years.
” As an outcome, we need to keep monitoring the activity of HTHH in the coming days, months, and years,” said Professor Zhou.
In line with such monitoring efforts, the team will be extending their research by running some experiments based on ideal cases (circumstance hypothesis in their simplification, however beneficial to make the models easier to comprehend) to attempt to expose the possible environment effect of a bigger HTHH volcanic eruptions need to they occur in the future.
Recommendation: “Volcanoes and climate: Sizing up the impact of the recent Hunga Tonga-Hunga Haapai volcanic eruption from a historical viewpoint” by Meng Zuo, Tianjun Zhou, Wenmin Man, Xiaolong Chen, Jian Liu, Fei Liu and Chaochao Gao, 1 March 2022, Advances in Atmospheric Sciences.DOI: 10.1007/ s00376-022-2034-1.
A fresh analysis of the possible cooling effect of the sulfur dioxide injected into the environment by the Hunga Tonga-Hunga Haapai volcano in January 2022 has concluded that the effect will be much smaller than initially believed– however the scientists accountable include some significant caveats to this conclusion.
The analysis appears in the journal Advances in Atmospheric Sciences on March 1, 2022.
