The study published in Nature Geoscience says that climate change is causing the Arctic Ocean to release significant amounts of iodine into the atmosphere, substantially destroying ground-level ozone.
- Ground-level ozone is a pollutant that forms when oxides of nitrogen (NOx) react with volatile organic compounds (VOC).
- Ground-level ozone differs from stratospheric ozone, which protects the Earth from harmful ultraviolet rays.
- The depletion of the ground-level ozone pollutant is positive for the Arctic. But this reduction does not match anthropogenic emissions of ozone.
- The Arctic has been warming nearly four times faster than the rest of the world in the last 43 years, according to a recent study.
- Hundreds of global researchers set sail on an expedition to the Arctic called “Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC)” to study the Arctic Ocean.
- During the expedition, researchers studied ozone depletion in the Arctic, which is known to drop to near-zero levels in March, April and May, the study highlighted. The rest of the year, ozone concentration rises to 10-40 parts per billion.
- Bromine, an ozone-destroying agent, was thought to be the main driver.
- The concentration of Bromine oxide in the atmosphere is 14.8 ± 0.8 parts per trillion, according to the paper. It escapes into the atmosphere from the sea-ice region.
- But concentration of bromine, the study added, is not observed to be high during the rest of the year.
- In contrast, iodine is observed throughout the year, observations from the MOSAiC expedition showed.
- Iodine is one of the most potent ozone destruction agents. The maximum individual single-day contribution of bromine to ozone loss was roughly 70 per cent, recorded on April 3, 2020, the findings showed.
- As for iodine, the maximum single-day contribution to ozone loss was about 75 per cent, recorded on March 26, 2020.
- The findings suggested that, on average, iodine and bromine contribute about 56 per cent of the ozone loss during spring.
(Source: Nature)
