By contrast, laboratory experiments have long shown that a gaseous form of iodine can gobble up ozone– but there were just hints of a connection between dust and iodine.
In one image, for example, “iodine seemed to associate with dust … however not definitely clearly,” he stated. “Iodine and ozone clearly connect, however there werent any photos of both with dust,” stated Koenig, who is now an air pollution scientist at Peking University in China.
The data from TORERO (the “Tropical Ocean Troposphere Exchange of Reactive Halogens and Oxygenated Hydrocarbons,” a field project moneyed by the National Science Foundation) caught those three characters together, lastly, in one image he said, and it was clear that where desert dust consisted of substantial levels of iodine– like dust from the Atacama and Sechura deserts in Chile and Peru– the iodine was rapidly transformed into a gaseous type and ozone dropped to very low levels.
The brand-new finding, he said, has ramifications for not only air quality, but climate, too– iodine chemistry can make greenhouse gases stick around longer and should give us pause to re-think geoengineering schemes including dust.
” Our understanding of the iodine cycle is incomplete,” Volkamer said. “There are land-based sources and chemistry we didnt understand about, which we need to now think about.”
Atmospheric scientists have long been interested in the observation that dirty layers of air are frequently extremely low in the air toxin ozone, which, when focused, can damage peoples lungs and even crops. By contrast, lab experiments have actually long shown that a gaseous form of iodine can gobble up ozone– however there were only hints of a connection between dust and iodine.
Dust seen blowing offshore from South America had striking levels of gaseous iodine. In one image, for example, “iodine appeared to associate with dust … but not definitely plainly,” he stated. “Iodine and ozone plainly connect, but there werent any photos of both with dust,” stated Koenig, who is now an air contamination scientist at Peking University in China.
The data from TORERO (the “Tropical Ocean Troposphere Exchange of Reactive Halogens and Oxygenated Hydrocarbons,” a field campaign moneyed by the National Science Foundation) caught those three characters together, lastly, in one image he stated, and it was clear that where desert dust included significant levels of iodine– like dust from the Atacama and Sechura deserts in Chile and Peru– the iodine was quickly changed into a gaseous type and ozone dropped to very low levels. But how did that dust-based iodine transform? “The system still stays elusive,” Volkamer said. “Thats future work.”
The image is another blurred one, Koenig stated, however still, the science is sharper than it was. “I have more concerns at the end of the project than at the start,” he stated. “But theyre much better, more specific concerns.”
Theyre also extremely essential, for anyone thinking about the future of the environment, Volkamer stated. Iodines reactions in the atmosphere are understood to contribute in decreasing levels of OH, for instance, which can increase the lifetime of methane and other greenhouse gases. Possibly more importantly, various geoengineering ideas include injecting dust particles high into Earths atmosphere, to show inbound solar radiation. There, in the stratosphere, ozone is not a pollutant; rather, it forms a crucial “ozone layer” that helps shield the world from inbound radiation.
If iodine from dust was chemically changed into an ozone-depleting type in the stratosphere, Volkamer said, “well, that d not be great, as it could postpone the healing of the ozone layer. Lets avoid including anthropogenic iodine into the stratosphere!”
Referral: “Ozone deficiency due to dust release of iodine in the free troposphere” by Theodore K. Koenig, Rainer Volkamer, Eric C. Apel, James F. Bresch, Carlos A. Cuevas, Barbara Dix, Edwin W. Eloranta, Rafael P. Fernandez, Samuel R. Hall, Rebecca S. Hornbrook, R. Bradley Pierce, J. Michael Reeves, Alfonso Saiz-Lopez and Kirk Ullmann, 22 December 2021, Science Advances.DOI: 10.1126/ sciadv.abj6544.
Atacama desert photographed from the plane. Credit: Sam Hall New CU Boulder study shows iodine from desert dust can reduce ozone air pollution but might prolong greenhouse gas lifetimes.
When winds loft fine desert dust high into the environment, iodine because dust can activate chemical responses that ruin some air contamination, but likewise let greenhouse gases remain longer. The finding, published on December 22, 2021, in the journal Science Advances, might force researchers to re-evaluate how particles from land can affect the chemistry of the atmosphere.
” Iodine, the same chemical added as a nutrient to salt, is eating up ozone in dirty air high in the environment,” stated Rainer Volkamer, a CIRES Fellow and professor of chemistry at CU Boulder. Volkamer led the team that made precision atmospheric measurements by airplane over the eastern Pacific Ocean several years earlier. The brand-new finding, he said, has ramifications for not just air quality, however climate, too– iodine chemistry can make greenhouse gases remain longer and must offer us stop briefly to re-think geoengineering plans including dust.
