Scientists believe they have found the place that contains the cleanest air in the world, free of particles caused by human activity, and is located over the southern ocean that surrounds Antarctica.
In the study, published last Monday in the journal "Proceedings of the National Academy of Science," scientists described the region as "truly pure."
This study is the first of its kind, undertaken by Professor at Colorado State University, Sonia Creednoys and her research group, by measuring the composition of aerosols vital to the Southern Ocean, south of latitude 40 ° S around Antarctica.
aerosol
Air pollution usually occurs due to aerosols, which are solid and liquid particles and gases suspended in the air, consisting of smoke, dust, sand, ash and chemical salts suspended in the air.
And they are in varying proportions from one region to another, as their proportions increase in industrial cities and decrease in the countryside, and they come from factory smoke, fires, dust, and fragmentation of living and non-living bodies.
Weather and climate are closely related, and they link all parts of the world to each other, and with climate change rapidly due to human activity, scientists and researchers struggle to find a corner of the earth that is not affected by what a person does.
Sourced from the ocean itself
CredoNews and her team assumed that the air located directly above the far south ocean that surrounds Antarctica would be the least affected by humans and dust coming from other continents.
So they decided to research the components of this air and find out how far the particles produced by industry and human activity reach them, using bacteria in the air as a diagnostic tool to infer the properties of the lower atmosphere.
The researchers found that the boundary layer air that feeds the lower clouds over the southern ocean is free of particles of aerosols caused by human activity or transported from distant lands and other continents, including aerosols caused by burning fossil fuels, growing certain crops, producing fertilizers, and disposing Of wastewater.
"We were able to use bacteria in the air over the southern ocean as a tool to infer the main properties of the lower atmosphere. It appeared that the aerosols that control the properties of the clouds of the southern ocean are closely related to the biological processes of the ocean itself, and that Antarctica seems insulated from soil emissions and pollution from other continents.
"In general, the results indicate that the Southern Ocean is one of the very few places on Earth, which is little affected by human activities," he added.
Aerosols do not travel south
The research samples were collected during the field campaign of the research project "Socrates" (SOCRATES), funded by the American National Science Foundation (NSF).
Scientists sampled air at the sea boundary level - part of the atmosphere that has direct contact with the ocean - while riding a research boat heading south to the edge of the ice in the South Pole from Tasmania, Australia. Then scientists examined the composition of the airborne microbes that are present in the atmosphere and scattered by wind over thousands of kilometers.
Using DNA sequences, tracing the source and wind paths, "John Utic", the first author of the study, found that these microbes are free, that is, their source is the ocean itself.
It was also found to the researchers, through the bacterial structure they obtained, that aerosols from remote land masses and human activities, such as pollution or soil emissions from land use change, do not travel south to Antarctic air.