Production: Jesús Nicolás
Climate is a complex process that connects every part of the world with every other region; it is difficult to find any area or process on Earth that has not been influenced by human activity. But there is an atmospheric region that is unchanged by human-related activities.
Colorado State University professor Sonia Kreidenweis and her research group suspected that the air directly over the remote Southern Ocean surrounding Antarctica would be the least affected by humans and dust from the continents. They set out to find out what was in the air and where it came from.
Indeed, their results showed that the boundary layer air that feeds the lower clouds over the Antarctic Ocean is pure, pristine, free of particles produced by anthropogenic activities or transported from distant places.
It is the conclusion of a team from Colorado State University, which studied the concentration and origin of microbes in the lower clouds over the Southern Ocean. His conclusion was that Antarctica appears to be isolated from the dispersal of microorganisms from the southern continents. The air was so clean that there was very little DNA to work with.
“We were able to use airborne bacteria over the Southern Ocean as a diagnostic tool to infer key properties of the lower atmosphere,” in the words of study co-author Thomas Hill. “For example, that the aerosols that control the properties of clouds are strongly linked to ocean biological processes, and that Antarctica appears to be isolated from the dispersal of microorganisms to the south and the deposition of nutrients from the southern continents. Overall, it suggests that the Southern Ocean is one of the few places on Earth that has been minimally affected by anthropogenic activities.
Using DNA sequencing, source tracking, and rewind trajectories, the scientists determined that the origins of the microbes were marine, coming from the ocean. Bacterial composition also differed over broad latitudinal areas, suggesting that particles from distant land masses and human activities, such as pollution or soil emissions caused by land use change, do not travel. heading south in the Antarctic air.
Referencias:
C. S. McCluskey,T. C. J. Hill, R. S. Humphries, A. M. Rauker, S. Moreau, P. G. Strutton, S. D. Chambers, A. G. Williams, I. McRobert, J. Ward, M. D. Keywood, J. Harnwell, W. Ponsonby Observations of Ice Nucleating Particles Over Southern Ocean Waters. Geophisycal Reseach Letters (2017) https://doi.org/10.1029/2018GL079981
