A new study led by the CSIC’s Institut de Ciències del Mar (ICM-CSIC) and the University of Birmingham (United Kingdom) has revealed that the melting of Antarctica reinforces the formation of aerosol sprays in the atmosphere, favoring the formation of clouds in summer, which could help reduce the solar radiation that the region receives and have important consequences on the climate.
Cloud formation requires the presence of small atmospheric particles called aerosols that allow water to condense and form droplets
Clouds play a key role in regulating the planet’s temperature, as they reflect and filter the solar radiation And without them, the climate would be much warmer. However, at present very little is known about how they form, and this limits the accuracy of climate projections.
What is known is that cloud formation requires the presence of small atmospheric particles called aerosols that allow water to condense and form drops. Many of these aerosols come from the human activity, but in the remote regions of the planet they originate mainly in natural processes such as the rise, due to the wind, of sea salt and gases of biological origin in the ocean.
To prepare the work, published in the journal Nature Geoscience, the research team used data collected during the Antarctic campaign PI-ICE 2019, led by researcher Ramon y Cajal from ICM Manuel Dall’Osto. As part of this campaign, which lasted more than three months, the international team of researchers analyzed airborne particles in the region around the Antarctic peninsula.
Thanks to this, the scientists warned that when the air masses come from the area of the sea ice margin, the episodes of aerosol formation are more frequent. According to the work, these air masses contain high concentrations of sulfuric acid Y amines, which are compounds of biological origin that interact with each other to transform from gases to particles.
High concentrations of sulfuric acid and amines
Although the role of sulfuric acid in the formation of polar aerosols was already known, this is the first study to demonstrate the key role of amines, organic compounds that contain nitrogen and are produced by the degradation of organic matter in microorganisms. that inhabit sea ice. This confirms that emissions from the marine plankton and the melting of the sea play a crucial role in regulating the antarctic climate.
Current climate models underestimate the abundance of clouds over the Antarctic Ocean and therefore overestimate the solar radiation reaching those cold waters.
“We already knew the importance of organic nitrogen for the formation of aerosols and clouds in temperate terrestrial environments, but during the 2019 PI-ICE expedition we were able to use instruments that have allowed us to demonstrate the importance of this process in Antarctica,” says Dall ‘ Osto, who adds that “this discovery will force us to review the models of the effect of marine life on climate regulation.”
“In a previous expedition (PEGASO 2015) we had already observed the emission of amines by sea ice, but until now we had not shown that these substances allow the formation of new aerosols in a region so far from any human activity and with an atmosphere so clean ”, explains another of the study authors, the ICM researcher Rafel Simó, which is now immersed in the preparation, together with Dall’Osto, of a new campaign that will take place in 2023 and will try to delve into the complex machinery of climate that results from the interactions between the ocean, ice, life and the atmosphere.
At present, Antarctica is experiencing a drastic climate change which is difficult to predict because, among other reasons, there is great ignorance about the consequences that changes in the ecosystem will have on the formation of aerosols and clouds.
Current climate models underestimate the abundance of clouds over the Antarctic Ocean and therefore overestimate the solar radiation reaching those cold waters. Therefore, the publication of studies like this one is key to improving the future projections.
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