Thursday, October 28

Thaw in the Antarctic favors the formation of clouds, according to a study

Cloudy intervals over an ice sheet

Cloudy intervals over an ice sheet

The melting that is taking place in the Antarctic seas favors the formation of clouds, which can help reduce the solar radiation that the region receives, according to research led by the Institute of Marine Sciences (ICM-CSIC) of Barcelona.

The study, in which the University of Birmingham (United Kingdom) has also participated and published in the journal ‘Nature Geoscience’, shows that particles from gases released by ice-inhabiting microorganisms are formed in the atmosphere of Antarctica marine and surrounding waters, and these particles they generate aerosols in the atmosphere that favor the formation of clouds in summer.

According to the researchers, this phenomenon can have important consequences on the climate, since clouds influence the regulation of the planet’s temperature because they reflect and filter solar radiation and, without them, the climate would be much warmer. However, currently very little is known about how they form, which limits the accuracy of climate projections. What is known is that the formation of clouds requires the presence of small atmospheric particles that allow the water to condense and generate drops.

Many of these aerosols come from human activity, but in remote regions of the planet they mostly originate in natural processes such as lifting, due to the wind, sea salt and gases of biological origin in the ocean.

The research has used data collected during the PI-ICE 2019 Antarctic campaign, led by ICM researcher Manuel Dall’Osto. In this campaign, which lasted more than three months, the researchers analyzed airborne particles in the region around the Antarctic Peninsula and found that, when air masses come from the sea ice margin area, episodes of aerosol formation are more frequent.

According to this work, these air masses contain high concentrations of sulfuric acid and amines, compounds of biological origin that interact with each other to transform themselves from gases into particles. 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.

“We already knew the importance of organic nitrogen for the formation of aerosols and clouds in temperate terrestrial environments, but now we have been able to demonstrate the importance of this process in Antarctica,” says Dall’Osto, who believes that “this discovery will force review models of the effect of marine life on climate regulation“.” In a previous expedition in 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 away from any human activity and with an atmosphere so clean “, details the ICM researcher Rafel Simó.

Dall’Osto and Simó are preparing a new scientific expedition to 2023 that will try to delve into the complex machinery of climate that results from the interactions between ocean, ice, life and atmosphere.

According to the researchers, Antarctica is currently experiencing drastic climate change that is difficult to predict, among other reasons, because the consequences that changes in the ecosystem will have on the formation of aerosols and clouds are unknown. “Current climate models underestimate the abundance of clouds over the Antarctic Ocean and, therefore, overestimate the solar radiation that reaches those cold waters. Therefore, the publication of studies like this is key to improve future projections,” they conclude .

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