Penguin poop gives Antarctic cloud formation a boost

Penguins’ poop may be making Antarctica cloudier — and helping mitigate the regional impacts of climate change.

Gases emitted from the birds’ guano are supplying key chemical ingredients to form the seeds of clouds — the tiny particles that clouds coalesce around, researchers report May 22 in Communications Earth & Environment.

What penguin guano primarily contributes to the equation is ammonia. Previous studies have found that gaseous ammonia in the atmosphere can combine with sulfuric acid emitted by marine phytoplankton to form tiny particles called cloud condensation nuclei — the seeds of clouds. Those clouds may help cool the planet by reflecting more sunlight back into space. Researchers are keen to understand what drives climate and cloudiness over the Southern Ocean and Antarctica, which can have a powerful impact on the global climate.

Near Argentina’s Marambio station on the Antarctic peninsula, the snow and soil are frequently blanketed with excrement from a nearby breeding colony of Adélie penguins. Matthew Boyer, an atmospheric scientist at the University of Helsinki, and colleagues wanted to assess how this natural fertilizer might be affecting cloud formation in the region.

The researchers measured concentrations of ammonia, dimethylamine and other gases over the Antarctic Peninsula from January 10 to March 20, 2023, to better understand how different gases are contributing to the region’s cloud formation. They observed concentrations of ammonia up to 13.5 parts per billion, 1,000 times higher than the concentration in areas without penguins.

Then, taking measurements over a single day, they observed how the concentration of those tiny aerosol particles changed when the wind direction shifted: Winds blowing from the direction of the penguin colony brought a sharp spike in aerosol particle concentrations (and a bit of fog). Overall, the penguins’ contributions to the atmospheric chemical soup boosted particle formation rates by up to 10,000 times in the region, the team found.

And the impact lingered even after the birds had left the region, heading out on their annual migration. The guano had “fertilized” the soil so much that a month after the penguins’ departure, ammonia emissions were still 100 times higher than baseline measurements.