In Antarctica, penguin poop, or guano, can cover the ground for miles, especially around penguin colonies with thousands of individuals. In fact, large, brown guano stains on Antarctica’s white ice have even helped scientists discover new penguin colonies from space. A recent study now finds that the massive amounts of guano play a critical role: ammonia gas released from the droppings helps form clouds over Antarctica, which can cool surface temperatures and potentially reduce the impacts of climate change in the region.
Adélie penguins (Pygoscelis adeliae) in Antarctica mainly eat fish and krill, so their droppings are rich in nitrogen. In the soil, the nitrogen supports thriving communities of mosses, lichens and invertebrates, but it also breaks down to form ammonia gas. Ammonia then reacts with other atmospheric gases containing sulfur to create aerosols, tiny particles on which water vapor can condense to form clouds.
Between Jan. 10 and March 20, 2023, researchers measured the amount of atmospheric ammonia at an observatory located near Marambio Station, a research facility maintained by Argentina in the Antarctic Peninsula. The station is located about 8 kilometers (5 miles) from a 60,000-strong Adélie penguin colony.
The researchers found that when winds blew from the direction of the colony, the ammonia concentration recorded at the observatory was more than 1,000 times higher than the typical background amount. Ammonia levels remained more than 100 times higher than the baseline even after the penguins migrated from the area, suggesting the guano left behind continued to emit the gas.
After ammonia concentrations spiked, the researchers observed that aerosol levels also increased. Within a few hours, there was “a period of fog” and the formation of cloud droplets.
Study co-author Matthew Boyer from the University of Helsinki in Finland told Popular Science that in Antarctica, gases like ammonia released from penguin guano are “an important source of aerosol particles in the region.” That’s especially true in remote Antarctica, far from human sources of pollution, which can otherwise serve as aerosols.
Clouds are insulating and have a cooling effect on surface temperatures in general. So the authors say “penguin guano may be helping to reduce the effects of climate change on the penguins’ own habitat of Antarctica,” according to a press release. Antarctica is warming faster than the global average, and its sea ice extent is shrinking.
Ken Carslaw, an atmospheric scientist at the University of Leeds, U.K., who wasn’t involved in the study, told The Washington Post that lab experiments have previously shown that gases from guano help form particles in the atmosphere. He added the findings are a “valuable confirmation that what has been observed in the lab can explain what’s going on in the real atmosphere.”
“These observations are another piece of the puzzle that will help to improve how clouds are represented in climate models,” Carslaw added.
Banner image: Adélie penguins on Cape Hallet, Antarctica. Image by Andrew Mandemaker via Wikimedia Commons (CC BY-SA 2.5).
Credits
