Ammonia from penguins drives cloud formation in coastal Antarctica
A groundbreaking study reveals that penguin colonies are unexpectedly powerful players in the formation of climate-relevant clouds over Antarctica
The icy wilderness of Antarctica might seem an unlikely place for groundbreaking atmospheric chemistry - but new research has uncovered a striking link between penguin colonies and cloud formation. A study published in Communications Earth & Environment reveals that ammonia released from penguin guano plays a crucial role in forming airborne particles that seed clouds, influencing climate processes in this pristine environment.
Using highly sensitive instruments deployed at Marambio Station on the Antarctic Peninsula, researchers measured ammonia concentrations in the air and traced them to nearby penguin colonies. When winds blew from the direction of these colonies, ammonia levels spiked as high as 13.5 parts per billion. These emissions came not only from live birds but also from ornithogenic soils - ground enriched with old guano - which continued to release ammonia long after the penguins had left for the winter.
Crucially, the study shows that this ammonia combines with sulfuric acid, emitted by marine phytoplankton, to form new atmospheric particles. These particles can grow to become cloud condensation nuclei (CCN), critical for cloud formation. When sufficient ammonia is present (over 100 parts per trillion), particle formation is greatly enhanced - sometimes by factors of up to 10,000 compared to sulfuric acid alone.
Multicomponent mechanisms and a starring role for dimethylamine
The researchers also detected traces of dimethylamine (DMA), likely sourced from penguin guano, within the forming particles. DMA is known to turbocharge the nucleation of sulfuric acid particles, and while levels were too low to measure directly, its presence in the clusters suggests a strong amplifying effect on particle formation. This combination of ammonia, sulfuric acid, and DMA defines a multicomponent mechanism for new particle formation (NPF) over coastal Antarctica.
Interestingly, the study’s findings diverge from previous research suggesting DMA from sea-ice sources was the dominant driver. Here, ammonia - predominantly penguin-derived - was the main contributor. The researchers observed frequent NPF events, especially when air masses passed over penguin colonies, with particle counts sometimes exceeding 15,000 per cubic centimetre.
From penguin colonies to Antarctic clouds
The particles formed through these processes were not merely theoretical. During a particularly clear case on 1 February 2023, newly formed particles grew rapidly in size and were subsequently scavenged into fog droplets. This event directly demonstrated the transition from particle formation to cloud condensation, with chemical analysis confirming that the resulting cloud droplets were composed largely of ammonium sulfate - a direct consequence of ammonia emissions from the penguin colonies.
This connection highlights how biological processes can directly influence atmospheric composition and, in turn, cloud properties such as brightness and lifetime. Such changes can ultimately affect the Earth’s energy balance and climate.
Wider climate implications of penguin-mediated cloud formation
The implications are far-reaching. In regions like Antarctica, where natural sources of atmospheric particles are scarce, penguin colonies provide strong, localised sources of ammonia that can impact cloud formation and even global climate patterns. As sea ice retreats and ecosystems shift due to warming, the distribution and abundance of penguins are also changing - potentially altering these critical atmospheric interactions.
Moreover, while ammonia itself is short-lived in the atmosphere, the particles it helps generate can persist for days, travelling across coastal and even inland Antarctica. As such, penguins may be influencing not just local conditions, but the wider atmospheric environment of the continent.
Declines in penguin populations - already observed in some species due to habitat loss and warming seas - may therefore have an unexpected feedback on climate. Fewer penguins may mean less ammonia, fewer cloud-seeding particles, and consequently, reduced cloud cover - possibly amplifying warming in the region.
Closing the loop: Ecosystems and climate, interconnected
This study provides a striking example of how interconnected Earth systems are. From penguin colonies on remote Antarctic islands to cloud processes in the upper atmosphere, the links between biology and climate are both intricate and impactful. It’s a timely reminder that even in the planet’s most remote corners, life leaves a chemical footprint - one that may shape the sky itself.
June 2025
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