Antarctica, that frozen and remote corner where human presence is infrequent, hides natural processes that are as surprising as they are little known. One of the most striking has to do with the cloud formation and the unexpected prominence of an element that goes unnoticed: penguin guano. The life cycle of these birds is essential to understand how certain clouds are generated over the white continent and how this process can influence the global climate.
Although clouds are usually considered to be the exclusive product of the condensation of water vapor, recent scientific research has brought into focus the importance of biological processes in the Antarctic atmosphere. Marine animals in particular, and especially Adélie penguins, are crucial players in the region's atmospheric cycle.
The role of guano in Antarctic cloud formation
During the southern summer, teams of researchers have been collecting air samples near important penguin colonies near bases such as Marambio, on Seymour Island. Their analysis detected a significant increase in ammonia concentrations Every time the wind carried air from the areas inhabited by these animals.
The origin of this ammonia is in the penguin guano. Since they feed primarily on krill and small fish, their feces are especially rich in nitrogen. Once deposited on the ground, this guano degrades and releases nitrogen. gases such as ammonia and dimethylamine to the atmosphere.
Cloud formation is accelerated when these compounds bind in the air to substances derived from marine phytoplankton, especially vapors of sulfurThis mixture generates tiny particles that act as condensation nucleiWater droplets use these particles to gather and form clouds over the Antarctic continent. To better understand how these particles influence the region's climate, you can read our article on the impact of seabirds on climate change.
An important aspect is that this process doesn't stop after the birds' migration. Even weeks after the penguins have left, the ground continues to release gases thanks to the accumulation of guano, maintaining high levels of ammonia that favor the formation of new clouds.
Climate implications and global reach
The clouds formed by the activity of penguins They have a significant impact on the region's equilibrium. By reflecting solar radiation, they help maintain the low temperatures typical of Antarctica and slow the melting of sea and continental ice. However, this effect can change if the density or height of these clouds changes, potentially trapping more heat and altering the regional climate.
Any change in penguin populations, such as a significant decline in their numbers, could affect the formation of atmospheric particles and, consequently, alter the climate in the area. In areas near large colonies, the presence of these animals can increase the creation of particles in the air compared to areas farther away.
Measurements have shown that, in certain events, the number of particles suitable for condensation nuclei can increase 10.000-fold compared to periods without biological input. Moreover, these effects persist for weeks after the birds migrate, due to the guano-saturated soil, which continues to release gases and fuel cloud formation.
What techniques were used in the investigations?
To obtain these results, the scientists placed atmospheric measuring equipment in areas near the colonies. They used laser spectrometers to detect ammonia, mass analyzers to identify aerosol precursor compounds, and meteorological sensors to monitor particle chemistry and dynamics.
The observation days included notable events, such as in early February 2023, when an increase in the formation and size of atmospheric particles was detected, coinciding with the appearance of fog. This made it possible to evaluate the effectiveness of the ammonium sulfates produced by penguins in the formation of clouds.
The presence of was also noted dimethylamine, a compound that, although at low levels, helps in the generation of condensation nuclei and, therefore, in cloud development.
The research reveals the importance of biogenic processes in cloud formation in Antarctica and the influence of marine animals on the global climate, highlighting the need to conserve these species and their habitats to maintain atmospheric balance in the region.