Penguins are one of the animals symbol of Antarctica. And apparently, their presence is not only suggestive, but contributes to maintaining stable the climatic conditions of the southernmost continent of our planet, and thus helps to contrast the increase in temperatures that looms due to human activities. All this, thanks to an unexpected ally: their excrements, capable of conditioning the formation of clouds in the Antarctic area, and thus reducing the amount of sunlight that affect the region. This was revealed by a new research published in the Communications magazine Earth & Environment by a team of researchers from the University of Helsinki.
To make the clouds, it takes the guano
The climate-hallies of the pinguine guano arise from a secret ingredient, of which the excrements of these birds are particularly rich: ammonia, a gas that in the highest layers of the atmosphere can act from condensation core, transforming water vapor into clouds and starting the precipitation. The role of ammonia in the training of clouds – in fact – has been known for some time. What was not clear, however, is whether the one contained in the pinguine guano was able, or not, to influence the formation of clouds on the Antarctic continent. And this is where the new study carried out by Finnish researchers comes into play.
Fortunately, the Antarctic has unique characteristics that make this kind of research much easier. In fact, human pollution is almost null, as well as vegetation. And without those that in the rest of the world are the main sources of ammonia that reaches the atmosphere, it remains practically only one possible: the great colonies of penguins that meet on the coasts of the continent.
The study
To study the situation on the field, the Finnish researchers monitored the atmosphere in the area of the Argentina Marambio base on the island of Seymour. An infrastructure near which many colonies of penguins meet in the summer months. The researchers monitored the concentration of ammonia, speed and direction of the winds, and the presence of aerosol. The analyzes revealed that when the base is under wind compared to the largest colony of Adelia penguins (Pygoscelis Adeliae) of the area, about eight kilometers away and consisting of over 60 thousand specimens, the concentration of ammonia in the air salt about a thousand times, up to over 13.5 parts per million.
Also following the departure of the animals for their annual migration, moreover, the levels of ammonia in the air remained about 100 times higher than the average for over a month, due to the slow release of this substance by the soil imbued with guano. Furthermore, the arrival of the ammonia proved to be the perfect catalyst for the creation of aerosol: mixing with the sulphurous compounds produced by the phytoplankton Oceanic has shown to increase by about 10 thousand times the amount of particles present in the area, sometimes coming to create a dense fog.
Climate effects
The analyzes have therefore shown that the pinguine guano is probably one of the main sources for creating clouds in the Antarctic continent. And according to the authors of the study, it is likely that the same will also take place at the other head of the globe, in the Arctic. This means that the decline of the populations of these animals, extremely at risk due to climate change, could trigger a vicious circle: with less ammonia in the atmosphere, fewer clouds will be created, and in this way the amount of sunlight that reach the glacial cap, speeding up their dissolution and thus contributing to global warming, could increase.
This is not a certainty, because the atmospheric processes are very complex: the ice is an extremely reflective surface, and if the clouds are formed on the surface of the ice, and not on the sea, in the right conditions they can trap the light reflected from the ground and therefore produce an opposite effect, increasing the temperature. The study therefore is unable to predict the impact of the climate penguin sheath, and what will have in the coming years the decline of the populations of penguins that nest at the South Pole. The results, however, demonstrate the incredible interconnection that exists among all the elements that make up our planet, from the biosphere, up to the highest layers of the atmosphere.
“This is another example of the profound connection that exists among ecosystems and atmospheric processes”, underlines Matthew Boyer, researcher of the University of Helsinki who coordinated the study. “And it reminds us why we should have biodiversity at heart, and its conservation.”