Cloud formation: for ISAC-CNR it depends on polar sea ice
Polar sea ice seems to be crucial not only for the biology of oceans but also for the composition of the atmosphere overhead. This is one of the conclusions of an international team including researchers of the Institute of Atmospheric Sciences and Climate of the National Research Council-ISAC-CNR, in a paper published in the Scientific Reports.
Polar sea ice is one of the largest ecosystems on the planet and consists of a complex environment, characterized by extreme conditions, which however hosts a wide range of micro-organisms that tolerate them. The presence of these micro-organisms and their life inside sea ice has proven crucial not only for the oceans’ biology, but also for the composition of the atmosphere overhead, with important potential impact on global climate.
“The study coordinated by the Institute of Marine Sciences, ICM-CSIC in Barcelona (Spain), states that sea ice, thanks to the metabolism of the organisms living inside it, is one of the main sources of organic nitrogen contained in atmospheric particulate matter of some regions of the Austral Ocean near the Antarctic ice sheet. The concentration and composition of atmospheric particulate matter (or aerosol) in turn substantially contribute to the formation of the clouds and their peculiar features, key elements in the regulation of the planet’s climate”, said Marco Paglione, research fellow at ISAC-CNR in Bologna.
The aerosol sources that contribute to the formation of clouds in the uncontaminated atmosphere of the Antarctic region have never been studied in detail to date. This was the objective of the Pegaso–Plankton-derived Emission of Gases and Aerosols in the Southern Ocean campaign.
“The international team involved in the project – said Paglione, who took part in the Antarctic expedition – has analysed samples of the air, sea water and sea ice to study the interaction between the ocean and the atmosphere for two months. These synergic measures have shown that the microbiota contained in the sea ice and in the areas near the ocean is a significant source, previously unknown, of nitrogen-containing organic components measured in the atmosphere”.
“Because of the crucial role – said Cristina Facchini from ISAC-CNR – of nitrogen-containing compounds in the formation, evolution and reduction of acidity in aerosols, these results require greater efforts in simulating the behaviour of marine ecosystems in climate models with the objective of predicting climate change in the Antarctic Ocean”.
The Pegaso project, besides ICM-CSIC and ISAC-CNR, has also involved the National University of Ireland (Galway), the University of Birmingham and the Plymouth Marine Laboratory (United Kingdom), the University of Mainz (Germany), the Institute for Biodiversity and Environment Research (Argentina), the Finnish Meteorological Institute (Finland) and the technological research company Aerodyne Inc (USA).