Abstract View
Bioaerosols and Dust Are the Dominant Sources of Organic P in Atmospheric Particles
KALLIOPI VIOLAKI, Athanasios Nenes, Maria Tsagaraki, Marco Paglione, Stéphanie Jacquet, Richard Sempéré, Christos Panagiotopoulos, EPFL, LAPI, Lausanne
Abstract Number: 352
Working Group: Bioaerosols
Abstract
The Eastern Mediterranean Sea, as many regions throughout the world, is strongly P-limited, with atmospheric nutrients deposition affecting its primary productivity. Numerous previous studies highlighted the importance of atmospheric inorganic P in fertilizing oligotrophic areas, which been thought primarily originated from dust. The amount and origin of organic forms of P, however, is virtually unknown. A new methodology developed to characterize phospholipids in aerosol was applied to a year-long aerosol dataset collected in the Mediterranean. This information, together with other biomarkers were used to characterize the sources of organic P in aerosol using Positive Matrix Factorization (PMF). The results revealed that dominant sources of organic P compounds are the bioaerosols and the dust. The co-existing of those sources in the spring period increased the organic P up to 53% of total P with more than a half to originate from bioaerosols. The soluble P content from dust aerosols is the similar magnitude of potential bioavailable organic P emitted from bioaerosols (~4 Gg P y-1), especially during the stratification period, when surface water is mostly nutrient exhausted.
The atmospheric deposition of dissolved P contribute as much as 9% to new production, however, the role of the atmospheric deposition of P may be more important in the future since recent results based on observations and modeling predict a decrease in phytoplankton productivity in oceans due to an enhancement in stratification caused by the warming climate.