Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur Graph Search.
The PMF receptor model was applied to a combined dataset using specific markers such as phospholipids and sugars together with other metals (e.g. Al, Pb, V) and ions (e.g. K+, Ca2+, SO42-, NO3-) as tracers of main aerosol sources in order to characterize the sources of P in atmospheric particles. The samples were collected from East Mediterranean; an oligotrophic region, strongly P-limited, with atmospheric nutrients deposition affecting its primary productivity. The results revealed that dominant sources of P compounds are the dust (43%) and the bioaerosols (34%). The coexistence of these sources in the spring period increased the organic P up to 53% of total P with more than a half to originate from bioaerosols. Dust is the major source of inorganic P forms with almost equal contribution to the phosphate ions and to the condensed P forms (e.g pyrophosphate or phosphorous minerals). Based on the results of source apportionment analysis and the atmospheric concentration of P species, the maximum annual deposition scaled to the East Mediterranean surface was 21.5 Gg P with almost equal deposition of org-P and phosphate ions. 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 starved. Anthropogenic pollution contributes slightly higher to organic P comparing with phosphate ions, while the latter is produced mainly secondary. Biomass burning emissions in the area are associated mainly with the more soluble P.
Athanasios Nenes, Kalliopi Violaki, Christos Panagiotopoulos
Julia Schmale, Jakob Boyd Pernov