Abstract View
Size Distribution of Chemical and Biological Particles during the Saharan Dust Episodes over Europe in February 2021
KALLIOPI VIOLAKI, Andrea Mario Arangio, Athanasios Nenes, EPFL, Switzerland
Abstract Number: 639
Working Group: Bioaerosols
Abstract
Dust plays a major role in Earth’s climate, by absorbing and scattering radiation, and modifying clouds that alter the planetary radiation balance and hydrological cycle. Dust also affects ecosystems through its nutrient content. Aeolian dust is a significant carrier of iron and phosphorus which are limiting nutrients in many regions of the global ocean. This deposition of dust is thought to significantly increase ocean primary productivity, hence its carbon uptake through photosynthesis. Annually, Europe receives millions of tons of dust affecting public health and ecosystems – and with climate change, the frequency and severity of dust episodes are expected to change as well.
During this study, aerosol particles were collected with a size-segregated hi-volume sampler (Tisch 230-High Volume Cascade Impactor). The impactor separated the particles in five different stages; from larger than 7.2µm to less than 0.49µm. Those samples were used to characterize the properties of dust particles during the severe dust episodes in Spring, 2021 in a forest site near Lausanne, Switzerland. We analyzed trace metals and nutrients (Fe, Cu, P, N), inorganic ions, sugars, phospholipids, and biological particle content (fungi, bacteria, and pollen). The deposition flux of nutrients is also quantified and related to their acidity state. We found that one dust episode alone can be responsible for a large fraction of the deposition of soluble metals and P – and that biological P may constitute a significant fraction of the total deposition of the nutrient. These results are related to work we have carried out in the E. Mediterranean (Violaki et al., 2021) and provide an overall synthesis of the importance of dust events for nutrient deposition.