A035-0006
Diurnal Cycle in Sea Spray Aerosols Amount
Tuesday, 8 December 2020
Poster
J. Michel Flores1, Guillaume Bourdin2, Alexander B Kostinski3, Orit Altaratz1, Guy Dagan4, Fabien Lombard5, Nils Haëntjens2, Emmanuel Boss2, Matthew B Sullivan6, G Gorsky7, Naama Lang-Yona8, Miri Trainic1, Sarah Romac9, Christian R Voolstra10, Yinon Rudich1, Assaf Vardi8 and Ilan Koren1, (1)Weizmann Institute of Science, Earth and Planetary Sciences, Rehovot, Israel, (2)University of Maine, Orono, ME, United States, (3)Michigan Technological University, Houghton, MI, United States, (4)University of Oxford, Department of Physics, Oxford, United Kingdom, (5)Laboratoire d'Océanographie de Villefranche (LOV), UMR 7093, Sorbonne Université, Villefranche-sur-Mer, France, (6)Ohio State University Main Campus, Microbiology, Columbus, United States, (7)CNRS, Laboratoire d'Océanographie de Villefranche-sur-Mer, Villefranche-sur-Mer, France, (8)Weizmann Institute of Science, Plant and Environmental Science, Rehovot, Israel, (9)Sorbonne Universite, CNRS, Station Biologique de Roscoff, Roscoff, France, (10)University of Konstanz, Konstanz, Germany
Abstract:
The production mechanism of sea spray aerosol (SSA) is crucial for understanding and accurate modelling of maritime aerosol, its radiative impact and cloud microphysical properties. Nevertheless, the related processes are not fully known.
Here we provide analysis of direct in situ measurements, over 42,000 km of the Atlantic and Pacific oceans, showing that concentrations of sea spray aerosol, with dry diameters > ~0.58 μm, have a distinct diel behavior, with an average of 2.3 times higher number concentrations during daytime than at night. Possible reasons for the diurnal cycle were checked, but no correlation with atmospheric radiation, pollution nor oceanic physical properties were found.
In parallel to the sea spray aerosol measurements, we observed an increase of the mean particle size in the ocean water during daytime (driven by particles of ~1μm). This measurement is related to photosynthetic growth and consequently to secretion of extracellular polymeric substances, which thus suggests an impact of microbial processes at the ocean surface on bubble-bursting dynamics as the cause of the observed diel cycle of SSA.
A diel change in SSA emissions can have significant implications on marine microbial transport, cloud and rain processes and it brings new light into our understanding of ocean-atmosphere interactions.
