Conference Publication Details
Mandatory Fields
Vaishya, A, Ovadnevaite, J, Bialek, J, Jennings, SG, Ceburnis, D, O'Dowd, C
19th International Conference on Nucleation & Atmospheric Aerosols
Marine organics effect on sea-spray light scattering
Optional Fields
Marine Aerosols Scattering enhancement Hygroscopic growth Radiative forcing
DeMott, P, O'Dowd, CD
Fort Collins, Colorado, USA
Primary-produced sea-spray is typically composed of sea-salt, but in biologically-active regions, the spray can become enriched with organic matter which reduces hygroscopicity of sea-spray, thereby having a potential impact on aerosol scattering. This study shows that scattering enhancement of marine aerosol, as a function of increasing relative humidity, is reduced when enriched with organics whose results are used to develop a new hygroscopicity growth-factor parameterization for sea-spray enriched in organic matter. The parameterization reveals a dual state which flips from high-hygroscopicity and high-scattering enhancement to low-hygroscopicity and low-scattering enhancement as the organic volume fraction increases from below similar to 0.55 to above similar to 0.55. In terms of organic enrichment, the effect on Top of Atmosphere (TOA) direct radiative forcing (Delta F) is to reduce the cooling contribution of sea-spray by similar to 5.5 times compared to pure sea-salt spray. The results presented here highlight a significant coupling between the marine biosphere and the direct radiative budget through alteration of sea-spray chemical composition, potentially leading to accelerated global warming should biological activity increase with future projected temperature increases.
DOI 10.1063/1.4803371
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