Marine Aerosol Dynamics and Chemical Properties

Marine aerosols originate predominantly from bursting bubbles at the sea surface, injecting a mixture of inorganic salts, organic matter and, increasingly recognised, microplastic fragments into the atmosphere. Their production is governed by wind speed, wave state and the physico-chemical composition of the sea surface microlayer, which itself reflects biological activity and dissolved organic carbon content. Once airborne, particle size and chemical composition dictate interactions with water vapour, light and atmospheric oxidants. Submicrometre aerosols can act as cloud condensation nuclei, influencing cloud formation and albedo, while coarse mode particles scatter solar radiation and contribute to deposition of salts and pollutants. Chemical ageing processes—such as oxidation of organics and halogen-driven reactions on sea salt surfaces—alter hygroscopicity and surface properties, with feedbacks on cloud droplet activation and atmospheric chemistry. The global distribution of marine aerosols shapes regional climate patterns, biogeochemical cycles and air quality, making accurate representation of their dynamics and chemical properties vital for climate modelling and environmental assessment.

Research from Nature Portfolio

Studies have demonstrated that intense meteorological events can entrain ocean-sourced microplastic particles into the atmosphere, with hurricane-strength winds transporting and depositing significant loads in remote regions. Observations during a North Atlantic storm reveal deposition rates exceeding 10^5 particles m^−2 day^−1 and identify ocean gyre sources via back-trajectory analysis, underscoring a global pathway for microplastic dispersal. Parallel work on inorganic sea salt revises its hygroscopic growth behaviour, showing that real-world particles absorb 8–15 % less water than pure sodium chloride due to hydrates. This size-dependent reduction in growth leads to lower aerosol optical depths in climate simulations when a corrected hygroscopicity parameter (κ≈1.1 at 90 % RH) is applied, refining estimates of aerosol–radiation interactions at different latitudes.

Marine Aerosol Dynamics and Chemical Properties publication trend

The graph below shows the total number of articles in marine aerosol dynamics and chemical properties across all publications each year (not limited to Nature Index journals).

Technical terms

Sea spray aerosol (SSA): Particles emitted into the atmosphere by bursting bubbles at the ocean surface, composed of salts and organic matter.

Hygroscopicity (κ): Measure of a particle’s ability to take up water vapour and grow in size under humid conditions.

Cloud condensation nuclei (CCN): Aerosol particles around which cloud droplets can form when supersaturated.

Submicrometre: Describes particles smaller than one micrometre in diameter, with long atmospheric lifetimes and distinct cloud-forming potential.

Sea surface microlayer (SML): The uppermost layer of the ocean, enriched in organic compounds and serving as the primary interface for aerosol generation.

References

1. Glucose Enhances Salinity-Driven Sea Spray Aerosol Production in Eastern Arctic Waters. Environmental Science and Technology (2024).
2. Revealing the Impacts of Chemical Complexity on Submicrometer Sea Spray Aerosol Morphology. ACS Central Science (2023).
3. Transport and deposition of ocean-sourced microplastic particles by a North Atlantic hurricane. Communications Earth & Environment (2023).
4. Ocean-atmosphere interactions: Different organic components across Pacific and Southern Oceans. The Science of The Total Environment (2023).
5. Revising the hygroscopicity of inorganic sea salt particles. Nature Communications (2017).
6. The Ocean's Vital Skin: Toward an Integrated Understanding of the Sea Surface Microlayer. Frontiers in Marine Science (2017).
7. A sea spray aerosol flux parameterization encapsulating wave state. Atmospheric Chemistry and Physics (2014).
8. A review of sea-spray aerosol source functions using a large global set of sea salt aerosol concentration measurements. Atmospheric Chemistry and Physics (2014).
9. Global distribution of sea salt aerosols: new constraints from in situ and remote sensing observations. Atmospheric Chemistry and Physics (2011).