Effect of organic compounds on cloud condensation nuclei (CCN) activity of sea spray aerosol produced by bubble bursting

The emission of sea spray aerosol (SSA) and dimethylsulfide (DMS) from the ocean results in marine boundary layer aerosol particles that can impact Earth&#8217;s radiation balance by directly scattering solar radiation and by acting as cloud condensation nuclei (CCN), thereby altering cloud properties. The surface ocean is projected to warm by 1.3 to 2.8&#176;C globally over the 21st century. Impacts of this warming on plankton blooms, ocean ecosystems, and ocean-to-atmosphere fluxes of aerosols and their precursor gases are highly uncertain. A fundamental understanding of linkages between surface ocean ecosystems and ocean-derived aerosols is required to address this uncertainty. One approach for improved understandings of these linkages is simultaneous measurements of relevant surface ocean and aerosol properties in an ocean region with seasonally varying plankton blooms and a minimally polluted overlying atmosphere. The western North Atlantic hosts the largest annual phytoplankton bloom in the global ocean with a large spatial and seasonal variability in plankton biomass and composition. Periods of low aerosol number concentrations associated with unpolluted air masses allow for the detection of linkages between ocean ecosystems and ocean-derived aerosol.&#160;Five experiments were conducted in the western North Atlantic between 2014 and 2018 with the objective of finding links between the bloom and marine aerosols. These experiments include the second Western Atlantic Climate Study (WACS-2) and four North Atlantic Aerosol and Marine Ecosystem Study (NAAMES) cruises. This series of cruises was the first time the western North Atlantic bloom was systematically sampled during every season with extensive ocean and atmosphere measurements able to assess how changes in the state of the bloom might impact ocean-derived aerosol properties. Measurements of unheated and heated number size distributions, cloud condensation nuclei (CCN) concentrations, and aerosol composition were used to identify primary and secondary aerosol components that could be related to the state of the bloom. Only periods of clean marine air, as defined by radon, particle number concentration, aerosol light absorption coefficient, and back trajectories, were included in the analysis.&#160;CCN concentrations at 0.1% supersaturation were best correlated (r2 = 0.73) with accumulation mode nss SO4=. Sea spray aerosol (SSA) was only correlated with CCN during November when bloom accumulation had not yet occurred and dimethylsulfide (DMS) concentrations were at a minimum. The fraction of CCN attributable to SSA was less than 20% during March, May/June, and September, indicating the limited contribution of SSA to the CCN population of the western North Atlantic atmosphere. The strongest link between the plankton bloom and aerosol and cloud properties appears to be due to biogenic non-seasalt SO4=.&#160;

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The sensitivity of Southern Ocean aerosol concentrations to sea spray and DMS emissions in the HadGEM3-GA7.1 chemistry–climate model

10.5194/egusphere-egu2020-5976 ◽

2020 ◽

Author(s):

Laura Revell ◽

Stefanie Kremser ◽

Sean Hartery ◽

Mike Harvey ◽

Jane Mulcahy ◽

...

Keyword(s):

Wind Speed ◽

Southern Ocean ◽

Source Function ◽

Climate Model ◽

Cloud Condensation Nuclei ◽

Number Concentration ◽

Sea Spray ◽

Condensation Nuclei ◽

Sea Spray Aerosol ◽

Aerosol Source

With low concentrations of tropospheric aerosol, the Southern Ocean offers a "natural laboratory" for studies of aerosol&#8211;cloud interactions. Aerosols over the Southern Ocean are produced from biogenic activity in the ocean, which generates sulfate aerosol via dimethylsulfide (DMS) oxidation, and from strong winds and waves that lead to bubble bursting and sea spray emission. Here, we evaluate the representation of Southern Ocean aerosols in the Hadley Centre Global Environmental Model version 3, Global Atmosphere 7.1 (HadGEM3-GA7.1) chemistry&#8211;climate model. Compared with aerosol optical depth (AOD) observations from two satellite instruments (the Moderate Resolution Imaging Spectroradiometer, MODIS-Aqua c6.1, and the Multi-angle Imaging Spectroradiometer, MISR), the model simulates too-high AOD during winter and too-low AOD during summer. By switching off DMS emission in the model, we show that sea spray aerosol is the dominant contributor to AOD during winter. In turn, the simulated sea spray aerosol flux depends on near-surface wind speed. By examining MODIS AOD as a function of wind speed from the ERA-Interim reanalysis and comparing it with the model, we show that the sea spray aerosol source function in HadGEM3-GA7.1 overestimates the wind speed dependency. We test a recently developed sea spray aerosol source function derived from measurements made on a Southern Ocean research voyage in 2018. In this source function, the wind speed dependency of the sea spray aerosol flux is less than in the formulation currently implemented in HadGEM3-GA7.1. The new source function leads to good agreement between simulated and observed wintertime AODs over the Southern Ocean; however, it reveals partially compensating errors in DMS-derived AOD. While previous work has tested assumptions regarding the seawater climatology or sea&#8211;air flux of DMS, we test the sensitivity of simulated AOD, cloud condensation nuclei and cloud droplet number concentration to three atmospheric sulfate chemistry schemes. The first scheme adds DMS oxidation by halogens and the other two test a recently developed sulfate chemistry scheme for the marine troposphere; one tests gas-phase chemistry only, while the second adds extra aqueous-phase sulfate reactions. We show how simulated sulfur dioxide and sulfuric acid profiles over the Southern Ocean change as a result and how the number concentration and particle size of the soluble Aitken, accumulation and coarse aerosol modes are affected. The new DMS chemistry scheme leads to a 20% increase in the number concentration of cloud condensation nuclei and cloud droplets, which improves agreement with observations. Our results highlight the importance of atmospheric chemistry for simulating aerosols and clouds accurately over the Southern Ocean.

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Small fraction of marine cloud condensation nuclei made up of sea spray aerosol

Nature Geoscience ◽

10.1038/ngeo3003 ◽

2017 ◽

Vol 10 (9) ◽

pp. 674-679 ◽

Cited By ~ 67

Author(s):

P. K. Quinn ◽

D. J. Coffman ◽

J. E. Johnson ◽

L. M. Upchurch ◽

T. S. Bates

Keyword(s):

Cloud Condensation Nuclei ◽

Sea Spray ◽

Condensation Nuclei ◽

Sea Spray Aerosol

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The sensitivity of Southern Ocean aerosols and cloud microphysics to sea spray and sulfate aerosol production in the HadGEM3-GA7.1 chemistry-climate model

10.5194/acp-2019-629 ◽

2019 ◽

Author(s):

Laura E. Revell ◽

Stefanie Kremser ◽

Sean Hartery ◽

Mike Harvey ◽

Jane P. Mulcahy ◽

...

Keyword(s):

Wind Speed ◽

Southern Ocean ◽

Source Function ◽

Climate Model ◽

Cloud Condensation Nuclei ◽

Number Concentration ◽

Sea Spray ◽

Condensation Nuclei ◽

Sea Spray Aerosol ◽

Aerosol Source

Abstract. With low concentrations of tropospheric aerosol, the Southern Ocean offers a natural laboratory for studies of aerosol-cloud interactions. Aerosols over the Southern Ocean are produced from biogenic activity in the ocean, which generates sulfate aerosol via dimethylsulfide (DMS) oxidation, and from strong winds and waves that lead to bubble bursting and sea-spray emission. Here we evaluate the representation of Southern Ocean aerosols in the HadGEM3-GA7.1 chemistry-climate model. Compared with aerosol optical depth (AOD) observations from two satellite instruments (the Moderate Resolution Imaging Spectroradiometer, MODIS-Aqua c6.1 and the Multi-angle Imaging Spectroradiometer, MISR), the model simulates too-high AOD during winter and too-low AOD during summer. By switching off DMS emission in the model, we show that sea spray aerosol is the dominant contributor to AOD during winter. In turn, the simulated sea spray aerosol flux depends on near-surface wind speed. By examining MODIS AOD as a function of wind speed from the ERA-Interim reanalysis and comparing it with the model, we show that the sea spray aerosol source function in HadGEM3-GA7.1 overestimates the wind speed dependency. We test a recently-developed sea spray aerosol source function derived from measurements made on a Southern Ocean research voyage in 2018. In this source function the wind speed dependency of the sea spray aerosol flux is less than in the formulation currently implemented in HadGEM3-GA7.1. The new source function leads to good agreement between simulated and observed wintertime AOD over the Southern Ocean, however reveals partially compensating errors in DMS-derived AOD. While previous work has tested assumptions regarding the seawater climatology or sea-air flux of DMS, we test the sensitivity of simulated AOD, cloud condensation nuclei and cloud droplet number concentration to three atmospheric sulfate chemistry schemes. The first scheme adds DMS oxidation by halogens and the other two test a recently-developed sulfate chemistry scheme for the marine troposphere; one tests gas-phase chemistry only while the second adds extra aqueous-phase sulfate reactions. We show how simulated sulfur dioxide and sulfuric acid profiles over the Southern Ocean change as a result, and how the number concentration and particle size of the soluble Aitken, accumulation and coarse aerosol modes are affected. The new DMS chemistry scheme leads to a 20 % increase in the number concentration of cloud condensation nuclei and cloud droplets, which improves agreement with observations. Our results highlight the importance of atmospheric chemistry for simulating aerosols and clouds accurately over the Southern Ocean.

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Prediction of cloud condensation nuclei activity for organic compounds using functional group contribution methods

Geoscientific Model Development ◽

10.5194/gmd-9-111-2016 ◽

2016 ◽

Vol 9 (1) ◽

pp. 111-124 ◽

Cited By ~ 27

Author(s):

M. D. Petters ◽

S. M. Kreidenweis ◽

P. J. Ziemann

Keyword(s):

Organic Compounds ◽

Field Experiments ◽

Functional Group ◽

Cloud Condensation Nuclei ◽

Organic Aerosol ◽

Group Contribution ◽

Condensation Nuclei ◽

Aerosol Composition ◽

Group Contribution Methods ◽

Ccn Activity

Abstract. A wealth of recent laboratory and field experiments demonstrate that organic aerosol composition evolves with time in the atmosphere, leading to changes in the influence of the organic fraction to cloud condensation nuclei (CCN) spectra. There is a need for tools that can realistically represent the evolution of CCN activity to better predict indirect effects of organic aerosol on clouds and climate. This work describes a model to predict the CCN activity of organic compounds from functional group composition. Following previous methods in the literature, we test the ability of semi-empirical group contribution methods in Köhler theory to predict the effective hygroscopicity parameter, kappa. However, in our approach we also account for liquid–liquid phase boundaries to simulate phase-limited activation behavior. Model evaluation against a selected database of published laboratory measurements demonstrates that kappa can be predicted within a factor of 2. Simulation of homologous series is used to identify the relative effectiveness of different functional groups in increasing the CCN activity of weakly functionalized organic compounds. Hydroxyl, carboxyl, aldehyde, hydroperoxide, carbonyl, and ether moieties promote CCN activity while methylene and nitrate moieties inhibit CCN activity. The model can be incorporated into scale-bridging test beds such as the Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) to evaluate the evolution of kappa for a complex mix of organic compounds and to develop suitable parameterizations of CCN evolution for larger-scale models.

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Prediction of cloud condensation nuclei activity for organic compounds using functional group contribution methods

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-7445-2015 ◽

2015 ◽

Vol 8 (9) ◽

pp. 7445-7475 ◽

Cited By ~ 1

Author(s):

M. D. Petters ◽

S. M. Kreidenweis ◽

P. J. Ziemann

Keyword(s):

Organic Compounds ◽

Field Experiments ◽

Functional Group ◽

Cloud Condensation Nuclei ◽

Organic Aerosol ◽

Group Contribution ◽

Condensation Nuclei ◽

Aerosol Composition ◽

Group Contribution Methods ◽

Ccn Activity

Abstract. A wealth of recent laboratory and field experiments demonstrate that organic aerosol composition evolves with time in the atmosphere, leading to changes in the influence of the organic fraction to cloud condensation nuclei (CCN) spectra. There is a need for tools that can realistically represent the evolution of CCN activity to better predict indirect effects of organic aerosol on clouds and climate. This work describes a model to predict the CCN activity of organic compounds from functional group composition. The model combines Köhler theory with semi-empirical group contribution methods to estimate molar volumes, activity coefficients and liquid-liquid phase boundaries to predict the effective hygroscopicity parameter, kappa. Model evaluation against a selected database of published laboratory measurements demonstrates that kappa can be predicted within a factor of two. Simulation of homologous series is used to identify the relative effectiveness of different functional groups in increasing the CCN activity of weakly functionalized organic compounds. Hydroxyl, carboxyl, aldehyde, hydroperoxide, carbonyl, and ether moieties promote CCN activity while methylene and nitrate moieties inhibit CCN activity. The model can be incorporated into scale-bridging testbeds such as the Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere to evaluate the evolution of kappa for a complex mix of organic compounds and to develop suitable parameterizations of CCN evolution for larger scale models.

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The sensitivity of Southern Ocean aerosols and cloud microphysics to sea spray and sulfate aerosol production in the HadGEM3-GA7.1 chemistry–climate model

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-15447-2019 ◽

2019 ◽

Vol 19 (24) ◽

pp. 15447-15466 ◽

Cited By ~ 5

Author(s):

Laura E. Revell ◽

Stefanie Kremser ◽

Sean Hartery ◽

Mike Harvey ◽

Jane P. Mulcahy ◽

...

Keyword(s):

Wind Speed ◽

Southern Ocean ◽

Source Function ◽

Climate Model ◽

Cloud Condensation Nuclei ◽

Number Concentration ◽

Sea Spray ◽

Condensation Nuclei ◽

Sea Spray Aerosol ◽

Aerosol Source

Abstract. With low concentrations of tropospheric aerosol, the Southern Ocean offers a “natural laboratory” for studies of aerosol–cloud interactions. Aerosols over the Southern Ocean are produced from biogenic activity in the ocean, which generates sulfate aerosol via dimethylsulfide (DMS) oxidation, and from strong winds and waves that lead to bubble bursting and sea spray emission. Here, we evaluate the representation of Southern Ocean aerosols in the Hadley Centre Global Environmental Model version 3, Global Atmosphere 7.1 (HadGEM3-GA7.1) chemistry–climate model. Compared with aerosol optical depth (AOD) observations from two satellite instruments (the Moderate Resolution Imaging Spectroradiometer, MODIS-Aqua c6.1, and the Multi-angle Imaging Spectroradiometer, MISR), the model simulates too-high AOD during winter and too-low AOD during summer. By switching off DMS emission in the model, we show that sea spray aerosol is the dominant contributor to AOD during winter. In turn, the simulated sea spray aerosol flux depends on near-surface wind speed. By examining MODIS AOD as a function of wind speed from the ERA-Interim reanalysis and comparing it with the model, we show that the sea spray aerosol source function in HadGEM3-GA7.1 overestimates the wind speed dependency. We test a recently developed sea spray aerosol source function derived from measurements made on a Southern Ocean research voyage in 2018. In this source function, the wind speed dependency of the sea spray aerosol flux is less than in the formulation currently implemented in HadGEM3-GA7.1. The new source function leads to good agreement between simulated and observed wintertime AODs over the Southern Ocean; however, it reveals partially compensating errors in DMS-derived AOD. While previous work has tested assumptions regarding the seawater climatology or sea–air flux of DMS, we test the sensitivity of simulated AOD, cloud condensation nuclei and cloud droplet number concentration to three atmospheric sulfate chemistry schemes. The first scheme adds DMS oxidation by halogens and the other two test a recently developed sulfate chemistry scheme for the marine troposphere; one tests gas-phase chemistry only, while the second adds extra aqueous-phase sulfate reactions. We show how simulated sulfur dioxide and sulfuric acid profiles over the Southern Ocean change as a result and how the number concentration and particle size of the soluble Aitken, accumulation and coarse aerosol modes are affected. The new DMS chemistry scheme leads to a 20 % increase in the number concentration of cloud condensation nuclei and cloud droplets, which improves agreement with observations. Our results highlight the importance of atmospheric chemistry for simulating aerosols and clouds accurately over the Southern Ocean.

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Sea spray aerosol formation: Results on the role of different parameters and organic concentrations from bubble bursting experiments

Chemosphere ◽

10.1016/j.chemosphere.2020.126456 ◽

2020 ◽

Vol 252 ◽

pp. 126456 ◽

Cited By ~ 1

Author(s):

Chen Lv ◽

Narcisse T. Tsona ◽

Lin Du

Keyword(s):

Sea Spray ◽

Aerosol Formation ◽

Bubble Bursting ◽

Sea Spray Aerosol

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On the sea spray aerosol originated from bubble bursting jets

Journal of Fluid Mechanics ◽

10.1017/jfm.2019.1061 ◽

2020 ◽

Vol 886 ◽

Cited By ~ 3

Author(s):

Francisco J. Blanco–Rodríguez ◽

J. M. Gordillo

Keyword(s):

Sea Spray ◽

Bubble Bursting ◽

Sea Spray Aerosol ◽

Image Position

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Effect of primary organic sea spray emissions on cloud condensation nuclei concentrations

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-89-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 89-101 ◽

Cited By ~ 46

Author(s):

D. M. Westervelt ◽

R. H. Moore ◽

A. Nenes ◽

P. J. Adams

Keyword(s):

Surface Tension ◽

Southern Ocean ◽

Source Function ◽

Cloud Condensation Nuclei ◽

Organic Aerosol ◽

Sea Salt ◽

Sea Spray ◽

Aerosol Emission ◽

Sea Spray Aerosol ◽

Surfactant Effects

Abstract. This work estimates the primary marine organic aerosol global emission source and its impact on cloud condensation nuclei (CCN) concentrations by implementing an organic sea spray source function into a series of global aerosol simulations. The source function assumes that a fraction of the sea spray emissions, depending on the local chlorophyll concentration, is organic matter in place of sea salt. Effect on CCN concentrations (at 0.2% supersaturation) is modeled using the Two-Moment Aerosol Sectional (TOMAS) microphysics algorithm coupled to the GISS II-prime general circulation model. The presence of organics affects CCN activity in competing ways: by reducing the amount of solute available in the particle and decreasing surface tension of CCN. To model surfactant effects, surface tension depression data from seawater samples taken near the Georgia coast were applied as a function of carbon concentrations. A global marine organic aerosol emission rate of 17.7 Tg C yr−1 is estimated from the simulations. Marine organics exert a localized influence on CCN(0.2%) concentrations, decreasing regional concentrations by no more than 5% and by less than 0.5% over most of the globe, assuming direct replacement of sea salt aerosol with organic aerosol. The decrease in CCN concentrations results from the fact that the decrease in particle solute concentration outweighs the organic surfactant effects. The low sensitivity of CCN(0.2%) to the marine organic emissions is likely due to the small compositional changes: the mass fraction of OA in accumulation mode aerosol increases by only ~15% in a biologically active region of the Southern Ocean. To test the sensitivity to uncertainty in the sea spray emissions process, we relax the assumption that sea spray aerosol number and mass remain fixed and instead can add to sea spray emissions rather than replace existing sea salt. In these simulations, we find that marine organic aerosol can increase CCN by up to 50% in the Southern Ocean and 3.7% globally during the austral summer. This vast difference in CCN impact highlights the need for further observational exploration of the sea spray aerosol emission process as well as evaluation and development of model parameterizations.

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