LACIS-measurements and parameterization of sea-salt particle hygroscopic growth and activation

Abstract. The Leipzig Aerosol Cloud Interaction Simulator (LACIS) was used to investigate the hygroscopic growth and activation of sea-salt particles which were generated from three different sea-water samples. The measurements showed that the sea-salt particles exhibit a slightly reduced hygroscopic growth compared to pure NaCl particles. Köhler theory was utilized to model the hygroscopic growth of these particles. Some parameters used in this model are unknown for sea-salt. These parameters are combined in an "ionic density" ρion. For each sea-salt sample an average ρion was determined by fitting the Köhler equation to the data from the hygroscopic growth measurements. LACIS was also used to measure the activation of the sea-salt particles at three different supersaturations: 0.11%, 0.17% and 0.32%. A CCN-closure was tested by calculating the critical diameters Dcrit for the sea-salt particles at these supersaturations, using the Köhler model and the corresponding ρion as derived from the hygroscopic growth data. These calculated critical diameters were compared to the measured ones. Measured and calculated values of Dcrit agree within the level of uncertainty. Based on this successful closure, a new parameterization to describe sea-salt-particle hygroscopic growth (at RH>95%) and activation has been developed.

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LACIS-measurements and parameterization of sea-salt particle hygroscopic growth and activation

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-11511-2007 ◽

2007 ◽

Vol 7 (4) ◽

pp. 11511-11544

Author(s):

D. Niedermeier ◽

F. Stratmann ◽

H. Wex ◽

E. Brüggemann ◽

A. Kiselev ◽

...

Keyword(s):

Water Samples ◽

Sea Water ◽

Sea Salt ◽

Hygroscopic Growth ◽

Growth Data ◽

Salt Particle ◽

Aerosol Cloud ◽

Salt Sample ◽

Kohler Theory ◽

Ionic Density

Abstract. The Leipzig Aerosol Cloud Interaction Simulator (LACIS) was used to investigate the hygroscopic growth and activation of sea-salt particles which were generated from three different sea-water samples. Köhler theory was utilized to model the hygroscopic growth of these particles. Some parameters used in this model are unknown for sea-salt. These parameters are combined in an "ionic density" ρion. For each sea-salt sample an average ρion was determined by fitting the Köhler equation to the data from the hygroscopic growth measurements. LACIS was also used to measure the activation of the sea-salt particles at three different supersaturations: 0.10%, 0.16% and 0.30%. A CCN-closure was tested by calculating the critical diameters Dcrit for the sea-salt particles at these supersaturations, using the Köhler model and the corresponding ρion as derived from the hygroscopic growth data. These calculated critical diameters were compared to the measured ones. Measured and calculated values of Dcrit agree within the level of uncertainty. Based on this successful closure, a new parameterization to describe sea-salt-particle hygroscopic growth (at RH>95%) and activation has been developed.

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A thermodynamic description for the hygroscopic growth of atmospheric aerosol particles

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-14939-2018 ◽

2018 ◽

Vol 18 (20) ◽

pp. 14939-14948 ◽

Cited By ~ 7

Author(s):

Dimitri Castarède ◽

Erik S. Thomson

Keyword(s):

Radiative Forcing ◽

Thermodynamic Description ◽

Liquid Droplets ◽

Hygroscopic Growth ◽

Salt Particle ◽

Aerosol Radiative Forcing ◽

Condensation Nucleation ◽

Kohler Theory ◽

Kelvin Effect ◽

Brine Layer

Abstract. The phase state of atmospheric particulate is important to atmospheric processes, and aerosol radiative forcing remains a large uncertainty in climate predictions. That said, precise atmospheric phase behavior is difficult to quantify and observations have shown that “precondensation” of water below predicted saturation values can occur. We propose a revised approach to understanding the transition from solid soluble particles to liquid droplets, typically described as cloud condensation nucleation – a process that is traditionally captured by Köhler theory, which describes a modified equilibrium saturation vapor pressure due to (i) mixing entropy (Raoult's law) and (ii) droplet geometry (Kelvin effect). Given that observations of precondensation are not predicted by Köhler theory, we devise a more complete model that includes interfacial forces giving rise to predeliquescence, i.e., the formation of a brine layer wetting a salt particle at relative humidities well below the deliquescence point.

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A thermodynamic description for the hygroscopic growth of atmospheric aerosol particles

10.5194/acp-2018-460 ◽

2018 ◽

Author(s):

Dimitri Castarède ◽

Erik S. Thomson

Keyword(s):

Radiative Forcing ◽

Thermodynamic Description ◽

Liquid Droplets ◽

Hygroscopic Growth ◽

Salt Particle ◽

Aerosol Radiative Forcing ◽

Condensation Nucleation ◽

Kohler Theory ◽

Kelvin Effect ◽

Brine Layer

Abstract. The phase state of atmospheric particulate is important to atmospheric processes and aerosol radiative forcing remains a large uncertainty in climate predictions. That said, precise atmospheric phase behavior is difficult to quantify and observations have shown that precondensation of water below predicted saturation values can occur. We propose a revised approach to understanding the transition from solid soluble particles to liquid droplets, typically described as cloud condensation nucleation – a process that is traditionally captured by Köhler theory, which describes a modified equilibrium saturation vapor pressure due to I. mixing entropy (Raoult's law) and II. droplet geometry (Kelvin effect). Given that observations of precondensation are not predicted by Köhler theory, we devise a more complete model which includes interfacial forces giving rise to predeliquescence, i.e., the formation of a brine layer wetting a salt particle at relative humidities well below the deliquescence point.

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SITE-SPECIFIC EQUATIONS OF STATE FOR COASTAL SEA AREAS AND INLAND WATER BODIES

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b9452bebe47.34318019 ◽

2017 ◽

Author(s):

Natalia Andrulionis ◽

Ivan Zavialov ◽

Elena Kovaleva ◽

...

Keyword(s):

Equation Of State ◽

Black Sea ◽

Water Samples ◽

Equations Of State ◽

Sea Water ◽

Ionic Composition ◽

Water Bodies ◽

Aral Sea ◽

The Black Sea ◽

Coastal Sea

This article presents a new method of laboratory density determination and construction equations of state for marine waters with various ionic compositions and salinities was developed. The validation of the method was performed using the Ocean Standard Seawater and the UNESCO thermodynamic equation of state (EOS-80). Density measurements of water samples from the Aral Sea, the Black Sea and the Issyk-Kul Lake were performed using a high-precision laboratory density meter. The obtained results were compared with the density values calculated for the considered water samples by the EOS-80 equation. It was shown that difference in ionic composition between Standard Seawater and the considered water bodies results in significant inaccuracies in determination of water density using the EOS-80 equation. Basing on the laboratory measurements of density under various salinity and temperature values we constructed a new equation of state for the Aral Sea and the Black Sea water samples and estimated errors for their coefficients.

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Carbon-14 in the Southern Indian Ocean

Radiocarbon ◽

10.1017/s0033822200010055 ◽

1980 ◽

Vol 22 (3) ◽

pp. 684-692 ◽

Cited By ~ 6

Author(s):

Georgette Delibrias

Keyword(s):

Surface Water ◽

Indian Ocean ◽

Water Samples ◽

Sea Water ◽

Time Lag ◽

Vertical Profiles ◽

Carbon 14 ◽

Middle Latitudes ◽

The North ◽

The Indian Ocean

14C measurements were carried out on sea water samples collected in 1973, in the Indian ocean. The results obtained for 9 vertical profiles between 27° S and 48°S are presented. In surface water, the bomb 14C content is maximum at middle latitudes. A time lag relative to the north hemisphere bomb 14C delivery is apparent. In the more southern latitudes, 14C content remains very low.

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Linking variations in sea spray aerosol particle hygroscopicity to composition during two microcosm experiments

10.5194/acp-2016-36 ◽

2016 ◽

Author(s):

Sara D. Forestieri ◽

Gavin C. Cornwell ◽

Taylor M. Helgestad ◽

Kathryn A. Moore ◽

Christopher Lee ◽

...

Keyword(s):

Light Scattering ◽

Relative Humidity ◽

Salt Content ◽

Sea Salt ◽

Sea Spray ◽

Hygroscopic Growth ◽

Phytoplankton Blooms ◽

Aerosol Composition ◽

Sea Spray Aerosol ◽

Indoor And Outdoor

Abstract. The extent to which water uptake influences the light scattering ability of marine sea spray aerosol (SSA) particles depends critically on SSA chemical composition. The organic fraction of SSA can increase during phytoplankton blooms, decreasing the salt content and therefore the hygroscopicity of the particles. In this study, subsaturated hygroscopic growth factors at 85 % relative humidity (GF(85 %)) of SSA particles were quantified during two induced phytoplankton blooms in marine aerosol reference tanks (MARTs). One MART was illuminated with fluorescent lights and the other was illuminated with sunlight, referred to as the "indoor" and "outdoor" MARTs, respectively. GF(85 %) values for SSA particles were derived from measurements of light scattering and particle size distributions, concurrently with online single particle and bulk aerosol composition measurements. During both microcosm experiments, the observed bulk average GF(85 %) values were depressed substantially relative to pure, inorganic sea salt, by 10 to 19 %, with a one (indoor MART) and six (outdoor MART) day lag between GF(85 %) depression and the peak chlorophyll-a concentrations. The fraction of organiccontaining SSA particles generally increased after the peak of the phytoplankton blooms. The GF(85 %) values were inversely correlated with the fraction of particles containing organic or other biological markers. This indicates these particles were less hygroscopic than the particles identified as predominately sea salt containing and demonstrates a clear relationship between SSA particle composition and the sensitivity of light scattering to variations in relative humidity. The implications of these observations to the direct climate effects of SSA particles are discussed.

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The relative importance of non-sea-salt sulphate and sea-salt aerosol to the marine cloud condensation nuclei population: An improved multi-component aerosol-cloud droplet parametrization

Quarterly Journal of the Royal Meteorological Society ◽

10.1002/qj.1999.49712555610 ◽

1999 ◽

Vol 125 (556) ◽

pp. 1295-1313 ◽

Cited By ~ 108

Author(s):

Colin D. O'Dowd ◽

Jason A. Lowe ◽

Michael H. Smith ◽

Andrew D. Kaye

Keyword(s):

Cloud Condensation Nuclei ◽

Cloud Droplet ◽

Sea Salt ◽

Relative Importance ◽

Condensation Nuclei ◽

Sea Salt Aerosol ◽

Aerosol Cloud

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Sewage contamination of coastal bathing waters in england and wales A bacteriological and epidemiological study

Epidemiology and Infection ◽

10.1017/s0022172400020301 ◽

1959 ◽

Vol 57 (4) ◽

pp. 435-472 ◽

Cited By ~ 72

Author(s):

Keyword(s):

Water Samples ◽

Sea Water ◽

Test Procedure ◽

Great Majority ◽

Controlled Study ◽

England And Wales ◽

Representative Sampling ◽

Small Series ◽

Bathing Waters ◽

Ranking Order

1. Bacteriological surveys of more than forty popular bathing beaches around the coasts of England and Wales have been made during the past 5 years. The great majority of the beaches studied were subject to contamination with sewage.2. A rough grading of the beaches studied gave a similar ranking order whether the results of the presumptive coliform test or faecal coli counts were used as the basis of grading.3. Grading of beaches was valid only when surveys were carefully planned to ensure representative sampling from the areas on the beaches concerned where bathing actually took place.4. The coliform test as used in the bacteriological examination of drinking waters was the main test procedure used but had certain limitations. Promising results with plate counts on relatively non-inhibitory media were obtained.5. Various salmonella serotypes, notablySalm. paratyphi B, were isolated in small numbers from a high proportion of sea-water samples. The proportion of positive results for salmonella isolation increased from 13·3% in samples with less than 1000 coliform organisms per 100 ml. to 40·1% in samples with over 10,000 coliforms per 100 ml. Comparison of the numbers of salmonellae isolated with what is known of the minimum infective doses of these organisms suggested that very large volumes of sea water would require to be ingested for infection to occur.6. Poliovirus was not isolated from a small series of sea-water samples examined. Because of the very large dilution factor, special concentration procedures would probably be required to isolate this virus from sea water.7. Four cases of paratyphoid fever probably due to bathing were recorded. Surveys of the two associated beaches had given median presumptive coliform counts of more than 10,000 per 100 ml., and both showed gross macroscopic pollution with sewage.8. A statistically controlled study of the bathing histories of 150 poliomyelitis cases in children living permanently by the seaside gave no evidence that bathing had played any part in causing the disease.

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