Measurements of atmospheric aerosol hygroscopic growth based on multi-channel Raman-Mie lidar

Abstract. A calibration for LACIS (Leipzig Aerosol Cloud Interaction Simulator) for its use as a CCN (cloud condensation nuclei) detector has been developed. For this purpose, sodium chloride and ammonium sulfate particles of known sizes were generated and their grown sizes were detected at the LACIS outlet. From these signals, the effective critical super-saturation was derived as a function of the LACIS wall temperature. With this, LACIS is calibrated for its use as a CCN detector. The applicability of LACIS for measurements of the droplet activation, and also of the hygroscopic growth of atmospheric aerosol particles was tested. The activation of the urban aerosol particles used in the measurements was found to occur at a critical super-saturation of 0.46% for particles with a dry diameter of 75 nm, and at 0.42% for 85 nm, respectively. Hygroscopic growth was measured for atmospheric aerosol particles with dry diameters of 150, 300 and 350 nm at relative humidities of 98 and 99%, and it was found that the larger dry particles contained a larger soluble volume fraction of about 0.85, compared to about 0.6 for the 150 nm particles.

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Ageing and hygroscopicity variation of black carbon particles in Beijing measured by a quasi-atmospheric aerosol evolution study (QUALITY) chamber

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-10333-2017 ◽

2017 ◽

Vol 17 (17) ◽

pp. 10333-10348 ◽

Cited By ~ 21

Author(s):

Jianfei Peng ◽

Min Hu ◽

Song Guo ◽

Zhuofei Du ◽

Dongjie Shang ◽

...

Keyword(s):

Black Carbon ◽

Atmospheric Aerosol ◽

Ambient Air ◽

Reaction Chamber ◽

Flow Chamber ◽

Study Quality ◽

Hygroscopic Growth ◽

Coating Materials ◽

Average Growth ◽

Evolution Study

Abstract. Measurements of ageing and hygroscopicity variation of black carbon (BC) particles in Beijing were conducted using a 1.2 m3 quasi-atmospheric aerosol evolution study (QUALITY) chamber, which consisted of a bottom flow chamber through which ambient air was pulled continuously and an upper reaction chamber where ageing of BC particles occurred. Within the reaction chamber, transmission of the solar ultraviolet irradiation was approximately 50–60 %, wall loss of primary gaseous pollutants was negligible, and BC exhibited a half-lifetime of about 3–7 h. Typically, equilibrium for the primary gases, temperature and relative humidity between the reaction chamber and ambient air was established within 1 h. Rapid growth of BC particles occurred, with an average total growth of 77 ± 33 nm and average growth rate of 26 ± 11 nm h−1. Secondary organic aerosols (SOA) accounted for more than 90 % of the coating mass. The O ∕ C ratio of SOA was 0.5, lower than the ambient level. The hygroscopic growth factor of BC particles decreased slightly with an initial thin coating layer because of BC reconstruction, but subsequently increased to 1.06–1.08 upon further ageing. The κ (kappa) values for BC particles and coating materials were calculated as 0.035 and 0.040 at the subsaturation and supersaturation conditions, respectively, indicating low hygroscopicity of coated SOA on BC particles. Hence, our results indicate that initial photochemical ageing of BC particles leads to considerable modifications to morphology and optical properties but does not appreciably alter the particle hygroscopicity in Beijing.

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Hygroscopic growth of atmospheric aerosol particles based on active remote sensing and radiosounding measurements

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-10293-2014 ◽

2014 ◽

Vol 7 (10) ◽

pp. 10293-10326

Author(s):

M. J. Granados-Muñoz ◽

F. Navas-Guzmán ◽

J. A. Bravo-Aranda ◽

J. L. Guerrero-Rascado ◽

H. Lyamani ◽

...

Keyword(s):

Remote Sensing ◽

Aerosol Particle ◽

Atmospheric Aerosol ◽

Enhancement Factor ◽

Volume Concentration ◽

Mineral Dust ◽

Concentration Profiles ◽

Hygroscopic Growth ◽

Backscatter Coefficient ◽

Growth Effects

Abstract. A new methodology based on combining active and passive remote sensing and simultaneous and collocated radiosounding data to study the aerosol hygroscopic growth effects on the particle optical and microphysical properties is presented. The identification of hygroscopic growth situations combines the analysis of multiespectral aerosol particle backscatter coefficient and particle linear depolarization ratio with thermodynamic profiling of the atmospheric column. We analysed the hygroscopic growth effects on aerosol properties, namely the aerosol particle backscatter coefficient and the volume concentration profiles, using data gathered at Granada EARLINET station. Two study cases, corresponding to different aerosol loads and different aerosol types, are used for illustrating the potential of this methodology. Values of the aerosol particle backscatter coefficient enhancement factors range from 2.10 ± 0.06 to 3.90 ± 0.03, being similar to those previously reported in the literature. Differences in the enhancement factor are directly linked to the composition of the atmospheric aerosol. The largest value of the aerosol particle backscatter coefficient enhancement factor corresponds to the presence of sulphate and marine particles that are more affected by hygroscopic growth. On the contrary, the lowest value of the enhancement factor corresponds to an aerosol mixture containing sulphates and slight traces of mineral dust. The Hänel parameterization is applied to these case studies, obtaining results within the range of values reported in previous studies, with values of the γ exponent of 0.56 ± 0.01 (for anthropogenic particles slightly influenced by mineral dust) and 1.07 ± 0.01 (for the situation dominated by anthropogenic particles), showing the convenience of this remote sensing approach for the study of hygroscopic effects of the atmospheric aerosol under ambient unperturbed conditions. For the first time, the retrieval of the volume concentration profiles for these cases using the Lidar Radiometer Inversion Code (LIRIC) allows us to analyse the aerosol hygroscopic growth effects on aerosol volume concentration, observing a stronger increase of the fine mode volume concentration with increasing relative humidity.

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Deliquescence and Hygroscopic Growth of Mixed Inorganic−Organic Atmospheric Aerosol

Environmental Science & Technology ◽

10.1021/es9907109 ◽

2000 ◽

Vol 34 (20) ◽

pp. 4313-4319 ◽

Cited By ~ 251

Author(s):

Celia N. Cruz ◽

Spyros N. Pandis

Keyword(s):

Atmospheric Aerosol ◽

Hygroscopic Growth

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Hygroscopic growth of atmospheric aerosol sampled in Prague 2008 using humidity controlled inlets

Atmospheric Research ◽

10.1016/j.atmosres.2010.04.009 ◽

2010 ◽

Vol 98 (2-4) ◽

pp. 237-248 ◽

Cited By ~ 6

Author(s):

L. Štefancová ◽

J. Schwarz ◽

W. Maenhaut ◽

X. Chi ◽

J. Smolík

Keyword(s):

Atmospheric Aerosol ◽

Hygroscopic Growth

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A single parameter representation of hygroscopic growth and cloud condensation nucleus activity – Part 2: Including solubility

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-5939-2008 ◽

2008 ◽

Vol 8 (2) ◽

pp. 5939-5955 ◽

Cited By ~ 2

Author(s):

M. D. Petters ◽

S. M. Kreidenweis

Keyword(s):

Atmospheric Aerosol ◽

Unit Volume ◽

Condensation Nucleus ◽

Single Parameter ◽

Cloud Condensation Nucleus ◽

Hygroscopic Growth ◽

Organic Fraction ◽

Solubility In Water ◽

Organic Species ◽

Pure Compounds

Abstract. The ability of a particle to serve as a cloud condensation nucleus in the atmosphere is determined by its size, hygroscopicity and its solubility in water. Usually size and hygroscopicity alone are sufficient to predict CCN activity. Single parameter representations for hygroscopicity have been shown to model successfully complex, multicomponent particles types. Under the assumption of either complete solubility, or complete insolubility of a component, it is not necessary to explicitly include that components solubility into the single parameter framework. This is not the case if sparingly soluble particles are present. In this work we explicitly account for solubility by modifying the single parameter equations. We demonstrate that sensitivity to the actual value of solubility emerges only in the narrow regime of 1×10−1–5×10−3, where the solubility values are expressed as volume of solute per unit volume of water present in a saturated solution. Since only a few pure compounds fall inside this sparingly soluble envelope and those only make up a small fraction of the total organic fraction most organic species in the atmospheric aerosol can be adequately modeled assuming they are either infinitely soluble in water or completely insoluble .

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Reformulating atmospheric aerosol thermodynamics and hygroscopic growth into haze and clouds

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-849-2007 ◽

2007 ◽

Vol 7 (1) ◽

pp. 849-910 ◽

Cited By ~ 3

Author(s):

S. Metzger ◽

J. Lelieveld

Keyword(s):

Activity Coefficients ◽

Atmospheric Chemistry ◽

Atmospheric Aerosol ◽

Cloud Microphysics ◽

Cloud Formation ◽

Organic Salt ◽

Hygroscopic Growth ◽

Thermodynamical Equilibrium ◽

Aerosol Composition ◽

Aerosol Properties

Abstract. Modeling atmospheric aerosol and cloud microphysics is rather complex, even if chemical and thermodynamical equilibrium is assumed. We show, however, that the thermodynamics can be considerably simplified by reformulating equilibrium to include water, and transform laboratory-based concepts to atmospheric conditions. We generalize the thermodynamic principles that explain hydration and osmosis – merely based on solute solubilities. In chemical and thermodynamical equilibrium the relative humidity (RH) determines the saturation molality, including solute and solvent activities (and activity coefficients), since the water content is fixed by RH for a given aerosol concentration and type. As a consequence, gas/liquid/solid aerosol equilibrium partitioning can be solved analytically and non-iteratively. Our new concept enables an efficient and accurate calculation of the aerosol water mass and to directly link the aerosol hygroscopic growth to haze and cloud formation. We apply our new concept in the 3rd Equilibrium Simplified Aerosol Model (EQSAM3). Its input is limited to the species' solubilities from which a newly introduced stoichiometric coefficient for water is derived. Analogously, we introduce effective stochiometric coefficients for the solutes to account for complete or incomplete dissociation. We show that these coefficients can be assumed constant over the entire activity range and calculated for various inorganic, organic and non-electrolyte compounds, including alcohols, sugars and dissolved gases. EQSAM3 calculates the aerosol composition and gas/liquid/solid partitioning of mixed inorganic/organic multicomponent solutions and the associated water uptake for almost 100 major compounds. It explicitly accounts for particle hygroscopic growth by computing aerosol properties such as single solute molalities, molal based activities, including activity coefficients for volatile compounds, and deliquescence relative humidities of mixed solutes. Various applications and a model inter-comparison indicate that a) the application is not limited to dilute binary solutions, b) sensitive aerosol properties such as the pH of binary and mixed inorganic/organic salt solutions up to saturation can be computed accurately, and c) aerosol associated water is important for atmospheric chemistry, visibility, weather and climate.

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UManSysProp v1.0: an online and open-source facility for molecular property prediction and atmospheric aerosol calculations

Geoscientific Model Development ◽

10.5194/gmd-9-899-2016 ◽

2016 ◽

Vol 9 (2) ◽

pp. 899-914 ◽

Cited By ~ 44

Author(s):

David Topping ◽

Mark Barley ◽

Michael K. Bane ◽

Nicholas Higham ◽

Bernard Aumont ◽

...

Keyword(s):

Open Source ◽

Atmospheric Aerosol ◽

Organic Liquid ◽

Cloud Condensation Nuclei ◽

Single Point ◽

Relevant Information ◽

Pure Component ◽

Hygroscopic Growth ◽

Liquid Systems ◽

The University

Abstract. In this paper we describe the development and application of a new web-based facility, UManSysProp (http://umansysprop.seaes.manchester.ac.uk), for automating predictions of molecular and atmospheric aerosol properties. Current facilities include pure component vapour pressures, critical properties, and sub-cooled densities of organic molecules; activity coefficient predictions for mixed inorganic–organic liquid systems; hygroscopic growth factors and CCN (cloud condensation nuclei) activation potential of mixed inorganic–organic aerosol particles; and absorptive partitioning calculations with/without a treatment of non-ideality. The aim of this new facility is to provide a single point of reference for all properties relevant to atmospheric aerosol that have been checked for applicability to atmospheric compounds where possible. The group contribution approach allows users to upload molecular information in the form of SMILES (Simplified Molecular Input Line Entry System) strings and UManSysProp will automatically extract the relevant information for calculations. Built using open-source chemical informatics, and hosted at the University of Manchester, the facilities are provided via a browser and device-friendly web interface, or can be accessed using the user's own code via a JSON API (application program interface). We also provide the source code for all predictive techniques provided on the site, covered by the GNU GPL (General Public License) license to encourage development of a user community. We have released this via a Github repository (doi:10.5281/zenodo.45143). In this paper we demonstrate its use with specific examples that can be simulated using the web-browser interface.

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