scholarly journals Hygroscopic growth of sub-micrometer and one-micrometer aerosol particles measured during ACE-Asia

2006 ◽  
Vol 6 (6) ◽  
pp. 12267-12300 ◽  
Author(s):  
A. Massling ◽  
S. Leinert ◽  
A. Wiedensohler ◽  
D. Covert

Abstract. Hygroscopic properties of aerosol particles in the sub-micrometer and one-micrometer size range were measured during the ACE-Asia study (Aerosol Characterization Experiment-Asia) in spring 2001. The measurements took place off the coasts of Japan, Korea, and China. All instruments contributing to this study were deployed in a container on the forward deck of the NOAA Research Vessel Ronald H. Brown. Air masses with primarily marine influence and air masses from the Asian continent affected by both anthropogenic sources and by the transport of desert dust aerosol were encountered during the cruise. Two different systems were used to determine hygroscopic growth of the ambient marine boundary layer aerosol at 90% relative humidity (RH). An H-TDMA-system (Hygroscopicity-Tandem Differential Mobility Analyzer) (Massling et al., 2003) and a newly developed H-DMA-APS-system (Hygroscopicity-Differential Mobility Analyzer-Aerodynamic Particle Sizer) (Leinert and Wiedensohler, 2006) were applied to analyze sub-micrometer and one-micrometer aerosol particles, respectively. Results showed very different hygroscopic behavior in the sub-micrometer size range compared to the one-micrometer size range. In general, for all continentally influenced air masses, the one-micrometer particle population was characterized by two different particle fractions – a nearly hydrophobic fraction with growth factors around 1.0 representative of dust particles and a sea salt fraction with hygroscopic growth factors around 2.0. The number fraction of dust particles was generally about 60% independent of long-range air mass origin. For sub-micrometer particles, a dominant, more hygroscopic particle fraction with growth factors between 1.5 and 1.9 (depending on dry particle size) indicating ammonium sulfate as major component was always found. In marine air masses and for larger sizes within the sub-micrometer range (Dp=250 and 350 nm), a sea salt fraction with growth factors between 2.0 and 2.1 was also observed. For all other air masses, the more hygroscopic particle fraction in the sub-micrometer size range was mostly accompanied by a less hygroscopic particle fraction with growth factors between 1.20 and 1.55 depending on both the continental sources and the dry particle size. Number fractions of this particle group varied between 4 and 39% depending on dry particle size and air mass type. Nearly hydrophobic particles indicating dust particles in the sub-micrometer size regime were only found for particles with Dp=250 and 350 nm during a time period when the aerosol was significantly influenced by transport from Asian desert regions.

2007 ◽  
Vol 7 (12) ◽  
pp. 3249-3259 ◽  
Author(s):  
A. Massling ◽  
S. Leinert ◽  
A. Wiedensohler ◽  
D. Covert

Abstract. Hygroscopic properties of aerosol particles in the sub-micrometer and one-micrometer size ranges were measured during the ACE-Asia study (Aerosol Characterization Experiment-Asia) in spring 2001. The measurements took place off the coasts of Japan, Korea, and China. All instruments contributing to this study were deployed in a container on the forward deck of the NOAA Research Vessel Ronald H. Brown. Air masses with primarily marine influence and air masses from the Asian continent affected by both anthropogenic sources and by the transport of desert dust aerosol were encountered during the cruise. Results showed very different hygroscopic behavior in the sub-micrometer size range compared to the one-micrometer size range. In general, for all continentally influenced air masses, the one-micrometer particle population was characterized by two different particle groups – a nearly hydrophobic fraction with growth factors around 1.0 representative of dust particles and a sea salt fraction with hygroscopic growth factors around 2.0. The number fraction of dust particles was generally about 60% independent of long-range air mass origin. For sub-micrometer particles, a dominant, more hygroscopic particle fraction with growth factors between 1.5 and 1.9 (depending on dry particle size) consistent with ammonium sulfate or non-neutralized sulfates as major component was always found. In marine air masses and for larger sizes within the sub-micrometer range (Dp=250 and 350 nm), a sea salt fraction with growth factors between 2.0 and 2.1 was also observed. For all other air masses, the more hygroscopic particle fraction in the sub-micrometer size range was mostly accompanied by a less hygroscopic particle fraction with growth factors between 1.20 and 1.55 depending on both the continental sources and the dry particle size. Number fractions of this particle group varied between 4 and 39% depending on dry particle size and air mass type. Nearly hydrophobic particles indicating dust particles in the sub-micrometer size regime were only found for particles with Dp=250 and 350 nm during a time period when the aerosol was influenced by transport from Asian desert regions.


2018 ◽  
Vol 11 (4) ◽  
pp. 2325-2343 ◽  
Author(s):  
Xiaoli Shen ◽  
Ramakrishna Ramisetty ◽  
Claudia Mohr ◽  
Wei Huang ◽  
Thomas Leisner ◽  
...  

Abstract. The laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF, AeroMegt GmbH) is able to identify the chemical composition and mixing state of individual aerosol particles, and thus is a tool for elucidating their impacts on human health, visibility, ecosystem, and climate. The overall detection efficiency (ODE) of the instrument we use was determined to range from  ∼  (0.01 ± 0.01) to  ∼  (4.23 ± 2.36) % for polystyrene latex (PSL) in the size range of 200 to 2000 nm,  ∼  (0.44 ± 0.19) to  ∼  (6.57 ± 2.38) % for ammonium nitrate (NH4NO3), and  ∼  (0.14 ± 0.02) to  ∼  (1.46 ± 0.08) % for sodium chloride (NaCl) particles in the size range of 300 to 1000 nm. Reference mass spectra of 32 different particle types relevant for atmospheric aerosol (e.g. pure compounds NH4NO3, K2SO4, NaCl, oxalic acid, pinic acid, and pinonic acid; internal mixtures of e.g. salts, secondary organic aerosol, and metallic core–organic shell particles; more complex particles such as soot and dust particles) were determined. Our results show that internally mixed aerosol particles can result in spectra with new clusters of ions, rather than simply a combination of the spectra from the single components. An exemplary 1-day ambient data set was analysed by both classical fuzzy clustering and a reference-spectra-based classification method. Resulting identified particle types were generally well correlated. We show how a combination of both methods can greatly improve the interpretation of single-particle data in field measurements.


2019 ◽  
Vol 59 (3) ◽  
Author(s):  
Inga Garbarienė ◽  
Vidmantas Remeikis ◽  
Agnë Mašalaitė ◽  
Andrius Garbaras ◽  
Tpmasz Petelski ◽  
...  

We analysed δ13C of total carbon (TC) and δ15N of total nitrogen (TN) in submicron (PM1) and size segregated aerosol particles (PM0.056–2.5) collected during a cruise in the Baltic Sea from 9 to 17 November 2012. PM1 were characterized by the highest δ13C (–26.4‰) and lowest δ15N (–0.2 and 0.8‰) values when air masses arrived from the southwest direction (Poland). The obtained δ13C values indicated that combined emissions of coal and diesel/gasoline combustion were the most likely sources of TC. The depleted δ15N values indicated that TN originated mainly from liquid fuel combustion (road traffic, shipping) during this period. The lowest δ13C and highest δ15N values were determined in PM1 samples during the western airflow when the air masses had no recent contact with land. The highest δ15N values were probably associated with chemical aging of nitrogenous species during long-range transport, the lowest δ13C values could be related to emissions from diesel/gasoline combustion, potentially from ship traffic. The δ13C analysis of size-segregated aerosol particles PM0.056–2.5 revealed that the lowest δ13C values were observed in the size range from 0.056 to 0.18 µm and gradual 13C enrichment occurred in the size range from 0.18 to 2.5 µm due to different sources or formation mechanisms of the aerosols.


2020 ◽  
Vol 12 (5) ◽  
pp. 785 ◽  
Author(s):  
Tong Wu ◽  
Zhanqing Li ◽  
Jun Chen ◽  
Yuying Wang ◽  
Hao Wu ◽  
...  

Water uptake by aerosol particles alters its light-scattering characteristics significantly. However, the hygroscopicities of different aerosol particles are not the same due to their different chemical and physical properties. Such differences are explored by making use of extensive measurements concerning aerosol optical and microphysical properties made during a field experiment from December 2018 to March 2019 in Beijing. The aerosol hygroscopic growth was captured by the aerosol optical characteristics obtained from micropulse lidar, aerosol chemical composition, and aerosol particle size distribution information from ground monitoring, together with conventional meteorological measurements. Aerosol hygroscopicity behaves rather distinctly for mineral dust coarse-mode aerosol (Case I) and non-dust fine-mode aerosol (Case II) in terms of the hygroscopic enhancement factor, f β ( R H , λ 532 ) , calculated for the same humidity range. The two types of aerosols were identified by applying the polarization lidar photometer networking method (POLIPHON). The hygroscopicity for non-dust aerosol was much higher than that for dust conditions with the f β ( R H , λ 532 ) being around 1.4 and 3.1, respectively, at the relative humidity of 86% for the two cases identified in this study. To study the effect of dust particles on the hygroscopicity of the overall atmospheric aerosol, the two types of aerosols were identified and separated by applying the polarization lidar photometer networking method in Case I. The hygroscopic enhancement factor of separated non-dust fine-mode particles in Case I had been significantly strengthened, getting closer to that of the total aerosol in Case II. These results were verified by the hygroscopicity parameter, κ (Case I non-dust particles: 0.357 ± 0.024; Case II total: 0.344 ± 0.026), based on the chemical components obtained by an aerosol chemical speciation instrument, both of which showed strong hygroscopicity. It was found that non-dust fine-mode aerosol contributes more during hygroscopic growth and that non-hygroscopic mineral dust aerosol may reduce the total hygroscopicity per unit volume in Beijing.


2020 ◽  
Author(s):  
Chang Hoon Jung ◽  
JiYi Lee ◽  
Junshik Um ◽  
Yong Pyo Kim

<p>In this study, simplified analytic type of expression for size dependent MEs (Mass efficiencies) are developed. The entire size was considered assuming lognormal size distribution for sulfate, nitrate and NaCl aerosol species and the MEE of each aerosol chemical composition was estimated by fitting Mie’s calculation. The obtained results are compared with the results from the Mie-theory-based calculations and showed comparable results.</p><p>The mass efficiencies of all aerosol components for each size range are compared with Mie’s results and approximated as a function of geometric mean diameter in the form of a power law formula. Finally, harmonic mean type approximation was used to cover entire particle size range.</p><p>Also, analytic expression of approximated scattering enhancement factor which stands for the effect of hygroscopic growth factor for polydispersed aerosol on aerosol optical properties are obtained.</p><p>Based on aerosol thermodynamic models, mass growth factor can be obtained and their optical properties can be obtained by using Mie theory with different aerosol properties and size distribution. Finally, scattering enhancement factor was approximated fRH for polydispersed aerosol as a function of RH.</p><p>Finally, we also compared the simple forcing efficiency (SFE, W/g) of polydisperse aerosols between the developed simple approach and by the method using the Mie theory. The results show that current obtained approximated methods are comparable with existing numercal calculation based results for polydipersed particle size.</p>


The Analyst ◽  
2018 ◽  
Vol 143 (12) ◽  
pp. 2765-2774 ◽  
Author(s):  
Victor W. Or ◽  
Armando D. Estillore ◽  
Alexei V. Tivanski ◽  
Vicki H. Grassian

AFM-PTIR is utilized to analyze atmospherically relevant multicomponent substrate deposited aerosol particles.


2014 ◽  
Vol 14 (6) ◽  
pp. 8257-8285
Author(s):  
J. Jung ◽  
K. Kawamura

Abstract. To investigate the hygroscopic property of ultrafine particles during the new particle formation event, hygroscopic growth factors (g(RH)) of size-segregated atmospheric particles were measured at an urban site in Sapporo, northern Japan, during the summer of 2011. Hygroscopic growth factors at 85% RH (g(85%)) of freshly formed nucleation mode particles were measured at a dry particle diameter (Dp) centered at 20 nm to be 1.11 to 1.28 (average 1.16 ± 0.06), which are equivalent to 1.17 to 1.35 (1.23 ± 0.06) for a dry Dp centered at 100 nm after considering the Kelvin effect. These values are comparable with those of secondary organic aerosols, suggesting that low-volatility organic vapors are important to the burst of nucleation mode particles at the measurement site surrounded by a deciduous forest. Gradual increases in mode diameter after the burst of nucleation mode particles were obtained under southerly wind condition with a dominant contribution of intermediately-hygroscopic particles. However, sharp increases in mode diameter were obtained when wind direction shifted to northwesterly or northeasterly with a sharp increase in highly-hygroscopic particle faction in the Aitken mode particles, indicating that local wind direction is an important factor controlling the growth of newly formed particles and their hygroscopic properties. Higher g(85%) values (1.27 ± 0.05) were obtained at a dry Dp of 120 nm when the air masses originated from the Asian Continent, whereas lower g(85%) values (1.19 ± 0.06) were obtained when clean marine air masses arrived at the urban site. These results indicate that the hygroscopic property of large Aitken and small accumulation mode particles (80–165 nm) is highly influenced by the long-range atmospheric transport of particles and their precursors.


2019 ◽  
Vol 19 (4) ◽  
pp. 2115-2133 ◽  
Author(s):  
Liya Guo ◽  
Wenjun Gu ◽  
Chao Peng ◽  
Weigang Wang ◽  
Yong Jie Li ◽  
...  

Abstract. Calcium- and magnesium-containing salts are important components for mineral dust and sea salt aerosols, but their physicochemical properties are not well understood yet. In this study, hygroscopic properties of eight Ca- and Mg-containing salts, including Ca(NO3)2⚫4H2O, Mg(NO3)2⚫6H2O, MgCl2⚫6H2O, CaCl2⚫6H2O, Ca(HCOO)2, Mg(HCOO)2⚫2H2O, Ca(CH3COO)2⚫H2O and Mg(CH3COO)2⚫4H2O, were investigated using two complementary techniques. A vapor sorption analyzer was used to measure the change of sample mass with relative humidity (RH) under isotherm conditions, and the deliquescence relative humidities (DRHs) for temperature in the range of 5–30 ∘C as well as water-to-solute ratios as a function of RH at 5 and 25 ∘C were reported for these eight compounds. DRH values showed large variation for these compounds; for example, at 25 ∘C DRHs were measured to be ∼ 28.5 % for CaCl2⚫6H2O and >95 % for Ca(HCOO)2 and Mg(HCOO)2⚫2H2O. We further found that the dependence of DRH on temperature can be approximated by the Clausius–Clapeyron equation. In addition, a humidity tandem differential mobility analyzer was used to measure the change in mobility diameter with RH (up to 90 %) at room temperature, in order to determine hygroscopic growth factors of aerosol particles generated by atomizing water solutions of these eight compounds. All the aerosol particles studied in this work, very likely to be amorphous under dry conditions, started to grow at very low RH (as low as 10 %) and showed continuous growth with RH. Hygroscopic growth factors at 90 % RH were found to range from 1.26 ± 0.04 for Ca(HCOO)2 to 1.79 ± 0.03 for Ca(NO3)2, and the single hygroscopicity parameter ranged from 0.09–0.13 for Ca(CH3COO)2 to 0.49–0.56 for Ca(NO3)2. Overall, our work provides a comprehensive investigation of hygroscopic properties of these Ca- and Mg-containing salts, largely improving our knowledge of the physicochemical properties of mineral dust and sea salt aerosols.


Sign in / Sign up

Export Citation Format

Share Document