A Review of the Representation of Aerosol Mixing State in Atmospheric Models

Stevens, Robin; Dastoor, Ashu

doi:10.3390/atmos10040168

Cited by 36 publications

(31 citation statements)

References 247 publications

(493 reference statements)

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“…BC is emitted in hydrophobic and hydrophilic forms (80% and 20%, respectively) with a fixed aging timescale of 1.6 days (Cooke & Wilson, 1996). The two forms are considered to be mixed externally with respect to each other, but BC in hydrophilic form is internally mixed, which can activate cloud droplets (Emmons et al, 2010; Sadiq et al, 2015; Stevens & Dastoor, 2019). The dynamic parameterization scheme adopted is the finite volume dynamical core, with emphasis on the conservation, accuracy, and efficiency of the tracer transport process (Rasch et al, 2006).…”

Section: Methodsmentioning

confidence: 99%

Regional and Sectoral Sources for Black Carbon Over South China in Spring and Their Sensitivity to East Asian Summer Monsoon Onset

et al. 2020

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Besides local emissions, biomass burning (BB) emissions in peninsula Southeast Asia (PSEA) and domestic anthropogenic emissions in North China (NC) are also significant black carbon (BC) sources over South China (SC) in spring. Meanwhile, the East Asian summer monsoon (EASM) is established with the wind field reversal, influencing the region-based contributions to BC over SC. Herein, BC sources for SC were tracked by region and by sector using the Community Earth System Model with a BC-tagging technique. During the spring of 2000-2014, 27% of BC surface concentration (BCS) and 64% of BC column burden (BCC) over SC stems from nonlocal sources. BC from NC is mainly transported below 850 hPa. It is the dominant nonlocal contribution to BCS (17%) and largely composed of residential and industrial sectors. Nonlocal emissions inside and outside China contribute 28% and 36% to BCC, respectively. Generally transported above 850 hPa, BC from PSEA is the largest nonlocal contributor (20%) to BCC and contributes 80% of BCC in BB sector. Additionally, the interannual variation in EASM onset times bring a maximum of −5% to +7%/−2% to +7% variation in BCC/BCS. The BC outflow/inflow contributed from NC dominates the BC decrease/increase over SC with southerly/northerly wind anomaly induced by early/late EASM onset, yet regional transport from PSEA contributes minor BC changes. The simulated BC is significantly positively correlated with the varying EASM onset times, but not with emissions, indicating the decisive role of meteorology in the interannual variation of BC over SC during springtime.

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Section: Methodsmentioning

confidence: 99%

Regional and Sectoral Sources for Black Carbon Over South China in Spring and Their Sensitivity to East Asian Summer Monsoon Onset

et al. 2020

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“…Within the first three hours, which is the approximate cooking duration in our sampled households, tracheobronchial and alveolar depositions differed by no more than 1.1% and 0.28%, respectively. Taking into account hygroscopic growth but assuming an average mixing state on the other hand, underestimates deposition in the alveoli by up to 5% for aged soot and 20% for fresh soot 54 . These results suggest that neglecting PM hygroscopicity has a relatively small effect on regional deposition, but further work would be needed to determine its impact at a more granular level.…”

Section: Discussionmentioning

confidence: 93%

Size distribution and lung‐deposited doses of particulate matter from household exposure to biomass smoke

et al. 2020

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Exposure to high concentrations of particulate matter (PM) is associated with a number of adverse health effects. However, it is unclear which aspects of PM are most hazardous, and a better understanding of particle sizes and personal exposure is needed. We characterized particle size distribution (PSD) from biomass‐related pollution and assessed total and regional lung‐deposited doses using multiple‐path deposition modeling. Gravimetric measurements of kitchen and personal PM2.5 (<2.5 µm in size) exposures were collected in 180 households in rural Puno, Peru. Direct‐reading measurements of number concentrations were collected in a subset of 20 kitchens for particles 0.3‐25 µm, and the continuous PSD was derived using a nonlinear least‐squares method. Mean daily PM2.5 kitchen concentration and personal exposure was 1205 ± 942 µg/m3 and 115 ± 167 µg/m3, respectively, and the mean mass concentration consisted of a primary accumulation mode at 0.21 µm and a secondary coarse mode at 3.17 µm. Mean daily lung‐deposited surface area (LDSA) and LDSA during cooking were 1009.6 ± 1469.8 µm2/cm3 and 10,552.5 ± 8261.6 µm2/cm3, respectively. This study presents unique data regarding lung deposition of biomass smoke that could serve as a reference for future studies and provides a novel, more biologically relevant metric for exposure‐response analysis compared to traditional size‐based metrics.

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“…Results confirm that CCN activation analysis methods used here and in ambient data sets are robust and may be used to infer the mixing state of complex aerosol compositions of unknown origin. the mixing state and the chemical composition can greatly improve CCN predictions and has been the focus of several studies (e.g., but not limited to Bilde and Svenningsson, 2004;Abbatt et al, 2005;Henning et al, 2005;Svenningsson et al, 2006;King et al, 2007;Cubison et al, 2008;Kuwata and Kondo, 2008;Zaveri et al, 2010;Su et al, 2010;Wang et al, 2010;Spracklen et al, 2011;Ervens et al, 2010;Asa-Awuku et al, 2011;Lance et al, 2013;Liu et al, 2013;Jurányi et al, 2013;Paramonov et al, 2013;Padró et al, 2012;Moore et al, 2012;Meng et al, 2014;Bhattu and Tripathi, 2015;Almeida et al, 2014;Schill et al, 2015;Crosbie et al, 2015;Che et al, 2016;Ching et al, 2016;Mallet et al, 2017;Sánchez Gácita et al, 2017;Cai et al, 2018;Schmale et al, 2018;Mahish et al, 2018;Kim et al, 2018;Chen et al, 2019;Stevens and Dastoor, 2019).…”

mentioning

confidence: 99%

“…However, ambient measurements indicate complex aerosol populations consisting of both external and internal mixtures (e.g., but not limited to Ervens et al, 2007;Lance et al, 2013;Moore et al, 2012;Padró et al, 2012). By accounting for the mixing states and extent of mixing in field data sets, CCN concentration predictions can be greatly improved (e.g but not limited to Padró et al, 2012;Wex et al, 2010;Su et al, 2010;Kuwata and Kondo, 2008). However, dynamic changes in particle mixing states have not been reproduced in the laboratory and subsequent treatment of CCN measurement and analysis has not been readily studied in depth under controlled laboratory conditions.…”

mentioning

confidence: 99%

“…In this work, we seek to improve the experimental CCN activation analysis techniques of complex mixtures by investigating the influence of mixing state on activation curves with known aerosol composition. Theoretical postulations have already been developed and applied to ambient data sets (e.g., but not limited to Su et al, 2010;Padró et al, 2012;Bhattu et al, 2016) but never before has a systematic laboratory experiment controlled and validated the extent of particle heterogeneity for CCN activation. To understand the impact of mixing state on CCN activation, simplified twocomponent mixtures of known compounds with varying hygroscopicities are created under internal, external, and inbetween (transition) mixing conditions.…”

mentioning

confidence: 99%

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External and internal cloud condensation nuclei (CCN) mixtures: controlled laboratory studies of varying mixing states

Gao

Berte

et al. 2019

Atmos. Meas. Tech.

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Changes in aerosol chemical mixtures modify cloud condensation nuclei (CCN) activity. Previous studies have developed CCN models and validated changes in external and internal mixing state with ambient field data. Here, we develop an experimental method to test and validate the CCN activation of known aerosol chemical composition with multicomponent mixtures and varying mixing states. CCN activation curves consisting of one or more activation points are presented. Specifically, simplified two-component systems of varying hygroscopicity were generated under internal, external, and transitional mixing conditions. κ-Köhler theory predictions were calculated for different organic and inorganic mixtures and compared to experimentally derived kappa values and respective mixing states. This work employs novel experimental methods to provide information on the shifts in CCN activation data due to external to internal particle mixing from controlled laboratory sources. Results show that activation curves consisting of single and double activation points are consistent with internal and external mixtures, respectively. In addition, the height of the plateau at the activation points is reflective of the externally mixed concentration in the mixture. The presence of a plateau indicates that CCN activation curves consisting of multiple inflection points are externally mixed aerosols of varying water-uptake properties. The plateau disappears when mixing is promoted in the flow tube. At the end of the flow tube experiment, the aerosols are internally mixed and the CCN activated fraction data can be fit with a single-sigmoid curve. The technique to mimic externally to internally mixed aerosol is applied to non-hygroscopic carbonaceous aerosol with organic and inorganic components. To our knowledge, this work is the first to show controlled CCN activation of mixed nonhygroscopic soot with hygroscopic material as the aerosol population transitions from externally to internally mixed states in laboratory conditions. Results confirm that CCN activation analysis methods used here and in ambient data sets are robust and may be used to infer the mixing state of complex aerosol compositions of unknown origin.

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A Review of the Representation of Aerosol Mixing State in Atmospheric Models

Cited by 36 publications

References 247 publications

Regional and Sectoral Sources for Black Carbon Over South China in Spring and Their Sensitivity to East Asian Summer Monsoon Onset

Regional and Sectoral Sources for Black Carbon Over South China in Spring and Their Sensitivity to East Asian Summer Monsoon Onset

Size distribution and lung‐deposited doses of particulate matter from household exposure to biomass smoke

External and internal cloud condensation nuclei (CCN) mixtures: controlled laboratory studies of varying mixing states

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