Atmospheric Aerosol Chemistry: Spectroscopic and Microscopic Advances

Ault, Andrew P.; Axson, Jessica L.

doi:10.1021/acs.analchem.6b04670

Cited by 146 publications

(196 citation statements)

References 246 publications

Supporting

Mentioning

193

Contrasting

Order By: Relevance

“…Both direct and indirect effects are heavily influenced by the composition of aerosols on a per-particle level [4][5][6]. To better understand and predict the influence of industrialization, one aspect of particular interest is the effect that anthropogenic emissions have on the per-particle composition of aerosols and their impacts on local and global climate [2,7].…”

Section: Introductionmentioning

confidence: 99%

Elemental Mixing State of Aerosol Particles Collected in Central Amazonia during GoAmazon2014/15

et al. 2017

View full text Add to dashboard Cite

Two complementary techniques, Scanning Transmission X-ray Microscopy/Near Edge Fine Structure spectroscopy (STXM/NEXAFS) and Scanning Electron Microscopy/Energy Dispersive X-ray spectroscopy (SEM/EDX), have been quantitatively combined to characterize individual atmospheric particles. This pair of techniques was applied to particle samples at three sampling sites (ATTO, ZF2, and T3) in the Amazon basin as part of the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign during the dry season of 2014. The combined data was subjected to k-means clustering using mass fractions of the following elements: C, N, O, Na, Mg, P, S, Cl, K, Ca, Mn, Fe, Ni, and Zn. Cluster analysis identified 12 particle types across different sampling sites and particle sizes. Samples from the remote Amazon Tall Tower Observatory (ATTO, also T0a) exhibited less cluster variety and fewer anthropogenic clusters than samples collected at the sites nearer to the Manaus metropolitan region, ZF2 (also T0t) or T3. Samples from the ZF2 site contained aged/anthropogenic clusters not readily explained by transport from ATTO or Manaus, possibly suggesting the effects of long range atmospheric transport or other local aerosol sources present during sampling. In addition, this data set allowed for recently established diversity parameters to be calculated. All sample periods had high mixing state indices (χ) that were >0.8. Two individual particle diversity (D i ) populations were observed, with particles <0.5 µm having a D i of~2.4 and >0.5 µm particles having a D i of~3.6, which likely correspond to fresh and aged aerosols, respectively. The diversity parameters determined by the quantitative method presented here will serve to aid in the accurate representation of aerosol mixing state, source apportionment, and aging in both less polluted and more developed environments in the Amazon Basin.

show abstract

Section: Introductionmentioning

confidence: 99%

Elemental Mixing State of Aerosol Particles Collected in Central Amazonia during GoAmazon2014/15

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Atmospheric aerosols are emitted from a variety of sources and complex mixtures of organic and inorganic substances (Ault and Axson, 2017). Due to the complex components, aerosols have a wide range of physical and chemical properties (Hinds, 1999;Sullivan and Prather, 2005;Ault and Axson, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…Due to the complex components, aerosols have a wide range of physical and chemical properties (Hinds, 1999;Sullivan and Prather, 2005;Ault and Axson, 2017). Aerosols affect both the climate and human health on a global scale (IPCC, 2013;Pope and Dockery, 2006).…”

Section: Introductionmentioning

confidence: 99%

Electrospray surface-enhanced Raman spectroscopy (ES-SERS) for probing surface chemical compositions of atmospherically relevant particles

Gen

Chan

2017

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. We present electrospray surface-enhanced Raman spectroscopy (ES-SERS) as a new approach to measuring the surface chemical compositions of atmospherically relevant particles. The surface-sensitive SERS is realized by electrospraying Ag nanoparticle aerosols over analyte particles. Spectral features at v(SO Enhanced spectra of the solid AS and AS / SA particles revealed the formation of surface-adsorbed water on their surfaces at 60 % relative humidity. These observations of surface aqueous sulfate and adsorbed water demonstrate a possible role of surface-adsorbed water in facilitating the dissolution of sulfate from the bulk phase into its water layer(s). Submicron ambient aerosol particles collected in Hong Kong exhibited non-enhanced features of black carbon and enhanced features of sulfate and organic matter (carbonyl group), indicating an enrichment of sulfate and organic matter on the particle surface.

show abstract

“…Therefore, it is important to identify the sources of aerosol particles present in the southeastern United States, as well as their size and mixing state in order to accurately assess their impact on aerosol direct and indirect effects Moise et al, 2015;Posfai and Buseck, 2010). 5 Mixing state is described in terms of external and internal mixtures: an external mixture consists of particles that contain only one pure species per particle, while an internal mixture describes particles that contain equal amounts of all chemical species (Ault and Axson, 2017;Posfai and Buseck, 2010;Riemer and West, 2013). The mixing states of ambient aerosol populations are complex and can vary as a function of size, altitude, and particle age (Fu et al, 2012;Healy et al, 2014a;Moffet et al, 2010b;Pratt 10 and Prather, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…Aging, or atmospheric processing such as coagulation, condensation of secondary species, and heterogeneous reactions leads to internal mixing, while freshly emitted particles are more externally mixed (Schutgens and Stier, 2014;Weingartner et al, 1997). Here, mixing state is used to describe the distribution of chemical species in a population and is purely based on composition, not including particle morphology or other physical properties (Ault and Axson, 2017). Although the 15 representation of mixing state in models is still an open research question (Riemer and West, 2013), an appropriate description of mixing state is critical for modeling the optical properties (Chung and Seinfeld, 2005;Jacobson, 2001;Zaveri et al, 2010) and cloud condensation nuclei (CCN) activity of particles (Zaveri et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Diverse Chemical Mixing States of Aerosol Particles in the Southeastern United States

Bondy¹,

Bonanno²,

Moffet³

et al. 2018

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. Aerosols in the atmosphere are chemically complex with thousands or more chemical species distributed in different proportions across individual particles in an aerosol population. An internal mixing 15 assumption, with species present in the same proportions across all aerosols, is used in many models and calculations of secondary organic aerosol (SOA) formation, cloud activation, and aerosol optical properties. However, many of these effects depend on the distribution of species within individual particles, and important information can be lost when internal mixtures are assumed. Herein, we show that during the Southern Oxidant and Aerosol Study (SOAS) in Centreville, Alabama, at a rural, forested 20 location, that aerosols frequently are not purely internally mixed, even in the accumulation mode (0.2-1.0 µm). A range of aerosol sources and mixing states were obtained using computer controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX) and scanning transmission X-ray microscopy-near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS). Particles that were dominated by SOA and inorganic salts were the majority of particles by 25 number fraction from 0.2-5 microns with an average of 78% SOA in the accumulation mode. However, during certain periods contributions by sea spray aerosol (SSA) and mineral dust were significant to accumulation (22 % SSA and 26 % dust) and coarse mode number concentrations (38 % SSA and 63% dust). The fraction of particles containing key elements (Na, Mg, K, Ca, and Fe) were determined as a Atmos. Chem. Phys. Discuss., https://doi

show abstract

Atmospheric Aerosol Chemistry: Spectroscopic and Microscopic Advances

Cited by 146 publications

References 246 publications

Elemental Mixing State of Aerosol Particles Collected in Central Amazonia during GoAmazon2014/15

Elemental Mixing State of Aerosol Particles Collected in Central Amazonia during GoAmazon2014/15

Electrospray surface-enhanced Raman spectroscopy (ES-SERS) for probing surface chemical compositions of atmospherically relevant particles

Diverse Chemical Mixing States of Aerosol Particles in the Southeastern United States

Contact Info

Product

Resources

About