Progress in the Analysis of Complex Atmospheric Particles

Abstract

This article presents an overview of recent advances in field and laboratory studies of atmospheric particles formed in processes of environmental air-surface interactions. The overarching goal of these studies is to advance predictive understanding of atmospheric particle composition, particle chemistry during aging, and their environmental impacts. The diversity between chemical constituents and lateral heterogeneity within individual particles adds to the chemical complexity of particles and their surfaces. Once emitted, particles undergo transformation via atmospheric aging processes that further modify their complex composition. We highlight a range of modern analytical approaches that enable multimodal chemical characterization of particles with both molecular and lateral specificity. When combined, these approaches provide a comprehensive arsenal of tools for understanding the nature of particles at air-surface interactions and their reactivity and transformations with atmospheric aging. We discuss applications of these novel approaches in recent studies and highlight additional research areas to explore the environmental effects of air-surface interactions.

Microscopic Observations of Core‐Shell Particle Structure and Implications for Atmospheric Aerosol Remote Sensing

“…Desert dust was found more abundant in the supermicrometer size fractions. Indeed, desert dust particles may be transformed during transport through multiphase chemistry, resulting in internal mixing with condensed‐phase organic constituents (Laskin et al, ). Nitrates and sulfates can uptake onto mineral dust by forming a layer around the particle and transforming the shape of the nonspherical mineral dust into a spherical one (Hwang & Ro, ; Kojima et al, ; Laskin et al, ; Li & Shao, , b; Matsuki et al, ; Sullivan et al, ; Tang et al, ; D. Zhang et al, ).…”

Aerosol Mixing State: Measurements, Modeling, and Impacts

“…The continuous evolution of mixing state for an aerosol in the atmosphere is shown conceptually in Figure 2 and is the result of a number of processes. As an air parcel containing an internally mixed, background aerosol is advected over an urban area (1), the population becomes more externally mixed as primary particle Reviews of Geophysics 10.1029/2018RG000615 physicochemical properties of particles and understand their contribution to the mixing state of an aerosol in increasing detail (Ault & Axson, 2017;Laskin et al, 2016;Prather et al, 2008;Pratt & Prather, 2012a). Concurrently, atmospheric models have become sufficiently complex to incorporate aspects of aerosol mixing state in their predictions (Riemer & West, 2013;Riemer et al, 2010).…”

Visualizing reaction and diffusion in xanthan gum aerosol particles exposed to ozone

“…Organic matter in atmospheric aerosol stems from a variety of natural and anthropogenic sources and is found in significant quantities in almost every single particle. [1][2][3] Aerosol particles can both scatter and absorb light to varying degrees depending on their morphology and chemical composition, and they significantly impact the global radiative balance. 4,5 These particles also act as nuclei for liquid droplets and ice in clouds.…”

“…Our STXM/NEXAFS spatio-chemical data allows a novel constraint for modeling aerosol internal chemical profiles, i.e. simultaneous reproduction of bulk Fe 2+ depletion and the spatio-temporal evolution of O 3 and Fe 2+ reaction. In the context of our results, we discuss the applicability of the reacto-diffusive limiting case and the importance of direct observational constraints on model predictions of atmospheric aerosol chemical aging.…”