Journal article
Effect of Dust Morphology on Aerosol Optics in the GEOS‐Chem Chemical Transport Model, on UV‐Vis Trace Gas Retrievals, and on Surface Area Available for Reactive Uptake
Journal of advances in modeling earth systems, Vol.16(10), e2023MS003746
10/2024
DOI: 10.1029/2023MS003746
Abstract
Abstract Many chemical transport models treat mineral dust as spherical. Solar backscatter retrievals of trace gases (e.g., OMI and TROPOMI) implicitly treat mineral dust as spherical. The impact of the morphology of mineral dust particles is studied to assess its implications for global chemical transport model (GEOS‐Chem) simulations and solar backscatter trace gas retrievals at ultraviolet and visible (UV‐Vis) wavelengths. We investigate how the morphology of mineral dust particles affects the simulated dust aerosol optical depth; surface area, reaction, and diffusion parameters for heterogeneous chemistry; phase function, and scattering weights for air mass factor (AMF) calculations used in solar backscatter retrievals. We use a mixture of various aspect ratios of spheroids to model the dust optical properties and a combination of shape and porosity to model the surface area, reaction, and diffusion parameters. We find that assuming spherical particles can introduce size‐dependent and wavelength‐dependent errors of up to 14% in simulated dust extinction efficiency with corresponding error in simulated dust optical depth typically within 5%. We find that use of spheroids rather than spheres increases forward scattered radiance and decreases backward scattering that in turn decrease the sensitivity of solar backscatter retrievals of NO 2 to aerosols by factors of 2.0–2.5. We develop and apply a theoretical framework based on porosity and surface fractal dimension with corresponding increase in the reactive uptake coefficient driven by increased surface area and species reactivity. Differences are large enough to warrant consideration of dust non‐sphericity for chemical transport models and UV‐Vis trace gas retrievals.
Plain Language Summary Mineral dust is often treated as spherical in chemical transport and trace gas retrieval models. In this study, we investigate how dust shape affects gas‐particle and radiation‐particle interactions. We examine the impact of dust shape on optical properties and trace gas retrievals at ultraviolet and visible wavelengths. We find that treating dust as nonspherical in trace gas retrievals of nitrogen dioxide decreases the retrieval sensitivity to dust. We also examine the impact of dust shape on heterogeneous chemistry by developing and applying a theoretical model. We find that dust pores change particle surface area significantly and subsequently, reaction and diffusion parameters. Overall, this study signifies the importance of accounting for nonsphericity in chemical transport and trace gas retrieval models.
Key Points We implement a spheroidal model for dust shape along with the porosity to examine dust morphology effects in a chemical transport model Nonspherical dust particles with pores increase surface area available for reactive uptake Spheroidal rather than spherical dust treatment reduces the effects of aerosols on UV‐Vis NO 2 retrievals by factors of 2.0–2.5
Details
- Title: Subtitle
- Effect of Dust Morphology on Aerosol Optics in the GEOS‐Chem Chemical Transport Model, on UV‐Vis Trace Gas Retrievals, and on Surface Area Available for Reactive Uptake
- Creators
- Inderjeet Singh - Washington University in St. LouisRandall V. Martin - Washington University in St. LouisLiam Bindle - Washington University in St. LouisDeepangsu Chatterjee - Washington University in St. LouisChi Li - Washington University in St. LouisChristopher Oxford - Washington University in St. LouisXiaoguang Xu - University of Maryland, Baltimore CountyJun Wang - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of advances in modeling earth systems, Vol.16(10), e2023MS003746
- Publisher
- AMER GEOPHYSICAL UNION
- DOI
- 10.1029/2023MS003746
- ISSN
- 1942-2466
- eISSN
- 1942-2466
- Grant note
- National Aeronautics and Space Administration: 80NSSC22KO200
This work was supported by internal funds at Washington University and by NASA Grant 80NSSC22KO200. We acknowledge the free use of the TROPOMI surface DLER database provided through the Sentinel-5p+ innovation project of the European Space Agency (ESA). The TROPOMI surface DLER database was created by the Royal Netherlands Meteorological Institute (KNMI). We gratefully thank Kritika Sharma from Electrochemical Engineering Research Lab, Washington University, for many valuable discussions on the concepts of reaction engineering.
- Language
- English
- Date published
- 10/2024
- Academic Unit
- Physics and Astronomy; Electrical and Computer Engineering; Chemical and Biochemical Engineering; Civil and Environmental Engineering
- Record Identifier
- 9984721134302771
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