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Large-eddy simulation of aerosol concentrations in a realistic urban environment : Model validation and transport mechanism

Du, Yaxing ; Isaxon, Christina LU ; Roldin, Pontus LU ; Mattisson, Kristoffer LU orcid ; Karttunen, Sasu ; Li, Xiaoyu ; Malmqvist, Ebba LU orcid and Järvi, Leena LU (2024) In Environmental Pollution 358.
Abstract

Air pollution in urban environments exhibits large spatial and temporal variations due to high heterogeneous air flow and emissions. To address the complexity of local air pollutant dynamics, a comprehensive large-eddy simulation using the PALM model system v6.0 was conducted. The distribution of flow and vehicle emitted aerosol particles in a realistic urban environment in Malmö, Sweden, was studied and evaluated against on-site measurements made using portable instrumentation on a spring morning in 2021. The canyon transport mechanisms were investigated, and the convective and turbulent mass-transport rates compared to clarify their role in aerosol transport. The horizontal distribution of aerosols showed acceptable evaluation metrics... (More)

Air pollution in urban environments exhibits large spatial and temporal variations due to high heterogeneous air flow and emissions. To address the complexity of local air pollutant dynamics, a comprehensive large-eddy simulation using the PALM model system v6.0 was conducted. The distribution of flow and vehicle emitted aerosol particles in a realistic urban environment in Malmö, Sweden, was studied and evaluated against on-site measurements made using portable instrumentation on a spring morning in 2021. The canyon transport mechanisms were investigated, and the convective and turbulent mass-transport rates compared to clarify their role in aerosol transport. The horizontal distribution of aerosols showed acceptable evaluation metrics for both mass and number. Flow and pollutant concentrations were more complex than those in idealized street canyon networks. Vertical turbulent mass-transport rate was found to dominate the mass transport process compared with the convective transport rate, contributing more than 70% of the pollutant transport process. Our findings highlight the necessity of examining various aerosol metric due their distinct dispersion behaviour. This study introduces a comprehensive high-resolution modelling framework that accounts for dynamic meteorological and aerosol background boundary conditions, real-time traffic emission, and detailed building features, offering a robust toll for local urban air quality assessment.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aerosol particle, Large eddy simulation, PALM model system, Pollutant dispersion, Transport mechanism, Vehicle emission
in
Environmental Pollution
volume
358
article number
124475
publisher
Elsevier
external identifiers
  • scopus:85198968052
  • pmid:38950843
ISSN
0269-7491
DOI
10.1016/j.envpol.2024.124475
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2024 The Authors
id
75cce7ae-019f-424d-acaf-d7bfccdbdb74
date added to LUP
2024-08-28 14:19:46
date last changed
2024-08-28 14:27:37
@article{75cce7ae-019f-424d-acaf-d7bfccdbdb74,
  abstract     = {{<p>Air pollution in urban environments exhibits large spatial and temporal variations due to high heterogeneous air flow and emissions. To address the complexity of local air pollutant dynamics, a comprehensive large-eddy simulation using the PALM model system v6.0 was conducted. The distribution of flow and vehicle emitted aerosol particles in a realistic urban environment in Malmö, Sweden, was studied and evaluated against on-site measurements made using portable instrumentation on a spring morning in 2021. The canyon transport mechanisms were investigated, and the convective and turbulent mass-transport rates compared to clarify their role in aerosol transport. The horizontal distribution of aerosols showed acceptable evaluation metrics for both mass and number. Flow and pollutant concentrations were more complex than those in idealized street canyon networks. Vertical turbulent mass-transport rate was found to dominate the mass transport process compared with the convective transport rate, contributing more than 70% of the pollutant transport process. Our findings highlight the necessity of examining various aerosol metric due their distinct dispersion behaviour. This study introduces a comprehensive high-resolution modelling framework that accounts for dynamic meteorological and aerosol background boundary conditions, real-time traffic emission, and detailed building features, offering a robust toll for local urban air quality assessment.</p>}},
  author       = {{Du, Yaxing and Isaxon, Christina and Roldin, Pontus and Mattisson, Kristoffer and Karttunen, Sasu and Li, Xiaoyu and Malmqvist, Ebba and Järvi, Leena}},
  issn         = {{0269-7491}},
  keywords     = {{Aerosol particle; Large eddy simulation; PALM model system; Pollutant dispersion; Transport mechanism; Vehicle emission}},
  language     = {{eng}},
  month        = {{10}},
  publisher    = {{Elsevier}},
  series       = {{Environmental Pollution}},
  title        = {{Large-eddy simulation of aerosol concentrations in a realistic urban environment : Model validation and transport mechanism}},
  url          = {{http://dx.doi.org/10.1016/j.envpol.2024.124475}},
  doi          = {{10.1016/j.envpol.2024.124475}},
  volume       = {{358}},
  year         = {{2024}},
}