Large-eddy simulation of aerosol concentrations in a realistic urban environment : Model validation and transport mechanism
(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.
(Less)
- author
- Du, Yaxing
; Isaxon, Christina
LU
; Roldin, Pontus
LU
; Mattisson, Kristoffer
LU
; Karttunen, Sasu ; Li, Xiaoyu ; Malmqvist, Ebba LU
and Järvi, Leena LU
- organization
-
- Centre for Healthy Indoor Environments
- LTH Profile Area: Nanoscience and Semiconductor Technology
- LTH Profile Area: Aerosols
- Metalund
- Ergonomics and Aerosol Technology
- NanoLund: Centre for Nanoscience
- Combustion Physics
- LU Profile Area: Nature-based future solutions
- Nuclear physics
- MERGE: ModElling the Regional and Global Earth system
- CIRCLE
- Planetary Health (research group)
- Division of Occupational and Environmental Medicine, Lund University
- publishing date
- 2024-10-01
- 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
-
- pmid:38950843
- scopus:85198968052
- 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
- 2025-06-19 17:42:37
@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}}, }