Submitted as: model description paper
24 Mar 2023
Submitted as: model description paper |  | 24 Mar 2023
Status: this preprint is currently under review for the journal GMD.

IAQMS-street v2.0: a two-way coupled regional-urban–street-network model system for Beijing, China

Tao Wang, Hang Liu, Jie Li, Shuai Wang, Youngseob Kim, Yele Sun, Wenyi Yang, Huiyun Du, Zhe Wang, and Zifa Wang

Abstract. Owing to the substantial traffic emissions in urban areas, especially near road areas, the concentrations of pollutants, such as ozone (O3) and its precursors, have a large gap with the regional averages and their distributions cannot be captured accurately by traditional single-scale air-quality models. In this study, a new version of a regional-urban-street-network model (IAQMS-street v2.0) is presented. An upscaling module is implemented in IAQMS-street v2.0 to calculate the impact of mass transfer to regional scale from street network. The influence of pollutants in street network is considered in the concentration calculation on regional scale, which is not considered in a previous version (IAQMS-street v1.0). In this study, the simulated results in Beijing during August 2021 by using IAQMS-street v2.0, IAQMS-street v1.0, and the regional model (NAQPMS) are compared. On-road traffic emissions in Beijing, as the key model-input data, were established using intelligent image-recognition technology and real-time traffic big data from navigation applications. The simulated results showed that the O3 and nitrogen oxides (NOx) concentrations in Beijing were reproduced by using IAQMS-street v2.0 both on regional scale and street scale. The prediction fractions within a factor of two (FAC2s) between simulations and observations of NO and NO2 increased from 0.11 and 0.34 in NAQPMS to 0.78 and 1.00 in IAQMS-street v2.0, respectively. The normalized mean biases (NMBs) of NO and NO2 decreased from 2.67 and 1.33 to -0.25 and 0.08. the concentration of NOx at street scale is higher than that at the regional scale, and the simulated distribution of pollutants on regional scale was improved in IAQMS-street v2.0 compared with that in IAQMS-street v1.0. We further used the IAQMS-street v2.0 to quantify the contribution of local on-road traffic emissions to the O3 and NOx emissions and analyze the effect of traffic-regulation policies in Beijing. Results showed that heavy-duty trucks are the major source of on-road traffic emissions of NOx. The relative contributions of local traffic emissions to NO2, NO, and O3 emissions were 53.41, 57.45, and 8.49 %, respectively. We found that traffic-regulation policies in Beijing largely decreased the concentrations of NOx and hydrocarbons (HC); however, the O3 concentration near the road increased due to the decrease consumption of O3 by NO. To decrease the O3 concentration in urban areas, controlling the local emissions of HC and NOx from other sources requires consideration.

Tao Wang et al.

Status: open (until 25 Jun 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on gmd-2023-5', Anonymous Referee #1, 23 Apr 2023 reply
  • RC2: 'Comment on gmd-2023-5', Anonymous Referee #2, 29 May 2023 reply

Tao Wang et al.


Total article views: 377 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
294 71 12 377 16 4 5
  • HTML: 294
  • PDF: 71
  • XML: 12
  • Total: 377
  • Supplement: 16
  • BibTeX: 4
  • EndNote: 5
Views and downloads (calculated since 24 Mar 2023)
Cumulative views and downloads (calculated since 24 Mar 2023)

Viewed (geographical distribution)

Total article views: 362 (including HTML, PDF, and XML) Thereof 362 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 05 Jun 2023
Short summary
This paper developed a two-way coupled module in latest version of a regional-urban-street-network model IAQMS-street v2.0, the mass flux from streets to background is considered. Test cases are defined to evaluate the performance of IAQMS-street v2.0 in Beijing by comparing it with that simulated by IAQMS-street v1.0 and regional model. The contribution of local emissions and the influence of on-road vehicle-control measures on air quality are evaluated by using IAQMS-street v2.0.