The challenges of air quality modelling when crossing multiple spatial scales

• Published in: Air quality, atmosphere and health atmosphere and health, 2019-09, Vol.12 (9), p.1003-1017
• Main Authors: Silveira, Carlos, Ferreira, Joana, Miranda, Ana Isabel
• Format: Article
• Language: English
• Subjects: Air pollution; Air quality; Air quality assessments; Air quality models; Atmospheric models; Atmospheric processes; Atmospheric Protection/Air Quality Control/Air Pollution; Computer simulation; Domains; Earth and Environmental Science; Environment; Environmental Health; Health Promotion and Disease Prevention; Mesoscale models; Multiscale analysis; Nesting; On-line systems; Organic chemistry; Ozone; Pollutant deposition; Pollutants; Pollution dispersion; Quality; Quality assessment; Quality control; State-of-the-art reviews; Uncertainty analysis
• ISSN: 1873-9318; 1873-9326
• DOI: 10.1007/s11869-019-00733-5

Multiscale air quality assessment implies understanding the interaction among atmospheric processes and scales. In this perspective, the use of air quality models has a fundamental role and the way they address these interactions is very important for the quality of results. However, in multiscale air quality modelling, the relationship between models, simulation domains and resolutions remains a challenging research issue. This paper presents a state-of-the-art review on multiscale air quality modelling applications from the regional to the street level, identifying which models are used, the methodological principles and the required input datasets. Based on the findings, an analysis of the current limitations associated with the integration of different models and multiple spatial scales in a single modelling system is presented and discussed. Lastly, taking as support the reviewed contents, a set of guidelines for strengthening the synergy among scales and harmonizing different types of models within a system is proposed. Unsuitable or non-existent urban canopy parametrizations (UCP), limited grid resolutions, discarded microscale impacts on upper domains, inadequate input data and simplified chemistry are some important aspects contributing to large uncertainties when analyzing multiscale air quality results. To overcome these shortcomings in current multiscale modelling systems, more research aimed at improving the modelling performance is required, focusing on (i) UCP coupled to mesoscale models, (ii) developing modelling systems with two-way nesting capability to boost feedbacks among domains and (iii) promoting the use, improvement and development of multiscale online modelling systems, in order to have a comprehensive multiscale understanding of all atmospheric processes that govern the transport, dispersion, transformation and deposition of air pollutants.