1 Mar 2024EFT 12 update for ADMS-Roads, ADMS-Urban and ADMS-Airport

The UK Department for Environment, Food & Rural Affairs and the Devolved Administrations have released version 12 of the Emissions Factors Toolkit (EFT). Details of the changes for this version are given in the EFT user guide.

We have processed the new EFT and published an update for ADMS-Roads, ADMS-Urban and ADMS-Airport version 5 on the Other downloads page of our User Area. If you are registered, you can go straight to the download folder. If you are not registered, follow the instructions on the User Area main page.

29 Feb 2024DHAQ-SEA - Demonstration of High-resolution Air Quality forecasting in South East Asia

There is an increased risk of certain health conditions where ambient air pollution levels are high. CERC are working on a feasibility study for high-resolution (street-scale) air quality forecasting in South East Asia. ASEAN countries can be subject to poor air quality as a consequence of transboundary pollution as well as local pollutant sources. Alerting the public prior to air pollution episodes allows vulnerable and other individuals to take action to reduce the health impacts of poor air quality. The MAQS coupled system is being used to ensure that both regional (using data from CAMS) and local (modelled using ADMS-Urban) contributions to pollution are accounted for.

CERC is working closely with project partners from the Institute for Environment and Resources, Vietnam National University, Ho Chi Minh City and the Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia. The project will generate high resolution pollution maps corresponding to air pollution episodes for two distinct domains, one in Malaysia and one covering parts of southern Vietnam and Cambodia. Key ASEAN stakeholders will be invited to an online workshop to discuss project outcomes during May 2024.

This project will demonstrate that regional to-local-scale air quality forecasting systems could be implemented throughout ASEAN because: the modelling system relies primarily on open data sources; MAQS allows both local and regional contributions to ambient pollution to be accounted for; and CERC are highly experienced in the provision of air quality forecasting services.

The study has received Official Development Assistance (ODA) funding from the UK government Foreign, Commonwealth & Development Office (FCDO) under the Research and Innovation for Development in ASEAN (RIDA) programme. The project focus is on the RIDA priority area 'Health', addressing Sustainable Development Goal (SDG) 3 'Ensure healthy lives and promote well-being for all at all ages.'

30 Jan 2024Exploring air quality model evaluation techniques

Comparisons of modelled and measured data are a key part of evaluating model performance. CERC's latest project for the Atmospheric Dispersion Modelling Liaison Committee (ADMLC) is investigating approaches to air quality model evaluation. A literature review is identifying established and emerging model evaluation techniques and performance metrics for a variety of model types and applications. Case studies will then be used to test the different performance metrics individually and in combination. The project aims to develop best practice recommendations for evaluating a broad range of model applications, reporting late in 2024.

CERC have extensive experience of model evaluation through assessments of the ADMS family of models and inter-comparisons with other models. Jenny Stocker, CERC's Associate Director (Research) has been a long-standing participant in the Forum for Air Quality Modelling (FAIRMODE) initiative which has developed model quality and model performance indicators. CERC have developed and made public the 'Model Evaluation Toolkit' which allows user-friendly access to a broad selection of graphical and statistical model evaluation analyses. The Model Evaluation Toolkit was originally developed under the FP7 PASODOBLE project and recently extended under the SPF Clean Air Programme MAQS-Health project. It makes use of Openair functions and can additionally generate the statistics and graphics recommended by FAIRMODE. The image shows polar plots of the measured and modelled variation of hourly average NO_x concentrations (units ppb) with wind speed and direction at the Schildhornstrasse site in Berlin produced using the Model Evaluation Toolkit, as published in Seaton et al. (2022).

24 Jan 2024Published recommendations for use of NWP meteorological data in dispersion modelling

CERC's investigation of the impacts of using modelled (NWP) meteorological data on dispersion modelling outcomes has now been published by the Atmospheric Dispersion Modelling Liaison Committee (ADMLC). The project was commissioned to examine the effects of NWP model grid resolution on dispersion modelling, in both regulatory and emergency planning contexts, and to make recommendations for the use of NWP data in dispersion modelling.

The report begins with an evaluation of NWP outputs in comparison with meteorological observations at eight UK sites (shown on the map). This is followed by a comparison of ADMS and AERMOD dispersion outcomes for idealised sources at four locations with observed and modelled meteorological data. The report also includes an investigation of the interaction between fine-scale NWP data and local flowfield modelling using the FLOWSTAR model for flow over complex terrain in ADMS. Finally, there are results from the UK Health Security Agency (UKHSA) investigation of the effects of NWP grid resolution on the outcomes of probabilistic accident consequence modelling with the PACE model.

Interim results from the project were presented at CERC's ADMS User Group Meetings in 2022 and 2023; the presentations are available from the User Area. Christina Hood from CERC will also present the sensitivity of ADMS and AERMOD dispersion outputs to varying input meteorological data at the international conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes (Harmo) in June 2024.

19 Dec 2023Street-scale pollution maps for Ireland now available

Results from CERC's modelling of street-scale air pollution in Ireland have been published as part of the Irish Environmental Protection Agency (EPA) report 'Air quality in Ireland 2022'. The full CERC report with high-resolution maps for a wider range of regulated air pollutants is also available. The predicted concentrations were evaluated with measured concentrations with generally good performance for both years at all site types, meeting the FAIRMODE model quality objectives. Modelled concentrations were compared to current Irish air quality standards air quality standards, with exceedances generally associated with the major road network. Most of Ireland meets the World Health Organisation (WHO) guideline for annual average NO₂ concentrations, with exceedences in urban areas, while a substantial proportion of Ireland does not meet the lowest guideline for annual average PM_2.5 concentrations.

CERC were commissioned by the Irish EPA to provide street-scale modelling of Ireland for 2018 and 2019. This used the Multi-model Air Quality System (MAQS) coupled system (developed by CERC) to link regional scale hourly pollution predictions from the EMEP model with local ADMS-Urban modelling. The UK Centre for Ecology & Hydrology (UK CEH) ran the WRF mesoscale meteorological model and EMEP chemical transport model with 1 km horizontal grid resolution over Ireland. CERC carried out detailed road traffic emissions calculations in EMIT based on traffic flow data supplied by the National Transport Authority (NTA) and Transport Infrastructure Ireland (TII). Gridded emissions from non-traffic sources were obtained from the MapEire inventory.

Street canyon effects on dispersion were included in major urban areas. Three major road tunnels were also included in the modelling using the ADMS-Urban tunnels module, with high concentrations noticeable around the portals of the Dublin Port tunnel. The model output is at hourly temporal resolution and irregular spatial resolution. The MAQS PostProcessor utility was used to calculate annual average and high percentile hourly concentrations on regular grids for plotting, at 20 m resolution for whole country maps and 5 m resolution for individual cities.

The 2019 mapped concentrations were uploaded to the recent FAIRMODE composite mapping exercise, which combines and assesses modelling results for different parts of Europe. Preliminary results from this exercise were presented in October 2023, with CERC's modelling results showing good performance in the 'high resolution, unassimilated' category. Presentations describing the Irish emissions inventory development and coupled system modelling were given by CERC at the 2023 ADMS-Urban and ADMS-Roads User Group Meeting.