CERC news

ADMLC seminar on the use of NWP meteorological data in modelling

Wed, 04 Sep 2024 00:00:00 GMT

The Atmospheric Dispersion Modelling Liaison Committee (ADMLC) and Institute of Air Quality Management (IAQM) are hosting an in-person seminar: Investigating the impact of applying different grid resolutions of NWP data in atmospheric dispersion modelling. More information and an Agenda can be found via the ADMLC web site.

The seminar will run from 9:30 to 14:00 on Friday 18th October 2024.

The ADMLC funded an investigation into the consequence of using different spatial and temporal resolutions of Numerical Weather Prediction (NWP) met data on:

(a) model predictions of annual mean concentration and high percentile hourly concentrations for a regulatory assessment; and

(b) model endpoints derived by way of probabilistic accident consequence assessments.

CERC and the UK Health Security Agency (UKHSA) worked collaboratively to address the needs of the ADMLC, producing a report which documents the study’s findings and recommendations.

The seminar will provide an opportunity:

for the authors to share their findings and recommendations.
for discussion of any potential issues raised in the context of the study.

If these topics are of interest to you, please join us for this seminar; your attendance and contributions would be welcomed.

There is no fee to attend. However, you must register. Please request attendance by contacting the ADMLC Secretariat at: admlc@ukhsa.gov.uk by Friday 4th October.

Address: UKHSA (Training Centre), Harwell Campus, Didcot, Oxfordshire, OX11 0RQ. Directions: Radiation Protection Services - Chilton office (ukhsa-protectionservices.org.uk).

Low Traffic Neighbourhoods in London

Fri, 30 Aug 2024 00:00:00 GMT

CERC consultants are carrying out air quality modelling to calculate the health impact of changes in air pollution due to the introduction of Low Traffic Neighbourhoods (LTNs) across four London boroughs. The modelling uses ADMS-Urban and the emissions inventory tool EMIT.

The work is being carried out as part of the Low Traffic Neighbourhoods in London Research Study: a mixed methods study of benefits harms and experiences (Award ID: NHIR135020). It will examine the potential benefits and harms of new LTN schemes and understand the experiences of those living in or near LTNs.

CERC’s modelling of air pollution levels, with and without the LTNs in place, will account for changes in traffic, speed and congestion on roads within the LTNs and surrounding areas. These data will be used to calculate the air pollution health impact of the schemes, as part of wider health impact assessments that include changes in the levels of walking and cycling, and road injury risks.

The project is led by University of Westminster and London School of Hygiene and Tropical Medicine, in collaboration with the University of Cambridge, Imperial College London and Transport for All.

York air quality forecasting and alert service

Fri, 19 Jul 2024 00:00:00 GMT

City of York Council commissioned CERC to develop an air quality forecasting and alert service to give York residents advance warning of when air pollution is expected to be higher than usual, up to 3 days ahead. The service provides daily air quality forecast maps at 5 metre resolution and zone-based air quality, pollen, UV and temperature forecasts. Residents can sign up to receive free air quality text, email or voice alerts; the expected alert level in each zone is also posted on X (Twitter). Forecasts are issued twice a day and routinely compared with monitored levels to maintain accuracy.

Commenting on the service, Cllr Jenny Kent, Executive Member for Environment and Climate Emergency at City of York Council, said: “This is a really simple and easy to use tool to help residents with health conditions affected by air pollution plan ahead and reduce exposure. We hope these forecasts will also raise awareness of air pollution across the city and encourage people to consider their air quality impact in helping to protect everyone’s health. Poor air quality is a contributory factor in 1 in 22 deaths in York. We can all improve this statistic; share a lift to work, work from home or walk, catch the bus or cycle, if possible, especially on days with high pollution. Solid fuel fires should also be avoided wherever possible. The new website will display maps outlining day-to-day air pollution levels. The alerts sent out will offer guidance on whether people are at risk from air pollution on a particular day and provide advice on how to stay healthy and aware.”

CERC’s air quality forecasting system for York combines weather forecasts, European-scale pollution forecasts from the Copernicus Atmosphere Monitoring Service (CAMS) and very detailed dispersion modelling of pollution sources across York using CERC's ADMS-Urban model. The cloud-based containerised system uses Microsoft’s Azure Kubernetes Service (AKS), GDAL and GeoServer to process model data to create maps and calculate alert levels. CERC provide similar services for London and South-East England (airTEXT), Manchester (Clean Air for Greater Manchester) and Riga (Riga airTEXT).

Benchmarking nitrogen deposition models

Tue, 09 Jul 2024 00:00:00 GMT

CERC are taking part in a model inter-comparison study led by RIVM in the Netherlands to benchmark local scale nitrogen deposition dispersion models. The project was motivated by the significant number of nitrogen deposition limit value exceedances in Dutch Natura 2000 areas and a 2019 High Court Ruling, which concluded that the current Dutch policy to reduce nitrogen deposition was inadequate. In response, the Dutch Ministry of Agriculture, Fisheries, Food Security and Nature initiated a research programme to propose and implement improvements in the Dutch measurement and modelling system that is used to evaluate the nitrogen deposition on nature areas. This model-intercomparison study for local scale is part of that research programme.

The study has two parts. Firstly, participating models have been set up to represent a wide range of source types and terrain, for example agricultural and traffic sources in mixed land use areas. Ten years of hourly and annual concentration and deposition values have been generated for each model configuration, and then inter-compared. The second stage of the project involves evaluation of model outputs using measurement data from a number of field campaigns. RIVM are currently finalizing the campaign datasets, and models will be set up and run over the summer.

The UK Centre for Ecology and Hydrology, VITO (Belgium), and Aarhaus University (Denmark) are also participating in the benchmarking study using Gaussian dispersion models. In addition, a group from the Dutch Wageningen University is running Large Eddy Simulations to inform the study outcomes. Results will be made public following project completion, which is scheduled for the end of 2024.

The Atmospheric Dispersion Modelling Liaison Committee (ADMLC), which has been supporting research into atmospheric dispersion modelling methods for over 25 years, has part-funded CERC's participation in this project.

Source apportionment analysis for London’s bus fleet

Tue, 18 Jun 2024 00:00:00 GMT

The Transport for London (TfL) red-liveried bus fleet are part of the city's identity, but were a key area for improvement in the Mayor of London's 2018 Environment Strategy. Southwark Borough Council commissioned CERC consultants to assess the contribution of bus emissions to total pollutant concentrations in Southwark.

Using the ADMS-Urban model and emissions inventory tool EMIT, we created air quality maps of the borough for nitrogen dioxide and particulates, based on all emissions and then on bus emissions only. We also modelled pollutant concentrations at a large set of roadside receptors along Southwark's bus routes.

We took traffic data from the London Atmospheric Emissions Inventory, using EMIT to create a traffic scenario including only buses. The figure shows source apportionment results for NO_x, with concentrations due to bus emissions shown as a proportion of the concentration from all emissions sources.

At locations where the modelled annual average NO₂ objective is exceeded, buses may contribute to less than 10% of the total NO_x, as seen along Old Kent Road. In contrast, at Elephant Square and St. George's Circus, buses can be responsible for over 40% of total NO_x. This highlights key areas where improving bus infrastructure would result in tangible improvements to air quality.

ADMS 6.0.2 released

Wed, 15 May 2024 00:00:00 GMT

CERC are pleased to announce the release of ADMS 6.0.2. This is a minor update providing additional output options that were requested at the 2023 ADMS User Group Meeting.

The first of these new options is the ability to output additional plume properties for point sources to the .cen file. The plume density and Richardson number used in the plume rise calculations can now be output, which can be useful when examining the behaviour of elevated dense releases. Additionally, wind speed and turbulence values at the mean plume height can now be output allowing for greater understanding of the behaviour of the plume.

The other new output option is the ability to output the accumulated horizontal concentration flux at specific locations. This output is given per wind direction sector making for easy comparison with measurements obtained from directional passive air samplers.

In addition to these new output options we have decreased run times for runs with spatially varying deposition. For full details on the changes within ADMS 6.0.2 please see the What's New document.

ADMS 6.0.2 is available to download from the User Area for licence holders with current support.

Air quality assessment of amine-based carbon capture

Fri, 03 May 2024 00:00:00 GMT

The Environment Agency commissioned CERC to carry out a project instigated by their modelling team AQMAU, entitled Improving Post-Combustion Carbon Capture Air Quality Risk Assessment Techniques. The project aimed to increase confidence in risk assessments for regulatory purposes, to integrate practical tools and evidence, and to inform decision-making.

The decarbonisation of industry is pushing the evolution of air dispersion modelling to assess the risk of emissions from emerging techniques such as amine-based post-combustion carbon capture.

As developers of the state-of-the-art ADMS amines chemistry module, CERC were ideally placed to carry out this project and have published their report.

The project addresses the uncertainties of ADMS input data and assumptions and improves the transparency and significance of the assessment process. It will further increase confidence and understanding of the ADMS approach and assessment strategies.

As part of the project, CERC developed an additional user-friendly tool and user guide to help model users calculate and document the amine-related input parameters.

Booking is now open for the ADMS User Group Meetings, 4-5 December 2024, Cambridge

Thu, 02 May 2024 00:00:00 GMT

You can now book your tickets for the 2024 ADMS User Group Meetings, which will be held at Murray Edwards College on 4th and 5th December.

The annual ADMS User Group Meetings are a great opportunity to hear the latest ADMS model news and advice from CERC consultants and model developers, to hear talks by model users about their own applications of the software, and to network with other model users.

Tickets are available to order through Eventbrite until 23:30 on Tuesday 12th November. Organisations with a valid software support contract are entitled to one or more tickets free of charge depending on the type of licence held. The draft programme will be published soon.

Air quality impact of paint spraying facilities

Mon, 29 Apr 2024 00:00:00 GMT

CERC has carried out assessments of the air quality impact of exhaust plumes from vehicle and aircraft paint spraying facilities to support planning applications, using ADMS 6.

CERC's consultancy team worked from a list of paint products, together with Safety Data Sheets and Technical Data Sheets for paint components. These were combined with paint usage data and Emission Limit Values (ELVs) to calculate emission rates of particulates, VOCs and isocyanates from spray booth exhaust stacks.

Process-specific ELVs are provided in Defra Process Guidance Notes such as 6/47(11): Statutory guidance for original coating of road vehicles and trailers.

The Guidance Note 6/47(11) refers to the calculation of a suitable stack height using HMIP Technical Guidance Note (Dispersion) D1, now obsolete. The Note states that alternative dispersion models may be used.

We have found that the application of ADMS can lead to the calculation of a lower stack height than screening methods such as D1, especially where working hours are represented.

2024 ADMS User Group Meetings: 4-5 December 2024, Cambridge

Mon, 18 Mar 2024 00:00:00 GMT

The 2024 ADMS User Group Meetings will be held at the Murray Edwards College, Cambridge, on the following dates:

ADMS 6, Wednesday 4 December
ADMS-Urban and ADMS-Roads, Thursday 5 December

EFT 12 update for ADMS-Roads, ADMS-Urban and ADMS-Airport

Fri, 01 Mar 2024 00:00:00 GMT

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.

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

Thu, 29 Feb 2024 00:00:00 GMT

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.'

Exploring air quality model evaluation techniques

Tue, 30 Jan 2024 00:00:00 GMT

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).

Published recommendations for use of NWP meteorological data in dispersion modelling

Wed, 24 Jan 2024 00:00:00 GMT

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.

Street-scale pollution maps for Ireland now available

Tue, 19 Dec 2023 00:00:00 GMT

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.