4 Sep 2024ADMLC seminar on the use of NWP meteorological data in modelling

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).

30 Aug 2024Low Traffic Neighbourhoods in London

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.

19 Jul 2024York air quality forecasting and alert service

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).

9 Jul 2024Benchmarking nitrogen deposition models

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.

18 Jun 2024Source apportionment analysis for London’s bus fleet

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.