29 Apr 2026Tribute to Julian Hunt

It is with great sadness we announce that Julian Hunt died on 20 April 2026.

As a brilliant scientist, Julian applied his mind and inexhaustible energy to a wide range of fluid mechanical problems. These ranged from fundamental studies of turbulence near surfaces and around obstacles, including his seminal papers on the rapid distortion theory of turbulence, to many ground-breaking studies with more immediate applications, including: turbulent airflow over hills; structure of the atmospheric boundary layer; atmospheric dispersion of pollutants over complex terrain; and airflow in urban and coastal environments.

Julian was always keen on communicating his research and applying it to practical applications. This led to him being a founding director of Cambridge Environmental Research Consultants in 1985; as he told me, he was motivated by his research being applied in the USA, "so why not in the UK?" At CERC, he was the leading force in the development of a range of fast environmental models incorporating state-of-the-art science. The first of these was FLOWSTAR for turbulent flow over hills, accounting for stratification and roughness. However, the most well-known is, of course, the Atmospheric Dispersion Modelling System, ADMS. ADMS was first released in 1991 and is now widely used across the world. Making extensive use of his theoretical advances, Julian constructed a model that was pioneering in its treatment of the atmospheric boundary structure and in extending treatment of Gaussian plume dispersion modelling to complex flows. Its advanced treatment of dispersion in inhomogeneous flow and turbulence over complex terrain has still not been replicated in any other Gaussian plume dispersion model.

Julian remained as Chairman of CERC until as recently as 2022, when he was still full of new ideas! He will be greatly missed.

David Carruthers, 27 April 2026

Image shows Julian (right) outside CERC offices in Cambridge in the 1990s, alongside other CERC Directors David Carruthers, Paul Linden and Tim Newton.

24 Apr 2026Air Quality Lifecourse Assessment Tool (AQ-LAT) featured in Air Quality News

The Air Quality Lifecourse Assessment Tool (AQ-LAT) has been featured in the April 2026 issue of Air Quality News. The article outlines how the tool links air quality modelling outputs with estimates of health and economic impacts to support policy development.

Developed by the University of Birmingham, the tool combines high-resolution air pollution data with population datasets and established epidemiological relationships to quantify outcomes such as premature mortality, disease incidence, healthcare costs, and productivity losses.

In current applications, high-resolution air pollution maps are generated by CERC using ADMS-Urban. These outputs provide the exposure data required for AQ-LAT to calculate health and economic impacts at a local scale.

This method has been applied to evaluate policy scenarios in the West Midlands, as a part of the WM-Air project, and in Oxfordshire, by OxonAir (a partnership between Oxfordshire County Council and the county's city and district councils).

This approach allows users to quantify the impacts of air quality interventions in terms of both pollutant concentrations and their associated health and economic outcomes. If you would like to know more about combining ADMS-Urban with AQ-LAT, please get in touch.

14 Apr 2026HARMO conference papers & other recent co-author publications

The outcomes of several projects have recently been shared through international conference presentations, co-authored publications and technical reports. We were co-authors on four peer-reviewed papers during 2025, with another article already published in 2026. These studies reflect ongoing collaboration with universities, government and research institutes across a range of applied air quality topics.

CERC's Dr Martin Seaton and Dr Victoria Hamilton attended the HARMO conference Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes), which aims to improve consistency and best practice in atmospheric dispersion modelling.

Martin presented work assessing the impact of thermally driven flows on regulatory air dispersion modelling (paper here). This is particularly important in complex terrain and coastal environments, and forms part of CERC's contribution to the Environment Agency's research on the thermal transport of air pollution from regulated industries.

RIVM (the Dutch National Institute for Public Health and the Environment) presented results from a study comparing eight widely used atmospheric dispersion and deposition models, including ADMS, to which CERC contributed. The study investigated ammonia and nitrogen oxides at the local scale (paper here) and highlighted the variability and complexity associated with modelling deposition.

Victoria presented an extension of the study, evaluating alternative concentration-dependent deposition (CDD) methods against current UK guidance (paper here). The image shows the modelled concentration and deposition results for the four CDD methods tested. Depending on model choice, resulting deposition can differ by up to a factor of 10 for low concentration values, and a factor of 3 for high values. Models accounting for bi-directional exchange of ammonia ('Big-leaf' and DEPAC) predict more accurate values for this case study.

The presentations and extended abstracts are now available on the HARMO website:

https://www.harmo.org/conference.php?id=23

Further recent co-authored work includes:

• Ongoing research with Dr Zhong (University of Greenwich) in the West Midlands, including studies of urban heat islands and scenario modelling of bus electrification as a part of the WM-Adapt, WM-Net-Zero and WM-Air projects
• Work led by Dr Tom Clemens (University of Edinburgh) examining the effects of air pollution on birth outcomes in Scotland

The studies make use of a range of CERC tools, including ADMS-Urban, ADMS-Urban Temperature & Humidity, ADMS 6.

Links to all the publications are available here:

https://cerc.co.uk/environmental-software/CERC-coauthor-publications.html

We look forward to continuing these collaborations during 2026.

23 Mar 2026Booking is now open for the ADMS User Group Meetings, 11-12 November 2026, Manchester

You can now book your tickets for the 2026 ADMS User Group Meetings, which will be held at voco Manchester on 11th and 12th November.

• ADMS 6 User Group Meeting, 11th November
• ADMS-Urban and Roads User Group Meeting, 12th November

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 Monday 26th October. 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 in the summer.

6 Mar 2026Modelling data centres in ADMS 6 - free upgrade to 1000 point sources

CERC first released ADMS in 1994, and much has changed since then. Computers are more powerful, disc space more plentiful and the modelling requirements of users have changed. After listening to the feedback during the 2025 ADMS UGM, we have revisited ADMS 6's 'point' source limit.

Anyone attending the UGM will have noted that data centres were a hot topic. Modelling data centres demands the inclusion of hundreds of point sources, and the current default licence limit is proving too restrictive. We are therefore increasing the default from 300 to 1000 in the next ADMS 6 release, due in late Spring / early summer 2026.

However, there is no need to wait for that release if you are finding the current point source count is holding you back. For any user with support, simply get in touch with us, giving your licence details, and we will issue you with an upgraded licence, free of charge.

We are working hard on ADMS 6.1 right now. As well as increasing the number of point sources, we are also adding functionality for determining the probability of exceeding air pollution limits for sources which are only on for a limited number of hours, such as back-up generators supporting data centres. Details on this and more will be given as we progress towards the next ADMS release.

Hint: If you select Contact helpdesk from the Help menu in ADMS, it will pre-fill a new email for you with the relevant licence information we need, so you don’t need to type it.