14 May 2021Modelling the temperature impact of cold plumes

CERC was commissioned to carry out a novel assessment of the impact of plumes of cold air from an array of Air Source heat Pumps (ASHPs) on the surrounding air temperature.

In work commissioned by Sustainable Energy Ltd, the CERC consultancy team used ADMS 5 and the dense gas dispersion model GASTAR to carry out dispersion modelling of the plumes of cold air. A single elevated jet, representing the emissions from a single ASHP unit, was represented in each model, and plume centreline height and temperature were output.

The ADMS 5 and GASTAR results agreed well; in both cases, temperature reductions decrease quickly with distance downstream. ADMS 5 gives more flexibility in generating and presenting results.

ADMS 5 was used to determine the meteorological conditions giving rise to the largest and smallest reduction in temperature due to the modelled jet. Stable conditions with low wind speeds gave the largest temperature reduction downstream of the release, and neutral conditions with high wind speeds gave the smallest temperature reduction; however, the difference in impact between these conditions was small.

For all meteorological conditions modelled, at receptors of various heights (trees, car park, offices and footpaths), the calculated temperature reduction was in the range 0-2 °C. Below a height of 5 m, the calculated temperature reduction was less than 1 °C.

Please click here to view the top image and here to view the bottom image in high resolution.

31 Mar 2021Breathe London Pilot network extended into the COVID-19 recovery period

The Breathe London Pilot network of static AQMesh air quality sensors has been extended into the COVID-19 recovery period. This will create a fully validated dataset covering the latest phases of the recovery. Furthermore, it will provide critical analysis, including source apportionment and emission index quantification, and data assimilation to determine emissions during the recovery phase where unprecedented changes in pollutant sources are occurring. The methodologies and techniques have wide applicability for air quality monitoring, analysis and policy beyond London and would inform similar issues elsewhere in the UK. The measurement data from the sensors is available on www.breathelondonpilot.org.

The Breathe London Pilot project was a 2-year project funded by the Clean Air Fund and delivered by a consortium led by Environmental Defense Fund (EDF) and including the current partners (University of Cambridge, CERC, ACOEM and NPL). The Breathe London Pilot network has been extended into the COVID-19 recovery period under a NERC grant.

18 Feb 2021CERC presenting on elevated roads at DMUG 2021

CERC are pleased to be involved in the Institute of Air Quality Management's Dispersion Modellers User Group (DMUG 2021) meeting, which has been rescheduled from last year due to COVID 19 and will take place on Wednesday 24^th February 2021. This 'unapologetically technical conference' allows Dr Jenny Stocker to share details of the latest developments in the ADMS-Roads model to improve the representation of dispersion of pollutants from elevated roads. These developments were sponsored by Highways England under an SBRI competition to support innovations to tackle air quality around the country's motorways and major A roads.

The meeting features a number of topical presentations, including Simon Gant (HSE) presenting 'An introduction to the latest dispersion modelling guidelines' and Glyn Rhys-Tyler discussing 'Light vehicle dynamics and NO_x emissions on the motorway network'. Registration for this online conference is open until 22^nd February.

9 Feb 2021Advanced street canyon model derivation and validation published

CERC's article specifying a detailed derivation of the ADMS-Urban and ADMS-Roads advanced street canyon model has been published in the Journal of the Air and Waste Management Association. The advanced street canyon model feature has been included in the ADMS-Urban and ADMS-Roads models since the release of version 4.0 in 2015 and is now widely used by the ADMS modelling community.

The paper also includes the results of validation studies comparing advanced street canyon, non-canyon and basic canyon modelled concentrations with measurements recorded within three individual European street canyons from the TRAPOS study, and with routine air quality monitoring sites across London. The advanced canyon model is shown to have improved performance relative to the basic canyon or non-canyon modelling, particularly in relation to the variation of concentrations with wind direction and prediction of high concentrations.

The picture shows a vertical cross-section of annual average NO₂ concentrations at the Marylebone Road monitoring site in London for 2012. The monitored value is shown in a diamond with the corresponding colour.

CERC are currently investigating and developing the advanced street canyon model for a wider range of street canyon configurations, in relation to monitoring data from the UK and Hong Kong. Details of other publications relating to CERC's research are given on the CERC co-author publications page.

4 Feb 2021Webinar: how can data supercharge efforts to lower air pollution in cities?

Public webinar Tuesday 9 Feb 16:00-17:00 GMT

The evidence is clear: air pollution has severe health impacts around the world. New technology is allowing us to map pollution street-by-street, identify hotspots and share unprecedented amounts of air quality data. The Breathe London pilot was an ambitious two-year project that measured pollution across the city using 100 lower-cost sensor 'pods' and specially-equipped Google Street View cars, serving as a world-leading example of how emerging technology can help accelerate clean air action. CERC was a partner in the pilot project, providing the public project data platform and ADMS-Urban modelled data and analysis.

Join this webinar for a discussion of key lessons from the pilot project and the launch of the Breathe London Blueprint, as well as how new efforts to leverage air quality data are shining a light on pollution at a scale and scope across the globe like never before.

Amy Stidworthy from CERC will discuss how the ADMS-Urban model was used in the pilot project to produce detailed, location-specific information on pollution sources and to assess the impact of potential future policies on reducing air pollution in London.

Also featuring:

• Matt Whitney from Clean Air Fund, a philanthropic initiative tackling air pollution around the world
• Elizabeth Fonseca from Environmental Defense Fund Europe, which managed the Breathe London pilot project
• Jeremy Taub from OpenAQ, a platform that is fighting air inequality with open data

See the LinkedIn event page for more information and to register for the webinar.