Air Quality and Emissions Conference features SAQN members

13 – 14 October, online

AQE is a focused meeting for Air Quality and Emission Monitoring professionals who are looking for the latest product solutions, technical advice, methods and applications to measure, test and analyse Air Quality and Emissions. The conference programme features many faces from the SAQN, including Professor Rod Jones, Professor Rob Kinnersley, Dr David Green and the network’s Principal Investigator, Dr Sarah Moller.

Held online this year, the event is free and offers access to over 60 hours of unique content from the conference, seminar and training presentations which will also be available for registered attendees to reference and revisit up to 6 months after the event. Over 100 instrument and service suppliers will be exhibiting at the AQE virtual event, allowing participants to be the first to see new product introductions, technology innovations and live demonstrations. Product specialists will be available to discuss testing and monitoring requirements.

Topics this year include policy updates, indoor air quality, climate change and air quality, new sensor technology, modelling and innovations. Dr Sarah Moller will be sharing research from the SAQN with the conference on Day 1.

Jim Mills, SAQN Steering Group member and conference Chair outlines the themes of this year’s meeting in the short video below.

Explore the full programme and register for free on the conference website.

Using high-resolution techniques to assess the potential health and climate impacts of biomass burning aerosol

Each month we welcome a guest blog post from our Scoping Studies, to find out more about the air quality issue they are researching and how STFC capabilities are being used. This month, Dr Sari Budisulistiorini shares the aims and background to her team’s project.

Wildfire events are occurring worldwide due to dry and warm conditions linked to climate change. Wildfires are a major biomass burning source that makes up a substantial amount of global aerosol particles. Aerosols are a collection of microscopic liquid droplets and solid particles that are suspended in the air. Moreover, they can scatter or absorb the incoming solar radiation depends on their physicochemical characteristics (Figure 1).1 Besides climate impacts, exposure to aerosols cause adverse respiratory effects, such as lung inflammation, which adversity and characteristics related to the aerosols physicochemical properties.2

Biomass burning emits primary carbonaceous aerosol (black carbon and primary organic aerosol) and inorganic and organic vapour that are precursors to secondary organic aerosol formation. The primary and secondary organic aerosols make up the total organic aerosol from biomass burning. Moreover, previous studies reported that spectral and chemical characteristics of biomass burning organic aerosol are close to humic-like species, which has unique spherical morphology, very low volatility characteristic, and unusual stability in the atmosphere.3 However, these characteristics evolve because of chemical reactions in the atmosphere/aging process, such as photooxidation and ozonolysis.4 Therefore, physicochemical characterisation of atmospherically aged biomass burning organic aerosol is important to provide a clearer picture of their impacts.

The Biomass Burning Aerosol Impacts study aims to develop a holistic approach for characterising biomass burning aerosol and assessing their impacts on climate and human health. We will (i) characterise organic molecules composition and structure of biomass burning organic aerosol using high-resolution spectrometry and spectroscopy, (ii) measure the refractive index, and (iii) assess the preliminary biological effects. It is key that the OA is studied as a component in the PM2.5 to replicate the original conditions accurately. Hence, we will use PM2.5 from Singapore during an episode of wildfire, previously reported containing substantial light-absorbing organic constituents.5 The study will be conducted at the University of York, and STFC Central Laser Facility and ISIS Muon and Neutron Source for the physicochemical characteristics experiment and at Public Health England for the biological response experiment.

Biomass burning is part of daily life and impacts outdoor and indoor air quality. Hence, understanding the climate and health impacts of biomass burning would provide clearer pictures to the government locally and globally for improving air quality policy related to biomass burning and wildfires. Additionally, the high-resolution spectrometry and in-vitro approaches can be expanded to other air pollution sources, for example, wood-burning stoves and secondary organic aerosol. Thus, these methods would advance scientific knowledge and capabilities.

Figure 1. Scheme of wildfires and biomass burning aerosol particles interactions with climate change and air quality.
Figure 2. (Top panel) Chromatograms at near-UV and visible wavelengths of ambient aerosols collected when OA mass concentrations are (a) high (79 μg m–3) and (b) low (12 μg m–3). (Bottom panel, c) Light-absorbing brown carbon constituents and organic aerosol mass concentration were measured when Singapore was affected by smoke from Indonesia peatland fires in 2015. Points labelled a and b in the bottom panel refer to the top panels as well as the periods when ambient OA concentrations are high and low, respectively. Adapted from Budisulistiorini et al.5

Project team:


  1. IPCC. (Cambridge University Press, 2013)
  2. Guo, C. et al. Nanotoxicology 13, 733–750 (2019)
  3. Laskin, A. et al. Chemical Reviews (2015)
  4. Hems, R. F. et al. ACS Earth and Space Chemistry 5, 722–748 (2021)
  5. Budisulistiorini, S. H. et al. Environmental Science & Technology 51, 4415–4423 (2017)

SAQN Featured on ‘101 jobs that change the world’

UKRI have launched a campaign called 101 jobs that change the world focused on the people who work, often behind the scenes, to make research and innovation happen. This aims to publicise the many different and diverse roles and career paths in research and innovation that go beyond the traditional image of an academic, researcher or innovator. It also wants to recognise the diverse range of skills and talent needed to enable our world-class research and innovation system to function. There are some really interesting profiles on the website including one from our very own Network Manager, Fleur Hughes.

As many of you who are actively involved in the network will know, Fleur is the one that makes everything that SAQN does actually happen. She maintains the website, generates content, writes and sends out the newsletter to members, sets up the contracts for the scoping studies we have funded, liaises with the SPF Clean Air Networks, sets up all our meetings, including working with our facilitator to design the very effective Collaboration Building Workshops we have run, and so much more. It’s worth having a read of Fleur’s profile and browsing some of the others up there, as well as publicising this resource to students and colleagues who may be looking to find their own place within the research and innovation landscape.

PhD Studentship Opportunities: Air Quality, Agriculture & Climate Measures

Two PhD studentships are currently available at the Centre for Environment Policy, Imperial College London. To apply please send a CV with academic qualifications and 2 referees, plus why you think you would be a strong candidate, to Professor Helen ApSimon ( by 8 September. Selected candidates will be interviewed in the following week to start in October 2021 or shortly after.

Synergies between climate measures and air quality strategies

Supervisors: Prof Helen ApSimon and Dr Iain Staffell

This research project will involve investigation of a range of future energy and transport scenarios in the UK up to 2050, exploring emissions of air quality pollutants and their impacts on human health. It will be linked to a Defra contract on support for national air pollution control strategies, and build on existing work on electrification of road transport and other net zero climate measures modelled with our UK Integrated Assessment Model, UKIAM. This derives pollutant concentrations and exposure of the UK population, and the student will have access to it. There are many uncertainties in such modelling and the assumptions made. In particular the optimal deployment of air quality control measures to control atmospheric pollutants needs to take account of the temporal development of energy generation, and the capacity of non-polluting renewables to produce electricity and hydrogen/ammonia as alternative fuels in parallel with demands from electrification of road transport and other climate measures. The purpose of this studentship will be to look into these uncertainties in greater depth with respect to the relationship between projections for energy generation and climate measures, and abatement of air quality pollutants and associated benefits for health. Comparison will also be made with parallel modelling for other European countries undertaken by IIASA with the GAINS model. The student will be based in the Integrated Assessment Unit of the Centre for Environmental Policy at Imperial College and will benefit from the expertise of energy and climate policy specialists and the Energy Futures Lab at Imperial. It will require good computing skills and a good degree in a relevant discipline, plus a strong interest in computer modelling related to environmental policy.

Effects of future agricultural scenarios on air quality and ecosystem protection

Supervisors: Prof Helen ApSimon and Dr Huw Woodward

Agriculture is a key sector in terms of air quality, biodiversity and climate change. It is the dominant source of ammonia resulting in modification of the cycling of nitrogen in the environment with major consequences for biodiversity, and atmospheric chemical reactions producing small particles with adverse effects on human health. Agriculture is also a large source of greenhouse gas emissions such as nitrous oxide and methane, playing a crucial role in net zero climate pathways and competing future land uses. A shift in diet away from meat and dairy products between now and 2050 may also result in significant changes in the agricultural sector, with potential implications for healthy diets and obesity. What the UK’s agricultural sector will look like in 2050 is therefore highly uncertain. The aim of this studentship will be to define potential future scenarios and explore the resulting consequences with respect to the UKs climate change, air quality and biodiversity targets. Comparison will be made with related work in other European countries. The studentship will be linked to work for Defra to support national air pollution control strategies, and will be based in the Integrated Assessment Unit of the Centre for Environmental Policy at Imperial College. It will draw on expertise within a Defra research consortium including the UK Centre for Ecology and Hydrology, UKCEH, and will have access to modelling undertaken for Defra including use of the UK Integrated Assessment Model, UKIAM, developed to model future UK emission scenarios with respect to ecosystem protection and human health. It will require good computing skills and a good degree in a relevant discipline, plus a strong interest in computer modelling and protection of the natural environment.

Feature Scoping Study: Developing a compact, low-cost DELTA-Mi with flow sensing for low-time resolution measurement of atmospheric gases and aerosols

Tang Y.S1., Peters D2., McGurk C2., Ul-Haq I2. and Emekwuru, N3

1UKCEH, 2STFC-UKRI, 3Coventry University

Each month we highlight one of our Scoping Studies, each funded through our Collaboration Building Workshops. This month we welcome a blog post from Dr Yuk Sim Tang and the team developing a next generation DELTA-Mi sensor that can be deployed in a wider range of settings, particularly in low-resource regions.

Nitrogen pollution, in particular increasing global emissions of ammonia (NH3), is a major driver of biodiversity loss in the 21st century. The reaction of NH3 with atmospheric acid gases also forms secondary inorganic ammonium (NH4+) aerosols (Figure 1) that contribute to fine-mode particulate matter (PM2.5) implicated in adverse health impacts and increased mortality.

Figure 1: Reaction scheme showing the emissions, atmospheric chemistry and fate of NH3, acid gases and secondary inorganic NH4+ aerosols [1].

Understanding chemical species composition is necessary to assess impacts on ecosystems and human health, and to direct and target options to mitigate poor air quality. Worldwide, observation data on the reactive gas and aerosol phase components are sparse. In this context, there is an ongoing need for cost-effective, easy-to-operate, time-integrated atmospheric measurement at sufficient spatial and temporal scales.

The UKCEH DELTA® system [2] is a leading diffusion denuder-filter pack method for speciated measurement of reactive gases and aerosols, implemented in high density air quality networks (e.g. UK [3] and China [4]) and recommended in EMEP Level I monitoring [5]. A study from a European DELTA® network (Figure 2) for example provided evidence for the dominance of NH3 gas and NH4NO3 aerosol in the inorganic atmospheric pollution load.

The DELTA-Mi project aims to upgrade the UKCEH DELTA® system with flow sensing capabilities and telemetry, to achieve miniaturisation and permit remote monitoring of air flow. We will modify and test components from a UAV-ready sensor” developed by STFC RAL Space UAV facility in a previous SAQN scoping study [6]. In parallel, we will also field test compact gas and aerosol sample trains, based on UKCEH Mini-ANnular DEnuders (MANDE), for further miniaturisation.

Figure 2: Atmospheric chemical species composition measured in a European DELTA® network [2].

Other key challenges are in optimising power requirements and to produce a DELTA-Mi with low unit cost, to maximise flexibility in deployment options and affordability, particularly in low-resource countries. Collaboration with Coventry University and their work in Sub-Sahara regions will identify pathways to build infrastructure in air quality monitoring to increase data availability for understanding air quality drivers and impacts in low-resource regions.

Find out more about all our Scoping Studies on our dedicated web pages.


[1] Tang, Y. S., Flechard, C. R., Dämmgen, U., Vidic, S., Djuricic, V., Mitosinkova, M., Uggerud, H. T., Sanz, M. J., Simmons, I., Dragosits, U., Nemitz, E., Twigg, M., van Dijk, N., Fauvel, Y., Sanz, F., Ferm, M., Perrino, C., Catrambone, M., Leaver, D., Braban, C. F., Cape, J. N., Heal, M. R., and Sutton, M. A.: Pan-European rural monitoring network shows dominance of NH3 gas and NH4NO3 aerosol in inorganic atmospheric pollution load, Atmos. Chem. Phys., 21, 875–914,, 2021.


[3] Tang, Y. S., Braban, C. F., Dragosits, U., Simmons, I., Leaver, D., van Dijk, N., Poskitt, J., Thacker, S., Patel, M., Carter, H., Pereira, M. G., Keenan, P. O., Lawlor, A., Conolly, C., Vincent, K., Heal, M. R., and Sutton, M. A.: Acid gases and aerosol measurements in the UK (1999–2015): regional distributions and trends, Atmos. Chem. Phys., 18, 16293–16324,, 2018.

[4] Xu, W., Wu, Q., Liu, X. et al. Characteristics of ammonia, acid gases, and PM2.5 for three typical land-use types in the North China Plain. Environ Sci Pollut Res 23, 1158–1172 (2016).


[6] Feature Scoping Study: A UAV-ready sensor package for rapid deployment during volcanic crisis (

Lessons learned from our Collaboration Building Workshops

Collaboration Building Workshop 2021

SAQN hosted a second Collaboration Building Workshop in 2021 (14 – 25 June), using the same format as the first workshop, but with improvements identified through the review process. Here we reflect on the impact these changes had on the process. 

Launch event

We began the workshop with a brief ‘launch event’ one week before the start of the main workshop. This had several benefits:

  • Participants were introduced to the facilitators and mentors;
  • We started using Mural, allowing participants to get familiar with it and solve any technical issues in real time;
  • Participants started to meet each other, having one to one chats in Zoom breakout rooms;
  • Sharing the workshop aims and funding criteria at the start reduced the number of questions asked about funding later on in the workshop;
  • Participants had the opportunity to try out a new networking platform, ‘Wonder’, which was then used by many to host their ‘cafe time’ conversations.

Improved support for mentors

We recognised that mentors needed more support in order to give most value to the participants and to feel more engaged in the process. The two aims of this were to make mentors feel better informed about the process and their roles and to allow participants to become more familiar with mentors so that they felt comfortable asking for their support. Changes to the mentor programme were:

  • A short introductory meeting, outlining the mentor role and giving a broad overview of the process;
  • A mentor briefing session one week before the workshop, giving details of the mentors’ activities in week one;
  • Involving and introducing the mentors to the participants at the launch session;
  • Asking the mentors to lead the initial discussion activity in the first session;
  • A second mentor briefing session at the start of week two to review project ideas and give clear directions to the mentors for the remaining sessions;
  • Appointing a facilitator as ‘mentor support’, who acted as first point of contact during sessions and sent communications in between sessions;

Our mentors noted that they had appreciated the extra support they were given, and that they themselves benefited from taking part, as they could keep in touch with developments in the field of air quality, make new connections and influence the direction of research.

Improved use of online tools for facilitation

Building on our experience of running online events, we trialled using ‘SessionLab’, an event planning tool which can have multiple collaborators, and also made use of Google Docs and drive, so that all the workshop materials were accessible by the event team at any time. This had the following benefits:

  • Detailed notes on the running of the workshop were available in SessionLab and updated in real time, reducing email traffic and version control issues;
  • Notes sections in SessionLab were used to keep details of activities required between sessions (such as texts and timings of emails to participants), meaning that all team members could see and edit messages to participants, while being clear on who was responsible for each action and when it had been completed;
  • Relevant documents could be accessed and edited as needed in Google Docs throughout the event, and links to documents placed in the event plan, allowing any of the event team to access information and share it quickly and easily;
  • Planning all the activities between workshop sessions reduced the burden on the events team, as no one was having to keep all the information in their head.

Workshop highlights

We thoroughly enjoyed hosting our second workshop, and were delighted with the outcomes. These were some of our highlights:

  • We welcomed colleagues from departments of STFC that have not been extensively used in air quality research (ISIS and Central Laser Facility) and were able to fund projects making use of their technology;
  • One project was able to make use of sensors developed in a previous SAQN Scoping Study, and is developing a new piece of technology with significant commercialisation potential;
  • Having encouraged research into health aspects of air quality, we were pleased to have involvement from medical researchers, including from Public Health England, and that two of our funded projects are exploring issues around toxicology;
  • The projects teams that were not funded said they had found it a valuable experience, as they had established new collaborations, had useful feedback and been signposted to other funding sources;
  • Feedback from our participants was very positive, with most reporting that they had appreciated the opportunity to collaborate with people beyond their usual network in a friendly and encouraging environment;
  • Our workshop format has inspired another air quality network (TAPAS) to host their own Collaboration Building Workshop based on the same format.

The SAQN website is kept up to date with all the latest information and contact details for our funded projects.

This is an extract from our case study, reflecting on the lessons we learned from running two Collaboration Building Workshops.

SAQN funds new research into air quality

SAQN has funded four new Scoping Studies through the innovative online Collaboration Building Workshop. The workshop was the second run by the network, and aimed to develop new interdisciplinary collaborations between air quality scientists and researchers at the Science and Technology Facilities Council (STFC). Participants came from a range of backgrounds, including particle physics, public health, social science, software engineering, modelling and many more.

Workshop participants celebrate
Workshop participants celebrate the closing session

The funded projects address the workshop question ‘ How might we respond collaboratively to societal air quality challenges using STFC capabilities to explore the potential of new research ideas?’. The projects focus on nanoparticles in the brain, Persistent Organic Particles (POPs), developing a next generation Delta sensor and biomass burning. Each project has been awarded £8,000. Further details of the Scoping Studies will be shared on the SAQN website, where blog posts and presentations from past Scoping Studies are currently available.

SAQN PI, Dr Sarah Moller said, “We are delighted to be funding these new studies. All of them are taking a first step towards tackling a major air quality research gap, and we look forward to seeing the outcomes. We are keen to support the Scoping Studies to develop their research idea and apply for future funding as a result of strong, productive collaborations.”

Feature Scoping Study: A UAV-ready sensor package for rapid deployment during volcanic crisis

Each month we highlight one of our Scoping Studies, each funded through our Collaboration Building Workshops. This month we welcome a blog post from Dr Dan Peters and the team using RAL Space’s expertise in sensor development to expand our knowledge of air quality in volcanic plumes.

Volcanic hazards are varied in nature, and among these, issues relating to volcanic gas and particulates can be investigated from the perspective of air quality research.

Volcanic ash poses a threat on a range of scales, ranging from ashfall in local communities to regional risks to aviation. Volcanic gases pose a further threat to the surrounding area, stemming largely from emissions of sulphur dioxide. For example, “vog” – volcanic smog – is a recurring issue in Hawaii, formed as volcanic SO2 interacts with the surrounding atmosphere to produce sulphuric acid aerosols.

Small eruptions of the kind common at volcanoes such as Stromboli (Italy) and Kilauea (Hawaii) produce plumes reaching up to hundreds of metres in the atmosphere, which drift in the direction of the prevailing wind (Figure 1). Whilst plume dispersion models can predict the direction of travel of plumes, local measurements are needed to constrain the volume of pollutants present and verify the predictions of models.

Figure 1. Plumes of gas and ash during an eruption of Stromboli in September 2019. Image: Jean-François Smekens

Although many active volcanoes have established monitoring networks, a network of ground-based sensors is unlikely to be sufficiently dense to fully monitor the development of a moving plume; and monitoring networks may not be present at all around newly active volcanoes. Additionally, it is desirable to be able to measure pollutants at altitude within the plume and along its dispersal axis, as these may later affect communities further downwind.

To address these challenges Jean-François Smekens [1] joined the SAQN Collaboration Building Workshop, where the consortium expertise in volcanology, UAVs, aerosol and gas sampling were brought together. The consortium are aiming to develop a new instrument for monitoring particulates and sulphur dioxide in volcanic plumes, as well as carbon dioxide, another important measurement in volcanological studies. Our aim is to build an instrument utilising commercial off the shelf components suitable for mounting on a small Unmanned Aerial Vehicle (UAV). We will utilise the STFC RAL Space UAV facility [2], expertise in payload design and operation [3], and STFC’s expertise in aerosol and gas handling [4]. The instrumented UAV will be available to other researchers via STFC for air quality studies.

Whilst a number of published studies have been conducted using UAVs to monitor volcanic emissions, a remaining challenge is to combine unbiased sampling of particulates with simultaneous measurements of gas concentrations. Such co-located measurements are necessary to understand the interactions between gas and particles during transport, and to more accurately model the dispersal of both. To support this aim, our instrument is designed to be mounted on a fixed-wing UAV, which not only enables longer range than multirotor UAVs but also permits a relatively stable airflow across the airfoil. Using modelling and simulations capabilities from the Computational Engineering Group in the Scientific Computing Department [5] at STFC, we aim to configure an instrument for isokinetic sampling to enable us to simultaneously carry out gas measurements and unbiased sampling of particulates.






Running a Funding Sandpit in a Digital Environment: A Case Study

Our next Collaboration Building Workshop takes place this month, and we’ve been reflecting on what we learned from the first workshop, which took place last November. Online events are likely to be more prevalent, even once lockdown restrictions are gone, so we have published a case study of our workshop. The paper outlines some of the key factors that made the workshop successful, and also shares our plans to make the next workshop even better.

The case study will be of interest to anyone looking to organise workshops, and in particular those running funding sandpits. 

Feature Scoping Study: On Track of NH3

Cross-validation of satellite and ground-level measurements

Each month we highlight one of our Scoping Studies, each funded through our Collaboration Building Workshops. This month we welcome a blog post from Dr Anna Font (Imperial College London), who is working with STFC colleagues in RAL Space and the Hartree Centre to improve our understanding of ammonia concentrations through satellite and ground-level measurements.

Ammonia (NH3) is mostly emitted to the atmosphere from agricultural and farming activities including the use of fertilizers, manure, cattle and dairy farming, among others. NH3 is an important precursor of fine particles due to its reaction with available acids (i.e. nitric and sulfuric acid) to form ammonium nitrate and ammonium sulphate. Airborne fine particles are a significant human health thread and are associated with cardiovascular and respiratory diseases. Further, gaseous ammonia and ammonium compounds are deposited into the ecosystems damaging sensitive habitats. In the UK, agricultural activities represent more than 80% of the atmospheric ammonium emissions and there are no regulations in place to limit these emissions. The Clean Air Strategy published in 2018 aims to reduce NH3 emissions in the UK making available a code of good agricultural practice (COGAP).

Hotspots of ammonia have been identified by means of satellite measurements from both CrIS and the IASI instruments onboard the Suomi NPP and MetOp satellites, respectively. In Europe these include areas in the UK and neighbouring countries such as France, Belgium and The Netherlands. NH3 emissions from agricultural fields in north-west Europe have been associated with particle episodes which accumulate on a regional scale especially during springtime in south-east England. In the UK, hotspots of NH3 are observed in the intense agricultural regions in southern England. 

In the UK, a network of 85 sites distributed in the country have been measuring ammonia at the surface level since mid-1990s. Despite the network provides a good coverage of the UK land, there is a large heterogeneity of concentrations related to the large variation in emission sources at ground level as it can be seen in Figure 1. Concentrations are reported as monthly means. Recently, on-line concentrations of NH3 are available at two rural locations in the country comprising one agricultural site in Scotland and one in south-east England; and also in urban areas comprising London, Manchester and Birmingham. On-line techniques report high time resolve data of NH3 concentrations, usually at hourly basis.

Figure 1. Monthly concentrations of NH3 gas as measured by the Defra UKEAP National Ammonia Monitoring Network in 2019. Only active samplers (delta) are shown in this graph. Data from UK-air website.

Satellite observations are column-integrated and have larger footprints compared to the ground-level measurements. Little is known if satellite retrievals of NH3 concentrations are representative of ground-level measurements in the UK and how they are related. Despite the mistime and misdistance errors which are introduced by comparing measurements of a very reactive species such as NH3 that are not perfectly collocated in time and space, such comparison of column-integrated and ground-level measurements is still important to validate satellite products.

The SAQN workshop on last autumn 2020 was the perfect platform to establish collaboration links between scientists working with satellite data, in-situ observations and big data specialists. The project is establishing links between STFC RAL space, STFC Hartree Centre and Imperial College London. With this project we are aiming to evaluate the ability of satellite observations of NH3 to reproduce temporal variability of surface air concentrations across the UK to before estimate long-term changes in air pollution to assess the efficacy of air quality policies in recent years. The integration of satellite data and ground-level measurements will help us identify hot-spots of NH3 in the UK and monitor possible changes over time.