Precise and representative quantification of greenhouse gas (GHG) emissions is essential for evaluating the effectiveness of mitigation strategies aimed at achieving net-zero targets, and for providing rigour and integrity to the voluntary carbon credit market. This project focuses on the accurate and representative monitoring of of three powerful GHGs - methane, nitrous oxide, and carbon dioxide - in farmland, water, and forest environments. These environments are major producers/absorbers of these gases. However, their realistic monitoring is greatly undermined by the substantial spatial and temporal variability of emissions, which conventional methods, despite their precision, fail to capture comprehensively. Current monitoring techniques use expensive techniques for acquiring precise measurements only representative of a small footprint (e.g. closed chambers, optical sensors). Eddy covariance towers have a much larger sensing footprint (roughly 200m diameter), and provide continuous measurements in time. However, these are pieces of costly capital infrastructure, requiring complex operation and maintenance, and their representativeness is quite limited by their height and static position. We propose the deployment of a robotic flux tower system, comprising low-cost sensor arrays tethered to a ground robot by an aerodynamic balloon. The adaptable sensing altitude of the platform (via adjustable tether length) will allow spatially representative measures over complex natural environments. Being tethered to a robot, the flux tower can be easily transported to sites where GHG measurements are needed. Additionally, a balloon can stay in place for long durations, giving sufficient time resolution to fully capture the gas dynamics of the study location. The system will allow emissions data collection in a way that is scalable and transferable to any site where GHG emissions are a concern (e.g. agriculture, water treatment, landfill, oil and gas). Autonomous ground vehicles and tethered balloons are both well-established technologies, and the robotic component of the study can be implemented quickly by experienced engineers. The most significant challenge is instead the provision of accurate sensors that are sufficiently lightweight that they can be integrated with a small robot. This is challenging but feasible using the latest off-the-shelf miniature sensors, when enhanced with additional conditioning electronics and data postprocessing. By combining cutting edge sensing / robotics innovation with modern techniques in data science, the project's datasets and collection techniques will become a platform for further development of robotic environmental monitoring which can support sustainable development and will ultimately help to ensure emissions targets can be reached in the UK.

Local and global consequences of climate change (enhanced urban heat islands, worsening environmental conditions) affect most of the world's urban population, but only recently have cities been represented, albeit crudely, in weather forecast models. To manage and develop sustainable, resilient and healthy cities requires improved forecasting and observations that cross neighbourhood-influenced scales which the next generation weather forecast models need to resolve. ASSURE addresses the critical issue of which processes need to be parameterised, and which resolved, to capture urban heterogeneity in space and time. We will advance understanding to develop new approaches and parameterisations for larger-scale urban meteorological and dispersion models by combining the results of field observations, high-resolution numerical simulations and wind tunnel experiments. Field work and modelling will focus on Bristol, as its physical geography provides suitably high levels of complexity and allows whole-city approaches. With mid-sized cities being large sources of greenhouse gases, and where large numbers of people live, it is critical agencies can provide predictions of weather and climate variability across cities of this scale as they need this information to manage and provide their services. ASSURE will include idealised simulations and theoretical analyses to ensure generic applicability. The ASSURE objectives are: * To understand how sources of urban heterogeneity (physical setting, layout of buildings and neighbourhoods, human activities) combine to influence the urban atmosphere in space and time. * To quantify effects of urban heterogeneity at different scales (street to neighbourhood, to city and beyond) on flow, temperature, moisture and air quality controlling processes and to determine how these processes interact. * To develop a theoretical framework that captures key processes and feedbacks with reduced complexity to aid mesoscale and larger model parameterisations. * To inform the development priorities of current weather and climate models that have meso-scale capabilities and are used in decision-making processes (e.g. integrated urban services). The ASSURE high-fidelity simulations and carefully designed experiments will allow us to explore implications of urban heterogeneity in isolated and combined configurations; interpret and integrate field observations (e.g. 3D meteorological and city-scale tracer dispersion experiments); integrate different approaches to understand the magnitude, source, and geographical extent of uncertainties in process models at different scales; synthesize the new knowledge to conduct theoretical analyses; develop algorithms reflecting this analysis. Novel in ASSURE are simulations resolving street to city-scale features that are linked to mesoscale models; field observations capturing vertical and horizontal variations in the urban boundary- and canopy-layers, including novel multi-source gas tracer experiments; and wind tunnel simulations across atmospheric stabilities and model resolution. New insights will be gained on the role of variations in the building morphology (or form), local topography, and human activities (e.g. waste heat, and AQ emissions). ASSURE will produce detailed datasets; in-depth understanding across the scale of atmospheric processes involved; high-fidelity multiscale urban modelling tools; theoretical models taking account of multiscale effects; improved assessment of current meso-scale model skill and the data used by practitioners to explore future urban scenarios as city form and function change. We will work with local and international organisations and companies to ensure the project benefits a broad range of society. They include: Avon Longitudinal Study of Parents and Children, CERC, COWI, ECMWF, Met Office, Delft University of Technology, Stanford University, University Hannover, RWDI, Surrey Sensors and UKCRIC.

Aerosol science, the study of airborne particles from the nanometre to the millimetre scale, has been increasingly in the public consciousness in recent years, particularly due to the role played by aerosols in the transmission of COVID-19. Vaccines and medications for treating lung and systemic diseases can be delivered by aerosol inhalation, and aerosols are widely used in agricultural and consumer products. Aerosols are a key mediator of poor air quality and respiratory and cardiac health outcomes. Improving human health depends on insights from aerosol science on emission sources and transport, supported by standardised metrology. Similar challenges exist for understanding climate, with aerosol radiative forcing remaining uncertain. Furthermore, aerosol routes to the engineering and manufacture of new materials can provide greener, more sustainable alternatives to conventional approaches and offer routes to new high-performance materials that can sequester carbon dioxide. The physical science underpinning the diverse areas in which aerosols play a role is rarely taught at undergraduate level and the training of postgraduate research students (PGRs) has been fragmentary. This is a consequence of the challenges of fostering the intellectual agility demanded of a multidisciplinary subject in the context of any single academic discipline. To begin to address these challenges, we established the EPSRC Centre for Doctoral Training in Aerosol Science in 2019 (CDT2019). CDT2019 has trained 92 PGRs with 40% undertaking industry co-funded research projects, leveraged £7.9M from partners and universities based on an EPSRC investment of £6.9M, and broadened access to our unique training environment to over 400 partner employees and aligned students. CDT2019 revealed strong industrial and governmental demand for researchers in aerosol science. Our vision for CDT2024 is to deliver a CDT that 'meets user needs' and expands the reach and impact of our training and research in the cross-cutting EPSRC theme of Physical and Mathematical Sciences, specifically in areas where aerosol science is key. The Centre brings together an academic team from the Universities of Bristol (the hub), Bath, Birmingham, Cambridge, Hertfordshire, Manchester, Surrey and Imperial College London spanning science, engineering, medical, and health faculties. We will assemble a multidisciplinary team of supervisors with expertise in chemistry, physics, chemical and mechanical engineering, life and medical sciences, and environmental sciences, providing the broad perspective necessary to equip PGRs to address the challenges in aerosol science that fall at the boundaries between these disciplines. To meet user needs, we will devise and adopt an innovative Open CDT model. We will build on our collaboration of institutions and 80 industrial, public and third sector partners, working with affiliated academics and learned societies to widen global access to our training and catalyse transformative research, establishing the CDT as the leading global centre for excellence in aerosol science. Broadly, we will: (1) Train over 90 PGRs in the physical science of aerosols equipping 5 cohorts of graduates with the professional agility to tackle the technical challenges our partners are addressing; (2) Provide opportunities for Continuing Professional Development for partner employees, including a PhD by work-based, part-time study; (3) Deliver research for end-users through partner-funded PhDs with collaborating academics, accelerating knowledge exchange through PGR placements in partner workplaces; (4) Support the growth of an international network of partners working in aerosol science through focus meetings, conferences and training. Partners and academics will work together to deliver training to our cohorts, including in the areas of responsible innovation, entrepreneurship, policy, regulation, environmental sustainability and equality, diversity and inclusion.