Mercury is a toxic metal released to our environment through mankind's activities (e.g., coal burning) and natural processes. Once it gets into the sea or other aqueous environments it can be transformed into toxic forms, which can then get into the food chain and can cause damage to the central nervous systems of animals. Mercury pollution is a grave human health concern and so it is important to understand its different global sources. Recent work has shown that continuously degassing volcanoes represent a significant source of mercury to the atmosphere compared to other sources on the global scale. Recent measurements at active volcanic craters have also shown that volcanic mercury is primarily emitted as a gas. This gas is not very soluble (e.g., in rainwater) and so would not be very efficiently removed from the atmosphere meaning that it could be transported very long distances from its source making volcanic mercury a global environmental hazard. However reactive bromine compounds have also been observed in volcanic plumes downwind from the point of emission. In the Polar Regions and at the Dead Sea reactive bromine compounds are thought to lead to the rapid transformation of gaseous mercury (present in these environments at low levels due to remote sources) into more soluble form that are then rapidly deposited to the local environment. If similar chemistry occurs in volcanic plumes then they will represent a significant mercury hazard to local ecosystems as this chemistry would not only lead to the rapid deposition of low levels of atmospheric mercury from remote sources but also the very significantly enhanced levels present in volcanic plumes. We want to understand the behaviour of mercury in volcanic plumes and the balance between local deposition and global dispersion. We will make measurements of the levels and types of mercury found in the persistent non-explosive volcanic plume from Masaya volcano in Nicaragua at the crater rim and at two locations downwind of the volcano where the plume is known to ground regularly. We will also measure reactive bromine levels and other constituents of the volcanic plume at these locations and will put out a network of samplers to measure the deposition flux of mercury to the local downwind environment from the volcano. These measurements will allow us to test our hypothesis that in volcanic plumes, gaseous mercury will be rapidly transformed to more reactive forms that are then deposited to the local environment. These measurements will then be used to adapt existing computer models of the atmospheric chemistry occurring in volcanic plumes to include mercury chemistry. This will allow us to further our understanding of volcanic mercury processing as well as to build up a picture of the fate of the mercury emitted from active volcanoes and specifically to understand whether volcanic mercury emissions pose a local or global hazard.

Elections in autocracies are a particularly puzzling phenomenon: Why would an autocratic regime hold regular elections - a process that is usually considered a cornerstone of democracy? And why, given the opportunity, do voters not simply vote the autocratic regime out of power? Seen from a historical perspective, cases of authoritarian regimes holding elections are not new. For example, dictators in Malaysia, Singapore or South Korea held elections as early as in the 1960s. However, there is consensus among scholars that the number of these regimes has greatly increased over the past two decades, as about 60 per cent of all non-democratic regimes now conduct regular elections (Croissant and Lueders 2012). This trend has sparked great interest among political scientists. In particular, two bodies of literature have focused their attention on the 'power of elections' under authoritarian rule: the 'new institutionalism' in the study of authoritarianism and the democratisation literature. However, the two bodies of literature come to contradicting conclusions: The authoritarianism literature argues that elections are just another weapon in the dictator's arsenal and will further consolidate the authoritarian hold on power. The democratisation literature, on the other hand, argues that elections can facilitate regime change - either through the mechanism of 'creeping democratisation' or through 'liberalising election outcomes' (Howard and Roessler 2006). One possible explanation for these contradicting conclusions is that both strains of literature derive much of the empirical evidence from highly biased case samples. While the 'democratisation through elections' literature looks primarily at Sub-Sahara Africa (Lindberg 2006; Wahman 2012), the 'authoritarian resilience' literature has mostly focused on cases in Eastern Europe and - to some extent - the Middle East (e.g. Lust-Okar 2006). Other regions, such as Latin America and - in particular - Pacific Asia, have been mostly neglected. Outside of academia, organisations working in the area of democracy promotion have been troubled by similar questions: When do elections threaten authoritarian rule and, when do they contribute to the reproduction of non-democratic governance? In other words, these organisations struggle to decide in which cases supporting the electoral process will lead to democratisation and in which cases programmes of democracy promotion run the risk of provoking the opposite - that is, helping the autocratic regime to consolidate its power. The proposed seminar series aims to provide, for the first time, a platform to discuss the role and impact of elections under authoritarianism from the four perspectives just described: (1) area studies, (2) democratisation studies, (3) authoritarianism studies, and (4) the practitioner's point of view. So far, these four groups have been working on the same question - Do elections democratise or consolidate autocratic rule? - but have largely done so in isolation within their own disciplines and professions. The proposed seminar series offers a unique opportunity to considerably further our understanding of the phenomenon of 'electoral authoritarianism' by organising a joint forum to ~ - integrate single case studies - produced by area-studies experts and practitioners - into an international, multilateral network that allows to compare findings in a systematic and sustained programme. - discuss methodological issues in the study of electoral authoritarianism and provide recommendations for future research. - translate research findings into a strategic framework to guide practical work in the field of democracy promotion.

The UK Met Office is one of the world leaders in weather and climate prediction, and the Met Office's global forecast model is used by many other centres worldwide to drive their individual local area models. However, many short scale phenomena as well as important longterm dynamics are still difficult to predict accurately due to the limited spatial resolution of global models and the additional errors introduced by local area models. Novel computing architectures with more than 10^5 cores provide a chance to push these boundaries and to keep the UK Met Office at the forefront of developments. Decades of experience with numerical weather and climate prediction have produced a good understanding of the core dynamics inherent in atmospheric flow and of their stable and accurate numerical approximations. As outlined in the call, the Met Office's Unified Model uses lattitude-longitude grids and achieves high efficiency on parallel computers with up to 1000 cores. However, (artificial) grid clustering at the poles renders these grids impractical for large-scale computations, and so one of the core tasks in this NERC Programme is the search for suitable alternative grids. Several separate proposals address this issue. However, the equations governing atmospheric flow form a time-dependent system of differential equations which strongly couple the solution everywhere on the globe (the famous "butterfly effect"). Most current atmospheric dynamics models use semi-implicit time discretisation schemes which provide some global coupling of the equations at each time step. This prevents the system from becoming unstable and as a consequence it allows for larger time steps than fully explicit schemes, which include no global coupling. Since the cost of the forecast is proportional to the number of time steps, a scheme that allows for larger time steps (with satisfactory accuracy) seems preferable. But these benefits come at a price, especially in the context of large-scale problems and on massively parallel architectures. An elliptic system for the pressure has to be solved in each time step, leading to a very large, ill-conditioned algebraic system, the solution of which is difficult to parallelise efficiently. There are two main factors that make the scaling of this elliptic solve to large problem sizes and to large processor numbers difficult: algorithmic scalability and parallel scalability. Since the solution operator for the elliptic equation couples the pressures globally, only multilevel iterative solvers which use a hierarchy of discretisations on grids of varying resolution allow optimal, linear growth in cost (algorithmic scalability). But in a massively parallel computing environment, where global communication is costly, it is necessary to implement these solvers well, keeping most of the communication local, to ensure that the computational cost continues to scale optimally to 100K or more processors (parallel scalability). This proposal addresses this problem and will thus facilitate the best possible decisions on the design of the Met Office's future dynamical core, thus guaranteeing the UK's competitiveness in this key societal/technological challenge. An optimal scalability of semi-implicit schemes has not been achieved in atmospheric flow up to now, but success of the Project Partners, IWR Heidelberg and Lawrence Livermore National Lab, on simpler model elliptic problems shows that it is possible. The PIs experience over the years in obtaining optimal scalability of elliptic solvers on the most current architectures in various application areas, most notably for elliptic problems from atmospheric flow discretised on latitude-longitude grids up to 256 cores, as well as his status as one of the world's leading theoretical analysts of multilevel iterative elliptic solvers and his links to other world leading groups in this field, mean that that he is ideally equipped to achieve this goal.

Access to safe drinking water is centrally linked to public health, well-being and economic prosperity. Although water quality is strongly linked to many of the UN Sustainable Development Goals (SDG 6: Clean Water & Sanitation, 3: Good Health & Well-Being, 5: Gender Equality, and 2: Zero Hunger), there is still a long way to go to achieve equitable access to safe drinking water, particularly in the Global South. To accelerate progress, we need new interdisciplinary approaches to tackle complex water quality challenges, especially with increasing stressors like rapid urbanisation and climate change impacting groundwater resources widely used for drinking. The aim of my FLF is to create a roadmap towards improved groundwater quality management in the context of the Global South by bringing together systematic approaches to improve the understanding of dominant groundwater processes and to support evidence-based decision-making for effective groundwater remediation. We will develop and demonstrate this approach in relation to two selected contrasting locations in South Asia (e.g. Bihar, India) and East Africa (e.g. Uganda) and for selected priority groundwater contaminants relevant to those locations. The roadmap approach developed here could then be applied to different scenarios in the future. We will bring together expertise in groundwater pollution (e.g. chemical, microbial, emerging contaminants, antimicrobial resistance), (bio)geochemical processes, remediation technologies, machine learning, decision science (e.g. agent based modelling, multi-criteria decision analysis) and social science to address local water quality and remediation challenges in these two areas. We will co-design decision tools, iteratively integrating scientific data with modelled predictions, to enable informed, locally-relevant decision-making for effective groundwater remediation. We will address an integrated set of key objectives and hypothesis (see objectives) through a series of Workpackages (WP) implemented as: (i) WP 1: Field-based Investigations comprising of WP 1.1 Multipollutant & Process Investigation and WP 1.2 Community Science; (ii) WP 2: Lab-based Investigations comprising of WP 2.1: Water & Sediment Characterisation and WP 2.2 Remediation Evaluation; (iii) WP 3: Predictive Modelling comprising of WP 3.1 Machine Learning; WP 3.2 Agent Based Modelling; and WP 3.3 Multi-Criteria Decision Analysis; and (iv) WP 4: Synthesis & Communication comprising of WP 4.1 Stakeholder Engagement and WP 4.2 Open Resource Bank Development. Our project team brings together highly complementary expertise and skillsets. I am an environmental engineer with expertise in groundwater pollution and remediation, with substantial experience managing and implementing complex, multi-partner research projects in South/Southeast Asia, Africa and South America. I am joined by Co-Investigators from The University of Manchester, British Geological Survey, University of Birmingham and University of Bath, along with international Project Partners from University of Melbourne (Australia), KTH Royal Institute of Technology (Sweden), Mahavir Cancer Sansthan (India), University of Heidelberg (Germany), Mbarara University of Science and Technology (Uganda) and independent affiliates from India and Malaysia. Collectively we bring together decades of interdisciplinary expertise in water science, remediation, water management, water and health, biotechnology, decision science, social science, participatory science, stakeholder engagement and extensive local knowledge in India and East Africa. The results and tools generated will improve the understanding of the complex natural and anthropogenic processes impacting groundwater quality in the selected locations and will better enable evidence-based decision making for effective groundwater remediation, with the roadmap generated able to be applied to other scenarios in the future.

Around two decades ago reactive halogen compounds (iodine, chlorine and bromine) were found to cause sudden ozone loss in the lowest part of the troposphere in the Arctic. In the meantime reactive halogens were also found in many other parts of the troposphere, mainly in the marine boundary layer but also over salt lakes, in the plumes of volcanoes, in the free troposphere and even in the middle of the continents. The sources for reactive halogens in the troposphere appear to be mainly natural, mostly linked to halides contained in sea water or salt deposits. The scientific community has made great progress in the measurement of these compounds and also in the understanding of the underlying release and transformation processes. Very detailed process models have been successful in reproducing the intricate chemistry which involves reactions in the gas phase, in and on aerosol particles as well as cloud droplets, which is why we refer to this as multiphase chemistry. Comparisons with field data show that the contribution of reactive halogens to ozone destruction is often on the order of 30-50% (e.g. at the Cape Verde observatory). However very few global models include reactive halogens in the troposphere. The models that do usually have to make crude assumptions regarding the sources and have to employ a reduced reaction mechanism to make it computationally feasible to perform global model runs. Another recent discovery is that chlorine atoms can contribute up to 15% to the chemical loss of methane in the tropics; this loss is not included in any of the climate models. In many continental settings several hundred parts per trillion (ppt) of chlorine have been found indicating that chlorine chemistry can be relevant there as well. It is important to stress that methane and tropospheric ozone are strong greenhouse gases. In this project we aim to strengthen the theoretical foundation for global models by thoroughly revisiting the reaction mechanisms, providing reduced reaction mechanisms that have been tested in process models for a variety of scenarios encountered in the global troposphere and by developing parameterisations for the release of reactive halogens. The outcomes from this work will be included in a state-of-the-art global chemistry-aerosol model in order to quantify the global impacts of reactive halogen chemistry on ozone destruction and production, methane destruction as well as the formation and growth of aerosol particles. Furthermore, we will compare current day scenarios with preindustrial scenarios in order to establish the importance of anthropogenic pollutants for the release of reactive halogens. This is motivated by the fact that many halogen release mechanism involve acidity and some are linked to nitrogen oxides. Anthropogenic activity has increased both atmospheric acidity and nitrogen oxide concentrations. This project brings together the UEA group with a long-standing experience in tropospheric halogen chemistry in virtually all tropospherically relevant areas and the Leeds group with a very strong track record in global modelling including halogen chemistry. This project is very timely as in the last few years several data sets have become available and more are being collected that allow us to test our model predictions on a much larger scale than possible just a few years ago. Given the potentially large impacts on tropospheric chemistry and climate the relevance of this project is significant.