The project context: The World Meteorological Organisation is an understudied specialised agency of the United Nations which exists to foster international cooperation at a global scale. It facilitates exchange and interaction between the meteorological and hydrological institutions of members, like the Caribbean Meteorological Organisation, to support forecasting, monitoring, early warning, assistance, capacity development and resilience building. International meteorological cooperation is essential to managing the destructive impacts of climate change, but faces emerging risks today that are poorly understood. Norms and patterns of state behaviour are transforming, international power relations are shifting, and historical inequities that underwrite unequal vulnerabilities to climate change are being recognised. Climate change is entangled with systemic changes in international relations, alongside producing climate-based risks to security and resilience. The WMO is a principal location in which the interaction between international relations and climate change may be studied. The challenges the project addresses: Tropical storms and hurricanes in the Caribbean are expected to become more destructive as a consequence of climate change, causing significant harms to human life, infrastructure, industry and property in the small island developing states of the Caribbean Community. Caribbean States depend on international cooperation to prepare for and manage the impacts of tropical storms and hurricanes, to share resources and expertise across borders, and coordinate relief efforts. In studying the international relations of tropical storms in the Caribbean, this research project advances understanding of the challenges facing international meteorological cooperation in a changing world order, improves policy and practices of international collaboration around tropical storms and hurricanes, and supports the resilience and security of Caribbean states. The aims and objectives of the project: 1) To study the history of how states and societies interact and co-develop in relationship to tropical storms and hurricanes in the Caribbean, so as to develop understanding of how they shaped and continue to shape international orders. 2) To map the field of international expert actors that assemble around tropical storms and hurricanes in the Caribbean, for the purpose of prediction, mitigation and response, so as to better understand how international cooperation works today. 3) To interrogate the relationship between the Caribbean Meteorological Organisation and the World Meteorological Organisation so as to better understand the risks to international cooperation in responding to climate change. 4) To document the barriers to international cooperation in prediction, mitigation and response to tropical storms and hurricanes in the Caribbean so as to produce recommendations towards improving international collaboration in a changing international order.

Biological productivity (the growth of phytoplankton) is limited by the availability of iron (Fe) in at least 30% of the ocean. Fe is so insoluble in seawater that the large amounts entering from rivers cannot be transported far from the continental margins. The supply of Fe from dust falling on the ocean becomes the primary way to add Fe (and other elements important to life such as phosphorus) to the open ocean. The pattern and flux of Fe from the atmosphere to the surface ocean is therefore important for ocean ecosystems, and for the global carbon cycle (because ocean life consumes carbon). Despite this importance, the flux of dust and of its incorporated metals to the ocean is poorly known. It is challenging to measure this flux directly, and other observational approaches require quite fundamental assumptions, which limit accuracy. At present, therefore, most estimates of dust flux rely on atmospheric models, and are generally considered to be uncertain by a factor of ten, particularly in remote regions. In the proposed work, we will assess and use a new approach to quantify the inputs of dust and its associated micronutrients to the ocean. This approach relies on measurements of two biologically inactive, partially soluble components of dust: thorium (Th) and aluminium (Al). Two isotopes of Th are used in this assessment. 232Th, is present in continental rocks. If found dissolved in the open ocean, 232Th must have been recently added by dissolution of dust transported from the continents. Another isotope, 230Th, is formed within seawater by the decay of a uranium isotope. Its concentration in seawater reflects a competition between this known rate of formation, and removal due to its insoluble nature. We can therefore use 230Th to assess the removal rate of Th, including 232Th, from seawater. The 232Th removed must be replaced by input from dust to maintain the observed 232Th concentrations, so we can calculate the input of dust. There are two main challenges to the reconstruction of dust fluxes from Th isotopes. One is that the solubility of Th in dust, a critical term in the flux calculation, is not well known. Our new results indicate that Th is amongst a small group of elements whose solubility is very little impacted by transport of dust through the atmosphere, while the solubilities of Fe, Al and several other biologically active elements are all altered greatly during transport. Using aerosol samples collected on a series of research cruises, and at a sampling tower on Bermuda, we will assess the solubility of Th, the controls on how that varies during atmospheric transport, and its relationship to changes in Al and Fe solubility. We will also conduct laboratory studies on desert dust parent soils aimed at better understanding the unusual Th solubility in dust aerosols. Dust fluxes can also be calculated from dissolved Al concentrations, but these estimates are affected by changes in Al solubility during atmospheric transport. The second challenge is that we do not know how far 232Th from the continents might travel after input at the coast. We will address this by incorporating 232Th into an ocean model. Such models have a proven ability to reconstruct 230Th, and we will develop them to also model 232Th, and to indicate where 232Th is dominated by coastal inputs rather than by dust. These models will also be used to assess the uncertainty in using Th isotopes to reconstruct dust inputs. A large number of observations of Th isotopes in seawater has recently been measured during an international programme: GEOTRACES. We will add data from two further cruises, to complete a detailed coverage of Th and Al measurements for the Atlantic Ocean. Combined use of the Th and Al tracers will therefore allow us to produce robust maps of dust inputs (from Th) and soluble Fe inputs (by taking account of the changes in solubility during transport using Al) for the Atlantic (with associated maps of uncertainty).

There is a recognised gap in the communication of information generated by climate scientists and evidence needed by policy makers, in part because influencing policy through research is complex and requires skills that might not be valued or common in research systems. The current situation of our Earth's system, together with the social movements for climate justice, urge a step change in how policy and scientists approach Climate Change. Through this fellowship, I will develop new routes for impact in palaeoclimatology and will lead a vital step change in my field of research. Annual to decadal climate predictions may offer important information to Climate Services and Environmental Agencies, which would help guide short- and medium-term climate change strategies. For example, a better knowledge of the frequency and magnitude of floods in the UK. Decadal climate predictions are skilful for surface temperature, but confidence in projections of atmospheric pattern and the associated ecosystem response are less robust. This is, in part, because the amplitude of the decadal climate response is difficult to verify by the available instrumental data (reanalyses), which only goes back a century or two, and the impact of superimposed low-frequency variability might not be well represented. One way to provide more information on the decadal climate response is to include high-temporal resolution palaeoclimate timeseries in reanalyses. So far, the availability of proxy data suitable for this purpose is limited by the nature of the data (qualitative vs quantitative), chronological constrains (dating uncertainty and time-resolution of the proxy records) and geographical location of the proxy records (i.e limited to specific climate regions as ice-cores and corals), hence the study of decadal climate variability in the past is still in its infancy. In order to make developments in this field, I will lead an international research team that integrates palaeoclimatologists and climate modellers. We will combine emerging methodological approaches in proxy developments, chronological constraints, statistical tools and data-model comparison to provide advanced information of past decadal climate variability in the North Atlantic-European region such as shifting atmospheric circulation and occurrence of extreme weather events; and we will develop emergent constraints based on past climate scenarios to be applied to decadal prediction systems. Beyond the scientific goals, the fellowship aims at a better integration of palaeo evidence into climate policy to create a step change in how long-term climate data are viewed and used by policy and stakeholders. We will create a network of policy advisers, policy makers and other end users willing to engage. A co-development model of research will be adopted to develop shared understanding to design the research outputs, and ensure the research contributes to the specific and current needs of the decision makers across various sectors. The ultimate challenge is to create a leading centre for Palaeo Evidence for Policy at Royal Holloway University of London to: (1) build a palaeo-climate service feeding policy makers with evidence to assist decision-making; (2) support palaeoclimatologists in the UK and overseas to make impact cases studies; (3) train the next generation of early career researchers in policy skills. The fellowship will also explore art-based methods for impact. In particular, creative writing to promote climate science literacy for young children.

Title: Process analysis, observations and modelling - Integrated solutions for cleaner air for Delhi (PROMOTE) Air pollution has been widely recognized as a major global health risk. Given that 1 in every 10 total deaths can be attributed to air pollution (World Bank 2016), there are major implications for the cities of the world. As part of the Indo-Gangetic Plain (IGP), Delhi is subject to air pollution from a complex mixture of sources. As a consequence of the complex emissions and meteorology of the region, particulate matter (PM as PM10 and PM2.5), nitrogen oxides (NOx, NO2), sulphur dioxide (SO2), carbon monoxide (CO) and black carbon (BC) all peak during post-monsoon periods and remain elevated during winter making the National Capital Region (NCR) one of the most polluted areas. Open questions remain regarding the inability of models to accurately predict air pollution during winter time fog events and quantifying incoming air pollution from large distances into Delhi. Over 4 years, PROMOTE aims to reduce uncertainties in air quality prediction and forecasting for Delhi by undertaking process orientated observational and modelling analyses and to derive the most effective mitigation solutions for reducing air pollution over the urban and surrounding region. PROMOTE brings together a cross-disciplinary team of leading researchers from India and the UK to deliver the project aims. Its investigations will address three key questions: Q1 What contribution is made by aerosols to the air pollution burden in Delhi? Q2 How does the lower atmospheric boundary layer affect the long range transport of air pollution incoming into Delhi? Q3 What are the most effective emission controls for mitigation interventions that will lead to significant reductions in air pollution and exposure levels over Delhi and the wider National Capital Region? To address the three key questions we will: 1 Examine the contribution of secondary aerosols to the air pollution burden in Delhi during distinct meteorological seasons by developing a new representative model scheme for subtropical urban environments; 2 Investigate how boundary layer interactions lead to high air pollution events during pre-monsoon and stable winter fog periods affecting Delhi; 3 Quantify local, urban and regional contributions to Delhi's air quality through an improved understanding of aerosols, long-range transport and boundary layer processes; 4 Test the Delhi's air quality forecasting system incorporating improved understanding of aerosol pollution and atmospheric boundary layer processs; 5 Develop the first multiscale modelling system for predicting high resolution concentrations of PM2.5, PM10, NO2 and other pollutants and then provide the analysis for developing effective mitigation strategies for Delhi; 6 Synthesise and translate the outcomes of PROMOTE with other APHH projects to provide datasets for exposure and health studies and contribute to a roadmap for implementing effective local and regional mitigation strategies to meet current and future compliance and health requirements in Delhi and NCR. Through our analysis, we will deliver new knowledge on how local, urban and regional (LRT) sources of air pollution affect Delhi's air quality. With an improved understanding of aerosols and lower atmosphere dynamics, sensitivities between air pollutant concentrations and changes in local (e.g. traffic, industrial) and regional contributions will be quantified with a new multiscale modelling system for recommending interventions and mitigation options for Delhi.

Given limited progress in reducing greenhouse gas emissions and uncertain potential for adaptation to many impacts, attention in vulnerable regions and sectors is turning to the question of "loss and damage". Who should bear the costs of human influence on climate that cannot be neutralized by adaptation? This debate is impeded by lack of robust estimates of what these costs are. Despite concerted efforts to compile inventories of emissions, we still have no agreed method of establishing how countries, companies or individuals are being adversely affected by anthropogenic climate change in the context of other drivers of regional environmental change. Many of the most important impacts of climate change are related in some way to high-impact weather events (HIWEs), such as floods, storms, and droughts. Compiling an impact inventory requires documenting the impacts of individual events and how these events are affected by multiple climate drivers and internal climate variability. We will build on research into HIWEs and their impacts under THORPEX-Africa. Studies assessing the link between climate change and extreme weather have so far focused primarily on mid-latitude phenomena and the impact of rising greenhouse gases. Yet in many tropical regions, short-lived climate forcings (SLCFs) such as sulphate, mineral and black carbon aerosols and tropospheric ozone may have played a larger role in changing patterns of weather risk to date. Substantial reductions in anthropogenic SLCFs could be achieved in only 20 years. Including measures already planned to reduce emissions of sulphate aerosol precursors, SLCFs may dominate near-term changes in weather risk. Climate impact assessments used for adaptation planning typically focus on net multi-decadal anthropogenic change, dominated by greenhouse-induced warming. Few address uncertainty in SLCF forcing and response. Hence relying on these and extrapolation of recent trends risks "adapting to yesterday's problem" as key drivers of regional weather are reversed. Assessing the influence of external drivers on extreme weather is challenging because the most important events are typically rare. The only solution is to rely on simulation models, whose reliability can be tested and if necessary re-calibrated using well-established procedures developed for seasonal forecasting. We will also use the land-surface model JULES for indirect validation in regions with sparse meteorological data. Large ensembles of climate model simulations at relatively high resolution are required for robust statistics of extreme weather events, allowing for uncertainty in both external drivers and simulation models. This project makes use of the climateprediction.net weatherathome worldwide volunteer computing project. We will quantify the role of various external climate drivers on changing risks of extreme weather in Africa by implementing a regional climate model over the CORDEX-Africa domain and simulate observed weather statistics over recent decades using multi-thousand-member ensembles, systematically excluding the influence of different climate drivers to quantify their effects. Attribution studies of HIWEs to date have typically focussed on hydrometeorological events themselves, rather than modelling all the way through to their impacts. This can lead to "over-attribution": if a record-breaking weather event occurs that has been made more likely by some external driver, people tend to blame most of the impact of that event on that driver. But much of this impact might also have been caused by a lesser, non-record-breaking, event. Hence accurate assessment requires explicit modelling of changing impact risk, not simply weather risk, so a major focus of this project will using JULES to investigate various impacts and working with impact modellers across Africa to assess the implications of our weather simulations for changing impact risk in other sectors.