This project uses two novel inputs to address the fundamental problem of understanding observed variability and change in the Atlantic Ocean in the context of the global coupled atmosphere-ocean system. Using a combination of large-ensemble perturbed-physics experiments made possible with distributed computing and new adjoint-based estimates of the recent ocean state together with uncertainty therein, we aim to identify free-running versions of an atmosphere-ocean general circulation model that, for the first time, actually reproduce the full evolution of the large-scale climate system over the past 15 years. The ensemble of such models will provide unique insights into the origins, nature and predictability of recent changes in ocean state, together with a valuable tool for assessing future predictability and the risk of substantial Atlantic Meridional Overturning Circulation changes in the longer term. Coupled models currently used both for decadal prediction and longer-term projections of the response to changing boundary conditions typically rely on the comparison of model anomalies from the model climatology with observed anomalies from some estimate of the 'real world' climatology. This is a fundamental problem when either (a) the response to external forcing is uncertain and comparable to any predictability that may arise from the initial state or (b) the system contains significant non-linearities that are likely to impact on any forecast. We will use an entirely novel approach to initialising coupled models directly from a state-of-the-art ocean analysis, using direct perturbation of coupled model parameters to find model-versions that track the real world over the past 15 years. This very challenging objective is made feasible by the unprecedented computing resources, allowing multi-thousand-member ensembles with a fully coupled atmosphere-ocean general circulation model, provided by distributed computing. Our approach will be to initialize tens to hundreds of thousands of perturbed versions of two AOGCMs from the ECCOc ocean analysis, perturbed to allow for both observational and structural uncertainty, estimated from the discrepancies between ECCOc and other analyses. We will use the statistical techniques of likelihood profiling and importance sampling to identify parameter/analysis combinations that allow models to continue to 'shadow' the analysis initially for six months and subsequently, as we home in on promising perturbations, out to the full 15 years. The models used will be HadCM3, which is already set up for distributed computing applications, and a new model based on coupling the HadAM3P model to the MITgcm used in the ECCOc analysis, exploiting information on the parameter-sensitivities of both models that is already available from past ensemble experiments and (in the case of the MITgcm) from the model adjoint. Successful model-versions will then be run free over the full 20th century (for HadCM3) or from 1975 onward (for HadAM3P/MITgcm) to assess the range of AMOC trends they generate in response to total external forcing and anthropogenic forcing only over the past two decades. They will also provide an range of initial conditions for an ensemble prediction experiment to be performed by the VALOR consortium. In addition to its scientific benefits, this project will provide a significant public outreach opportunity, allowing participants to see RAPID data being used directly to address problems of clear and immediate concern.

The fellowship will support the completion of a book, titled 'How Does Speech Timing Work?'. Speakers manipulate speech sound durations for a variety of meaning-related purposes. This book will discuss the kinds of timing patterns people produce when they speak, and will evaluate theories of how speech articulation is controlled to produce these timing patterns. Because speech timing patterns are often termed rhythmic, it will also discuss available definitions of speech rhythm, and will evaluate rhythmicity claims for speech against available evidence. This book will be of interest to anyone interested in how speech production works, including linguists, psycholinguists, motor control specialists, speech technologists, and speech therapists.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Optical coatings are key components within almost all technology that surrounds us from our glasses to cameras. Extreme-performance coatings are used in optical atomic clocks and gravitaitonal-wave detectors which are the most sensitive clocks and distance meters ever built. Optical coatings are also essential for industrial applications in photonics, particularly for miniaturisation of laser diode devices and for increasing the laser damage threshold. Optical coatings consist of alternating layers of materials with different refractive indices and are only a few micrometers thick. Their performance is determined by the amount of light scattered and absorbed inside the coating and by their thermal noises caused by the Brownian motion of the atoms. Optical coatings can be manufactured out of a large variety of materials, such as tantalum oxide, silica, and amorphous silicon. However, the ultimate properties of the coatings depend both on the intrinsic properties of these materials and on the manufacturing process. Therefore, it is essential to have a robust experiment to test novel coatings for precision instruments. We propose to build an internationally-leading facility to directly measure the properties of novel optical coatings. This proposal emanates from two recent findings. First, the MIT LIGO group found that coating samples can be measured in one week using a multimode optical resonator. Second, groups in academia in the UK, USA, and Germany developed a new class of promising extreme-performance coatings for applications in precision measurements. The proposed centre is a crucial step in commercial manufacturing of high-quality coatings since we need to experimentally explore the whole parameter space of coating production, such as deposition rate, doping materials, and annealing temperature. The key idea of the proposed experiment is to embed a coating sample in the optical resonator and measure its properties using three co-resonating beams. This setup will make all displacement noises common to these beams, except for the coating thermal noises. The main advantage of the proposed facility is that it can test one coating sample per week at the telecom laser wavelength and has the potential to be the first in the world working with extreme-performance coatings in this parameter space. The centre will be able to directly measure coating samples for future optical atomic clocks, next generation of gravitational-wave detectors, fundamental physics experiments and for the commercial applications.

Carbon emissions from burning of fossil fuels and deforestation have led to increasing concentrations of carbon dioxide in the atmosphere, which in turn lead to an increase in radiative heating. When the carbon dioxide is emitted into the atmosphere, a significant fraction of the carbon is initially taken up by the oceans, which reduces the immediate radiative heating from the emissions. Eventually, the atmosphere and ocean approach an equilibrium state after several hundred to a thousand years. The carbon dioxide remaining within the atmosphere leads to a long-term radiative heating. The problem of understanding how the carbon cycle varies is usually addressed by integrating large, complicated climate models. While these climate models are useful, we wish to adopt a different approach focussing on a long-term equilibrium state for the atmosphere and ocean. At this equilibrium state, we predict that carbon emissions lead to an exponential increase in the atmospheric concentration of carbon dioxide and a linear increase in the long-term radiative heating. If all our conventional carbon reserves are utilised, then the longterm radiative heating is 4 times larger than the present-day increase in radiative heating from carbon emissions. We aim to test this prediction in a climate model including carbon and temperature feedbacks. In a similar manner, we aim to compare our predictions of how increasing ocean stratification and acidity will affect the carbon cycle. Our longterm equilibrium solutions will be compared with climate models representing the cycling of carbon in the ocean and the whole Earth System. This comparison will provide insight into how the carbon system operates and a longterm context for climate change which policy makers need to consider when comparing different carbon emission scenarios.