Concentrations of both greenhouse gases (GHG) and aerosols (tiny particles suspended in the atmosphere) have increased considerably since pre-industrial time. Whilst anthropogenic emissions of GHG warm the planet, aerosol emissions exert a significant, yet poorly quantified cooling that acts to offset a significant fraction of global warming from GHG. Despite decades of research, the Intergovernmental Panel on Climate Change Assessment Report continues to highlight the climate sensitivity and aerosol-cloud-interactions (ACI) as the two key uncertainties limiting our understanding of climate change. Improving model estimates of climate change sensitivity (global temperature change per unit climate forcing) to greenhouse gas emissions is primarily driven by inter-model differences how climate models represent the impacts of feedbacks between low-level clouds and the climate system as temperature increases. Reducing these inter-model differences is severely hampered by the accuracy by which low level marine boundary layer (MBL) clouds, key modulators of the net radiation budget, are represented in the Earth System Models (ESMs) we use to provide estimates of future climate scenarios. Due to computational limitations these ESMs cannot explicitly represent small-scale atmospheric processes key for the formation of MBL at the scale at which they occur in nature (down to the size of aerosols). Instead, atmospheric physical processes related to cloud formation have to be parameterised (a simplified form of the complex process). Creating simplified representations of complex cloud processes that occur over a wide range of temporal/spatial scales is a challenging undertaking for climate scientists. Uncertainties in these parameterisations propagates through to our ability to accurately represent MBL in ESMs. The focus of this project will be to improve understanding of small-scale MBL processes by addressing current deficiencies in ESM parameterisations of cloud droplet formation, the direct microphysical link between aerosols and clouds. This will be achieved by using new modelling frameworks to capitalise on detailed flight measurements of MBL clouds from the NASA Earth Venture Suborbital mission called ACTIVATE (Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment). ACTIVATE represents a novel measurement campaign of unprecedented scope for understanding MBL clouds as it will involve the deployment of two aircraft with well-matched groundspeeds. This strategy will allow for co-location of radiative properties of clouds from an aircraft flying above the MBL with an aircraft performing in-situ aerosol and cloud measurements within the MBL. This will provide a unique dataset with which we can constrain both process-scale cloud models, and large-scale ESMs to improve current small-scale ACI parameterisations, and subsequently the accuracy by which MBL clouds are represented in ESMs. To reach these goals the CLOSURE will use a new modelling framework in which a computationally fast cloud model known as a cloud parcel model (CPM). has been embedded in an ESM for the first time. These types of cloud models can accurately simulate the growth of a population of aerosol particles into cloud droplets in an ascending parcel of air. This embedded CPM framework will crucially allow for a detailed investigation of ACI in ESMs against measurements from ACTIVATE by providing additional model information for evaluation, e.g. droplet spectra. Furthermore, it will provide an efficient and seamless integration of process knowledge gained at the process scale from offline simulation to the large-scale when embedded in the ESM. This will be used to provide better understanding on the role of key small-scale processes involved in ACI for the representation of MBL clouds. The resulting improved theoretical descriptions of MBL cloud processes will reduce current uncertainties in future climate scenarios estimates.

The proposal presented here is important for quantifying how interfacial chemistry in the atmosphere is important in the assessment of modern climate change. It relies on three aspects of atmospheric science 1) Atmospheric aerosols are tiny solid or liquid particles suspended in air. They arise from human activity (e.g. burning of fossil fuels) and naturally (e.g. breaking ocean waves) and can exist in the atmosphere for minutes to days. These aerosol are a large source of uncertainty when assessing man-made contributions to climate change as they strongly influence (I) the amount of light reflected back to space (potentially cooling the planet) and (II) the formation of clouds, and how much sunlight they reflect back to space (again, potentially cooling the planet). 2) Some of these aerosol have thin films or coatings of organic material. As the size of these aerosol are similar to the wavelength of sunlight a thin coating can significantly alter their ability to scatter and 'reflect' sunlight and their potential to form clouds. 3) The atmosphere effectively acts as a low temperature, dilute fuel, combustion system oxidizing chemicals released from the Earth's surface. The rate at which chemicals released from the Earth's surface can be removed by oxidation is important in understanding the atmosphere's self-cleansing mechanism. Previously *proxies* of thin films on atmospheric aerosol have been shown to potentially alter the light scattering and cloud forming ability of clouds. These proxies have been chosen from a chemical catalogue and do not represent the mixture and variety found in the atmosphere. We will use *real* material extracted from different locations to characterize the thin films formed on real atmospheric aerosol, determine their film thicknesses, light scattering ability and their chemical reactivity in the atmosphere. Our own preliminary work demonstrates that laboratory proxy thin films are not representative of the real atmosphere. The film thicknesses are critical to the calculation of their light scattering ability which in turn is critical to calculation of the proportion of sunlight scattered back to space. The chemical reactivity is important in determining the lifetime of the film, because as the film reacts the optical properties of the particle will change significantly. If the film lifetime is longer than a typical aerosol lifetime then it can be simply included into atmospheric models, but if the film lifetime is much shorter then it may be ignored. However preliminary data suggests it is has a similar lifetime meaning the *changing* light scattering properties of a coated particle will need to be modelled. The project represents the first comprehensive study of atmospheric thin film oxidation and light scattering with real atmospheric matter from the atmosphere. The combined experimental and modelling approach will allow the demonstration of (I) core-shell (thin film behavior) from atmospheric samples, (II) calculation of their optical properties and change in radiative balance at the top of the atmosphere., (III) measurement of atmospheric oxidation rates of the film and inclusion in Co-I led complex aerosol kinetic modelling of complex mixture aerosol. The proposal will also continue to develop two emergent exciting techniques for atmospheric science: Laser trapping with Mie spectroscopy and neutron scattering. The ability of these technique to study films ~10nm thick in real time, with the correct morphology and with unprecedented precision is phenomenal. The proposal will also be an excellent training vehicle for two PDRAS in soft-matter, facility, and atmospheric experimental science with real world modelling of atmospheric outcomes. The data and model systems from this proposed work will be ready for including global climate models. The letters os support demonstrate that ends users for some off data with the Met. office(UK) and MPIC (Germany).

Intense extratropical cyclones are one of the major weather risks in the mid-latitudes. High winds and extreme precipitation from extratropical cyclones can result in windstorm damage, flooding and coastal storm surge. Understanding the impacts of climate change on extratropical cyclones is critical to assessing future weather risk. TEMPEST is a 3-year proposed programme of research addressing the climate science deliverable of the NERC Storm Risk Mitigation directed programme. The climate deliverable is to provide an improved understanding of how climate change and natural variability will affect the generation and evolution of extra-tropical cyclones. TEMPEST will achieve this improved understanding by addressing the scientific questions raised in the Storm Risk Mitigation climate deliverable. TEMPEST aims to address these questions by, Providing the first systematic assessment of how intense extratropical cyclones are predicted to change in the Fifth Coupled Model Intercomparison Project (CMIP5) climate models Performing an integrated set of sensitivity experiments with the Met Office Unified Model to quantify the key processes that determine the spread of climate model predictions Investigating the response of intense extratropical cyclones to climate change in very high-resolution global atmospheric model experiments capable of capturing mesoscale structures. The focus in TEMPEST is on intense extratropical cyclones that affect Europe. This is partly due to the socioeconomic impacts of such storms, but is also partly driven by the scientific need to address the particularly large spread in climate model predictions for extratropical cyclone activity over the North Atlantic and Europe. It is envisaged that the outcomes from TEMPEST will feed directly into the forthcoming IPCC assessment report (AR5). TEMPEST will also have strong synergies with other LWEC (Living With Environmental Change) programmes, most notably the JWCRP (Joint Met Office/NERC Weather and Climate Research Programme) and the CWC (Changing Water Cycle) research programme. The questions posed by the Storm Risk Mitigation climate deliverable cut across the traditional boundaries of weather and climate modelling communities. To tackle these questions, we aim to bring together scientists from the climate, weather and statistical communities at the Universities of Exeter, Oxford and Reading, the Met Office and ECMWF (European Centre for Medium-Range Weather Forecasts). By engaging the wider community within TEMPEST, we will enable the development of links with the Impacts and Numerical Weather Prediction projects in the Storm Risk Mitigation programme.

Modelling the global climate accurately, and developing tools which can predict the weather more reliably, is of fundamental importance us all. To improve the quality of atmospheric models we need increasingly widespread and more sensitive measurements of atmospheric constituents. In particular, clouds play an enormous role in the earth's atmospheric processes but currently they are still relatively poorly understood, partly due to a lack of measured data, and this lack of data means that atmospheric computer simulations are of limited validity. As global warming takes effect, this can result in more moisture in the atmosphere, increasing the frequency of extreme weather events. Thus, improving our ability to measure clouds is an important goal for climate researchers. Radars which operate with millimetre wavelengths are ideally placed to measure clouds, ice particles, aerosols and volcanic ash since their operating wavelength is appropriate to the scale of these atmospheric constituents. However, current millimetre wave cloud profiling radars, which are usually ground based and use narrow frequency band high power pulse amplifiers, have limited ability to detect the most tenuous ensembles of very fine particles, especially at very high altitudes, where their interaction with solar radiation is highly significant. Furthermore, the limited sensitivity of earlier generations of cloud profiling radars tended to mean they measured slowly and only looked in a single direction, usually vertically upwards. This limited view of clouds then fails to capture their true three dimensionality and dynamic behaviour. The next generation of cloud profiling radars will scan their beam around in space to reveal cloud structure and record the temporal evolution of cloud masses, but this requires increased transmit power. The aim of our project is to demonstrate a new class of high power, wideband millimetre wave amplifier, called a gyro-TWA, which offers a ten-fold increase in available bandwidth and a five-fold increase in available peak power over the amplifiers used in current cloud profiling radars. This will lead to greater radar sensitivity, enabling measurement of smaller or more tenuous particulates, with finer resolution, at longer ranges or in a shorter timescale. The technology also has the potential to be applied to the ground based mapping of space debris, a major consideration for all orbiting systems including environmental monitoring satellites. The proposal is a collaboration between two major millimetre wave groups at the University of Strathclyde and the University of St Andrews who collectively have decades of experience and vibrant international reputations in the development of high power millimetre wave sources, radars, instrumentation and components, plus a strong track record in commercialisation, industrial collaboration, and delivering on project objectives. The gyro-TWA represents a core technology that is likely to lead to UK leadership in the field of high power millimetre wave radar.

This proposal is for a new EPSRC Centre for Doctoral Training in Wind and Marine Energy Systems and Structures (CDT-WAMSS) which joins together two successful EPSRC CDTs, their industrial partners and strong track records of training more than 130 researchers to date in offshore renewable energy (ORE). The new CDT will create a comprehensive, world-leading centre covering all aspects of wind and marine renewable energy, both above and below the water. It will produce highly skilled industry-ready engineers with multidisciplinary expertise, deep specialist knowledge and a broad understanding of pertinent whole-energy systems. Our graduates will be future leaders in industry and academia world-wide, driving development of the ORE sector, helping to deliver the Government's carbon reduction targets for 2050 and ensuring that the UK remains at the forefront of this vitally important sector. In order to prepare students for the sector in which they will work, CDT-WAMSS will look to the future and focus on areas that will be relevant from 2023 onwards, which are not necessarily the issues of the past and present. For this reason, the scope of CDT-WAMSS will, in addition to in-stilling a solid understanding of wind and marine energy technologies and engineering, have a particular emphasis on: safety and safe systems, emerging advanced power and control technologies, floating substructures, novel foundation and anchoring systems, materials and structural integrity, remote monitoring and inspection including autonomous intervention, all within a cost competitive and environmentally sensitive context. The proposed new EPSRC CDT in Wind and Marine Energy Systems and Structures will provide an unrivalled Offshore Renewable Energy training environment supporting 70 students over five cohorts on a four-year doctorate, with a critical mass of over 100 academic supervisors of internationally recognised research excellence in ORE. The distinct and flexible cohort approach to training, with professional engineering peer-to-peer learning both within and across cohorts, will provide students with opportunities to benefit from such support throughout their doctorate, not just in the first year. An exceptionally strong industrial participation through funding a large number of studentships and provision of advice and contributions to the training programme will ensure that the training and research is relevant and will have a direct impact on the delivery of the UK's carbon reduction targets, allowing the country to retain its world-leading position in this enormously exciting and important sector.