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Efficient air traffic management depends on reliable communications between aircraft and the air traffic control centres. However there is a lack of ground infrastructure in the Arctic to support communications via the standard VHF links (and over the Arctic Ocean such links are impossible) and communication via geostationary satellites is not possible above about 82 degrees latitude because of the curvature of the Earth. Thus for the high latitude flights it is necessary to use high frequency (HF) radio for communication. HF radio relies on reflections from the ionosphere to achieve long distance communication round the curve of the Earth. Unfortunately the high latitude ionosphere is affected by space weather disturbances that can disrupt communications. These disturbances originate with events on the Sun such as solar flares and coronal mass ejections that send out particles that are guided by the Earth's magnetic field into the regions around the poles. During such events HF radio communication can be severely disrupted and aircraft are forced to use longer low latitude routes with consequent increased flight time, fuel consumption and cost. Often, the necessity to land and refuel for these longer routes further increases the fuel consumption. The work described in this proposal cannot prevent the space weather disturbances and their effects on radio communication, but by developing a detailed understanding of the phenomena and using this to provide space weather information services the disruption to flight operations can be minimised. The occurrence of ionospheric disturbances and disruption of radio communication follows the 11-year cycle in solar activity. During the last peak in solar activity a number of events caused disruption of trans-Atlantic air routes. Disruptions to radio communications in recent years have been less frequent as we were at the low phase of the solar cycle. However, in the next few years there will be an upswing in solar activity that will produce a consequent increase in radio communications problems. The increased use of trans-polar routes and the requirement to handle greater traffic density on trans-Atlantic routes both mean that maintaining reliable high latitude communications will be even more important in the future.

Carbon capture and storage (CCS) has emerged as a promising means of lowering CO2 emissions from fossil fuel combustion. However, concerns about the possibility of harmful CO2 leakage are contributing to slow widespread adoption of the technology. Research to date has failed to identify a cheap and effective means of unambiguously identifying leakage of CO2 injected, or a viable means of identifying ownership of it. This means that in the event of a leak from a storage site that multiple operators have injected into, it is impossible to determine whose CO2 is leaking. The on-going debate regarding leakage and how to detect it has been frequently documented in the popular press and scientific publications. This has contributed to public confusion and fear, particularly close to proposed storage sites, causing the cancellation of several large storage projects such as that at Barendrecht in the Netherlands. One means to reduce public fears over CCS is to demonstrate a simple method which is able to reliably detect the leakage of CO2 from a storage site and determine the ownership of that CO2. Measurements of noble gases (helium, neon, argon, krypton and xenon) and the ratios of light and heavy stable isotopes of carbon and oxygen in natural CO2 fields have shown how CO2 is naturally stored over millions of years. Noble gases have also proved to be effective at identifying the natural leakage of CO2 above a CO2 reservoir in Arizona and an oil field in Wyoming and in ruling out the alleged leakage of CO2 from the Weyburn storage site in Canada. Recent research has shown amounts of krypton are enhanced relative to those of argon and helium in CO2 captured from a nitrate fertiliser plant in Brazil. This enrichment is due to the greater solubility of the heavier noble gases, so they are more readily dissolved into the solvent used for capture. This fingerprint has been shown to act as an effective means of tracking CO2 injected into Brazilian and USA oil fields to increase oil production. Similar enrichments in heavy noble gases, along with high helium concentrations are well documented in coals, coal-bed methane and in organic rich oil and gas source rocks. As noble gases are unreactive, these enrichments will not be affected by burning the gas or coal in a power station and hence will be passed onto the flue gases. Samples of CO2 obtained from an oxyfuel pilot CO2 capture plant at Lacq in France which contain helium and krypton enrichments well above atmospheric values confirm this. Despite identification of these distinctive fingerprints, no study has yet investigated if there is a correlation between them and different CO2 capture technologies or the fossil fuel being burnt. We propose to measure the carbon and oxygen stable isotope and noble gas fingerprint in captured CO2 from post, pre and oxyfuel pilot capture plants. We will find out if unique fingerprints arise from the capture technology used or fuel being burnt. We will determine if these fingerprints are distinctive enough to track the CO2 once it is injected underground without the need of adding expense artificial tracers. We will investigate if they are sufficient to distinguish ownership of multiple CO2 streams injected into the same storage site and if they can provide an early warning of unplanned CO2 movement out of the storage site. To do this we will determine the fingerprint of CO2 captured from the Boundary Dam Power Plant prior to its injection into the Aquistore saline aquifer storage site in Saskatechwan, Canada. By comparing this to the fingerprint of the CO2 produced from the Aquistore monitoring well, some 100m from the injection well, we will be able to see if the fingerprint is retained after the CO2 has moved through the saline aquifer. This will show if this technique can be used to track the movement of CO2 in future engineered storage sites, particularly offshore saline aquifers which will be used for future UK large volume CO2 storage.

The atmosphere changes on time scales from seconds (or less) through to years. An example of the former are leaves swirling about the ground within a dust-devil, while an example of the latter is the quasibiennial oscillation (QBO) which occurs over the equator high up in the stratosphere. The QBO is seen as a slow meander of winds: from easterly to westerly to easterly over a time scale of about 2.5 years. This 'oscillation' is quite regular and so therefore is predictable out from months through to years. These winds have also been linked with weather events in the high latitude stratosphere during winter, and also with weather regimes in the North Atlantic and Europe. It is this combination of potential predictability and the association with weather which can affect people, businesses and ultimately economies which makes knowing more about these stratospheric winds desirable. However, it has been difficult to get this phenomenon reproduced in global climate models. We know that to get these winds in models one needs a good deal of (vertical) resolution. Perhaps better than 600-800m vertical resolution is needed. In most GCMs with a QBO this is the case, but why? We also know that there needs to be waves sloshing about, either ones that can be 'seen' in the models, or wave effects which are inferred by parameterisations. Get the right mix of waves and you can get a QBO. Get the wrong mix and you don't. Again we do not know entirely why. Furthermore, we also know convection bubbling up over the tropics and the slow migration of air upwards and out to the poles also has a big impact of resolving the QBO. All of these factors need to be constrained in some way to get a QBO. The trouble is that these factors are invariably different in different climate models. It is for this reason that getting a regular QBO in a climate model is so hard. This project is interested in exploring the sensitivity of the QBO to changes in resolution, diffusion and physics processes in lots of climate models and in reanalyses (models used with observations). To achieve this, we are seeking to bring together all the main modelling centres around the world and all the main researchers interested in the QBO to explore more robust ways of modelling this phenomena and looking for commonalities and differences in reanalyses. We hope that by doing this, we may get more modelling centres interested and thereby improve the number of models which can reproduce the QBO. We also hope that we can get a better understanding of those impacts seen in the North-Atlantic and around Europe and these may affect our seasonal predictions. The primary objective of QBOnet is to facilitate major advances in our understanding and modelling of the QBO by galvanizing international collaboration amongst researchers that are actively working on the QBO. Secondary objectives include: (1) Establish the methods and experiments required to most efficiently compare dominant processes involved in maintaining the QBO in different models and how they are modified by resolution, numerical representation and physics parameterisation. (2) Facilitate (1) by way of targeted visits by the PI and researchers with project partners and through a 3-4 day Workshop (3) Setup and promote a shared computing resource for both the QBOi and S-RIP QBO projects on the JASMIN facility

Microorganisms are the most abundant life forms on Earth. It is estimated that there are around 10 thousand, billion, billion, billion individual organisms belonging to two main microbial groups (the bacteria and archaea). This is 1 million times more than the estimated number of stars in the known Universe. It is believed that most of this vast population is found in deep sediments far below the ground and the sea floor. It is easy to think that this huge repository of buried biological (microbial) diversity is irrelevant to mankind, but nothing could be further from the truth. This intra-terrestrial microbiota has been coined the 'deep biosphere' and it is central to the cycling of matter over geological timescales. Of more immediate concern is the role that certain deep biosphere organisms have played in modifying oil in situ in petroleum reservoirs. Most of the world's oil (e.g. the giant tar sand deposits in Western Canada) has been degraded by microbes in situ long before humans recovered the first drop of crude oil. Research from our group has uncovered the microbial processes responsible for crude oil biodegradation in petroleum reservoirs and identified biological and geological factors that promote biodegradation. One of these factors is temperature. The temperature of the Earth's crust increases with depth by approximately 2-3 C every 100 meters and petroleum reservoirs at temperatures above 90 C are not subject to biodegradation. However cooler, shallower reservoirs are not always biodegraded. These non-degraded, cool shallow reservoirs once resided at greater depths but have been moved by geological uplift to shallower depths. It appears that they are not re-colonized by oil-degrading bacteria and the oil in these reservoirs remains intact. This process of transient heating of a petroleum reservoir which kills the resident oil-degrading microbiota has been termed palaeopasteurization. Research in the Arctic has provided a window into the petroleum reservoir deep biosphere. Cold Arctic sediments harbour bacteria that have optimal activity at around 50 C and may have come from leaky warm petroleum reservoirs because their closest relatives were previously identified in hot oil wells. These organisms form spores which are highly resistant to environmental extremes and act as survival capsules that protect the bacteria on their journey from deep within the Earth. These bacteria thrive without oxygen (anaerobes) and the spores resist exposure to oxygen. Sediments in the UK harbour spore-forming bacteria that degrade crude oil without oxygen, providing another link between bacteria and petroleum reservoirs. This project aims to determine if spore-forming oil-degrading and Arctic bacteria ultimately derive from petroleum reservoirs and if the process of palaeopasteurization kills them and prevents them seeding surface sediments. The project focuses on fundamental science at the interface between biology and geology and has practical implications. A supply of hydrocarbon degrading anaerobes from the deep biosphere has implications for microbial diversity in surface sediments where these bacteria may play a role in oil clean up in oxygen depleted sediments (i.e., in coastal sediments but also the deep Gulf of Mexico seafloor near the Macondo wellhead). Related bacteria also cause problems in the oil industry by producing the toxic gas hydrogen sulphide in a process known as reservoir souring. This reduces the value of oil and poses a hazard to workers. The UK hosts a major offshore oil industry that contributes significantly to employment and economic prosperity. During the transition between a fossil carbon energy economy and a renewable energy economy, the need remains for innovative operational practices to reduce the environmental impact of oil production and exploration; much of this is underpinned by an understanding of microorganisms associated with oil production and oil degradation in the environment.

Turbidity currents are the volumetrically most import process for sediment transport on our planet. A single submarine flow can transport ten times the annual sediment flux from all of the world's rivers, and they form the largest sediment accumulations on Earth (submarine fans). These flows break strategically important seafloor cable networks that carry > 95% of global data traffic, including the internet and financial markets, and threaten expensive seabed infrastructure used to recover oil and gas. Ancient flows form many deepwater subsurface oil and gas reservoirs in locations worldwide. It is sobering to note quite how few direct measurements we have from submarine flows in action, which is a stark contrast to other major sediment transport processes such as rivers. Sediment concentration is the most fundamental parameter for documenting what turbidity currents are, and it has never been measured for flows that reach submarine fans. How then do we know what type of flow to model in flume tanks, or which assumptions to use to formulate numerical or analytical models? There is a compelling need to monitor flows directly if we are to make step changes in understanding. The flows evolve significantly, such that source to sink data is needed, and we need to monitor flows in different settings because their character can vary significantly. This project will coordinate and pump-prime international efforts to monitor turbidity currents in action. Work will be focussed around key 'test sites' that capture the main types of flows and triggers. The objective is to build up complete source-to-sink information at key sites, rather than producing more incomplete datasets in disparate locations. Test sites are chosen where flows are known to be active - occurring on annual or shorter time scale, where previous work provides a basis for future projects, and where there is access to suitable infrastructure (e.g. vessels). The initial test sites include turbidity current systems fed by rivers, where the river enters marine or freshwater, and where plunging ('hyperpycnal') river floods are common or absent. They also include locations that produce powerful flows that reach the deep ocean and build submarine fans. The project is novel because there has been no comparable network established for monitoring turbidity currents Numerical and laboratory modelling will also be needed to understand the significance of the field observations, and our aim is also to engage modellers in the design and analysis of monitoring datasets. This work will also help to test the validity of various types of model. We will collect sediment cores and seismic data to study the longer term evolution of systems, and the more infrequent types of flow. Understanding how deposits are linked to flows is important for outcrop and subsurface oil and gas reservoir geologists. This proposal is timely because of recent efforts to develop novel technology for monitoring flows that hold great promise. This suite of new technology is needed because turbidity currents can be extremely powerful (up to 20 m/s) and destroy sensors placed on traditional moorings on the seafloor. This includes new sensors, new ways of placing those sensors above active flows or in near-bed layers, and new ways of recovering data via autonomous gliders. Key preliminary data are lacking in some test sites, such as detailed bathymetric base-maps or seismic datasets. Our final objective is to fill in key gaps in 'site-survey' data to allow larger-scale monitoring projects to be submitted in the future. This project will add considerable value to an existing NERC Grant to monitor flows in Monterey Canyon in 2014-2017, and a NERC Industry Fellowship hosted by submarine cable operators. Talling is PI for two NERC Standard Grants, a NERC Industry Fellowship and NERC Research Programme Consortium award. He is also part of a NERC Centre, and thus fulfils all four criteria for the scheme.

The Arctic is undergoing rapid climatic change, with dramatic consequences for the 'Frozen World' (the 'cryosphere'), including reductions in the depth, extent and duration of sea ice, and seasonal snow cover on land, retreat of ice sheets/glaciers, and melting of permafrost ("ground that remains at or below 0 degrees C for at least two consecutive years"). This is important not only for local and regional ecosystems and human communities, but also for the functioning of the entire earth system. Evidence is growing that organic matter frozen in permafrost soils (often for many millennia) is now thawing, making it available for decomposition by soil organisms, with the release of carbon dioxide (CO2) and methane (CH4), both greenhouse gases (GHGs), as by-products. A major concern now is that, because permafrost soils contain 1672 petagrams (1 Pg = 1 billion tonnes) of organic carbon (C), which is about 50% of the total global below-ground pool of organic C, and permafrost underlies ~ 25% (23 million km2) of the N hemisphere land surface, a melting-induced release of GHGs to the atmosphere from permafrost soils could result in a major acceleration of global warming. This is called a 'positive biogeochemical feedback' on global change; in other words, an unintentional side-effect in the global C cycle and climate system. Unfortunately, the interacting biological, chemical and physical controls on CO2 and CH4 emissions from permafrost (and melting permafrost) environments to the atmosphere are the subject of much speculation because the scientific community does not know enough about the interactions between C and water cycling in permafrost systems. Warmer and drier soils may release more CO2, while warmer/wetter soils might release more CH4. Permafrost thawing also causes changes in the way water flows though the landscape (because frozen ground if often impermeable to water), and some areas may become drier, while others wetter. How the relative proportions of CO2 and CH4 emissions change, and their absolute amount, is critical for the overall 'global warming potential' (GWP) because these two gases have different potency as GHGs. Release of C from soils into freshwaters also needs to be taken into account because down-stream 'de-gassing' and decomposition of organic materials also influences releases of CO2 and CH4 from freshwater, or delivery of C to lakes/oceans. All-in-all, predicting the GWP of permafrost regions is scientifically challenging, and the interactions between the water (hydrological) and C cycles are poorly known. In this project we recognise the key role that hydrological processes play in landscape-scale C fluxes in arctic and boreal regions. In permafrost catchments in NW Canada (including areas where permafrost is known to be thawing) we will measure the capture of C from the atmosphere (through photosynthesis), its distribution in plants and soils, and the biological, physical and chemical controls of C transport and delivery from soils to freshwaters, and ultimately to the atmosphere as CO2 and CH4. In essence we wish to 'close the C cycle'. Field-based measurements of key processes in the water and C cycles, including geochemical tracer and state-of-the-art C, hydrogen and oxygen isotope approaches, will be linked by computer modelling. The project team, together with partners in Canada, the US and UK, is in a unique position to link the water and C cycles in permafrost environments, and we will deliver essential scientific knowledge on the potential consequences of climate warming, and permafrost thawing, for GHG emissions from northern high latitudes. Both for local peoples directly dependent on arctic tundra/boreal forest ecosystems for their livelihoods and cultural identity, and for the global community who must respond to, and anticipate, potential consequences of climate and environmental change, this project will represent a significant step forward in understanding/predictive capacity.

The Gangetic Plain is a large fertile area at the foot of the Himalayas, covering most of northern India. Home to around 400 million inhabitants, it is one of the most densely inhabited regions in South-East Asia. With its fertile soils, monsoon precipitation and vast groundwater aquifers, the plains have been at the heart of the Indian agricultural revolution. Over the last 4 decades, the introduction of new fertilisers and crops, and the construction of large-scale irrigation systems have been major drivers of socio-economic development in the region. These practices have, however, also led to severe groundwater decline and strains on other water resources. Changing feedbacks of water and energy between the land-surface and atmosphere may have even altered the local climate system. A strong economic development is expected to continue these trends in the near future and future climate change is also expected to increase the pressure on local water resources systems. Identifying the major causes of observed historical changes in water availability and predicting the future impact of local water management strategies under climate change are particularly challenging, yet indispensable for the sustainable management of water resources. For example: assessing the sustainability of groundwater aquifers requires knowledge of global climate influences, but also of the influence of land-use, abstractions and soil moisture dynamics; furthermore, the unprecedented scale of land-use changes and increased irrigation are expected to have influenced local climate through feedbacks of water and energy. In order to unravel and quantify the impact of different drivers of change, a fully integrated analysis of the major water fluxes in the Gangetic Plain is needed. This study would be the first to analyse changes in the main water fluxes and feedbacks of the Gangetic Plain in a fully integrated modelling set-up. The approach will enable the separation of the impact of local and regional land use change from that of global climate drivers. We will develop a custom-built coupled hydrological model for the region using available groundwater and surface water modelling toolboxes. This model will be calibrated and tested using a variety of different sources of information, from local measurements, satellite observations and global climate (reanalysis) datasets. Subsequently, we will run the model with different land-use and water extraction scenarios. This will allow us to quantify the impact of land-use change and extraction on the main hydrological fluxes and water resources. At the same time, the hydrological model will generate high-resolution data about soil moisture changes resulting from historical land-use, as well as different hypothetical scenarios. By feeding these scenarios into a global climate model, we will study the potential feedbacks of large-scale changes in soil moisture on the Indian monsoon system. A pair of state-of-the-art global climate models will be used: the UK MetOffice Unified Model (MetUM) and the NCAR Community Atmosphere Model (CAM4). In a final step, the superimposed impact of climate change will be assessed and future predictions of water availability will be generated. For this purpose, we will use the new CMIP5 ensemble of climate models. Using a statistical approach, these models will be downscaled to a level useful for application over the Gangetic Plains. The integrated hydrological model can then be run with these future climate projections to assess the impact of future climate change on regional and local water availability. Two local case studies will address the usefulness of such projections and their uncertainties in a local ecosystem-oriented management setting.

The studies of ecology and evolution are closely related. Ecologists seek to understand the environmental factors that explain the distribution and abundance of species, while evolutionary biologists investigate the process of natural selection and the evolution that results, by examination of adaptation in phenotypes and genotypes. It is curious in these times of environmental change that one of the biggest gaps in our understanding of the natural world falls exactly at the intersection between ecology and evolution: we know less than we should about how the environment shapes the evolution of biodiversity. Although it is generally understood that the environment is the cause of adaptation, the links between them have seldom been explicitly explored. Many ecological studies do not consider how the environmental variation that they measure affects evolution, while many studies of evolution measure selection or adaptation without considering their environmental causes, concentrating instead on the consequences for evolution of what is genetically possible. Explicit study of the involvement of the environment in evolution has the potential to fuel a paradigm shift in our comprehension of fundamental evolutionary patterns. For example: (i) Divergence. Evolution has resulted in abundant diversity in the natural world, but the extent of this divergence within related groups of organisms is often circumscribed. Are these limits, on the kind of organisms that evolve, a consequence of what is genetically possible, or do they result from similarities in the environments to which the organisms are exposed? (ii) Convergence. Within the greater divergence, organisms have often apparently converged on similar evolutionary solutions, suggesting that evolutionary outcomes are to some extent repeatable. Is the repeated evolution of similar organisms in different places the result of genetic biases or environmental determinants? If the latter, do similar organisms always evolve in similar environments, or can different environments favour the same outcome of organismal form? Vice versa, do similar environmental combinations always result in essentially the same organism, or are there different evolutionary solutions to similar environmental problems? (iii) Novelty. Although similar organisms in different places often converge on repeated evolutionary solutions, evolution also occasionally comes up with solutions that are different from the general pattern, by dint of developing, or having lost, some distinguishing feature or combination of features. Is such evolutionary novelty the result of particularly unusual environments? Most previous studies of how the environment affects evolution have measured only a single, or small number of aspects of both the organism and the environment, but thorough answers to the questions we pose require a more comprehensive understanding of multiple different aspects of organism and environment, and of how they interact and affect other. Our approach requires the use of recently developed multivariate statistical methods that allow the simultaneous analysis of many organismal traits and many environmental variables. Adaptive radiation is the differentiation of an ancestral species into divergent new populations or species. The abundance of variation in both environment and biodiversity make adaptive radiations the perfect natural laboratories to address our questions. We will use data from replicated adaptive radiations of three-spined stickleback fish in Scotland, Iceland, western Canada and Alaska in order to answer our questions and achieve a comprehensive understanding of how the environment affects evolution. Three-spined stickleback are originally marine fish that have invaded freshwater throughout the northern hemisphere since the last ice age. Freshwater stickleback can occupy contrasting environments and exhibit great phenotypic variation, providing a perfect system for our study.

Our understanding of the biogeochemical cycling of carbon in the oceans has been revolutionised through our ability to analyse several of the parameters that describe the carbonate system via gas exchange and the aqueous acid-base thermodynamic equilibria. Thus, the individual, or more commonly, combined measurement of dissolved inorganic carbon (DIC), hydrogen ion concentration (pH), total alkalinity (TA) and the partial pressure of carbon dioxide (pCO2) has provided us with the ability to determine the influence that primary production, respiration, and calcium carbonate precipitation and dissolution have on the chemistry of the oceans. Although the geographical and temporal data coverage of the CO2 system has increased since the inception of techniques to measure all its directly observable parameters, large gaps still exist in the oceanic data base. Particular black spots are the polar oceans and especially under sea ice cover. This is an important consideration, especially as the polar oceans are experiencing environmental change as a result of ocean acidification, which is particularly rapid in the land-locked Arctic Ocean. In addition, the presence of sea ice adds complexity to the polar environment as it consists of a dynamic environment of numerous inter-connected or isolated micro-habitats that expand and contract during the seasonal cycle of formation and decay of sea ice. The study of the complex, sea ice environment is important as it in now recognized as an active interface in the interaction between the ocean and the atmosphere, through which carbon species, transform and migrate. The biogeochemical information about the polar oceans is limited in part due to its relative inaccessibility, especially when there is ice cover, the complexity of the environment and the difficulty in working in harsh conditions, but also due to a lack of appropriate methods to work at these temperatures and knowledge of the change in the value of equilibrium constants used in determining parameters of the CO2 system under these conditions. Thus, our knowledge of the CO2 system at near-zero polar waters and the sub-zero temperatures in the brine enriched micro-habitats of sea ice is currently rudimentary compared with that in oceanic waters where the temperature is above-zero.As not all of the parameters that can describe the CO2 system fully (TA, DIC, pH, pCO2) can be reliably measured in some of the polar environments, this has meant that the value of the unmeasured or unmeasurable parameters must be calculated, a process that requires extrapolation of physical-chemical equations that really should only be used with above-zero temperatures and salinity less than 50. This type of extrapolation of can lead to large differences in the calculated pCO2 and pH. Thus, the aim of our research is to provide the necessary analytical tools and experimental data so that the CO2 system in polar environments can be investigated with the same degree of sophistication as that currently afforded in temperate and tropical temperature and salinity conditions. To be able to achieve this, we have chosen existing methods of measuring pH and pCO2 in ocean waters, which we can reliable modify to measure the same parameters in brine enriched solutions at sub-zero temperatures. Using our high quality measurements, we will determine the coefficients that are essential for the determination of CO2 system and subsequently test the validity of this approach by measuring any 2 (out of 4) directly observable physical-chemical parameters of the CO2 system to predict the remaining two. In the marine community, the use of these constants, tools, and analytical methodology will aid investigation of ongoing and future changes in the CO2 chemistry, carbon-based fluxes, and saturation with respect to calcium carbonate minerals in high latitude oceans, setting important constraints on model predictions of past, present, and future climate excursions.

Recent work has shown that the single largest unknown in assessing the contribution of mountain glaciers and ice caps to contemporary global sea-level rise is the rate of mass loss by iceberg calving from large Arctic ice caps (Radic and Hock, 2011, Nature Geoscience). The largest ice caps in the Arctic, and indeed the largest ice masses outside the Antarctic and Greenland ice sheets, are those of the Canadian Arctic islands. Importantly, new findings indicate that, for 2004-2009, a sharp increase in the rate of mass loss also makes the Canadian Arctic Archipelago the single largest contributor to global sea-level rise outside Greenland and Antarctica (Gardner et al., 2011, Nature). Each of these large Canadian ice caps is divided into a series of drainage basins that flow into fjords via narrow, heavily crevassed fast-flowing outlet glaciers which dissect the islands' fringing mountains. A major question for scientists and policymakers is, therefore, how these ice caps will continue to react to the temperature rises that are predicted for the 21st century, noting that Atmospheric General Circulation Models predict that temperature rise will be significantly greater in the Arctic than at lower latitudes. Numerical modelling of large ice masses is constrained, however, by a lack of knowledge of the geometry and nature of the bed of these outlet glaciers. We will acquire geophysical data from ice-cap outlet glaciers draining the large ice caps on Ellesmere and Devon islands in the Canadian Arctic using an airborne ice-penetrating radar, laser altimeter, gravimeter, magnetometer and GPS instruments. We will focus on three key areas of each drainage basin: the heavily crevassed fast-flowing outlet glaciers themselves, an upper transition zone between the ice-cap interior and the narrow outlet glaciers; and the grounding zone marking the transition to floating ice tongues at the head of some Canadian High-Arctic fjords. Our scientific objectives are: (a) to determine ice-surface and subglacial-bed elevation; (b) to characterize the substrate, in particular whether it is bedrock or deformable sediment; (c) to establish the distribution of subglacial melting; (d) to reveal basal character changes at the transition zones between inland ice, outlet glaciers and the grounding zone; (e) to provide new estimates of outlet glacier calving fluxes and their variability on up to decadal timescales. This information, integrated with satellite datasets on outlet-glacier surface motion and our earlier observations of the regional-scale geometry of these ice caps, will provide fundamental boundary conditions for the numerical modelling of these ice caps and, thus, how they may respond to atmospheric and ocean warming over the coming decades, with implications for sea-level rise.