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Recent studies have revealed the presence of a complex freshwater system underlying the Aurora Subglacial Basin (ASB), a region of East Antarctica that contains ∼7 m of global sea level potential in ice mainly grounded below sea level. However, the impact that subglacial freshwater has on driving the evolution of the dynamic outlet glaciers that drain this basin has yet to be tested in a coupled ice sheet‐subglacial hydrology numerical modeling framework. Here, we project the evolution of the primary outlet glaciers draining the ASB (Moscow University Ice Shelf, Totten, Vanderford, and Adams Glaciers) in response to an evolving subglacial hydrology system and to ocean forcing through 2100, following low and high CMIP6 emission scenarios. By 2100, ice‐hydrology feedbacks enhance the ASB's 2100 sea level contribution by ∼30% (7.50–9.80 mm) in high emission scenarios and accelerate the retreat of Totten Glacier's main ice stream by 25 years. Ice‐hydrology feedbacks are particularly influential in the retreat of the Vanderford and Adams Glaciers, driving an additional 10 km of retreat in fully coupled simulations relative to uncoupled simulations. Hydrology‐driven ice shelf melt enhancements are the primary cause of domain‐wide mass loss in low emission scenarios, but are secondary to ice sheet frictional feedbacks under high emission scenarios. The results presented here demonstrate that ice‐subglacial hydrology interactions can significantly accelerate retreat of dynamic Antarctic glaciers and that future Antarctic sea level assessments that do not take these interactions into account might be severely underestimating Antarctic Ice Sheet mass loss. Plain Language Summary: Recent studies have revealed that ice sheet basal meltwater flows beneath a large sector of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels by ∼7 m if it were to all melt. Here, we develop a coupled ice sheet and subglacial hydrology model and use it to simulate the evolution of a large East Antarctic basin through 2100 under low and high climate forcing scenarios. Interactions between the ice sheet and the subglacial freshwater system cause this sector of East Antarctica to contribute 30% more to global sea level rise by 2100 in high emission scenarios. In addition, these interactions also drive accelerated retreat of up to 10 km of the coastal outlet glaciers that drain this ice sheet sector. Overall, we find that freshwater flowing beneath the Antarctic Ice Sheet can significantly accelerate retreat and the subsequent global sea level rise contribution of Antarctica's vulnerable outlet glaciers. Modeling studies that have attempted to quantify Antarctica's future contribution to global sea level have yet to take into account these ice sheet‐freshwater interactions, which may lead to an underestimate in future sea levels. Key Points: The 21st century evolution of the Aurora Subglacial Basin is modeled in a coupled ice sheet‐subglacial hydrology modelIce‐hydrology feedbacks accelerate projected grounding line retreat and mass loss of coastal outlet glaciersEnhanced ocean melt due to subglacial discharge is particularly influential under cooler ocean temperatures [ABSTRACT FROM AUTHOR]

The El Niño‐Southern Oscillation causes anomalous atmospheric circulation, temperature and precipitation across southern polar latitudes, but the influence of Central and Eastern Pacific El Niño events on Antarctic surface mass balance and snow accumulation has not yet been assessed. Here, we use reanalysis and reanalysis‐forced regional climate model output and find that Central Pacific El Niño results in significantly increased snow accumulation in the western Ross Sea sector and significantly decreased snow accumulation in the Amundsen Sea sector. Eastern Pacific El Niño is associated with similar but weaker patterns, with some regional exceptions. In some areas, like Dronning Maud Land, or the Wilkes Subglacial Basin, the effect of El Niño on snow accumulation changes from increased to reduced accumulation depending on the type of El Niño. Our results show that projecting El Niño types is important for constraining future changes in Antarctic surface mass balance. Plain Language Summary: The El Niño‐Southern Oscillation influences the climate in Antarctica with impacts on temperature, rainfall and snow accumulation. However, the effect of two different types of El Niño events, Central Pacific and Eastern Pacific El Niño, on the patterns of snow accumulation in Antarctica has not yet been studied. We show from reanalysis and reanalysis‐forced regional climate model output that Central and Eastern Pacific El Niño events have distinct effects on Antarctic snow accumulation patterns. During Central Pacific El Niño events, there is an increase in snow accumulation in the western Ross Sea sector, and decrease in the Amundsen Sea region. Eastern Pacific El Niño events cause similar regional effects, but to a lesser extent. In some areas, like Dronning Maud Land or the Wilkes Subglacial Basin, the effect of El Niño on snow accumulation changes from increased to reduced accumulation depending on the type of El Niño. Our findings emphasize the importance of understanding projected changes in El Niño types, as these will impact the future of Antarctica's snow accumulation. Key Points: Central and Eastern Pacific El Niño events have distinctly different seasonal impacts on Antarctic surface climateCentral Pacific El Niño accumulation anomalies develop earlier than Eastern Pacific El Niño, and persist through austral winter and springCentral Pacific El Niño impacts on West Antarctic accumulation are significantly greater than those of Eastern Pacific El Niño events [ABSTRACT FROM AUTHOR]

Ice deformation dominates the evolution of ice shelf flow and the slow‐moving regions in the interior of ice sheets. However, deformation may be poorly represented in large‐scale ice sheet models that use the Glen flow relation, due to its questionable applicability to the steady‐state flow of anisotropic ice that prevails in ice sheets, having been derived from secondary creep rates of isotropic ice. We assess the deformation regimes of Thwaites Glacier, West Antarctica, using the Glen and "Empirical Scalar Tertiary Anisotropy Regime", (ESTAR) flow relations, the latter being derived from steady‐state deformation rates of anisotropic ice. For grounded ice, the character of the flow relation determines the contribution of deformation to overall flow, with ESTAR producing greater bed‐parallel shear deformation than the standard Glen flow relation. The ESTAR experiments show larger basal shear stress maxima than the standard Glen experiment because ESTAR treats the responses to simple shear stresses and compression stresses differently, reducing the role of lateral and longitudinal stresses in momentum balance. On the Thwaites Glacier Tongue, ESTAR provides the best match to observed speeds by accounting for the differing effects of stresses on ice flow. Our results highlight the importance of the numerical description of anisotropy, particularly: In regions of transition from deformation‐dominated to sliding‐dominated flow; in the approach to the grounding line, and across ice shelves. Given the importance of these locations in determining mass flux into the ocean, our results have implications for projections of sea level change from Antarctic ice loss. Plain Language Summary: Glacial ice flows by stress‐driven deformation, involving movement within and between ice crystals, and also by sliding at the bedrock in the presence of meltwater. The rate of deformation in large‐scale models of polar ice sheets is usually described by the Glen flow relation, which is limited in how appropriately it describes deformation in the long‐term, nearly steady flows typical of ice sheets. We compare modeling of the deformation regimes of Thwaites Glacier, West Antarctica, using the Glen and Empirical Scalar Tertiary Anisotropy Regime (ESTAR) flow relations. ESTAR was formulated to represent more realistically the deformation rates that occur under prolonged stress, where the orientations of individual ice crystals develop into significantly organized patterns. ESTAR predicts more vertical shear deformation than the Glen relation, leading to faster flow over most of the Thwaites catchment, and particularly in slow‐moving regions in the interior where modeling with the Glen relation predicts unrealistic sliding. ESTAR also provides a better match to the observed surface speeds on the floating Thwaites Glacier Tongue. Our results highlight how improved descriptions of deformation change the distribution of stresses and the relative contributions of deformation and sliding to overall ice flow. Key Points: Flow relations that account for tertiary creep and anisotropy change the simulated contributions of deformation and sliding to overall flowIce in tertiary creep is softer leading to increased simulated vertical shear deformation where bed parallel shear stresses dominateHow flow relations account for anisotropy influences the simulated contributions of longitudinal and transverse stresses in momentum balance [ABSTRACT FROM AUTHOR]

Background: Preventing carbapenemase-producing Enterobacterales (CPE) transmission is a significant challenge for hospital infection prevention and control teams (IPCTs). Control measures include screening at-risk patients, contact tracing, and the isolation of carriers with contact precautions.Aim: The evolution of infection prevention and control measures was assessed in a tertiary acute care hospital with predominately multi-bedded patient accommodation, from 2011 to 2019 as cases of CPE increased. The implications for, and the response and actions of, the IPCT were also reviewed.Methods: CPE data collected prospectively from our laboratory, IPCT, and outbreak meeting records were reviewed to assess how the IPCT adapted to the changing epidemiology, from sporadic cases, to outbreaks and to localized endemic CPE.Findings: Of 178 cases, 152 (85%) were healthcare-associated and there was a marked increase in cases from 2017. The number of screening samples tested annually increased from 1190 in 2011 to 16,837 in 2019, and six outbreaks were documented, with larger outbreaks identified in later years. OXA-48 carbapenemase was detected in 88% of isolates and attendance at outbreak meetings alone accounted for 463.5 h of IPCT members, and related staff time.Conclusion: Despite considerable efforts and time invested by the IPCT, the number of CPE cases is increasing year-on-year, with more outbreaks being reported in later years, albeit partly in response to increased screening requirements. Infrastructural deficits, the changing epidemiology of CPE, and national policy are major factors in the increasing number of cases. [ABSTRACT FROM AUTHOR]

A major uncertainty in Antarctica's contribution to future sea‐level rise is the ice sheet response timescales to ocean warming. Totten Glacier drains a region containing 3.9 m global sea level equivalent and has been losing mass over recent decades. We use an ice sheet model coupled to an ice‐shelf cavity combined ocean box and plume model to investigate Totten's response to variable ocean forcing. Totten's grounding line is stable for a limited range of ocean temperatures near current observations (i.e., −0.95°C to −0.75°C), with topography influencing the discharge periodicity. For increases of ≥0.2°C in temperatures beyond this range, grounding line retreat occurs. Variable ocean forcing can reduce retreat relative to constant forcing, and different variability amplitudes can cause centennial‐scale delays in retreat through interactions with topography. Our results highlight the need for long‐term ocean state observations and to include forcing variability in ice sheet model simulations of future change. Plain Language Summary: Antarctica's contribution to future sea‐level rise is dominated by uncertainties in how the ice sheet will respond to ocean warming. Totten Glacier, East Antarctica, currently contributes to sea‐level rise and is the major outlet glacier in a region with potential to significantly raise sea levels. We use an ice sheet model coupled to a combined box and plume ocean model to investigate how variability in ocean temperatures can impact ice mass loss in this region. For scenarios of ocean temperatures that are near observed, the grounding line position is close to its present‐day location. In these scenarios, interactions between the ice shelf and topography are important in controlling the timing between peak ice shelf melting and peak mass changes. For small increases in background ocean temperature, we see grounding line retreat. In these scenarios, variability in ocean temperatures can reduce ice flux across the grounding line compared with when the ocean temperature is constant. Certain amplitudes of variability can delay grounding line retreat by centuries through interactions with the topography. This highlights the need for long‐term ocean observations in this region and to include ocean variability in ice sheet model simulations of future change. Key Points: Totten's grounding line is steady and close to present‐day only for current ocean temperatures and retreats for small temperature increasesOcean variability of various amplitudes can reduce discharge and cause centennial scale delays in grounding line migrationForcing variability needs to be taken into account in ice sheet model simulations of future climate change [ABSTRACT FROM AUTHOR]

Recent ice sheet mass loss in Antarctica has been attributed to an influx of warm ocean waters, which drove grounding‐line retreat and ice thinning. Episodic retreat and rapid thinning also occurred in the southwestern Ross Sea during the Holocene, which today accommodates cold ocean waters. We applied finite element ice‐flow modeling to investigate the roles of ocean temperature and bed topography in the deglaciation of this region. First, our experiments demonstrate that bed topography controlled the spatial pattern of grounding‐line retreat. Topographic pinning points limited the rate of ice loss until retreat progressed beyond a bathymetric threshold. Second, ocean thermal forcing determined the timing of this ice loss. Enhanced ocean‐driven melt is required during the Early‐to‐Mid Holocene to replicate geological records of deglaciation, possibly indicating that warm ocean waters were once present in this region. On multi‐centennial timescales, ocean temperature drove, while bed topography controlled, nonlinear rates of ice mass loss. Plain Language Summary: Parts of the Antarctic Ice Sheet are currently losing mass at an accelerating rate. The main cause is considered to be warming ocean waters, which melt the underside of floating ice shelves, initiating retreat and inland thinning of the ice sheet. Future ice loss will depend on when and where ocean warming occurs, and how the ice sheet responds. However, modern observations are too short to fully assess the effects of these processes. We use a state‐of‐the‐art numerical ice‐flow model to investigate the roles of ocean warming and bedrock geometry during a period of accelerated ice sheet thinning in the recent geological past. We find that seafloor mounts and banks helped to slow down the rate of ice sheet retreat. Once the grounded ice became detached from these parts of the bedrock, retreat accelerated across areas of deeper water, causing rapid inland thinning of the ice sheet. Crucially, we also find that this period of past rapid thinning was initiated by an enhanced rate of ocean warming. This work highlights that key processes governing modern and future ice sheet mass loss—ocean warming and feedbacks associated with bedrock geometry—occurred in the past on timescales of centuries to millennia. Key Points: Regional finite element ice‐flow modeling was used to investigate the drivers and controls of kilometer‐scale, Holocene ice sheet retreatTopographic pinning points controlled the rate of ice loss during retreat until a threshold was reached, after which retreat was rapidEnhanced ocean‐driven melt in the Early‐to‐Mid Holocene explains the timing of the rapid ice loss in this region [ABSTRACT FROM AUTHOR]

The Antarctic Ice Sheet (AIS) is out of equilibrium with the current anthropogenic‐enhanced climate forcing. Paleoenvironmental records and ice sheet models reveal that the AIS has been tightly coupled to the climate system during the past and indicate the potential for accelerated and sustained Antarctic ice mass loss into the future. Modern observations by contrast suggest that the AIS has only just started to respond to climate change in recent decades. The maximum projected sea level contribution from Antarctica to 2100 has increased significantly since the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report, although estimates continue to evolve with new observational and theoretical advances. This review brings together recent literature highlighting the progress made on the known processes and feedbacks that influence the stability of the AIS. Reducing the uncertainty in the magnitude and timing of the future sea level response to AIS change requires a multidisciplinary approach that integrates knowledge of the interactions between the ice sheet, solid Earth, atmosphere, and ocean systems and across time scales of days to millennia. We start by reviewing the processes affecting AIS mass change, from atmospheric and oceanic processes acting on short time scales (days to decades), through to ice processes acting on intermediate time scales (decades to centuries) and the response to solid Earth interactions over longer time scales (decades to millennia). We then review the evidence of AIS changes from the Pliocene to the present and consider the projections of global sea level rise and their consequences. We highlight priority research areas required to improve our understanding of the processes and feedbacks governing AIS change.Plain Language Summary: The Antarctic Ice Sheet (AIS) is an important component of the global climate system. Human activities have caused the atmosphere and especially the oceans to warm. However, the full effect of human caused climate change on the AIS has not currently been realized because the ice sheet responds on a range of time scales and to many different Earth processes. Modern observations show that West Antarctica has been melting at an accelerating rate since the 2000s, while the data for East Antarctica are less clear. Environmental records preserve the history of the climate and AIS, which extend beyond the instrumental record and reveal how the AIS responded to past climate warming. Estimates of how much the AIS will contribute to sea level rise by the Year 2100 have changed as a result of new information on how the AIS evolved in the past and research into the interactions between the ice sheet, solid Earth atmosphere, and ocean systems. This review brings together our knowledge of the major processes and feedbacks affecting the AIS and the evidence for how the ice sheet changed since the Pliocene. We consider the future estimates and consequences of global sea level rise from melting of the AIS and highlight priority research areas.Key Points: The AIS is a highly dynamic component of the Earth system, evolving on a broad range of temporal and spatial scalesPaleoenvironmental evidence highlights the centennial to millennial response time scales of the AIS to atmospheric‐ocean forcingCoupling feedbacks in Earth system components are required to reduce the uncertainty in AIS's contribution to past and future sea level rise [ABSTRACT FROM AUTHOR]

Reconstructing past hydroclimatic variability using climate-sensitive paleoclimate proxies provides context to our relatively short instrumental climate records and a baseline from which to assess the impacts of human-induced climate change. However, many approaches to reconstructing climate are limited in their ability to address sampling variability inherent in different climate proxies. We iteratively optimise an ensemble of possible reconstruction data series to maximise the Gaussian kernel correlation of Rehfeld et al. (2011) which reconciles differences in the temporal resolution of both the target variable and proxies or covariates. The reconstruction method is evaluated using synthetic data with different degrees of sampling variability and noise. Two examples using paleoclimate proxy records and a third using instrumental rainfall data with missing values are used to demonstrate the utility of the method. While the Gaussian kernel correlation method is relatively computationally expensive, it is shown to be robust under a range of data characteristics and will therefore be valuable in analyses seeking to employ multiple input proxies or covariates. [ABSTRACT FROM AUTHOR]

This study explores the opportunities for and barriers to the inclusion and influence of young people in local recreation policy by describing a group of young skateboarders’ attempt to build a skate park in their village. Central to the analysis is the relative importance of cultural and social capital and the identity and place of lifestyle sport for empowerment by community stakeholders. We present the skateboarders’ notes, conversations and celebrations through their journey to challenge the conventional use of a small community park and to promote local investment in a place that more closely reflected their needs. We conclude that the potential negative association of skateboarding as a ‘subversive’ activity did not appear to pose any barriers and, indeed, the close ties that skateboarding provided these young people was a significant enabler. However, their complex identities were more than simply ‘skateboarder’, and the notable cultural capital held by many of these young men garnered the support of key ‘agents’ in the community, which was also an important factor in the project’s success. The only barrier of note was the skateboarders’ lack of knowledge of procedures and the unfamiliar, ‘adult-centred’ environment and methods. [ABSTRACT FROM PUBLISHER]

Tuberous sclerosis complex (TSC) is an important cause of epilepsy and autism, as well as renal and pulmonary disease in adults and children. Affected individuals are subject to hamartomas in various organ systems which result from constitutive activation of the protein kinase mTOR (mammalian target of rapamycin). The clinical course, prognosis and appropriate therapy for TSC patients are often different from that for individuals with epilepsy, renal tumors, or interstitial lung disease, from other causes. Additionally, TSC serves as a model for other conditions in which the mTOR pathways are also up-regulated. This article reviews the molecular pathophysiology and management of neurological, renal and pulmonary manifestations of the disorder. The use of mTOR inhibitors such as rapamycin and everolimus is discussed and recent clinical trials of these drugs in TSC are reviewed. [ABSTRACT FROM AUTHOR]