A5023159094- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Winter Sports Injuries and Performance
- Climate variability and models
- Climate change and permafrost
- Landslides and related hazards
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Polar Research and Ecology
- Geophysics and Gravity Measurements
- Geophysics and Sensor Technology
- Smart Materials for Construction
- Geological Studies and Exploration
- Oceanographic and Atmospheric Processes
- Hydrocarbon exploration and reservoir analysis
- High Altitude and Hypoxia
- Meteorological Phenomena and Simulations
- Ecosystem dynamics and resilience
British Antarctic Survey
2018-2025
Antarctic Climate and Ecosystems Cooperative Research Centre
2017-2018
UNSW Sydney
2017-2018
ARC Centre of Excellence for Climate System Science
2017-2018
Australian Antarctic Division
2018
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2018
Abstract A potentially irreversible threshold in Antarctic ice shelf melting would be crossed if the ocean cavity beneath large Filchner–Ronne Ice Shelf were to become flooded with warm water from deep ocean. Previous studies have identified this possibility, but there is great uncertainty as how easily it could occur. Here, we show, using a coupled sheet-ocean model forced by climate change scenarios, that any increase likely preceded an extended period of reduced melting. Climate weakens...
Abstract Rapid ice loss is occurring in the Amundsen Sea sector of West Antarctic Ice Sheet. This assumed to be a long‐term response oceanographic forcing, but ocean conditions are unknown prior 1994. Here we present modeling study from 1920 2013, using an ensemble ice‐ocean simulations forced by climate model experiments. We find that during early twentieth century, likely experienced more sustained cool periods than at present. Warm become dominant over (mean trend 0.33°C/century) causing...
Abstract Ocean-driven melting of floating ice-shelves in the Amundsen Sea is currently main process controlling Antarctica’s contribution to sea-level rise. Using a regional ocean model, we present comprehensive suite future projections ice-shelf Sea. We find that rapid warming, at approximately triple historical rate, likely committed over twenty-first century, with widespread increases melting, including regions crucial for ice-sheet stability. When internal climate variability considered,...
Basal melting of Antarctic ice shelves is expected to increase during the twenty-first century as ocean warms, which will have consequences for sheet stability and global sea level rise. Here we present future projections shelf using Finite Element Sea Ice/Ice-Shelf Ocean Model (FESOM) forced with atmospheric output from models phase 5 Coupled Intercomparison Project (CMIP5). CMIP5 are chosen based on their agreement historical reanalyses over Southern Ocean; best-performing ACCESS 1.0...
Abstract Two decades into the 21st century there is growing evidence for global impacts of Antarctic and Southern Ocean climate change. Reliable estimates how system would behave under a range scenarios future external forcing are thus high priority. Output from new model simulations coordinated as part Coupled Model Intercomparison Project Phase 6 (CMIP6) provides an opportunity comprehensive analysis latest generation state‐of‐the‐art models following wider experiment types than previous...
Abstract Understanding changes in Antarctic ice shelf basal melting is a major challenge for predicting future sea level. Currently, warm Circumpolar Deep Water surrounding Antarctica has limited access to the Weddell Sea continental shelf; consequently, melt rates at Filchner‐Ronne Ice Shelf are low. However, large‐scale model projections suggest that Slope Front and coastal circulation may enhance inflows within this century. We use regional high‐resolution cavity ocean explore forcing...
Abstract Warm ocean waters drive rapid ice‐shelf melting in the Amundsen Sea. The heat transport toward ice shelves is associated with Undercurrent, a near‐bottom current that flows eastward along shelf break and transports warm onto continental via troughs. Here we use regional ice‐ocean model to show that, on decadal time scales, undercurrent's variability baroclinic (depth‐dependent). Decadal surface cooling tropical Pacific results cyclonic wind anomalies over These westward perturbation...
Abstract. Ocean-driven ice loss from the West Antarctic Ice Sheet is a significant contributor to sea-level rise. Recent ocean variability in Amundsen Sea controlled by near-surface winds. We combine palaeoclimate reconstructions and climate model simulations understand past future influences on winds anthropogenic forcing internal variability. The show strong historical wind trends. External greenhouse gases stratospheric ozone depletion drove zonally uniform westerly trends centred over...
Abstract. Observations of ocean-driven grounding-line retreat in the Amundsen Sea Embayment Antarctica raise question an imminent collapse West Antarctic Ice Sheet. Here we analyse committed evolution grounding lines under present-day climate. To this aim, first calibrate a sub-shelf melt parameterization, which is derived from ocean box model, with observed and modelled sensitivities to temperature changes, making it suitable for simulations future sea level projections. Using new...
Abstract. An increasing number of Southern Ocean models now include Antarctic ice-shelf cavities, and simulate thermodynamics at the ice-shelf/ocean interface. This adds another level complexity to simulations, as ice shelves interact directly with ocean indirectly sea ice. Here, we present first model intercomparison evaluation present-day ocean/sea-ice/ice-shelf interactions, simulated by two models: a circumpolar configuration MetROMS (ROMS: Regional Modelling System coupled CICE:...
Abstract. Observations of ocean-driven grounding line retreat in the Amundsen Sea Embayment Antarctica give rise to question a collapse West Antarctic Ice Sheet. Here we analyse committed evolution lines under present-day climate conditions locate underlying steady states that they are attracted and understand reversibility large-scale changes. To this aim, first calibrate sub-shelf melt module PICO with observed modelled sensitivities ocean temperature Using new calibration, run an ensemble...
Abstract. Glaciers along the Amundsen Sea coastline in West Antarctica are dynamically adjusting to a change ice-shelf mass balance that triggered their retreat and speed-up prior satellite era. In recent decades, ice shelves have continued thin, albeit at decelerating rate, whilst discharge across grounding lines has been observed increased by up 100 % since early 1990s. Here, ongoing evolution of components is assessed high-resolution coupled ice–ocean model includes Pine Island, Thwaites,...
Abstract. Societal adaptation to rising sea levels requires robust projections of the Antarctic Ice Sheet’s retreat, particularly due ocean-driven basal melting its fringing ice shelves. Recent advances in ocean models that simulate ice-shelf offer an opportunity reduce uncertainties ice–ocean interactions. Here, we compare several community-contributed, circum-Antarctic simulations highlight inter-model differences, evaluate agreement with satellite-derived melt rates, and examine...
Increased ice loss from the West Antarctic Ice Sheet plays a significant role in determining future sea level rise. Much of this originates within Amundsen Sea sector, where floating components sheets, shelves, are expected to melt more rapidly over coming century. This increased melting is caused by warm waters entering continental shelf and these shelves below. While models project an increase ocean warming century, causes behind little understood. In study, we untangle how climate change...
The West Antarctic Ice Sheet is rapidly losing mass due to ocean-driven ice shelf melt, contributing sea level rise. This melt typically studied using either global climate models without open cavities or regional with cavities. We will present updates on development work a  ¼° circumpolar NEMO configuration that extends from the continent 50 degrees south allow for interaction between regions and which includes ice, icebergs, BedMachinev3 bathymetry. While...
The Amundsen Sea sector in West Antarctica has undergone dramatic changes recently, with increased ice loss, widespread thinning and retreating grounding lines. This led to concerns about the future stability of region wider sheet, which could raise global mean sea level by several meters. Mass loss is predominantly driven basal melting at coast, where vulnerable shelves are exposed warm ocean waters. However, internal dynamics also plays a huge role how sheet responds ocean-induced melting....
The cavity underneath the second largest ice shelf in Antarctica, Filchner-Ronne Ice Shelf, could flip under strong climate warming from its current 'cold' state into a 'warm' (Hellmer et al., 2012). Numerical models show that this regime shift occurs relatively abrupt, within decade, with sub-shelf melt rates increasing 21-fold (Naughten 2021). increase melting will reduce shelfs buttressing capacity, thereby driving grounded loss, and contribution to sea-level rise. Moreover, changes...
ABSTRACT Open-ocean polynyas in the Weddell Sea of Antarctica are product deep convection, which transports Warm Deep Water (WDW) to surface and melts sea ice or prevents its formation. These occur only rarely observational record but a near-permanent feature many climate ocean simulations. A question not previously considered is degree polynya affects nearby Filchner–Ronne Ice Shelf (FRIS) cavity. Here we assess these effects using regional model simulations FRIS, where convection imposed...
Abstract. The Regional Ocean Modeling System (ROMS), including an ice shelf component, has been applied on a circum-Antarctic domain to derive estimates of basal melting. Significant improvements made compared previous models this scale are the inclusion tides and horizontal spatial resolution 2 km, which is sufficient resolve on-shelf heat transport by bathymetric troughs eddy-scale circulation. We run model with ocean–atmosphere–sea conditions from year 2007 represent nominal present-day...
Abstract. Glaciers along the Amundsen Sea coastline in West Antarctica are dynamically adjusting to a change ice-shelf mass balance that has triggered their retreat and speed-up prior satellite era. In recent decades, ice shelves have continued thin, albeit at decelerating rate, whilst discharge across grounding lines been observed increase by up 100 % since early 1990s. Here, ongoing evolution of components is assessed high-resolution coupled ice-ocean model includes Pine Island, Thwaites,...
Abstract. Ocean-driven ice loss from the West Antarctic Ice Sheet is a significant contributor to sea-level rise. Recent ocean variability in Amundsen Sea sector primarily controlled by near-surface winds. We combine paleoclimate reconstructions and climate model simulations understand past future influences on winds anthropogenic forcing internal variability. The show strong historical wind trends. External greenhouse gases stratospheric ozone depletion drove zonally-uniform westerly trends...
Ice shelves along the Amundsen Sea coastline in West Antarctica are continuing to thin, albeit at a decelerating rate, whilst ice discharge across grounding lines has been observed increase by up 100% since early 1990s. Here, ongoing and future evolution of ice-shelf mass balance components (basal melt, line flux, calving flux) is assessed high-resolution coupled ice-ocean model that includes Pine Island, Thwaites, Crosson Dotson shelves. For range idealized ocean-forcing scenarios, combined...