Periodic Reporting for period 1 - OCEAN ICE (Ocean Cryosphere Exchanges in ANtarctica: Impacts on Climate and the Earth system)
Période du rapport: 2022-11-01 au 2024-04-30
OCEAN:ICE assesses the impacts of key Antarctic Ice Sheet and Southern Ocean processes on the Earth system, as well as their influence on sea level rise, deep water formation, ocean circulation and climate. OCEAN:ICE seeks to improve predictions of how changes in the Antarctic ice sheet impact global climate, including via ocean-modulated feedbacks with the Greenland ice sheet.
Our focus areas are the following:
1) The new circumpolar and Atlantic ocean observations, both in-situ and from Earth Observation with a special focus on ESA-produced satellite datasets.
2) The assimilation of new and existing data into improved ice sheet, ocean and climate models.
3) The production of new estimates of ice sheet melt and its impacts on ocean circulation, including the Atlantic meridional overturning circulation (AMOC), which has a significant impact on European climate.
4) The development, calibration and evaluation of the numerical models used to predict the future evolution of the large polar ice sheets is important for reducing the deep uncertainty in timing and magnitude of the impact of their melt and OCEAN:ICE, therefore, seeks to produce projections of societally relevant environmental changes on decadal to multi-centennial time scales.
5) The assessment of the potential for passing ice sheet 'tipping points' and their consequences for ocean circulation and climate.
Through the set up of an extensive network of international collaboratoins OCEAN:ICE is advancing the state of the art in coupled ice sheet-climate modelling, it directly contributes to international climate assessments (e.g. IPCC) and delivers improved assessments of European climate impacts from the melting ice sheets, with actionable risk and timescales, to policymakers and the public.
Our focus areas are the following:
1) The new circumpolar and Atlantic ocean observations, both in-situ and from Earth Observation with a special focus on ESA-produced satellite datasets.
2) The assimilation of new and existing data into improved ice sheet, ocean and climate models.
3) The production of new estimates of ice sheet melt and its impacts on ocean circulation, including the Atlantic meridional overturning circulation (AMOC), which has a significant impact on European climate.
4) The development, calibration and evaluation of the numerical models used to predict the future evolution of the large polar ice sheets is important for reducing the deep uncertainty in timing and magnitude of the impact of their melt and OCEAN:ICE, therefore, seeks to produce projections of societally relevant environmental changes on decadal to multi-centennial time scales.
5) The assessment of the potential for passing ice sheet 'tipping points' and their consequences for ocean circulation and climate.
Through the set up of an extensive network of international collaboratoins OCEAN:ICE is advancing the state of the art in coupled ice sheet-climate modelling, it directly contributes to international climate assessments (e.g. IPCC) and delivers improved assessments of European climate impacts from the melting ice sheets, with actionable risk and timescales, to policymakers and the public.
The work performed so far has laid the foundations for the project: it has included fieldwork, the deployment of new instruments and set-up, the use of earth observation data to derive comprehensive pan-Antarctic data, and the development of climate and ice sheet models. More structurally, the project has also established an information ecosystem, with relevant stakeholders and the general public.
Some highlights of our work include:
1) the significant fieldwork milestones, including deploying instruments and making new observations in several Antarctic sectors and moorings in the South Sandwich Trench and across the South Atlantic 35ºS, the so-called SAMBA line-South Africa to Brazil Array.
2) The compilation, quality control and mapping of historical hydrographic data south of 45ºS made available to the research community.
3) A novel model realisations of iceberg interactions with bathymetry in the NEMO ocean model as well as set-up and verification of global-scale modelling with NEMO and NorESM including the implementation of freshwater fluxes.
4) A workshop in collaboration with the European Space Agency Earth Observation community that brought together the modelling community with in-situ and remote sensing communities to develop new machine-learning methods that can incorporate observations and models of ocean and ice sheet processes.
5) A comprehensive Earth observation-based dataset of Antarctic Ice Sheet (AIS) freshwater fluxes from dynamical processes, specifically basal melting under ice shelves and changes in the calving fronts related to both ice velocity and calving processes.
6) A co-organised online workshop to determine the optimal configuration of Coupled Model Intercomparison Project (CMIP7) models to account for freshwater fluxes from both ice sheets.
7) The fast-track delivery of initial ranges for projections of Antarctic runoff, calving and basal melt freshwater fluxes under a range of climate scenarios.
Some highlights of our work include:
1) the significant fieldwork milestones, including deploying instruments and making new observations in several Antarctic sectors and moorings in the South Sandwich Trench and across the South Atlantic 35ºS, the so-called SAMBA line-South Africa to Brazil Array.
2) The compilation, quality control and mapping of historical hydrographic data south of 45ºS made available to the research community.
3) A novel model realisations of iceberg interactions with bathymetry in the NEMO ocean model as well as set-up and verification of global-scale modelling with NEMO and NorESM including the implementation of freshwater fluxes.
4) A workshop in collaboration with the European Space Agency Earth Observation community that brought together the modelling community with in-situ and remote sensing communities to develop new machine-learning methods that can incorporate observations and models of ocean and ice sheet processes.
5) A comprehensive Earth observation-based dataset of Antarctic Ice Sheet (AIS) freshwater fluxes from dynamical processes, specifically basal melting under ice shelves and changes in the calving fronts related to both ice velocity and calving processes.
6) A co-organised online workshop to determine the optimal configuration of Coupled Model Intercomparison Project (CMIP7) models to account for freshwater fluxes from both ice sheets.
7) The fast-track delivery of initial ranges for projections of Antarctic runoff, calving and basal melt freshwater fluxes under a range of climate scenarios.
The OCEAN:ICE project has made advances beyond the state of the art in virtually all its elements so far including:
1) Field observations, where OCEAN:ICE has made the first of its kind deployment of two mooring arrays in the South Sandwich Trench as well as contributing to deployments in the SAMBA array.
2) Observations with Autonomous Underwater Vehicles have led to the first underside mapping of the Thwaites glacier ice shelf cavity in addition to resurveys of the Dotson ice shelf where new high-resolution maps will allow us to quantify highly variable and highly uncertain basal melting.
3) In ice sheet modelling, we have delivered the first-ever comprehensive estimation of the basal freshwater discharge from the grounded AIS based on surface-to-bed inversion and testing a range of different sliding parameterizations.
4) We have also pioneered a new integrated ensemble Kalman smoothing algorithm into an ice shelf model to better assimilate observational data into simulations.
5) OCEAN:ICE is committed to bringing together different methods as well as communities and the comprehensive Earth Observation dataset of AIS freshwater fluxes combines dynamical processes, specifically basal melting under ice shelves and changes in the calving fronts related to both ice velocity and calving processes. This will be used for data assimilation in models and for evaluation going forward.
6) OCEAN:ICE has also produced a new dataset of sea ice production (SIP) in Antarctic coastal polynyas, critical regions for sea ice formation and dense water formation. This dataset is an innovative fusion of Earth Observation data and atmospheric modelling, using sea ice concentration (SIC) from passive microwave sensors and ERA5 reanalysis for wind speed and surface air temperature.
1) Field observations, where OCEAN:ICE has made the first of its kind deployment of two mooring arrays in the South Sandwich Trench as well as contributing to deployments in the SAMBA array.
2) Observations with Autonomous Underwater Vehicles have led to the first underside mapping of the Thwaites glacier ice shelf cavity in addition to resurveys of the Dotson ice shelf where new high-resolution maps will allow us to quantify highly variable and highly uncertain basal melting.
3) In ice sheet modelling, we have delivered the first-ever comprehensive estimation of the basal freshwater discharge from the grounded AIS based on surface-to-bed inversion and testing a range of different sliding parameterizations.
4) We have also pioneered a new integrated ensemble Kalman smoothing algorithm into an ice shelf model to better assimilate observational data into simulations.
5) OCEAN:ICE is committed to bringing together different methods as well as communities and the comprehensive Earth Observation dataset of AIS freshwater fluxes combines dynamical processes, specifically basal melting under ice shelves and changes in the calving fronts related to both ice velocity and calving processes. This will be used for data assimilation in models and for evaluation going forward.
6) OCEAN:ICE has also produced a new dataset of sea ice production (SIP) in Antarctic coastal polynyas, critical regions for sea ice formation and dense water formation. This dataset is an innovative fusion of Earth Observation data and atmospheric modelling, using sea ice concentration (SIC) from passive microwave sensors and ERA5 reanalysis for wind speed and surface air temperature.