Next month, OCEAN:ICE will be celebrating its first birthday!
As we approach this milestone, where project members (in collaboration with EU Horizon 2020 project, SO-CHIC) will meet in Paris for the Annual Project Meeting, some Work Packages in OCEAN:ICE are meeting to discuss science, progress and future plans.
OCEAN:ICE Work Packages
WP1 – Subpolar circulation, heat delivery and water mass export
WP1 addresses the key processes, connectivity and circulation of the Antarctic shelf seas. An ambitious circumpolar programme of instrument deployments, including mooring and novel profiling float arrays over the continental shelf is proposed. This is supported by close partnerships with South Korean, New Zealand, Australian, German and Japanese collaborators. Combined with high-resolution modelling and satellite observations, this will reduce the existing spatial and process gap in understanding. It will establish the role of Antarctic marginal seas in regulating heat delivery to the ice shelves (supporting WP2-4) and in the formation and export of dense water to the global ocean (supporting WP5-6).
Markus Janout, WP1 Leader from AWI holds quarterly WP1 meetings where WP members gather together to ensure tasks are on-track and synergies and other matters are discussed.
WP2 – Cryosphere-ocean interaction, processes and feedbacks
WP2 focuses on the key role that ice sheet-ocean interaction plays in melting ice shelves and the export and freshwater distribution of icebergs.
Innovative AUV deployments under ‘warm’ ice shelves and the first such observations targeted at grounded icebergs will be conducted (supported by South Korean partners), along with observations of ‘cold’ ice shelf cavity circulation, isotopic concentrations and mixing via a Norwegian-supported borehole.
These observations will push forward the state-of-the-art in model basal melt tuning and the development of new parameterisations of iceberg dynamics and oxygen isotope tracking for key community models (NEMO, UKESM). These in turn will inform WP4-6 modelling, examining future ice sheet dynamics and climate coupling.
WP2 Leader, Nicolas Jourdain (CNRS) will lead the upcoming WP2 meeting on September 22, 2023.
WP3 – Ice sheet mass balance, forcing and dynamics
WP3 (O3) provide updated values and uncertainties for freshwater fluxes from the AIS to the ocean over the satellite observational period to the present day, including surface melt and runoff, ice flow, basal melt and calving.
This will be informed by new and existing EO data from ESA CCI and the Copernicus Climate Change Service (e.g. surface elevation change, grounding line location, surface damage, basal melt rates) and the collation of currently disparate datasets (e.g. ApRES ice radar, shallow ice cores and stake observations) together with model outputs.
WP3 assess uncertainty in the updated freshwater fluxes and will deliver improved dynamical ice sheet model process representation (surface and subglacial freshwater discharge) and initialisations to WP2, 4, 6.
Following the summer break, WP Leader and Project Coordinator, Ruth Mottram (DMI), gathered the WP3 team together for an online WP3 Meeting on August 29th, 2023. The program for the meeting set out to welcome the team back from summer holidays as well as welcoming newcomers to WP3.
The meeting covered progress made and milestones and deliverables (including the EO Workshop milestone held in Copenhagen in May 2023) as well as future plans for science talks among the researchers in OCEAN:ICE.
WP4 – Quantification of Antarctic Ice Sheet deep uncertainty and freshwater fluxes under climate forcing
WP4 (O4) utilises improved initialisation states from WP3 to project the freshwater fluxes of the AIS in ice sheet and coupled ice sheet-ocean models from 2020-2300 and its contribution to SLR. We provide first-of-their-kind spatiotemporal trends in calving rates, ice shelf basal melt and surface mass balance for all Antarctic basins. We apply surrogate modelling techniques in combination with high-resolution models to robustly quantify modelled freshwater flux uncertainties and sensitivities to a range of climate forcing scenarios and identify tipping points.
WP5 – Ice sheet impacts on global ocean circulation
WP5 (O5) examines the impact of ice sheet meltwater discharge on deep water formation and export from the poles, and the ultimate impact upon large-scale ocean circulation, including the AMOC and ACC.
We will make the first sustained mooring observations of the primary AABW pathway from the Weddell Sea to the global ocean. The fate of this water and its contribution to the AMOC will be observed via new instrumentation of the SAMBA array in collaboration with SAMOC partners.
In WP5, we also employ a novel inverse approach utilising oxygen isotope concentrations, resolving decadal to centennial changes in deep water properties. New model simulations will assess the impact of increased glacial melting (WP4) on global ocean circulation using a coupled Greenland Ice Sheet-climate model (NorESM-CISM) and an ocean model incorporating state-of-the-art deep ocean mixing parameterisations (NEMO). These models will investigate the relative role of northern vs southern sources of deep water and the influence of ice melt upon the AMOC on millennial timescales.
Close collaboration on AMOC variability is planned with WP6 and the EPOC project.
WP6 Members, led by NORCE partners, Elaine McDonagh and Petra Langebroek met at the close of summer holidays in August 2023.
WP6 – Role of Antarctica in the global climate:long-term impacts of short-term decision-making
WP6 (O6) quantify the impact of changes in the freshwater fluxes, including icebergs, from Antarctica on the global climate system.
Insights and model developments from WP1-5 are going to be incorporated into a coupled ice sheet-ocean model (BISICLES and NEMO) to determine spatially and temporally resolved freshwater and iceberg flux fields. Wider future global impacts and feedbacks upon the AIS will be quantified up to the year 2300 using the UKESM ESM fully coupled with ice sheet model BISICLES, and for millennial timescales using the PISM-MOMcoupled ice sheet-ocean model.
The impact analysis will specifically include interactions with other tipping elements in the Earth System such as the AMOC, and provide an improved understanding and quantification of potential impacts on global and regional temperatures, SLR and the global ocean circulation and water mass properties.
WP7 – Data management
WP6 (O6) quantify the impact of changes in the freshwater fluxes, including icebergs, from Antarctica on the global climate system.
Insights and model developments from WP1-5 are going to be incorporated into a coupled ice sheet-ocean model (BISICLES and NEMO) to determine spatially and temporally resolved freshwater and iceberg flux fields. Wider future global impacts and feedbacks upon the AIS will be quantified up to the year 2300 using the UKESM ESM fully coupled with ice sheet model BISICLES, and for millennial timescales using the PISM-MOMcoupled ice sheet-ocean model.
The impact analysis will specifically include interactions with other tipping elements in the Earth System such as the AMOC, and provide an improved understanding and quantification of potential impacts on global and regional temperatures, SLR and the global ocean circulation and water mass properties.