Northeast Greenland occupies an important position within the Arctic, linking the Greenland Ice Sheet and ice-free terrestrial landscapes with the Arctic Ocean and Greenland Sea. Geologically and environmentally, the region has undergone major change associated with the opening and deepening of Fram Strait, the onset and intensification of Arctic–Atlantic water exchange, the early formation of ephemeral glaciers, the later build-up of the Greenland Ice Sheet, and its repeated expansion and retreat throughout the Quaternary. Ice-core records from EGRIP provide insights into past climate and ice-sheet dynamics, while observations of the Northeast Greenland Ice Stream and its outlet glaciers reveal ongoing changes in one of the ice sheet's major drainage systems. Under ongoing anthropogenically forced warming, Northeast Greenland is particularly sensitive to Arctic amplification, resulting in rapid changes across its terrestrial, cryospheric, marine and atmospheric systems. Understanding these changes, their interactions and their future trajectories requires integration across disciplines and timescales.
We invite contributions from marine, cryospheric, terrestrial and atmospheric research focused on Northeast Greenland, extending from eastern North Greenland to northern East Greenland. Studies that improve our understanding of the region across geological timescales through the present and into the future, using geological and palaeoenvironmental archives, ice-core records, contemporary observations, process studies, remote sensing and numerical modelling, are all invited. We particularly encourage studies that explore connections among systems, including the dynamics and evolution of the Northeast Greenland Ice Stream, ice-sheet–ocean interactions, atmospheric and oceanic forcing, freshwater and sediment fluxes, ocean circulation and sea ice, long-term landscape evolution and its interactions with glaciation, permafrost dynamics, and terrestrial and marine ecosystem change.

This session covers climate predictions from seasonal to multi-decadal timescales and their applications. Continuing to improve such predictions is of major importance to society. The session embraces advances in our understanding of the origins of seasonal to decadal predictability and of the limitations of such predictions. This includes advances in improving forecast skill and reliability and making the most of this information by developing and evaluating new applications and climate services, including windows of opportunity.
The session welcomes contributions from dynamical modeling, machine-learning or other statistical methods and hybrid approaches. It will investigate predictions of various climate phenomena, including extremes, from global to regional scales, and from seasonal to multi-decadal timescales (including seamless predictions). Physical processes and sources relevant to seasonal to (multi-)decadal predictability (e.g. ocean, cryosphere, or land) as well as predicting large-scale atmospheric circulation anomalies associated with teleconnections will be discussed. Analysis of predictions in a multi-model framework, and ensemble forecast initialization and generation will be another focus of the session. We are also interested in approaches addressing initialization shocks and drifts. The session welcomes work on innovative methods of quality assessment and verification of climate predictions. We also invite contributions on the use of seasonal-to-decadal predictions for risk assessment, adaptation and further applications.

The Arctic plays a vital role in the Earth's climate system through complex interactions among the atmosphere, ocean, cryosphere, and biosphere. Its sea ice cover reflects most of the incoming solar radiation and regulates the surface energy balance. Freshwater and heat fluxes associated with river runoff, the melting of the Greenland Ice Sheet as well as the formation and melting of sea ice can influence deep-water formation in the North Atlantic and hence the Atlantic Meridional Overturning Circulation. Additionally, the meridional temperature gradient between low and high latitudes drives large-scale atmospheric circulation. In the meantime, Arctic permafrost and peatlands store vast amounts of carbon, and the region is home to unique and vulnerable ecosystems.
However, anthropogenic climate change is warming the Arctic nearly four times faster than the global average in recent decades. Numerous feedbacks amplify this Arctic warming, known as Arctic amplification, and modulate the response of climate. The resulting changes are affecting Arctic ecosystems and potentially also influence remote regions through atmospheric and oceanic teleconnections.
Past warm climates act as natural laboratories and provide valuable information for the understanding of key processes and feedbacks involved in Arctic changes, establishing a basis for constraining future Arctic projections. Climate models on the other hand, project that the Arctic Ocean could become nearly ice-free during summers within the next few decades. Nevertheless, substantial uncertainties remain regarding the future Arctic evolution, potential variation of its influence on the global climate system and its ecosystem responses under continued warming. The ERC synergy grant i2B (Into the Blue) aims to address these research gaps by an integrative approach, combining paleoclimate evidence, modern observations, and numerical modelling.
Building on this interdisciplinary perspective, this session brings together studies that explore Arctic processes and their wider implications across different climate states. Therefore, we welcome contributions from all career stages investigating the Arctic mechanisms, impacts and interconnections across past, present, and future warm climate states from observational, proxy, or modelling perspectives.

The tropical Atlantic exhibits significant ocean variability from daily to decadal time scales, driven by complex ocean dynamics and air-sea interactions. This session is devoted to advancing the understanding of these dynamics and their climatic impacts on both adjacent and remote regions, including their interactions with other tropical basins.

Relevant ocean processes include upper and deep ocean circulation, eddies, tropical instability waves, mixing, and upwelling. We further welcome studies analyzing marine heat waves, mechanisms related to climate modes such as Atlantic, Dakar and Benguela Niños, the Atlantic Meridional Mode and the South Atlantic Ocean Dipole, effects of climate change, extratropical as well as interbasin teleconnections, and local biological impacts of ocean variability.

Finally, we seek for studies that explore the causes and impacts of systematic model errors in simulating the local to regional Atlantic climate variability. Submissions based on direct observations, reanalysis, model simulations and machine learning techniques are welcome.

Natural variability in the North Atlantic spans interannual to centennial time scales and remains large enough to obscure emerging trends in observational records. Changes in the ocean circulation are nonetheless anticipated under continued warming, with consequences for the atmosphere and cryosphere, for regional sea level, and for the uptake and storage of heat and carbon. Understanding this circulation, and separating its natural variability from forced change, rests on sustained observing arrays such as OSNAP and RAPID, on satellite records, and on models spanning a wide range of complexity.

We invite contributions on:

- variability, dynamics and drivers of the Atlantic meridional overturning and gyre circulations
- water-mass transformation and the transport and storage of heat, freshwater and carbon
- ocean–atmosphere–cryosphere coupling, overflows, and exchanges between the open ocean and the marginal and shelf seas
- observed variability and its interpretation using theory, models, reanalyses and proxy records
- response to anthropogenic forcing, including detection and attribution of forced change
- predictability of North Atlantic circulation across time scales
- implications for regional climate and society, from extremes such as heatwaves, storms and floods to their consequences for infrastructure, health and livelihoods

The session brings together the observational, modelling and theoretical communities, and welcomes those working on impacts, to advance understanding of the North Atlantic from the processes governing its circulation and variability to the consequences of their change.

The oceans are changing rapidly in response to climate change. In this period of rapid change, long-term trends are now emerging across ocean variables, while natural variability operates across a wide range of spatial and temporal scales, placing long-term observations at fixed locations in a unique position to be compared with models and reanalyses to investigate this variability and assess how well they represent changes in the ocean across timescales.

In this session, we invite contributions that bring together long-term ocean time series and numerical models and/or reanalyses and satellite data to examine the representation of ocean variability, from daily and seasonal cycles to subseasonal and interannual variability, and longer-term changes and trends. We encourage studies that go beyond model–observation validation and use the comparison to identify processes and timescales that are not adequately represented and investigate the physical causes of observed differences. Such approaches can improve the representation of ocean variability and the processes driving it in models and reanalyses and contribute to better estimates of long-term trends and their uncertainties, improved understanding of ocean–climate interactions, and enhanced skill in seasonal-to-decadal predictions.

Contributions are welcome at global, basin-wide and regional scales, and across ocean compartments, from the air–sea interface to the deep ocean and seafloor. Studies addressing ocean circulation and transports, biogeochemical or biological variables are encouraged. Contributions using CMIP models, ocean reanalyses, high-resolution regional models, process models, or other modelling and statistical approaches are all welcome. We particularly welcome contributions demonstrating the scientific value of sustained, high-frequency and long-term observations for improving models and reanalyses and advancing our understanding of a changing ocean.

The Southern Ocean is vital to our understanding of the climate system. It is a key region for vertical and lateral exchanges of heat, freshwater, carbon, oxygen, and nutrients, with significant past and potential future global climate implications. The role of the Southern Ocean and the Antarctic Circumpolar Current in driving heat and biogeochemical exchanges as well as their response to changing atmospheric forcing and increased Antarctic melting remains uncertain. Indeed, the sparsity of observations of this system and its inherent sensitivity to small-scale physical processes, not fully represented in current Earth System Models, result in large climate projection uncertainties and considerable discrepancies between observations and models. To address these knowledge gaps, ongoing and upcoming efforts, such as Antarctica InSync, SYNCHRONY, ICED, IPY-5, exploit increasingly advanced observational platforms as well as theoretical, numerical and machine learning techniques. These efforts are providing deeper insight into the three-dimensional patterns of Southern Ocean dynamics and their changes on sub-annual, multi-decadal and millennial timescales, as well as their potential future modifications under a changing climate. In this session, we welcome contributions concerning the role of the Southern Ocean in past, present, and future climates. These include (but are not limited to) small-scale physics and mixing, water mass transformation, gyre-scale processes, nutrient and carbon cycling, ventilation, ocean productivity, climate-carbon feedbacks, and ocean-ice-atmosphere interactions. We also welcome contributions exploring the two-way interactions between the Southern Ocean and lower latitudes, including how changes in Southern Ocean circulation, heat and carbon transport affect lower latitudes and vice versa.

Energy conservation is a fundamental physical principle, yet it is generally not achieved in state-of-the-art models of geophysical flows owing to, for instance, the governing equations and their discretization, the coupling between model components, or the parameterization of unresolved processes. It is thus non-trivial to close the energy budget, which becomes even more challenging due to the multitude of oceanic processes that undergo nonlinear interactions and drive energy transfers across a range of scales: from eddies to internal waves to small-scale turbulence. This session is devoted to understanding these multi-scale interactions and associated energy transfers in the ocean, which are ultimately crucial for developing energetically consistent models, confidently predict climatic changes, and quantify associated uncertainties, and thus improve our understanding of the climate system.

We invite contributions on oceanic energy pathways and their consistent representation in numerical models from theoretical, modeling, and observational perspectives. These include, but are not limited to, the processes involving mesoscale eddies, internal gravity waves, instabilities, turbulence, small-scale mixing, and ocean-atmosphere coupling. Contributions on energy transfer processes and their quantification from in-situ measurements, (semi-)analytical approaches, and numerical models, as well as their parameterizations and spurious energy transfers associated with numerical discretizations, are also welcome along with interdisciplinary contributions such as novel applications in data science that diagnose, quantify, and minimize energetic inconsistencies and related uncertainties.
We particularly encourage early career researchers to participate in this session.

ENSO and the Tropical Pacific, together with their interactions with other tropical basins, are a dominant source of interannual climate variability in the tropics and across the globe. Improving our understanding and modelling of ENSO dynamics, predictability, and impacts, as well as anticipating how these may change in the future, is therefore important for society.

This session welcomes contributions addressing all aspects of ENSO, the Tropical Pacific, and tropical basin interactions, including dynamics; multi-scale interactions; decadal and paleo variability; theoretical approaches; ENSO diversity; global teleconnections; impacts on climate, society, and ecosystems; seasonal forecasting; climate change over recent decades, including changes in tropical ocean mean states; climate change projections; and interactions between ENSO and other tropical oceans. We also welcome studies of extreme ENSO events and their associated climate, societal, and ecosystem impacts, including emerging events such as the anticipated 2026 El Niño.

Studies aimed at evaluating and improving model simulations of ENSO, tropical ocean mean states, and tropical basin interactions are particularly encouraged, with special attention to the roles of mesoscale variability and ocean–atmosphere coupling.

The oceans are changing rapidly in response to the changing climate, as evidenced by record-breaking sea surface temperatures in several different regions around the world, altered ocean currents, and shifts in the marine carbon ecosystem. Additional transformations are expected in a warmer future climate. Identifying the mechanisms of oceanic climate change and variability are crucial to developing realistic ocean projections. Projections simulated using the recent Climate Model Intercomparison Project (CMIP) phase 6, provide meaningful insights on the ocean circulation responses under various climate change scenarios. These models are essential to quantify the impacts of oceanic warming and to develop successful adaptation strategies. This session will bring together researchers focused on shaping our understanding of future ocean circulation. First insights from CMIP7 simulations are very much encouraged!
We encourage submissions from studies covering global, basin wide, regional, and coastal oceanic changes. Topics covering altering ocean circulation and transports, variability and trends, tipping points and extremes, as well as temperature, salinity and biogeochemistry are welcomed. This session is not limited to CMIP analysis and submissions using other modelling datasets and statistical projections are very much encouraged.

The ocean surface layer mediates the transfer of energy, momentum, heat, matter, and trace gases between the ocean, atmosphere, and sea ice, and thus plays a central role in the dynamics of the climate system. This session will focus on the ocean surface layer globally, from the coasts – including the marginal sea ice zone – to the pelagic ocean, and its interactions with the overlaying low atmosphere. Of special interest will be contributions describing the impact of ocean surface-layer processes on air-sea fluxes and atmosphere-ocean feedback. These include the parameterization of air-sea interactions, the impact of tropical cyclones, and the role of extreme events. We also welcome studies about the understanding of ocean surface-interior interactions, particle and tracer dispersion, ice-ocean interactions, (sub-)mesoscale and internal-wave dynamics, as well as boundary-layer turbulence and surface-wave effects. Finally, we also encourage studies focusing on the coupling of physical, biological, and biogeochemical processes. Our session welcomes observational (from in-situ to remote sensing), theoretical, and numerical investigations focusing on the ocean surface layer and its interactions with the atmosphere and sea ice, regardless of the temporal and spatial scales considered.

The South Atlantic Ocean is a key component of the global climate system, connecting the tropical Atlantic with the Southern Ocean and linking the Atlantic, Indian, and Pacific Ocean basins. Its circulation mediates regional redistributions and inter-basin exchanges of heat and freshwater, as well as of carbon, oxygen, nutrients, and other tracers. These transports are shaped by interacting processes across a wide range of spatial and temporal scales, including air-sea interactions, small-scale turbulence and mixing, mesoscale dynamics, boundary currents, and basin-scale overturning circulation. Moreover, the South Atlantic features intricate regional ocean circulation patterns, such as the Agulhas leakage, Benguela Upwelling System and the Brazil-Malvinas confluence zone. Together, these processes influence regional to global climate, extreme events, biogeochemical cycles, marine productivity, and ecosystem variability. Yet, understanding the natural seasonal to interannual variability of these processes and how they evolve under long-term climate change remains challenging, as observations are often still too sparse and model simulations can show contrasting behavior.
We invite contributions that advance our knowledge of South Atlantic ocean processes across spatial and temporal scales, based on observations, modelling, theory, and paleo-proxy approaches. Interdisciplinary process studies linking physical oceanography, biogeochemistry, and marine ecosystems are particularly encouraged.
We aim to foster exchange across disciplines, methods, regions, and career stages, strengthen collaborations within the South Atlantic scientific community, and promote discussions on future inclusive South Atlantic observing and modelling strategies. We seek to identify knowledge gaps and future research priorities.

The interaction between the ocean and the cryosphere in the Southern Ocean has become a major focus in climate research. Antarctic climate change has captured public attention, which has spawned a number of research questions, such as: What to expect in a new Antarctic sea ice regime? Where and when will ocean-driven melting of ice shelves yield a tipping point in the Antarctic climate? Which processes drive the redistribution of heat around Antarctica and onto the shelf? How is Antarctic Bottom Water production affected by changing ice-ocean interactions? What role do ice-related processes play in nutrient upwelling on the continental shelf and in triggering carbon export to deep waters? We look out for progress in observing and understanding the interaction — and changes thereof — between ice shelf, sea-ice, ocean and atmosphere in a rapidly warming climate.

Recent advances in observational technology, data coverage, and modelling provide scientists with a better understanding of the mechanisms involving ice-ocean interactions in the far South. Processes on the Antarctic continental shelf have been identified as missing links between the cryosphere, the global atmosphere and the deep open ocean that need to be captured in large-scale and global model simulations.
This session calls for studies on physical and biogeochemical oceanography linked to ice shelves and sea ice. This includes work on all scales, from local to basin-scale to circumpolar; as well as paleo, present-day and future applications. As the community gears up for a circumpolar, year-round internationally coordinated campaign: Antarctica InSync, we would like to highlight the importance of seasonality and lack of winter data as an overarching challenge. Studies based on in-situ observations and remote sensing, and employing regional to global models as well as AI tools are welcome. We particularly invite cross-disciplinary topics involving glaciology, sea ice physics and biological oceanography.

Modes of tropical climate variability such as the El Niño-Southern Oscillation, Indian Ocean Dipole, tropical Atlantic variability, Madden Julian Oscillation, monsoons, and interactions among tropical basins, influence hydroclimate, extremes, ecosystems, and societies far beyond the tropics. Despite sustained development, climate models continue to exhibit biases in tropical mean states, precipitation, convection, air-sea coupling, circulation, variability, and teleconnections. These errors distort predictability and contribute to uncertainty in projections of climate modes and their impacts.
This session will connect three parts of the modelling challenge: identifying the origins and consequences of persistent biases; evaluating improvements in resolution, parameterizations, coupling, initialization, and data-driven or hybrid methods; and determining how better present-day simulations can yield more credible predictions and future projections. We welcome work using observations and reanalyses, hierarchy-of-model approaches, coupled model intercomparisons, large ensembles, initialized predictions, perturbed-physics experiments, emergent constraints, machine learning, and novel diagnostics.
Contributions may address tropical atmosphere-ocean-land interactions across weather, subseasonal, seasonal, interannual, decadal, and climate-change timescales. Studies that link process understanding to model development, compare generations of models, quantify uncertainty, or assess the global and regional impacts of tropical simulation errors are especially encouraged. By bringing together model developers, observational researchers, and prediction and projection communities, the session aims to identify advances, unresolved barriers, and practical priorities for the next generation of climate simulations.

We invite presentations on ocean surface waves, and wind-generated waves in particular, their dynamics, modelling and applications. This is a large topic of the physical oceanography in its own right, but it is also becoming clear that many large-scale geophysical processes are essentially coupled with the surface waves, and those include climate, weather, tropical cyclones, Marginal Ice Zone and other phenomena in the atmosphere and many issues of the upper-ocean mixing below the interface. This is a rapidly developing area of research and geophysical applications, and contributions on wave-coupled effects in the lower atmosphere and upper ocean are strongly encouraged.

Our understanding of the Indian Ocean’s physical, biogeochemical, and ecological characteristics and their variability across a range of spatiotemporal scales has advanced in recent years. However, there remain significant gaps in our knowledge in observing, modeling, and predicting the Indian Ocean’s changing environmental conditions and its role in regional and global climate.
This session invites Indian Ocean contributions based on observations, modelling, theory, and palaeo proxy evidence across a range of timescales from synoptic, interannual, decadal to centennial and beyond. Topics of interest include past, current, and projected changes in Indian Ocean physical and biogeochemical properties and their impacts on ecological processes, diversity in Indian Ocean modes of variability, interactions and exchanges between the Indian Ocean and other ocean basins via both oceanic and atmospheric pathways, as well as impacts on regional hydroclimate and the adjacent Asia-Australia-Africa monsoon systems.
Submissions are sought on assessing and predicting weather and climate extremes of societal relevance in the Indian Ocean and surrounding regions. We especially welcome submissions addressing compound extreme events that span across the ocean, atmosphere, land, and/or biogeochemical and ecological realms. Furthermore, studies evaluating climate risks, vulnerability, resilience, adaptation and mitigation strategies in coastal and watershed regions affected, for example, by a warming climate, tropical cyclones, and extremes in sea level are encouraged.
We also welcome contributions that address research on the Indian Ocean, using advanced techniques such as artificial intelligence/machine learning, and new technological advances in observing systems.

As the densest water mass in the abyssal ocean, Antarctic Bottom Water (AABW) occupies more than one-third of the global ocean volume and constitutes the lower limb of the global meridional overturning circulation. The production and properties of AABW are largely determined by Dense Shelf Water (DSW) that is formed by intense sea ice formation and brine rejection in coastal polynyas around Antarctica. As the precursor water mass, DSW cascades down the continental slope after crossing the shelf break, entrains ambient deep water, and ultimately transforms into AABW. Beyond driving abyssal circulation, these dense water masses also play a major role in the transport and long-term storage of heat, carbon, oxygen, nutrients, and other biogeochemical tracers in the abyss, and further modulate the productivity of marine ecosystems and biogeochemical cycles. Exploring the dynamics and variability of DSW and AABW is essential to improve our understanding of the global heat distribution, carbon budgets, and long-term climate variability.
Observational evidence has revealed a widespread contraction in AABW volume across global abyssal waters. At the same time, changes in DSW and AABW properties are not spatially uniform around Antarctica, highlighting substantial uncertainty in their future evolution. This session aims to advance a comprehensive and process-based understanding of AABW, bridging gaps between DSW and AABW transport, formation, transformation, and variability mechanisms, and corresponding impacts on climate variability and change and biogeochemical cycles. To encourage broad participation, we welcome contributions based on in-situ observations, remote sensing, and numerical simulations covering the full pathway from DSW formation and export to AABW transformation and spreading, with an emphasis on Ross Sea-originated DSW and AABW.

Marine heatwaves (MHWs) are prolonged and extreme warm ocean conditions, both surface and subsurface, with potential to cause substantial ecological and socio-economic damage. Understanding the physical mechanisms that generate MHWs is important to improving our capacity to predict them. Meanwhile, gaining a better understanding of MHW impacts on ecosystems, and their interactions with other parts of the climate system, is significant for promoting sustainable development in the face of climate change. We welcome abstract submissions across all aspects of MHW research and particularly encourage studies of the following themes.

Drivers and methods: novel physical analyses, definitions which challenge the now-traditional statistical framework, observational and modelling requirements for reliable monitoring, AI/ML-based detection and prediction for surface and subsurface MHWs.
Impacts and mitigation: Socio-economic damage to marine activities and industries including but not limited to tourism, fisheries, aquaculture; discussions with stakeholders.
Timescales of predictability: sub-seasonal to seasonal forecasting, long term projections, attribution, precursors, and sources of uncertainty.
Compound events: ecosystem and biogeochemical implications (e.g. on nutrient/oxygen availability/harmful algal blooms/ocean acidification and trophic web), compound extremes with atmospheric circulation/extreme weather events (e.g. tropical cyclones/monsoon circulation).
This session welcomes studies across all spatial and temporal scales; studies on compound extremes and subsurface events are particularly welcome.

To address societal concerns over rising sea levels, associated extreme events, and their impacts on coastal communities, ecosystems, and the global economy, it is essential to understand the drivers and contributions to these changes. This session responds to this need by inviting research from the international sea level community that advances knowledge of past, present, and future changes in global and regional sea levels, extreme events, and coastal impacts.
The session focuses on studies that explore the physical mechanisms of sea level rise and variability, as well as the underlying drivers, across timescales ranging from paleo records to high-frequency phenomena to long-term projections, using observations and/or model simulations. Research on linkages between sea level variability, heat and freshwater content, ocean dynamics, ice-sheet and glacier mass loss, land subsidence, and terrestrial water storage is welcome. We encourage studies addressing future sea level changes, including high-end projections from rapid ice-sheet mass loss, and those assessing short-, medium-, and long-term coastal impacts and their broader implications.

The Arctic region has undergone rapid and often abrupt changes over the past decades. Sea ice has become thinner, more mobile, and more prone to sudden breakup. Extreme temperature events have also become routine, with 2023 recording the warmest Arctic summer so far. The Arctic is warming nearly four times faster than the global average, driving ice sheet melt, sea ice retreat in the Kara and Laptev Seas, permafrost thaw, glacier loss, and wildfire activity. Consequently, the exposed ocean is increasingly prone to eddies, extreme events, and low-frequency climate oscillations and more susceptible to abrupt transitions in water mass structure and atmospheric circulation. Together with rising freshwater volumes, increased coastal runoff from Siberia and Greenland, and stronger exchange with the Atlantic and Pacific, these shifts are drastically reshaping the region's already fragile ecosystems.
Projections point to a seasonally ice-free Arctic Ocean by mid-century. This raises pressing questions: What might the future Arctic Ocean look like? How do Arctic changes interact with, and respond to, conditions at lower latitudes? What mechanisms drive the ongoing loss of sea ice, and how might they evolve in an increasingly ice-free system? Where should observational, remote sensing, and modeling efforts focus next?
This session invites contributions spanning the recent past, present, and future of the Arctic and subarctic oceans. We welcome studies of ocean-atmosphere-sea ice interactions; ocean eddies, extremes, and climate oscillations; the processes and feedbacks driving trends, transitions, and abrupt shifts in the Arctic system; small-scale dynamics, internal waves, and mixing; the sources and downstream impacts of freshwater change, including subarctic deep convection; and the broader coupling between the Arctic and global ocean circulation. Cross-disciplinary submissions are especially encouraged, particularly those connecting physical, cryospheric, biogeochemical, and ecological processes, as well as their links to terrestrial systems.
We welcome discussions on the future of Arctic Ocean observation, remote sensing, and modeling strategies (including the upcoming CMIP7 cycle) and on ways to validate and improve models against observations. Submissions drawing on recent field programs such as MOSAiC, the Nansen Legacy Project, and the Synoptic Arctic Survey are welcome, as are contributions from those planning the upcoming International Polar Year 2032-33.

Coastal oceanographic processes present important differences with deep water oceanography, resulting in higher prediction errors, where topo-bathymetry in shallow areas exerts a strong control on hydrodynamic fields, further modified by stratification, land boundaries and coastal infrastructure. Predictability is limited by strong non-linear interactions (e.g. breaking waves, nearshore circulation and sediment fluxes), choice of numerical strategies (e.g. nested meshes, finite-elements or smooth-particle simulations) or modulations typical of restricted domains (e.g. seiching or vegetation filtering). Coastal observations (in-situ and remote) are therefore necessary to enhance numerical models, where the advent of new satellite capabilities (e.g. Sentinel resolution and sensors) and modelling advances (e.g. coupling or unstructured grids), together with enhanced coastal observatories, are leading to qualitative advances for coastal oceanography applications. Coastal analyses under future scenarios become even more challenging, since transitional areas are more strongly impacted by changing climates (e.g. changing domains due to sea-level rise). For these reasons, it is timely to discuss recent advances in: a) coastal coupled hydro-morpho-ecological modelling at different scales; b) coastal aggregation of in-situ/satellite/numerical data from different sources; c) knowledge-based coastal applications, including the assessment of nature-based interventions; d) use of novel approaches, such as data assimilation or machine learning; and e) uncertainties in coastal decision-making. Building on these challenges, we invite presentations on coastal modelling, data assimilation, boundary effects or operational coastal predictions with/without interactions with Nature-based or traditional interventions. Contributions tackling open questions on non-linear response functions, artificial intelligence or big data for coastal applications are welcome. These coastal topics should conform a fruitful session for discussing coastal oceanography applications, including conventional and nature-based interventions under climate change.

Deltas and estuaries are dynamic landscapes shaped by interactions among river flow, tides, waves, sediment transport, and biota. Their hydrology and geomorphology support ecosystems and human activities, while interactions with ecological and biogeochemical processes influence their physical evolution. Accelerating sea-level rise, changes in river discharge and sediment supply, extreme storms and floods, subsidence, and human interventions are reshaping the delicate balance of processes that sustain these environments. Understanding how landscapes respond to these pressures, including nonlinear responses and thresholds of change, is essential for assessing their future trajectories and developing effective adaptation and management strategies.
This session brings together research on the biophysical processes shaping deltaic and estuarine landscapes and on strategies for their adaptation, restoration, and sustainable management. It aims to connect understanding of hydrological and biogeomorphological responses to climatic and anthropogenic pressures with the assessment of management interventions.
We welcome research on the hydrology, morphodynamics, and biogeomorphology of deltas and estuaries, for example addressing river–marine interactions, sediment transport and budgets, feedback between biota and sediment dynamics, and morphological change. Contributions may address the effects of sea-level rise, changing river discharge, storms and floods, subsidence, and human activities, including nonlinear landscape responses and the implications of crossing thresholds. Contributions on adaptation, restoration, and management are equally welcome, including studies of nature-based solutions and conventional engineering approaches grounded in an understanding of physical processes, biogeomorphological interactions, and landscape dynamics. The session embraces theoretical, numerical, and data-driven approaches, including AI, as well as field observations, remote sensing, and experimental studies. We encourage interdisciplinary contributions that connect understanding of physical and biogeomorphological processes with decisions about the future of deltas and estuaries.

Coastal and submarine environments are among the most dynamic landscapes on Earth, continuously reshaped by the interplay of hydrodynamic processes, sediment transport, tectonics, land subsidence, sea-level change, climate variability, and anthropogenic activities. Understanding the evolution of these interconnected systems is increasingly important in the face of accelerating climate change, growing coastal populations, and expanding offshore development. Recent advances in remote sensing, marine geophysics, bathymetric mapping, LiDAR, InSAR, unmanned aerial systems (UAS), numerical modelling, and field observations have substantially enhanced our ability to investigate geomorphic processes and landscape evolution across the land–sea continuum.
This session welcomes contributions investigating the evolution, morphodynamics, and sedimentary processes of coastal and submarine environments across a wide range of spatial and temporal scales. We encourage studies focusing on beaches, deltas, estuaries, tidal flats, coastal dunes, rocky coasts, cliffs, barrier systems, continental shelves, submarine canyons, submarine landslides, and other coastal and marine landforms. Contributions addressing shoreline evolution, land subsidence, relative sea-level rise, sediment budgets, coastal erosion and accretion, sediment connectivity, and interactions between terrestrial and marine geomorphic processes are particularly encouraged.
We especially welcome multidisciplinary studies integrating field observations with remote sensing, satellite data, LiDAR, InSAR, bathymetric surveys, seismic reflection, magnetic and other geophysical datasets, GIS analyses, machine learning, and process-based numerical modelling to improve our understanding of geomorphic evolution and sediment dynamics. Contributions exploring climate change impacts, coastal hazards, ecosystem resilience, nature-based solutions, and sustainable coastal management are also encouraged.
The session aims to provide a platform for coastal geomorphologists, marine geologists, geophysicists, remote sensing specialists, natural hazard scientists, and numerical modellers to exchange ideas, foster interdisciplinary collaborations, and advance our understanding of the processes shaping coastal and submarine landscapes across the land–sea continuum.

Coastal oceans are dynamic interfaces between land and sea, playing a critical role in global biogeochemical cycles with a high impact on socio-economic activities and social developments. The dynamic and physical processes as well as the human activities that take place in coastal areas make them natural laboratories to improve our knowledge about several biogeochemical interactions. In addition, these regions are affected by both natural and anthropogenic factors such as coastal acidification, organic matter, nutrients, and pollution, among others. All these factors have impacts on the natural cycles and the magnitude of these impacts should be studied and understood in order to propose solutions to the decision makers that could help to know, understand, take decisions, and protect or regulate the coastal environments.
This session aims to bring together researchers from diverse fields to discuss the latest findings on the biogeochemical processes occurring in coastal oceans, improve our knowledge, identify impacts, and propose solutions in terms of coastal management and blue economy. We welcome research studies that focus on both natural and anthropogenic processes that are affecting the biogeochemical cycles in coastal waters, trace metal chemistry, CO2 system, ocean acidification, ocean alkalinization, nutrient cycle, organic matter, CO2 sequestration, blue carbon, etc.

The expansion of offshore wind farms is altering shelf-sea hydrodynamics, stratification, biogeochemistry, and coastal communities. The methods and findings remain fragmented. This session seeks contributions employing qualitative and quantitative methods to investigate these impacts, connecting them to carbon cycling, energy systems, and transboundary marine spatial planning implications.

This session, organized by the UN Decade Program CoastPredict, aims to directly contribute to the UN Decade Challenge 6: Enhancing community resilience to ocean hazards. The focus is on addressing critical gaps in scientific knowledge, particularly in key areas such as coastal risk assessment, warning and mitigation strategies. Key topics include: (i) the collection and generation of observational and modeling datasets essential for risk assessment, including downscaled climate projections for coastal regions, all within a robust data-sharing frameworks; (ii) the promotion of interdisciplinary and international research and innovation to comprehensively address these challenges, with a particular emphasis on approaches like Digital Twin technology; (iii) the enhanced People Centred Early Warning Systems for Ocean-related Hazards through Machine learning and Predictive Modelling and the development of indicator and tools for climate adaptation in the coastal area, and (iv) the development of standards for risk communication at both national and international levels. The session will also explore multi-hazard early warning systems for events such as tsunamis, storm surges, marine heatwaves, and coastal biogeochemical hazards, including pollution and other extreme coastal events such as erratic extratropical cyclones. Contributions on machine learning applications, compound event analysis, and disaster risk reduction strategies are strongly encouraged, as are science-based management practices for enhancing coastal resilience. By leveraging innovative tools like digital twins, this session highlights how predictive modeling can significantly improve risk assessment, climate change adaptation and response strategies. Its relevance extends to policymakers, scientists, and coastal communities, fostering collaboration to strengthen coastal resilience.

Organised jointly by the UN Decade Programme CoastPredict, through its GlobalCoast initiative, and the European Digital Twin Ocean (EDITO), this session addresses how digital infrastructures such as EDITO and GlobalCoast’s prototype, ProtoCoast, can support coastal resilience services.
Advancing coastal predictive science is increasingly urgent, particularly in vulnerable regions. Yet effective predictive services depend on the capacity to federate coastal data, tools, applications and HPC resources for modelling.
GlobalCoast is developing an integrated, cloud-based digital platform for the global coastal ocean. ProtoCoast, its first operational prototype, is initially operating for the Mediterranean and other regions, with interoperability with infrastructures such as EDITO. EDITO is establishing the EU’s operational Digital Twin Ocean infrastructure and ecosystem, providing an interoperable environment where digital twin applications, data services, observations, modelling capabilities, AI tools and scenario-based services can be developed and delivered, with the ambition to be operational by 2030. This session will examine the scientific and technical challenges of making such systems interoperable, accessible and sustainable, and how they can be connected to strengthen coastal predictive capabilities and support resilience services.
We invite contributions on federated cloud architectures for coastal science; coastal digital twins and coupled modelling; FAIR data and semantic interoperability with Copernicus Marine, EMODnet, GOOS and national systems; and cloud-based use of satellite and in situ observations, including AI, for coastal resilience services. We also welcome contributions on AI infrastructure for operational coastal prediction, including curated training datasets, model hosting and versioning, ocean foundation models, computing, benchmarking and reproducibility.
Across all themes, we welcome contributions on user engagement and uptake: how public authorities reach these services; which interfaces, training and capacity-building make them usable where they are most needed; and which governance and funding models can sustain them beyond project funding. Contributions on federation between GlobalCoast, EDITO and other regional and national platforms are also encouraged, together with reflections on what the community must sustain beyond 2030 to secure the Ocean Decade’s digital legacy.

Global coastal zones are of high ecological and societal values. As the dynamic interface between land, sea, and air, they are heavily impacted by a combination of climate-driven environmental change and human interventions. Approaches to sustainably manage the coastal zone increasingly seek to provide co-benefits of risk mitigation, climate regulation, preserving biodiversity, and supporting coastal community resilience. These require scientific evidence and discourse that integrate across disciplines.
This session invites multi- and inter-disciplinary contributions focusing on coastal processes, their dynamic interactions, and their role in exchanges across coastal interfaces (e.g. land-sea, air-sea, river-sea, …) under a changing climate and changing human activities. We welcome observational, modelling and theoretical studies reporting on processes linked to coastal hydrodynamics, coastal biogeochemistry, coastal ecology, or coastal sediment dynamics and geomorphology. Studies may span the wide range of spatial and temporal scales characteristic of existing and projected change in coastal seascapes and landscapes from the inner shelf shoreward to reefs, seagrass meadows, beaches and dunes, estuaries, intertidal flats, mangrove forests, saltmarshes and coastal wetlands. We encourage the submission of holistic Earth system studies that explore the role of the coastal zone in coastal sea dynamics including exchanges across coastal interfaces under the impact of climate change and human activities. We also encourage studies that focus on impacts of coastal management or coastal adaptation approaches on coastal processes and dynamics, spanning engineered, hybrid, and nature-based options related to dynamic anthropogenic activities such as coastal protection, tourism, shipping, fisheries and aquaculture, and the expansion of renewable energies and other coastal infrastructure.

The growing demands on marine space for energy security and renewable infrastructure, such as offshore wind farms, are complicated by the challenges of climate change-induced hazards and the need for environmentally sustainable development. Addressing these challenges requires a holistic and interdisciplinary approach that integrates ocean and marine sciences, marine and geotechnical engineering, geomorphology, natural hazards, and environmental science. Such an approach is essential for improving our understanding of the interactions between climate change, seabed processes, infrastructure performance, and ecosystem health across the entire life cycle of offshore assets.
This session invites contributions that advance our collective capacity to plan, design and manage offshore infrastructure that is both climate-resilient and environmentally sustainable. Key themes include, but are not limited to:
• Marine geomorphology and seabed processes: characterization of seabed morphology, sediment dynamics, erosion and deposition, and their evolution in offshore environments.
• Offshore geohazards identification: mapping and assessing geohazard potential, towards a holistic geological understanding of submarine mass movement initiation and evolution, particularly landslides.
• Geohazards and infrastructure modelling, monitoring and characterization: application of state-of-the-art data science, hydroacoustic, geophysical and in-situ monitoring approaches, and development of novel physical/numerical modelling to predict initiation, development and runout of sediments and performance of offshore infrastructure.
• Climate-resilient design: novel approaches and case studies coupling engineering optimisation with ecological and geomorphological considerations for building and retrofitting critical offshore infrastructure to withstand climate-induced hazards.
We particularly encourage contributions showcasing cross-disciplinary research, including those developed within intersectoral and international consortia. By bringing together diverse perspectives, this session aims to foster a new vision for a sustainable and resilient future for the coexistence of offshore infrastructures and the marine environment.

Contributions are invited on recent advances in our understanding of circulation and fluid dynamical processes in coastal and shelf seas. We welcome observational, modelling, theoretical and interdisciplinary studies spanning a wide range of temporal and spatial scales, from the shelf break to the coastal zone. The session aims to bring together studies addressing the diverse and dynamic processes that shape coastal and shelf environments, including shelf circulation, canyon flows, exchange flows in semi-enclosed seas, mesoscale and submesoscale eddies and dynamics, river plumes and estuaries, as well as flow interactions with biogeochemistry, sediment dynamics and nearshore physics. Contributions addressing the effects of climate change, extreme events, and anthropogenic activities—including offshore wind farms and other marine renewable-energy developments—on coastal seas and estuaries are also welcome. Early-career scientists are especially encouraged to submit their work to this session.

Coastal zones are rapidly changing environments exposed to interacting processes and hazards across a wide range of spatial and temporal scales. Understanding and anticipating these changes requires continuous observations that capture both long-term trends and rapid responses to extreme events. Synthetic Aperture Radar (SAR) provides unique advantages for coastal monitoring through its all-weather, day-and-night imaging capability and sensitivity to surface roughness. Combined with multisource Earth observation, in situ measurements, numerical and data-driven modelling and artificial intelligence (AI), SAR offers new opportunities for integrated coastal monitoring, forecasting and dynamic virtual platforms for simulation and interactive scenario testing (digital twins).
This session welcomes contributions presenting new methods and innovative applications of SAR and advanced SAR techniques to support coastal monitoring, understanding, forecasting, adaptation and management. We invite studies addressing applications including multiscale coastal geomorphology, coastal hydro-morphodynamics and coastal–ocean interactions, coastal hazards and their drivers (e.g. flooding, erosion, subsidence and extreme events), coastal vegetation and ecosystems, and land-cover and land-use change.
Contributions combining SAR with complementary data sources, AI/ML and numerical modelling across different coastal typologies and scales are particularly encouraged, from the reconstruction of historical changes to forecasting, near-real-time applications, as well as the development and continuous updating of coastal digital twins.
The session aims to bring together the SAR and broader Earth observation, coastal and ocean science and management communities to exchange new methodologies and applications. It will explore how SAR-derived information can contribute to the continuum from coastal observation and monitoring to forecasting and digital twins, supporting coastal adaptation pathways, planning and management.
Attendees will gain an overview of emerging methods, applications and opportunities in this fast-developing frontier, while connecting with researchers and practitioners across the coastal, Earth observation, modelling and management communities. The session will provide an opportunity to hear updates on work progressing across Europe, understand how these efforts are being integrated, and identify potential synergies, knowledge gaps and avenues for future collaboration.

The Mediterranean, Marmara, and Black Seas - collectively referred to here as the Southern European Seas, are experiencing rapid climate-driven transformations. Recent trends reveal accelerating sea surface warming, intense marine heatwaves, intermediate and deep-water salinization, sea-level rise, and expanding deoxygenation. Given their semi-enclosed nature, strong interbasin connectivity, densely populated coasts, and vulnerability to climate change, understanding the physical and biogeochemical drivers behind these trends is critical.
Recent years have seen significant progress in deciphering basin-scale circulation, strait exchange dynamics, wave dynamics and extremes, sea-level variability, and land-coast-ocean interactions - spanning high-frequency meteo-oceanographic extremes to long-term climate projections. Crucial to this progress are sustained and innovative observing systems (especially in regions where in-situ observations remain sparse or have recently declined, as is the case in the Black Sea and the Eastern Mediterranean), citizen science integration, high-resolution numerical modelling and reanalyses including data assimilation, validation and intercomparison frameworks, and advanced data-driven or AI/ML approaches complementing operational ocean and wave forecasting systems.
This session welcomes multidisciplinary contributions on physical and biogeochemical processes across the Mediterranean, Marmara, and Black Seas. We invite submissions addressing:
Novel Monitoring Strategies: Basin-scale to coastal observing systems, autonomous platforms, remote sensing, innovative measurement approaches, and citizen science, addressing in-situ observational gaps and long-term observing capacity.
Process Understanding: Short-to long-term variability, basin circulation and interbasin connectivity, strait dynamics, land-sea interfaces, wave dynamics and extremes, biogeochemical dynamics and deoxygenation, and extreme event impacts.
Modeling & AI Advancements: Numerical models, data-driven ML//AI frameworks and approaches, including methods for data-sparce regions (such as the Black Sea and Eastern Mediterranean), validation frameworks and data assimilation.
Operational Oceanography & Climate services: Forecasting systems, downstream applications, digital twins, coastal and marine hazards, climate indicators and tools to support climate adaptation and coastal resilience.

Organic carbon (OC) plays a fundamental role in the Earth’s climate system and biogeochemical cycles. Understanding the sources, transport, transformation, and fate of OC, as well as exchanges between dissolved and particulate phases, is critical for constraining regional and global carbon budgets, assessing carbon sequestration, and predicting ecosystem responses to natural and anthropogenic environmental change.

The land–ocean continuum, which encompasses rivers and coastal waters to continental margins and the deep ocean, provides important pathways for carbon transfer, transformation, and storage across a wide range of spatial and temporal scales. During transport, biological, chemical, and physical processes, such as mineral-organic interactions and hydrodynamic transport, could profoundly alter the composition, reactivity, and age of OC, thereby influencing its preservation, redistribution, and ultimate burial. As a result, identifying carbon sources, quantifying carbon fluxes, assessing carbon burial efficiency, and constraining long-term carbon sequestration remain major challenges in understanding land-to-ocean carbon cycle research.

This session aims to bring together researchers investigating OC transport and cycling across the land–ocean continuum, from terrestrial and freshwater sources to coastal and marine sinks. We welcome observational, experimental, paleoenvironmental, and modelling studies addressing carbon sources, fluxes, transport pathways, transformation processes, preservation, burial, and sequestration in both particulate and dissolved forms. Contributions spanning the water column to the sedimentary record, including water sample, suspended particulate matter, sediment-trap observations, aquatic sediments, and sediment cores, are particularly encouraged. Remote sensing, autonomous observations, and numerical modelling approaches, either as standalone tools or integrated with field and laboratory studies, are likewise encouraged. We also welcome studies exploring the impacts of human activities and climate variability on carbon cycling across both modern and past environments.

Coastal wetlands, such as salt marshes, mangroves, seagrass beds, and tidal flats provide numerous ecosystem services, including coastal protection, biodiversity provision and climate change mitigation. However, coastal wetlands are under pressure from both natural and anthropogenic drivers of coastal change, and shifting climatic boundary conditions, hence are declining in area and habitat quality globally. At the same time, these environments are increasingly in the focus of restoration and nature-based solutions for coastal adaptation, where the aim is to work with, rather than against, the natural processes to build and maintain wetlands. Understanding how sedimentation, vegetation establishment, and self-organisation sustain these systems is therefore essential to designing interventions that remain functional over decadal timescales. This is the case for pristine, natural, managed, and restored systems alike.
This session will bring together studies of coastal wetlands across different climates and geomorphological settings to enhance the understanding of ecosystem service provisioning, interactions between hydrodynamics, sediment, and ecology, and to identify best future management practices and effective nature-based solutions. Studies of all processes occurring within coastal wetlands are invited. This includes, but is not limited to, hydro- and morphodynamics, bio-morphodynamics, bio-geochemistry, ecological change and evolution, and impacts and management implications of climate change, sea level rise, and anthropogenic pressures. We equally invite social science and interdisciplinary contributions, including stakeholder participation and co-design in wetland restoration, governance and institutional arrangements, public perception and acceptance of coastal nature-based solutions, and the distribution of costs, benefits and ecosystem services among coastal communities. This session aims to enhance our understanding of basic processes governing coastal wetland dynamics and to propose sustainable management solutions for contemporary environmental pressures.

Methane (CH4) and nitrous oxide (N2O) are major, long-lived greenhouse gases (GHG), which foster global warming and significantly impact atmospheric chemistry dynamics. As a vast component of the Earth System, the aquatic realm is key for the balance between sources and sinks of these gases and largely determines their contribution to the global radiative balance. Hence, understanding the mechanisms of production, consumption, and emissions of these aquatic GHG is crucial for improving predictions of their future changes with ongoing climate change.

While the overall distribution of CH4 and N2O across the water column and sediments in marine, estuarine, and lacustrine systems is well documented, understanding of GHG cycling and emissions in the aquatic realm remains a major scientific challenge. This is largely due to the complex interactions between geological, oceanographic/limnological, biological, and anthropogenic processes. Furthermore, although it is well established that CH4 and N2O emissions offset natural CO2 uptake by aquatic systems, the magnitude of this counteracting effect, as well as their temporal and spatial variability, is still highly uncertain.

This session invites contributions addressing recent advances in understanding the biogeochemical cycling, microbial pathways, and fluxes of CH4 and N2O in aquatic environments. We welcome studies based on laboratory and mesocosm experiments, field observations, remote sensing and modelling approaches. Topics of interest include, but are not limited to:

• CH4 and N2O cycling in estuaries, bays, fjords, coastal lagoons and other transitional water bodies across all latitudes, as well as fluxes across the sediment-water(ice)-air interfaces.

• The role of current and projected environmental perturbations such as eutrophication, deoxygenation and warming as drivers of CH4 and N2O cycling at the land-ocean continuum (e.g. through riverine input and submarine groundwater discharge).

• The impact of extreme events (e.g. heat waves, storms, floods) on CH4 and N2O cycling and emissions.

• CH4 and N2O formation, transport, and consumption, including specific microbial processes involved.

• Microbe-mineral and microbe-animal interactions (including symbioses) and how these affect CH4 and N2O turnover.

• Quantification of the contribution of CH4 and N2O emissions to overall radiative balance of aquatic systems.

The ocean’s Biological Carbon Pump (BCP) plays a pivotal role in the oceanic carbon cycle by transporting organic carbon from the surface to the deep ocean, thereby regulating atmospheric CO₂ levels and long-term climate. A critical, yet poorly constrained component of the BCP is the velocity at which marine snow particles sink in the ocean. Various observations, imaging, laboratory experiments, and modeling have revealed significant variability in marine snow sinking velocities, influenced by factors such as particle composition, size, density, ballast minerals, but also hydrodynamic conditions such as vertical currents. The oceanic vertical currents are extremely difficult to assess since very variable and up to several orders of magnitude smaller than their horizontal counterparts. Nonetheless vertical velocities about 1 mm/s (~100 m/day) can have strong influences on sinking velocities.
This session invites contributions, , based on models or observations, exploring the physical, chemical and biological controls on marine snow sinking velocities as well as their biogeochemical feedback and parameterization. We welcome studies assessing sinking velocities using novel methodologies and biogeochemical models investigating the role of particle composition on sinking rates, examining the impact of environmental drivers (e.g., temperature, currents, internal tides, turbulence) on particle sinking rates and studies integrating observational, experimental, and modeling approaches to improve parameterizations of sinking velocities in global biogeochemical models.
By bringing together interdisciplinary research, this session aims to advance our understanding of the BCP’s efficiency and its representation in Earth system models, ultimately contributing to more accurate projections of ocean long term carbon sequestration.

The ocean is a major sink of anthropogenic carbon and heat, and dissolved oxygen has declined across all ocean basins, with consequences for marine ecosystems and biogeochemical cycling. Oxygen, carbon, and heat are coupled through shared pathways of ventilation, circulation, and biological processes. Their regional-scale relationships, however, remain poorly constrained, because internal variability and redistribution can reinforce, mask, or decouple changes at regional scales. A multi-tracer perspective is therefore key to interpreting ongoing changes and projecting future changes in regional biogeochemistry and marine ecosystems. Here we propose a session that brings together the physical oceanography, biogeochemistry, and climate communities to examine how ocean physics and climate variability shape the coupled cycling of oxygen, carbon, and heat across paleo, present-day, and future climates, drawing on theory, observations, modeling, and data-driven approaches.

We seek contributions that investigate variability, trends, and coupling among oxygen, carbon, and heat from regional to global scales. Topics can include ocean carbon uptake and storage, ocean heat uptake and redistribution, deoxygenation, and the ecological and biogeochemical consequences of these changes. Contributions using historical reconstructions and uncertainty assessments, models, model–observation synthesis, proxy records, technological developments, oceanic and atmospheric integral constraints, and data-driven approaches are particularly encouraged, as are approaches that foster cross-cutting exchanges across the physical–biogeochemical disciplines. We also welcome contributions to deepen our mechanistic understanding in driving the changes, including the roles of ventilation, circulation, mixing, air–sea exchange, and biological processes; the use of oxygen, carbon, heat, and related tracers to diagnose these processes; and the influence of climate variability, such as ENSO and Pacific decadal variability, on their regional co-variability. This session connects to ongoing international efforts, including the CLIVAR-O2CH Research Focus and the Gridded Observational Dataset Intercomparison Project (GODIP), and aims to provide a forum for advancing an integrated understanding of physical–biogeochemical coupling in a changing ocean.

Growing pressures from human activities (e.g., pollution, habitat alteration, and climate change) threaten marine ecosystems. To assess ocean environmental quality, large datasets from global observing systems and networks (e.g., GOOS, EMODnet) require observations across multiple spatial and temporal scales. These observations can be complemented by scalable and cost-effective technologies and integrated monitoring systems, particularly in coastal and highly dynamic environments, essential to improve data coverage and continuity, supporting integrated analyses of marine ecosystem processes. Citizen Science initiatives can further expand observations in space and time, while raising awareness and strengthening the connection between society and marine research.
This session, whose objectives are in line with UN 2030 Agenda Goal 14 and with the UN-launched “Decade of Ocean Science for Sustainable Development”, focuses on the effects of anthropogenic pressures on marine ecosystems and on observational approaches to detect, quantify, and monitor their impacts. Special attention will be given to innovative, scalable and cost-effective technologies, integrated monitoring approaches, and methods that can be replicated across different marine environments. Multidisciplinary contributions combining in-situ observations, remote sensing, autonomous and emerging technologies, modelling, data integration, and citizen science are encouraged to support biodiversity monitoring, ecosystem restoration, environmental assessment, and the sustainable use of marine resources.
Topics include the effect of natural and anthropogenic pollution; impacts of global change on marine ecosystems; assessment of cumulative anthropogenic pressures; scalable and cost-effective marine observations and innovative monitoring technologies; marine citizen science; advanced methods for data collection, integration, processing, and analysis; benthic and pelagic community dynamics; and ecosystem services evaluation.

There is growing awareness that ongoing efforts to reduce CO2 emissions will be insufficient to limit global warming to below 2℃ above pre-industrial levels. To meet this target, Carbon Dioxide Removal (CDR) on the order of 10 – 20 Gt CO2/year will be required before the end of the century. While most current CDR technologies applied at scale focus on terrestrial approaches, marine CDR (mCDR) includes methods with some of the largest removal potentials. Actual mCDR field deployments remain limited in scale and operational requirements are still being explored so further research is needed before mCDR can be considered for deployment at scale. This session will focus on the various mCDR technologies, their potential for large-scale deployment and safety considerations, as well as Monitoring, Reporting, and Verification (MRV) required to support them. We welcome contributions from laboratory and mesocosm experiments, small- and large-scale field trials, numerical modelling, and machine-learning approaches to data, with a particular interest in multidisciplinary submissions.

Limiting global warming to within planetary boundaries requires rapid emission reductions alongside robust carbon dioxide removal (CDR) frameworks. Compared with land-based approaches, marine CDR (mCDR) approaches are at an earlier stage of development, but offer the potential for negative emissions with less competition for space/resources and great scaling potential.. Evaluating the efficiency and impacts of these marine strategies is now critical to assess whether they are environmentally safe and socially just, and to determine their viability for national carbon accounting and the voluntary carbon market.
Current mCDR strategies encompass both abiotic methods (e.g., ocean alkalinity enhancement, direct ocean removal) and biotic approaches (e.g., macroalgae cultivation, iron fertilization, blue carbon ecosystem restoration). These techniques vary widely in their CDR potential, permanence of storage, and requirements for robust Monitoring, Reporting, and Verification (MRV). Additionally, their broader ecological impacts and full life-cycle assessments remain critical areas of uncertainty.
This session invites abstracts addressing ocean-related CDR that can contribute to advance the understanding of mCDR potential and impacts. We welcome contributions spanning mCDR modeling and observations across scales, e.g., idealized scenarios with novel mCDR implementations, observational and experimental studies ranging from mCDR pilot sites to laboratory experiments or mesocosm experiments, as well as the impacts of terrestrial CDR (e.g. enhanced rock weathering, river alkalinity enhancement) on the marine environment. Furthermore, we encourage submissions intersecting with the broader environmental, societal, political, legal, and economic implications of scaling marine CDR.

The ocean absorbs about a quarter of anthropogenic CO2 emissions each year, which slows climate change but changes ocean chemistry, lowering seawater pH. Ocean-atmosphere CO2 exchange and its consequences are governed by a set of reversible chemical reactions and parameters collectively known as the marine carbonate system. This session welcomes submissions that focus on observing, understanding and modelling the changing marine carbonate system and its role in the global carbon cycle. This includes studies on anthropogenic CO2 uptake and its chemical consequences, the physical and biological carbon pumps, biominerals and the alkalinity cycle, air-sea CO2 fluxes, internal consistency of the carbonate system variables, organic alkalinity, physical chemistry, measurement techniques and data compilations. Studies may be global or regional in scope and they may cover a range of different timescales. Results may be derived from a variety of sources including in situ observations, laboratory experiments, remote sensing, machine learning, and model output.

Dissolved organic matter (DOM) is a key component of biogeochemical cycles in the ocean and on land. It contains as much carbon as all living biomass on the continents and oceans combined. DOM accumulates in the ocean over several millennia and acts as a substantial carbon storage pool. On the other hand, microbes rely on dissolved molecules for carbon uptake, processing DOM on short time scales. DOM is therefore the main link between organic and inorganic carbon in marine and freshwater ecosystems. A multitude of biogenic and abiotic processes shape the so-called “DOM geometabolome” which parallels sedimentary records as an information-rich set of molecular tracers. These compounds carry the signatures of their source and subsequent journey through the environment. For our session, we invite contributions from all areas of research on DOM biogeochemistry, from empirical to modelling studies, from groundwaters and lakes across the freshwater-to-marine continuum. Molecular-level and interdisciplinary studies including modeling approaches are particularly welcome. Also, contributions that apply innovative analytical approaches, or identify novel concepts, fundamental challenges and the future directions of this fast-growing field of research are encouraged.

Marine sediments are an important sink of organic carbon and source of alkalinity, providing a valuable climate regulating function (“Blue Carbon”). Human activities that disturb the seabed might, however, compromise the effectiveness of the seabed in storing organic carbon through a net increase of organic carbon remineralisation, or reduction of its alkalinity-generation capacity by stimulating re-oxidation of reduced minerals. For example, intense mobile bottom fishing may lead to reductions of organic carbon and pyrite stocks, especially in muddy sediments. Other human activities that disturb marine sediment include marine construction, dredging and dumping, offshore wind infrastructure, and submarine cables and pipelines. Sediment disturbance impacts on coastal carbon cycling are largely site or region-specific and difficult to generalise due to the many mechanisms that support stock creation and responses to disturbance, often in opposing directions. In addition, the fate of the ‘lost’ organic carbon or oxidized minerals, and consequences for the marine environment and global climate are currently not well understood. The roles of benthic fauna and of the water column biological carbon pump in carbon cycling under disturbance are also unclear.

Until recently, field and modelling studies have focussed on processes in or near the seabed. It is, however, becoming increasingly clear that a holistic approach is necessary to assess the impacts. Only then will it be possible to provide robust advice for marine spatial management and policy.

We therefore invite abstracts that cover any aspects relating to understanding and quantifying the climate impacts of human activities disturbing the seabed that may be relevant for carbon cycling. These may be observational, experimental, predictive or frameworks to support management. Key topics of this session include, but are not limited to:
- Carbon stocks, accumulation rates, reactivity, and provenance
- The role of flora and fauna in mediating remineralisation, accumulation and burial of carbon, and how disturbance may alter these functions.
- Disturbance impacts on water column nutrients, ecosystem processes, inorganic carbon chemistry and alkalinity dynamics
- Management of carbon stocks under uncertain disturbance outcomes

Long spin-up times remain a major computational bottleneck in ocean and climate modelling, limiting our ability to investigate past climate states, understand model biases, and quantify parameter uncertainty. Developing more efficient spin-up methods can help overcome these limitations and support the use of past climate information to strengthen confidence in future climate projections.

This session will bring together results from the Past-to-Future Global Ocean Circulation Model Spin-Up Competition. The competition challenges participants to bring a global ocean model to equilibrium using as few computational resources as possible. Participants access the model as a time-forward black box, advancing the ocean state through a prescribed routine without modifying the underlying model or its physical configuration. This common framework enables a systematic comparison of alternative approaches.

The session will focus on three core aspects:

• presenting the methods developed by participating teams and comparing their performance against the common benchmark;
• discussing computational efficiency, convergence, and reproducibility, including the costs associated with training data where machine learning methods are used;
• exploring lessons learned and the potential for applying successful approaches more broadly in ocean and climate modelling.

We welcome competition participants and researchers interested in ocean and climate modelling, numerical analysis, scientific computing, and machine learning. The goal is to identify promising approaches, discuss remaining challenges, and encourage future collaborations on efficient model initialisation. Registration for the competition closes on 1 November 2026, with final results due on 1 March 2027.

Global coupled models that resolve ocean mesoscale eddies, and increasingly atmospheric storms, can now be run over multidecadal to centennial timescales. This allows us to ask whether small-scale processes change the large-scale climate: its mean state, its modes of variability and its response to forcing. This session focuses on the rectified effect of resolved small scales in the ocean, the atmosphere and at the air-sea interface on the climate system.

We welcome contributions from global km-scale models as well as from eddy-rich coupled configurations with coarser atmospheres, regional high-resolution setups and model hierarchies. Topics include the role of ocean mesoscale and submesoscale dynamics, boundary currents and fronts in climate; mesoscale air-sea coupling and its influence on storm tracks, jets, and precipitation; interannual to decadal to centennial variability including the AMOC, the Southern Ocean and tropical modes; whether resolution alters forced responses, climate sensitivity and SST trend patterns; sea ice, and ice-sheet-ocean interactions at high resolution; biogeochemistry, impacts on marine ecosystems, and km-scale mechanisms underlying the exchange of carbon at the air-sea interface and its subsequent transport in the ocean.
We also welcome studies exploring how resolved oceanic and atmospheric small-scale processes influence extremes, including heatwaves, marine heatwaves, ocean carbon uptake and acidification, heavy precipitation and compound events, particularly where these provide insight into climate variability and climate change.

We also invite studies using pacemaker or filtered-forcing experiments and resolved-versus-parameterised comparisons to isolate mechanisms or transfer insight to coarser models, as well as storyline approaches, pseudo-global-warming experiments, uniform warming experiments (e.g. +4 K frameworks), and related targeted methodologies used to understand the role of resolved small-scale processes in climate variability, extremes, and climate change, as well as work on challenges specific to long coupled simulations such as spin-up, drift, tuning, and initialisation.

Contributions from EERIE, DestinE, nextGEMS, WarmWorld, DYAMOND, DYAMOND3, MESACLIP, HighResMIP and related efforts are encouraged.

Connect with colleagues across disciplines at the 5th Lagrangian session!

This session provides an open venue for scientists to share the latest advances in Lagrangian techniques, explore diverse applications, and build new connections.

We invite presentations on topics including, but not limited to:
- Planetary circulations and variability (fundamental processes shaping jets, gyres, waveguides, overturning circulations, transport barriers across atmosphere and ocean)
- Mesoscale eddies and coherent structures (eddy transport, wave-mean flow interactions, blocking)
- Turbulence and mixing (turbulent and convective entrainment, breaking internal waves, boundary layers)
- Numerical and computational advances (incl. data-driven techniques, GPU acceleration, graph-theoretical formulations, adaptive methods, data assimilation)
- Inverse modeling techniques (long-range transport of volcanic plumes, wildfire smoke, hazardous material, aerosols, plastics, micro-organisms, and their impacts on global composition, health, and climate)
- Field campaigns (drifters, floats, superpressure balloons, etc)

Advanced remote sensing capabilities have provided unprecedented opportunities for monitoring and studying the ocean environment as well as improving ocean and climate predictions. Synthesis of remote sensing data with in situ measurements and ocean models have further enhanced the values of oceanic remote sensing measurements. This session provides a forum for interdisciplinary discussions of the latest advances in oceanographic remote sensing (using electromagnetic or acoustic waves) and the related applications and to promote collaborations.

We welcome contributions on all aspects of the oceanic remote sensing and the related applications. Topics for this session include but are not limited to: physical oceanography, marine biology and biogeochemistry, biophysical interaction, marine gravity and space geodesy, linkages of the ocean with the atmosphere, cryosphere, and hydrology, new instruments and techniques in ocean remote sensing, new mission concepts, development and evaluation of remote sensing products of the ocean, and improvements of models and forecasts using remote sensing data. Applications of multi-sensor observations to study ocean and climate processes and applications using international (virtual) constellations of satellites are particularly welcome.

Tropical reef ecosystems are facing a potential turning-point as they are experiencing the most extreme conditions on record. While the 4th global coral bleaching event (2023–25) exposed ~84% of the world's reefs to bleaching-level heat stress, the next extreme El Niño has started. Yet the observational baseline against which these events are assessed spans only a few decades, whereas the processes that determine whether certain reefs will persist can span centuries to millennia. To assess whether corals can adapt or have adapted to these extremes and which reefs will survive, we require baseline data that go far beyond current timespans alongside improved projections of the coming decades to centuries. Such information also provides an important foundation for restoration and conservation planning–a growing need. This session aims to bring together coral palaeoclimatology, reef (palaeo)ecology and (palaeo)biology, observations, and modelling relevant to restoration and conservation planning, policy-making, and understanding tropical climate dynamics.

We invite contributions from tropical and subtropical settings, including marginal, turbid and naturally extreme reefs, across timescales from deep time to future projections. Topics include, but are not limited to:

• high-resolution coral reconstructions and observations of ocean and climate variability (ENSO, IOD); oceanographic/ecological monitoring, remote sensing; skeletal growth/calcification, other marine biogenic archives (molluscs, sclerosponges, coralline algae)

• proxy development, process understanding; novel geochemical proxies (nitrogen, boron, clumped isotopes), biomineralisation

• coral reef ecology, biology, physiology under stress; thermal tolerance, trophic ecology, microbial symbiont dynamics, connectivity, community change, adaptation, reef refugia

• databases, synthesis, FAIR workflows; PAGES CoralHydro2k and CoralHydro2k-Seawater, CoralCache, GBR Coral Skeletal Records; proxy system modelling, isotope-enabled simulations, data assimilation, proxy-model comparison

• future projections of tropical climate and reef environments constrained by palaeorecords and observations; translation into baselines, thresholds, conservation planning

Contributions from coordinated programmes, such as PAGES working groups (e.g., 2k Network), DFG Priority Programme "Tropical Climate Variability & Coral Reefs", IODP research (e.g., IODP Exp. 389 Hawaiian Drowned Reefs), among others, are welcome.

This session focuses on recent developments and research on ocean data assimilation. Data assimilation is essential for ocean forecasting, reanalysis, and climate studies. By optimally combining numerical simulations with various observations, data assimilation provides a dynamically consistent and comprehensive estimate of the present and past ocean state. This session invites abstract submissions on developments of data assimilation for the physical ocean together with coupled components such as sea ice, marine ecosystems, land-sea interface and atmosphere for ensuring consistency with other parts of the Earth system. The session also focuses on impact of the assimilation and deployment of novel space-borne and in-situ observations such as autonomous platforms, wide-swath satellite tracks, and deep in-situ observations and biogeochemistry profilers.
Beyond state estimation, this session also welcomes contributions in parameter estimation, uncertainty quantification, and hybrid machine learning and data assimilation methods focused on the ocean.

Marine extreme events, including storm surges, marine heatwaves and cold spells, harmful algal and jellyfish blooms, acidification and deoxygenation extremes, ocean responses to severe storms and cyclones, and temporally or spatially compounding events, have major impacts on marine ecosystems, coastal communities and global economies. Under climate change, their frequency, intensity, duration and co-occurrence are changing, yet many of these events remain poorly understood, simulated and predicted.
Their dynamics span a broad range of spatial and temporal scales and often involve complex interactions and feedback within the ocean and across the atmosphere-ocean interface. Understanding these multi-scale processes, including interactions among physical, biogeochemical and biological extremes, their cascading effects, and ecosystem impacts, is crucial to improve their detection, attribution and predictability.
This session encourages contributions addressing the dynamics of marine, coastal and coupled atmosphere-ocean extremes, including event attribution and future projections. We welcome novel observations and detection strategies, numerical and coupled modelling, statistical and machine-learning approaches for understanding and forecasting extremes, as well as studies of compound and cascading events. Ecosystem and socio-economic impact assessments linked to marine extremes and relevant to risk reduction, mitigation and adaptation are also encouraged.

Coastal seas lie at the interface between the open ocean, land and society, yet observing, modelling and forecasting across these scales remains challenging. In a changing climate, improving coastal monitoring capabilities and developing innovative coastal products is vital to protect and manage coastal areas. Novel coastal observations (including satellite,land-based remote sensing and in situ data), advanced hydrological and coastal models, land-ocean data integration, coupling modelling and data assimilation all serve to improve coastal monitoring, and forecasting. Novel numerical model approaches and Artificial Intelligence (AI), including hybrid physics-AI methods, are further enabling pan-European transferable approaches. This session focuses on advanced, seamless ocean observing and forecasting, from global/regional systems to high-resolution coastal systems, through new and improved observations, models, methods, and co-produced (with national or regional authorities) coastal products and services. We particularly welcome contributions that bridge European and regional ocean products with coastal systems and demonstrate interoperable workflows, uncertainty quantification, integration with operational services, and uptake by end users. These advances aim to provide the marine knowledge needed for coastal applications addressing environmental and social challenges and those enhanced by climate change, such as: pollution and eutrophication hazard/risk mapping, coastal erosion and flooding, resource management, harmful algal blooms, and combating ecosystem degradation and restoration, supporting Marine Protected Areas, and addressing natural hazards and extreme events.

Ocean dynamics span a broad range of spatial and temporal scales, with interacting processes governing the transport, stirring, mixing and exchange of water masses, heat, salt, carbon, nutrients and other tracers. Understanding how these processes interact across scales, from the surface through the water column and across air–sea–ice boundaries, remains a major challenge, particularly under climate variability, climate change and extreme events.
This session welcomes studies addressing circulation, sea-level variability, currents, waves, fronts, eddies, filaments, and mesoscale and submesoscale dynamics. Topics may include transport pathways and connectivity, stirring and mixing, vertical and subsurface dynamics, air–sea–ice interactions, and links with biogeochemistry and marine ecosystems.
We encourage contributions using satellite and other remote-sensing observations, in situ measurements, numerical and Lagrangian modelling, theoretical approaches, and emerging data-driven methods.

This open PICO session welcomes presentations on a broad range of ocean processes and oceanographic techniques, including interdisciplinary studies that span several themes and may therefore not fit within a single specialised session.

The session covers all marine disciplines, including interactions of the ocean with the atmosphere and/or cryosphere, and welcomes both global studies and regional work with broader relevance across the open ocean and shelf seas. Contributions on ocean processes may include topics such as turbulent mixing, phytoplankton bloom characterisation, and air–sea interactions.

We also welcome advances enabled by new instruments and techniques, novel applications of established technologies, and the integration of complementary observational and modelling approaches. These may include gliders, autonomous vehicles, novel sensors, multi-platform observations, robotics, numerical model development and parameterisations, novel instrumentation, or new ways of combining established and emerging approaches.

Ocean stratification describes the layering of seawater, with lighter (warmer, fresher) water overlying denser (cooler, saltier) water. It plays a fundamental role in regulating the vertical exchange of heat, carbon, oxygen, and nutrients in the ocean, with important consequences for marine ecosystems, biogeochemical cycles, and climate. No single metric is appropriate for diagnosing ocean stratification across all applications. Different metrics may be better suited to different scientific question, spatial and temporal scales, and available datasets. As estimates of stratification change can be sensitive to the metric used, careful consideration of metric choice and comparability is essential. While ocean stratification is widely observed to have increased globally over recent decades, and is projected to continue increasing in the future, important questions remain regarding the spatial and temporal heterogeneity of these changes, their underlying controls, and their consequences. Improved quantification, continued development and evaluation of ocean models, and attribution of observed and simulated changes to key mechanisms are needed at both global and regional scales. Changes in ocean stratification can affect ocean deoxygenation, primary production and marine biomass, the carbon cycle, ocean circulation and overturning, ocean heat uptake, tropical cyclones, marine heatwaves, and ultimately human societies. Understanding these links is particularly important for assessing how changes in the ocean may feed back on the climate system. This session welcomes contributions from observers and modellers addressing ocean stratification over a wide range of spatial and temporal scales, including its measurement, variability, drivers, trends, modelling, and impacts. Interdisciplinary subject are particularly encouraged.

The Copernicus Marine Service provides regular and systematic reference information on the physical (including sea ice and wind waves) and biogeochemical states of the global ocean and European regional seas. In the coming years, Copernicus Marine will implement next-generation ocean monitoring and forecasting systems and prepare new services for the coastal ocean, marine biology, and regional climate projections. It will also leverage digital capabilities in synergy with EDITO, the European Digital Twin of the Ocean (DTO). EDITO will connect and enable interoperability between a wide range of ocean and coastal numerical tools on a common digital platform, supporting global-to-coastal configurations and the co-development of simulations and what-if scenarios for enhanced on-demand forecasting and ocean climate projections.
The session will address key scientific challenges for the coming years, including: (1) integrating Copernicus Sentinel expansion missions into the observation and modelling systems; (2) developing ocean observation design and impact assessment methods to support a harmonized, fit-for-purpose ocean observing system, in line with the ambitions of the European OceanEye; (3) improving the representation of interactions between ocean, waves, sea ice, biogeochemistry, high-trophic levels, land, and the atmosphere in modelling and data assimilation; (4) quantifying and propagating uncertainties across Copernicus Marine components; (5) further leveraging AI capacities for physical, biogeochemical and ecosystem variables, including direct observation prediction, hybrid AI-numerical modelling, quality control, field reconstruction, data assimilation, calibration, super-resolution, and subgrid-scale parametrisation; (6) developing user-oriented on-demand services and what-if scenarios that fully exploit DTO capabilities, including integration of associated datasets (e.g. socio-economic data); (7) strengthening the ocean science-policy interface through policy-relevant information to support marine hazard preparedness, conservation, early warning, climate adaptation, and evidence-based ocean governance.
Presentations are invited from teams involved in Copernicus Marine, the European DTO, in situ and satellite observing systems, downstream applications, and relevant R&D projects (e.g. Horizon Europe, ESA, etc.). Contributions from the international OceanPredict community and relevant UN Decade programmes and projects are strongly encouraged.

Plastic pollution is a widely recognized global problem with significant environmental and ecological risks which have been a long-standing focus of research, particularly in marine and estuarine environments. Despite extensive studies in recent years, gaps in consistent data and holistic knowledge persist. These gaps are particularly apparent regarding sources contributions, quantities, transformation and transport processes, and the distribution of plastic and litter across environmental matrices and ecosystem compartments from local to global scale. Addressing these knowledge gaps is critical to accurately assess potential risks, inform policy, and develop effective mitigation strategies.
In this session, we will explore the current state of knowledge and ongoing research on litter and macro-, micro-, and nanoplastics in estuarine and marine systems. The session will cover a wide range of topics, including:
• Recent findings on plastic distribution and accumulation in estuaries, shorelines, nearshore and open waters, and nearshore and deep seafloor environments.
• Source-to-sink investigations, considering quantities and distribution across environmental matrices (water, sediment and biota) and compartments (coastline, surface water, water column and seabed),
• Transport, accumulation and dispersal processes influenced by ocean currents, tides, density gradients, waves and gyres.
• The role of extreme weather events, such as storms and floods, in redistributing plastic debris.
• Impacts on biota, community structure and habitats, from estuaries and coastlines to open waters, including seabed.
• Modelling approaches to estimate marine plastic accumulation and their impacts at local, regional and global scales, and to assess the effectiveness of prevention and mitigation measures.
• Legislative and regulatory efforts, including international monitoring programs and measures aimed at reducing marine plastic pollution.

To study the pathways and fate of marine contaminants, such as anthropogenic hydrocarbons, marine litter (including plastics), heavy metals, HNSs, POPs, radionuclides, PFAS, pharmaceuticals, and other pollutants, researchers widely use oceanographic monitoring, modeling, and laboratory experiments. This session explores in situ and remote monitoring approaches, including satellite observations, aerial and marine drones, laboratory studies, computational tools, and digital applications (web- and mobile-based) to understand the distribution and impact of marine pollutants at various scales. It also welcomes emerging citizen science initiatives that help track pollution sources and validate remote observations, as well as transdisciplinary studies highlighting broader impacts on ecosystem services and related socioeconomic aspects affecting communities. Solicited topics include new and varied monitoring protocols, toxicity testing, ensemble and multi-model simulations, machine learning, and AI-based approaches.

Marine pollution and its effects on ecosystems continue to pose serious challenges for the sustainable management of coastal and open-ocean areas. Thus, studies linking marine pollution to broader ecosystem stressors, such as climate change and environmental degradation, are especially welcome. The growing human impact on the Arctic Ocean, driven by melting polar ice, underscores the need to understand the fate of marine pollutants in ice-covered waters. This session aims to answer key questions: What do we know about marine pollution sources? Which factors influence the dispersion of pollutants in the aquatic environment? What happens to contaminants in the water column, sediments, and at the sea surface? How do marine pollutants interact with biota?

The impact of other environmental stressors, such as artificial light, noise, and thermal pollution, on marine ecosystem resilience is also an important topic for discussion.

The Navier-Stokes equations, initially formulated in the early 19th century, have since become the cornerstone of fluid mechanics, subsequently extending their relevance to fluid geophysics. The existence and regularity of their solutions pose a significant challenge within a substantial domain of geophysics.

Over the years, a series of partial results have been obtained, particularly in the pursuit of proving one of the four statements proposed by Charles L. Fefferman for the Millennium Clay Prize. A definitive proof of the third statement regarding the breakdown of the Navier-Stokes equations was unveiled by OpenAI on September 8th, utilising extensive IA resources. This revelation has sparked a substantial debate, encompassing various aspects such as the physical significance of the blowing-up singularity, the utilisation of intensive AI resources in disruptive research, and the connections with concepts like intermittency, cascades, multifractals and enstrophy catastrophe. It may also inspire new approaches to resolve fundamental questions of geosciences.

This PICO session seeks to provide the geophysical community with an opportunity to contribute to this ongoing discourse.

The Atlantic Meridional Overturning Circulation (AMOC) plays a crucial role in shaping the dynamics of the Earth’s climate by distributing heat and nutrients across the Atlantic. It is important to understand the past, present and future changes in the dynamics of the AMOC, either gradual or abrupt, since such changes, and the possibility of its tipping, can have profound climatic and societal impacts. In this regard, big data and AI play an increasingly important role in studying AMOC dynamics based on diverse types of data. These range from geological proxies over contemporary in-situ and remote sensing observations to simulations of state-of-the-art ocean or coupled Earth system models and provide an ever increasing amount of more and more complex data on the AMOC. Advanced numerical methods and AI can help us to uncover critical aspects of the AMOC dynamics by extracting new patterns and highlighting the role of complex physical mechanisms and feedbacks, including early warnings of future regime shifts of the AMOC or some of its subcomponents like the Nordic Seas deep convection or the Northern hemisphere subpolar gyre.
In this session we welcome contributions exploring new ways of using big data and AI to elucidate AMOC dynamics. We aim to cover a broad variety of computational methods, making use of the wealth of AMOC-related observational and/or model data. These can range from statistical methods exploiting big datasets to machine learning and deep learning approaches, including neural-network emulators of the AMOC. The session is open to work on a wide range of timescales, from paleoclimate reconstruction, through current observations to future projections. Contributions may address the analysis of short-term AMOC dynamics, as well as longer-term behaviour, including tipping of the circulation and associated forecast and impact studies.

Nonlinear waves transfer energy, momentum, and information across scales in the atmosphere and ocean. Rossby waves, atmospheric gravity waves, and ocean surface and internal waves interact with mean flows, turbulence, and other waves, influencing circulation, atmospheric blocking, teleconnections, ocean mixing, predictability, and extreme events. Their multiscale behaviour, nonlinear interactions, and limited observability remain challenging for conventional analysis and modelling.

This session invites contributions exploring how artificial intelligence, machine learning, and data-driven methods can improve the understanding, representation, and prediction of atmospheric and oceanic waves.

We welcome studies on Rossby-wave propagation and breaking, wave packets, wave–mean-flow interactions, blocking, teleconnections, circulation regimes, extremes, and predictability. Contributions addressing atmospheric gravity waves, ocean surface and internal waves, planetary and topographic waves, and wave–wave interactions are also encouraged.

Relevant approaches may include deep learning, neural operators, physics-informed AI, computer vision, explainable AI, reduced-order modelling, causal discovery, hybrid modelling, and machine-learning parameterizations. Applications may address wave detection, reconstruction from sparse observations, simulation acceleration, unresolved processes, prediction of wave evolution, and forecasting of wave-related extremes.
We also welcome assessments of the physical consistency, interpretability, uncertainty, and generalizability of AI models under changing climatic conditions.

Potential topics include:
* AI-based detection and tracking of waves and wave packets
* Rossby-wave breaking, blocking, and circulation regimes
* Wave–mean-flow and wave–wave interactions
* Gravity-wave detection and parameterization
* Data-driven modelling of ocean waves
* Neural operators and reduced-order models
* Physics-informed and physics-constrained AI
* AI-based simulation and prediction of wave evolution
* Waves, teleconnections, and climate variability
* Wave-related extreme and compound events
* Explainability and uncertainty quantification
* Comparisons of AI, numerical, and theoretical models

The ice-ocean boundary is an important interface in global climate system, both due to the ocean’s ability to impact ice sheet mass balance and the cryosphere’s influence on global ocean circulation. Processes at the ice-ocean interface play a crucial role in the dynamics of tidewater glaciers and ice shelves, and associated fjord and cavity circulation. However, a complete understanding and accurate representation of these processes in models remains a major challenge and a source of uncertainty for projections of ice mass loss and sea-level rise. Recent work to understand ice-ocean interactions has led to significant progress in theory, idealised models, and coupled ice-ocean models. New observations of processes such as seawater intrusion at grounding lines and channelised ice-shelf melting can provide further insights into our understanding of this important climate interface. These continued efforts are essential for improving projections of future sea-level rise contributions and freshwater fluxes from the Earth’s cryosphere under climate change.
In this session we aim to bring together the most up to date work on ice-ocean interactions across all latitudes, covering in-situ observations, remote-sensing, modelling and theory. We seek a bi-directional perspective, investigating both the impact of the ocean on the cryosphere and vice-versa, from small scale physical processes to global impacts. Topics for submission include but are not limited to: coupled ice-ocean models, ice shelf cavity and fjord circulation, ice mélange, subglacial meltwater plumes, basal and submarine melting and freshwater fluxes into the ocean. New observational datasets and methodologies are encouraged.
We welcome and encourage submissions from groups who are underrepresented in the cryosphere community and will endeavour to provide reasonable adjustments to any presenter who requires them.

The observation of ocean velocities is of key importance for understanding the ocean and managing human activities at sea. Yet, these observations face challenges due to sampling issues and the absence of direct satellite measurements. Currently, High-Frequency Radars (HFR) stand as the sole operational tools capable of delivering extensive surface current observations. HFR can offer high-resolution velocity data, typically ranging from 1 to 5 km, for coastal areas extending up to 100 or 200 km, contingent on the frequency used. Over recent years, HFR networks have strengthened and emerged as a crucial source for measuring ocean velocities. This expansion has been paralleled by advancements in analysis techniques and an increase in HFR applications. Additionally, upcoming satellite missions like ESA's Harmony missions are anticipated to enhance the scope of coastal HFR measurements.

This session aims to foster interdisciplinary dialogue among scientists innovating HFR methods, oceanographers utilizing HFR data in their studies, and researchers exploring new satellite-based concepts for measuring surface velocities. We invite contributions covering all facets of HFR development and application in oceanographic research. Topics for discussion include, but are not limited to, the application of HFR data to oceanographic challenges, novel methods for HFR data analysis, and leveraging synergies with existing missions (such as the Sentinel constellation, SWOT, etc.) or future missions like Harmony.