The persistent rapid decline of the Arctic sea ice in the last decades is a dramatic indicator of climate change. The Arctic sea ice cover is now thinner, weaker and drifts faster. Extreme air temperatures over land and ocean are more common, contributing to accelerated ice sheet melting and summer sea ice loss in the Kara and Laptev Seas. On land, the permafrost is dramatically thawing, glaciers are disappearing, and forest fires are raging. The ocean is also changing: the volume of freshwater stored in the Arctic has increased as have the inputs of coastal runoff from Siberia and Greenland and the exchanges with the Atlantic and Pacific Oceans. As the global surface temperature rises, the Arctic Ocean is speculated to become seasonally ice-free by the mid 21st century, which prompts us to revisit our perceptions of the Arctic system as a whole. What could the Arctic Ocean look like in the future? How are the present changes in the Arctic going to affect and be affected by the lower latitudes? What aspects of the changing Arctic should observational, remote sensing and modelling programmes address in priority?
In this session, we invite contributions from a variety of studies on the recent past, present and future Arctic. We encourage submissions examining interactions between ocean, atmosphere and sea ice; on emerging mechanisms and feedbacks in the Arctic; and on how the Arctic influences the global ocean. Submissions taking a cross-disciplinary, system approach and focussing on emerging cryospheric, oceanic and biogeochemical processes and their linkages with land are particularly welcome.
We aim to promote discussions on future plans for Arctic Ocean modelling and measurement strategies, including on constraining models with observations, and encourage submissions on CMIP , as well as on recent observational programs, such as the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), which cosponsors this session.

The North Atlantic exhibits a high level of natural variability from interannual to centennial time scales, making it difficult to extract trends from observational time series. Climate models, however, predict major changes in this region, which in turn will influence sea level and climate, especially in western Europe and North America. In the last decade, several observational projects have been focused on the Atlantic circulation changes, for instance ACSIS, OSNAP, OVIDE, RACE and RAPID, and new projects have started such as CANARI and EPOC. Most of these programs include also a modelling component. Another important issue is the interaction between the atmosphere, the ocean and the cryosphere, and how this affects the climate.

This year we celebrate the 20th year of the RAPID array and we plan to dedicate part of the session to this anniversary. Abstracts for this part of the session are particularly welcome.

We also welcome contributions from observers and modellers on the following topics:

-- climate relevant processes in the North Atlantic region in the atmosphere, ocean, and cryosphere
-- response of the atmosphere to changes in the North Atlantic
-- atmosphere - ocean coupling in the North Atlantic realm on time scales from years to centuries (observations, theory and coupled GCMs)
-- interpretation of observed variability in the atmosphere and the ocean in the North Atlantic sector
-- comparison of observed and simulated climate variability in the North Atlantic sector and Europe
-- dynamics of the Atlantic meridional overturning circulation
-- variability in the ocean and the atmosphere in the North Atlantic sector on a broad range of time scales
-- changes in adjacent seas related to changes in the North Atlantic
-- role of water mass transformation and circulation changes on anthropogenic carbon and other parameters
-- linkage between the observational records and proxies from the recent past

The Indian and tropical Atlantic Oceans exhibit pronounced variability in ocean processes and air-sea interactions on daily to decadal time scales, and are fringed by some of the most densely populated regions in the world. Both basins host, and are in turn influenced by, processes and teleconnections that shape our global climate, for instance: monsoons, the Benguela and Dakar Niños, the Atlantic Meridional Mode, the Indian Ocean Dipole and the Madden-Julian Oscillation. Interactions between these systems and climate modes are complicated and lead to a dynamic environment that can remain challenging to predict.

This session invites contributions based on observations, modelling, theory and palaeo proxy reconstructions that advance our understanding of Indian and tropical Atlantic Ocean variability, and its physical, biogeochemical and ecological influence on the ocean and atmosphere. We welcome studies on high-impact events of societal relevance, such as marine heat waves, tropical cyclones and extreme rainfall, that might affect the human populations of the tropical Indo-Atlantic. Studies relating to the prediction of such events, and on the impacts of systematic model errors in simulating regional climate, are particularly welcome, including those that make use of novel methodologies such as machine learning.

The Southern Ocean is vital to our understanding of the climate system. It is a key region for vertical and lateral exchanges of heat, carbon, oxygen, and nutrients, with significant past and potential future global climate implications, especially around the latitudes of the Antarctic Circumpolar Current. The role of the Southern Ocean as a dominant player in heat and biogeochemical exchanges as well as its 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, the Southern Ocean is currently subject to investigations with 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 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 on how changes in Southern Ocean circulation as well as heat and carbon transport affect lower latitudes and global climate more generally.

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: Is Antarctic sea ice becoming more vulnerable in a changing climate? Where and when will ocean-driven melting of ice shelves yield a tipping point in the Antarctic climate? What drives the observed reduction in Antarctic Bottom Water production? How does the Antarctic Slope Current interact with the continental shelf? What role do ice-related processes play in nutrient upwelling on the continental shelf and in triggering carbon export to deep waters?

Recent advances in observational technology, data coverage, and modeling 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. Studies based on in-situ observations, remote sensing and regional to global models are welcome. We particularly invite cross-disciplinary topics involving glaciology, sea ice physics and biological oceanography.

The ocean surface layer mediates the transfer of matter, energy, momentum and trace gases between the atmosphere, ocean 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 to the pelagic ocean and its interactions with the overlaying low atmosphere. The session covers recent progress in understanding key processes in the ocean surface layer, including wind-driven turbulence, surface-wave effects, convection, surface-layer fronts, surface-layer instabilities, submesoscale dynamics, diurnal warm and rain layers, and surface layer communication with the ocean’s interior. Particular emphasis is placed on the impact of ocean surface-layer processes on air-sea fluxes and feedbacks in field experiments and coupled atmosphere-ocean models. This includes SST coupling with the atmospheric boundary layer, tropical cyclones, extreme events, and parameterizations of air-sea interactions. The interaction of the ocean surface layer with sea ice is also of particular interest. We welcome interdisciplinary studies including atmospheric deposition of nutrients and pollutants to the ocean and impacts on ocean biogeochemistry, ocean-atmosphere fluxes of climate-active species and potential feedbacks to climate. We encourage a diversity of approaches: observational (laboratory, in-situ and remote sensing), theoretical, and numerical modeling studies focusing on the ocean surface layer and its interactions with the atmosphere and sea ice, regardless of the temporal and spatial scales considered. This session also includes a focus on the legacy and activities of the 20-year Surface Ocean - Lower Atmosphere Study (SOLAS) and is jointly sponsored by SOLAS and GESAMP Working Group 38 on ‘The Atmospheric Input of Chemicals to the Ocean’.

Meso- and sub-mesoscale dynamics are vital components of the Earth’s oceanic circulation. They play a critical role in the horizontal and vertical transport of heat, freshwater, phytoplankton and biogeochemical tracers, at regional and local scales, and ultimately mediating local oceanic-atmospheric exchanges. Although more prominent in the upper layers, their impacts can be far-reaching into the ocean interior. Recent scientific and technological advancement have enabled the observations and modelling of the ocean across a wide spectrum of scales, spanning from hundreds of meters to tens of kilometres, and from hours to days. Extensive observational initiatives such as EUREC4A-OA/ATOMIC alongside high-resolution modelling studies are starting to yield new insights into the multidisciplinary impacts of mesoscale and submesoscale processes. Meso- and sub-mesoscale air-sea interaction in regions such as the Tropical Oceans, the Southern Ocean, the western boundary currents and their extensions may have basin and global scale impacts via oceanic and atmospheric teleconnection.

This session welcomes contributions from observational, theoretical and modelling studies focusing on mesoscale and submesoscale dynamics, and their potential impacts on the biogeochemistry, biology and air-sea interactions. Specific topics include:

1. Impacts of meso- and sub-mesoscale processes on the horizontal and vertical transport of physical/biogeochemical/biological tracers in the global ocean
2. Meso- and sub-mesoscale ocean and atmospheric interactions and air-sea fluxes
3. Large scale impacts of the meso- and sub-mesoscale processes

Knowledge of energy, heat, salt, and carbon transports between and within climate components is crucial in order to understand the Earth’s climate system behavior and its variability, predictability, and future changes. In the ocean, the role of the Atlantic Meridional Overturning Circulation and tropical and subtropical gyres is essential for the heat, salt, and carbon budget and the water mass distributions and transformations (in Eulerian, Lagrangian, and tracer coordinates) of individual basins and in both hemispheres. In the atmosphere, the zonal mean Hadley circulation determines meridional energy transport over the tropics, while Rossby and planetary-scale waves modulate the energy exchanges carried by extratropical eddies. Large-scale atmospheric and oceanic circulation, the hydrological cycle, and heat and salt transport are tightly intertwined through physical processes, phase changes, and energy conversions that are sensitive to natural and anthropogenic forcings and feedbacks. From a modelling perspective, understanding of energy transfers from oceanic and atmospheric large-scale circulation to the internal wave field through mesoscale and sub-mesoscale eddies is the basis for the development of new parameterizations for both oceanic and atmospheric small-scale processes.

We invite submissions addressing the interplay between Earth’s energy exchanges and the general circulation, using modeling, theory, and observations across all scales. We encourage contributions regarding the forced response and natural variability of the general circulation, understanding present-day climate, past and future changes, and impacts of global features and changes on global and regional climate, and their importance for climate predictability.

Marine heatwaves (MHWs) are discrete and prolonged warm ocean extremes that can cause substantial ecological and socio-economic impacts. Warming ocean temperatures due to climate change can be expected to exacerbate the severity of MHWs through the 21st century. Understanding of the physical mechanisms that generate MHWs is important to improving our capacity to forecast them. Meanwhile, gaining a better understanding of the impacts of MHWs on ecosystems is significant for promoting sustainable development in the face of climate change. We welcome abstract submissions across all aspects of marine heatwave research and particularly encourage submissions in the following areas:
• Processes and drivers of MHWs at the surface and subsurface: The role of local drivers and remote forcing in MHW generation and evolution.
• Methods for MHW detection and characterization: Discussion of MHW definition and ecologically based indices.
• MHWs in a changing climate: Projections of MHWs in the future under different scenarios.
• Historical analyses of MHWs: Process understanding of past pronounced MHW events and their impacts.
• MHWs and compound events: Interactions between MHWs and other systems (e.g., cyclonic storms, monsoons, and atmospheric heatwaves) or biogeochemical extremes.
• Ecological, socioeconomic, and biological impacts of MHWs.
• MHW predictability and prediction: Insights from advanced statistical methods, climate models, machine learning, etc.

The oceans are changing rapidly in response to the changing climate manifested in record-breaking temperatures in the North Atlantic, altered ocean currents, and changes in the marine carbon system. Further changes are expected in a warmer future climate. Understanding the mechanisms of oceanic climate change are crucial to develop realistic ocean projections. The latest 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 projections are essential to quantify the impacts of oceanic climate change and in developing successful adaptation strategies. This session will bring together people with the common interest of what the future ocean circulation will look like.

We encourage submissions from studies covering global, basin wide, regional, or coastal changes. Topics covering changing 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 but submissions using other modelling datasets and statistical projections are very much encouraged.

Ice shelves and tidewater glaciers are sensitive elements of the climate system. Sandwiched between atmosphere and ocean, they are vulnerable to changes in either. The recent disintegration of ice shelves such as Larsen B and Wilkins on the Antarctic Peninsula, current thinning of the ice shelves in the Amundsen Sea sector of West Antarctica, and the recent accelerations of many of Greenland's tidewater glaciers provide evidence of the rapidity with which those systems can respond. Changes in marine-terminating outlets appear to be intimately linked with acceleration and thinning of the ice sheets inland of the grounding line, with immediate consequences for global sea level. Studies of the dynamics and structure of the ice sheets' marine termini and their interactions with atmosphere and ocean are the key to improving our understanding of their response to climate forcing and of their buttressing role for ice streams. The main themes of this session are the dynamics of ice shelves and tidewater glaciers and their interaction with the ocean, atmosphere and the inland ice, including grounding line dynamics. The session includes studies on related processes such as calving, ice fracture, rifting and mass balance, as well as theoretical descriptions of mechanical and thermodynamic processes. We seek contributions both from numerical modelling of ice shelves and tidewater glaciers, including their oceanic and atmospheric environments, and from observational studies of those systems, including glaciological and oceanographic field measurements, as well as remote sensing and laboratory studies.

Ice sheets play an active role in the climate system by amplifying, pacing, and potentially driving global climate change over a wide range of time scales. The impact of interactions between ice sheets and climate include changes in atmospheric and ocean temperatures and circulation, global biogeochemical cycles, the global hydrological cycle, vegetation, sea level, and land-surface albedo, which in turn cause additional feedbacks in the climate system. This session will present data and modelling results that examine ice sheet interactions with other components of the climate system over several time scales. Among other topics, issues to be addressed in this session include ice sheet-climate interactions from glacial-interglacial to millennial and centennial time scales, the role of ice sheets in Cenozoic global cooling and the mid-Pleistocene transition, reconstructions of past ice sheets and sea level, the current and future evolution of the ice sheets, and the role of ice sheets in abrupt climate change.

In recent years, sea ice has displayed behaviour unseen before in the observational record, both in the Arctic and the Antarctic. This fast-changing sea-ice cover calls for adapting and improving our modelling approaches and mathematical techniques to simulate its behaviour and its interaction with the atmosphere and the ocean, both in terms of dynamics and thermodynamics.

Sea ice is governed by a variety of small-scale processes that affect its large-scale evolution. Modelling this nonlinear coupled multidimensional system remains a major challenge, because (1) we still lack the understanding of the physics governing sea-ice dynamics and thermodynamics, (2) observations to conduct model evaluation are scarce and (3) the numerical approximation and the simulation become more difficult and computationally expensive at higher resolution.

Recently, several new modeling approaches have been developed and refined to address these issues. These include but are not limited to new rheologies, discrete element models, advanced subgrid parameterizations, the representation of wave-ice interactions, sophisticated data assimilation schemes, often with the integration of machine learning techniques. Moreover, novel in-situ observations and the growing availability and quality of sea-ice remote-sensing data bring new opportunities for improving sea-ice models.

This session aims to bring together researchers working on the development of sea-ice models, from small to large scales and for a wide range of applications such as idealised experiments, operational predictions, or climate simulations, to discuss current advances and challenges ahead.

While observed volume, concentration and extent of Arctic sea ice have decreased dramatically over the last decades, climate model simulations of the recent past feature a slower sea-ice decline than observed. These same models are then used to project future sea ice changes, raising the question if even the most optimistic future emission scenarios will be enough to preserve the summer sea ice in the future.

Although the sea-ice decrease is the most pronounced in late summer, understanding coupled key processes of ocean/sea-ice/atmosphere-system during the so-called shoulder seasons, the onsets of the melt in spring and freeze up in autumn, is important since the timing of these set the boundaries for the length of the melt season and therefore strongly influence the total melt in any given year.

While the autumn freeze onset has received some attention, substantially less is known about the spring melt onset, partly because of a lack of observations to characterize and understand the processes controlling or leading up to it, on different scales. An improved understanding of this season is important, to inform model development crucial for simulations and assessments of future changes in the Arctic climate system.

This session focuses on the late winter and early spring in the Arctic and especially the onset of the summer sea-ice melt. We invite presentations broadly on ocean, sea-ice and atmospheric processes over a large spectrum of scales governing or being strongly affected by this transition, from long-term observations and reanalysis, process and climate modeling and especially from observations from new field campaigns covering this time period, such as MOSAiC and ARTofMELT.

Feedbacks within the Earth’s system involving the global carbon cycle, ice-sheet dynamics and oceanic circulation played a significant role in shaping the timing and amplitude of Quaternary deglaciations and their preceding glacial periods, as well as abrupt millennial-scale variability within the Last Glacial Cycle. For example, the deep ocean likely played a key role in modulating changes in atmospheric CO2; and ice sheet evolution exerts a strong control on atmosphere and ocean circulation. However, the precise combination of mechanisms and feedbacks responsible for glacial-interglacial and millennial-scale climate transitions remains unresolved. This session invites contributions from studies that provide an improved understanding of the processes and feedbacks occurring during glacial periods and deglaciations during the past 2.6 Ma. This includes new palaeo records, data syntheses and numerical simulations examining climate, the global carbon cycle, continental ice-sheets, ocean circulation, and sea-level.

ENSO and its interactions with other tropical basins are the dominant source of interannual climate variability in the tropics and across the globe. Understanding the dynamics, predictability, and impacts of ENSO and tropical basins interactions, and anticipating their future changes are thus of vital importance for society. This session invites contributions regarding all aspects of ENSO and tropical basins interactions, including: dynamics, multi-scale interactions; decadal and paleo variability; theoretical approaches; ENSO diversity; global teleconnections; impacts on climate, society and ecosystems; seasonal forecasting and climate change projections of tropical mean state changes, ENSO and its tropical basins interactions. Studies aimed at evaluating and improving model simulations of ENSO, the tropical mean state and the tropical basins interactions basin are especially welcomed.

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, as well as advances in improving the forecast skill and reliability and making the most of this information by developing and evaluating new applications and climate services. The session welcomes contributions from dynamical as well as statistical predictions (including machine learning methods) and their combination. This includes predictions of climate phenomena, including extremes and natural hazards, from global to regional scales, and from seasonal to multi-decadal timescales ("seamless predictions"). The session also covers physical processes relevant to long-term predictability sources (e.g. ocean, cryosphere, or land) and predictions of large-scale atmospheric circulation anomalies associated to teleconnections as well as observational and emergent constraints on climate variability and predictability. Also relevant is the time-dependence of the predictive skill and windows of opportunity. Analysis of predictions in a multi-model framework and innovative ensemble-forecast initialization and generation strategies are another focus of the session. The session pays particular attention to innovative methods of quality assessment and verification of climate predictions, including extreme-weather frequencies, post-processing of climate hindcasts and forecasts, and quantification and interpretation of model uncertainty. We particularly invite contributions presenting the use of seasonal-to-decadal predictions for assessing risks from natural hazards, adaptation and further applications.

To address societal concerns over rising sea level and extreme events, understanding and quantifying the contributions behind these changes is key to anticipate potential impacts of sea level change on coastal communities and the global economy. In this session, we address these challenges and we welcome contributions from the international sea level community that improve our knowledge of the past, present and future changes in global and regional sea level, extreme events and coastal impacts.
We focus on studies exploring the physical mechanisms for sea level rise and variability and the drivers of these changes, at any time scale (from high-frequency phenomena to paleo sea level). Investigations on linkages between variability in sea level, heat and freshwater content, ocean dynamics, land subsidence and mass exchanges between the land and the ocean associated with ice sheet and glacier mass loss and changes in the terrestrial water storage are welcome. Studies focusing on future sea level changes are also encouraged, as well as those discussing potential short-, medium-, and long-term impacts on coastal environments, as well as the global oceans.

One of the big challenges in Earth system science consists in providing reliable climate predictions on sub-seasonal, seasonal, decadal and longer timescales. The resulting data have the potential to be translated into climate information leading to a better assessment of global and regional climate-related risks.
The main goals of the session is (i) to identify gaps in current climate prediction methods and (ii) to report and evaluate the latest progress in climate forecasting on subseasonal-to-decadal and longer timescales. This will include presentations and discussions of the developments in predictions for the different time horizons from dynamical ensemble and statistical/empirical forecast systems, as well as the aspects required for their application: forecast quality assessment, multi-model combination, bias adjustment, downscaling, exploration of artificial-intelligence methods, etc.
Following the new WCRP strategic plan for 2019-2029, prediction enhancements are solicited from contributions embracing climate forecasting from an Earth system science perspective. This includes the study of coupled processes between atmosphere, land, ocean, and sea-ice components, as well as the impacts of coupling and feedbacks in physical, hydrological, chemical, biological, and human dimensions. Contributions are also sought on initialization methods that optimally use observations from different Earth system components, on assessing and mitigating the impacts of model errors on skill, and on ensemble methods.
We also encourage contributions on the use of climate predictions for climate impact assessment, demonstrations of end-user value for climate risk applications and climate-change adaptation and the development of early warning systems.
A special focus will be put on the use of operational climate predictions (C3S, NMME, S2S), results from the CMIP6 decadal prediction experiments, and climate-prediction research and application projects.
An increasingly important aspect for climate forecast's applications is the use of most appropriate downscaling methods, based on dynamical, statistical, artificial-intelligence approaches or their combination, that are needed to generate time series and fields with an appropriate spatial or temporal resolution. This is extensively considered in the session, which therefore brings together scientists from all geoscientific disciplines working on the prediction and application problems.

Contributions are invited on recent advances in the understanding of circulation and fluid dynamical processes in coastal and shelf seas. Observational, modelling and theoretical studies are welcome, spanning the wide range of temporal and spatial scales from the shelf break to the shore. In order to capture the dynamic nature of our coastal and shelf seas the session includes processes such as shelf circulation, exchange flows in semi-enclosed seas, eddies, sub-mesoscale processes, river plumes, and estuaries, as well as on flow interactions with bio-geochemistry, sediment dynamics, morphology and nearshore physics. Contributions on impacts of climate change and man-made structures on our shelf seas and estuaries are also welcome.

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. We offer the possibility, for interested authors, to submit evolved versions of their presentations to the currently open special issue in Ocean Sciences (see https://www.ocean-science.net/articles_and_preprints/scheduled_sis.html).

The Mediterranean and Black Seas, already referred to as climate 'hotspots', are experiencing rapid and extreme environmental stress that is straining the vulnerability of these semi-enclosed and densely populated basins. The sea surface warming and the increase of the thermal content in the deepest layers, the salinisation of intermediate and deep waters, the sea level rising, and the deoxygenation trend are all tangible elements of the ongoing environmental change in the last decades.

The risks associated with climate variability and, in particular, with extreme environmental events create unprecedented challenges that eventually lead to social and economic stresses. To tackle these challenges a multidisciplinary scientific approach is essential.

The main aim of this session is to bring together oceanographers working on physical and biogeochemical processes at different temporal and spatial scales in the Mediterranean and Black Seas, using new theoretical approaches, in situ observations of the entire water column, including the deep layers, as well as state-of-the-art ocean/climate models.
Studies that embrace these approaches and methodologies are thus invited to contribute in order to provide a comprehensive understanding of the complex interactions and processes occurring in these seas.
Furthermore, this multidisciplinary approach can enhance the predictability of thermohaline dynamics and the related variability of these unique marine environments, helping in the development of further adaptive economic strategies sustainable and resilient to the impacts of climate change.

Storm surges and tides are important drivers of coastal hazards, including flooding, erosion, and other impacts. They interact with each other, as well as with other coastal processes. Energy from the surface tide is also converted to internal tides, driving ocean processes. Both storm surges and tides show large seasonal and decadal variations. They are influenced by sea-level rise and climate change, and local anthropogenic changes such as dredging and alterations to estuaries. Flood defenses need to be designed and operated allowing for increasingly frequent coastal flooding due to sea-level rise, whilst understanding of tide and surge events is also critical for tidal energy generation. Changes in stratification may alter internal tides dynamics in coastal and global regions. This calls for an improved understanding of long-term trends and sea-level interactions. More precision is required of water level forecasts up estuaries and tidal rivers. Both observations (in-situ measurements and remote sensing) and models (numerical and data-driven) are important tools in understanding how storm surges and tide vary across space and time.

The aim of this session to share innovative approaches and recent advancements in understanding these complex processes and their implications for coastal regions globally. We welcome contributions that i) present novel approaches in measurement, numerical and empirical modelling of (surface and internal) tides and storm surges; ii) enhance our understanding of drivers of extreme sea level events and/or their interactions; iii) investigate the influence of past climate variability on storm surges, surface and internal tides, and their long-term variability; or iv) develop future projections of storm surges and tides and the impact of climate change.

With increasing coastal urbanisation and impacts from climate change, there is a pressing need for understanding, monitoring and predicting the environmental conditions and hazards in the global coastal ocean. This challenge requires ocean observing and modelling systems designed to monitor coastal variability at regional to local scales, as well as regional downscaling tailored to include coastal processes absent in the global Earth system models. This session is affiliated with CoastPredict, a UN Ocean Decade endorsed programme dedicated to the design and implementation of an integrated coastal observation and prediction system to support coastal community resilience. With this session we aim to provide a discussion platform around observing, forecasting and projecting coastal processes, from short time scale events to climate projections. We welcome contributions related to:
• Challenges and advances in observing and modelling the global coastal system with high temporal and spatial resolution (e.g. new community science platforms and modelling the coupled coastal system: ocean - atmosphere - hydrology - land – ecosystem - humans system).
• Complementary use of observations and models towards better short-term forecasting and early warnings along the coastal regions; and observing system design experiments focusing on the coastal seas.
• Dynamical and/or statistical downscaling and forecasting methodologies for the coastal ocean including machine learning, bias correction techniques and spectral nudging.
• Uncertainty treatment for short to long-term coastal ocean projections, e.g. ensemble approaches.
• Nature-based solutions for adaptation planning in coastal systems, and coastal carbon dioxide removal for climate mitigation.
• Coastal management, covering the full cycle of transdisciplinary information collection, planning, decision-making, management and monitoring of implementation.

The ocean floor hosts a tremendous variety of forms that reflect the action of a range of tectonic, sedimentary, oceanographic, biological and (bio)geochemical processes at multiple spatio-temporal scales. Many such processes are hazards to coastal populations and offshore installations, and their understanding constitutes a key objective of national and international research programmes and IODP expeditions. High quality bathymetry, especially when combined with sub-seafloor and/or seabed measurements, provides an exciting opportunity to integrate the approaches of geomorphology and geophysics, and to extend quantitative geomorphology offshore. 3D seismic reflection data has also given birth to the discipline of seismic geomorphology, which has provided a 4D perspective to continental margin evolution.
This interdisciplinary session aims to examine the causes and consequences of geomorphic processes shaping underwater landscapes, including submarine erosion and depositional processes, submarine landslides and canyons, sediment transfer and deformation, volcanic activity, fluid migration and escape, faulting and folding, and other drivers of seafloor geomorphic changes. The general goal of the session is to bring together researchers who characterise the shape of past and present seafloor features, seek to understand the sub-surface and surface processes at work and their impacts, or use bathymetry and/or 3D seismic data, combined with borehole petrophysics and geological cores, as a model input. Contributions to this session can include work from any depth or physiographic region, e.g. oceanic plateaus, abyssal hills, mid-ocean ridges, accretionary wedges, and continental margins (from continental shelves to abyss plains). Datasets of any scale, from satellite-predicted depth to ultra-high-resolution swath bathymetry, sub-surface imaging and sampling, are anticipated. We also aim at providing a window into the cross-disciplinary research of seismic geomorphology, exposing participants to differing perspectives, the latest workflows, examples of data integration, and, importantly, the potential pitfalls of equifinality in seismic interpretation and treating geophysical cross-sections as if they are outcrops. Emphasis will be given to contributions illustrating how the reflection seismic data have been investigated and how the results have been applied (e.g. paleogeography/paleoenvironmental reconstruction, seafloor engineering, or carbon/nuclear storage).