This session focuses on variability in the ocean circulation and its role in the climate system. We welcome contributions on all aspects of ocean circulation from observations, models and theory, from microscales to global scales, from timescales of seconds to millennia, from air-sea exchanges to abyssal mixing, from coastal processes to the open ocean, from the tropics to the polar oceans, from global energy budgets to small-scale turbulence, on externally forced and on internal physical processes. We particularly encourage submissions on interactions of the ocean with the atmosphere and cryosphere and their role in weather extremes and abrupt climate change. In addition, we are excited to see submissions that do not fit to any of the other sessions, including studies on the Pacific Ocean.

Air-sea interactions play a key role in the climate system. The ocean and atmosphere are intricately linked through the exchanges of momentum, mass, and energy. This drives processes on a wide range of spatial and temporal scales, from localised extreme events to the global climate. Air-sea interactions can dramatically impact extreme events such as tropical cyclones, marine heat waves, high precipitation events, and sea storms. They also shape the large-scale oceanic and atmospheric circulation affecting, for example, mesoscale eddies, Western Boundary Currents, convective precipitation, the Intertropical Convergence Zone, and ocean CO2 uptake. The complexity of air-sea interactions makes it hard to disentangle the different mechanisms at play, identify the driving processes, and properly model and parametrize them. This often results in widespread and persistent biases in coupled ocean-atmosphere models. Improving our knowledge of the physical and biogeochemical processes involved, through modeling or observations, is of fundamental importance to deepen our understanding of the Earth system and to improve the reliability of future projections as well as weather and ocean forecasts. This session aims to gather research efforts on air-sea interaction on global and regional scales over multiple temporal scales from interdisciplinary studies, modeling efforts, satellite, and in situ observations. This includes but is not limited to: turbulent air-sea fluxes, mesoscale eddies impact on CO2 fluxes, SSTs coupling with the atmospheric dynamic, tropical cyclones and cyclogenesis, extreme events onset, intensification and decay, parametrization of air-sea interactions, biases in coupled models, thermal and currents feedback, sea-spray role in air-sea exchanges and cloud formation.

The ocean surface mixed layer mediates the transfer of heat, freshwater, momentum and trace gases between atmosphere, sea ice and ocean, thus playing a central role in the dynamics of our climate. This session will focus on the surface mixed layer globally, from the coasts to the pelagic ocean. We will review recent progress in understanding the key processes taking place in the mixed layer: dynamic processes such as surface waves, Langmuir circulations and turbulence, shear-induced mixing, internal waves, coherent structures, fronts, frontal instabilities, entrainment and detrainment at the mixed layer base, convection, restratification induce physical effects on this important layer. From a biogeochemical perspective, the physical dynamics of the euphotic layer, as well as biogeochemical processes affecting the cycling of carbon, micro- and macronutrients, production and degradation of trace gases as well as microbial dynamics from basic to higher trophic levels affect the layer’s role and sensitivity as part of the earth system. The improvement of the representation of surface mixed layer processes in numerical models is a complex and pressing issue: this session will bring together new advances in the representation of mixed layer processes in high resolution numerical models, as well as evaluation of mixed layer properties in climate models using most recent observational datasets. The coupling of the ocean and atmospheric boundary layers as well as the special processes occurring under sea ice and in the marginal sea ice zone will be given special consideration. This session welcomes all contributions related to the study of the oceanic mixed layer, independent of the time- and space scales considered. This includes small scale process studies, short-term forecasting of the mixed layer characteristics for operational needs, studies on the variability of the mixed layer’s physical and biogeochemical properties from sub-seasonal to multi annual time scales and mixed layer response to external forcing. The use of multiple approaches (coupled numerical modeling, reanalyses, observations, experiments) is encouraged.

The rapid decline of the Arctic sea ice in the last decade is a dramatic indicator of climate change. The Arctic sea ice cover is now thinner, weaker and drifts faster. Freak heatwaves are common. 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 the 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 links with land are particularly welcome.
The session supports the actions of the United Nations Decade of Ocean Science for Sustainable Development (2021-2030) towards addressing challenges for sustainable development in the Arctic and its diverse regions. We aim to promote discussions on the future plans for Arctic Ocean modelling and measurement strategies, and encourages submissions on the results from IPCC CMIP and the 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 and the ocean as well as the cryosphere with the ocean, and how this affects the climate.

We welcome contributions from observers and modelers 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

Observations and model simulations illustrate significant ocean variability and associated air-sea interactions in the tropical Atlantic basin from daily-to-decadal time scales. This session is devoted to the understanding of ocean dynamics in the tropical and subtropical Atlantic Ocean, its interaction with the overlying atmosphere from the equator to the mid-latitudes and its climate impacts on adjacent to remote areas.
Relevant processes in the ocean include upper and deep ocean circulation, eddies, tropical instability waves, warm pools, cold tongues and eastern boundary upwellings. We are interested in air-sea interactions related to both the seasonal cycle and the development of modes of variability from local to basin scale (e.g. the Meridional Mode, the Atlantic Niño, and the Benguela Niño). We welcome studies on wind variations related to the development of these modes, as well as studies on high-frequency events, such as marine heat waves, the Madden-Julian Oscillation, tropical cyclones and convective systems. Furthermore, we seek studies on climate change in the region, and also of the climatic impacts of change and variability on marine ecosystems. Finally, we are also interested in contributions examining the causes and impacts of systematic model errors in simulating the local to regional Atlantic climate.
Studies based on direct observations, reanalysis, reconstructions as well as model simulations are welcome.

The Indian Ocean is unique among the other tropical ocean basins due to the seasonal reversal of monsoon winds and concurrent ocean currents, lack of steady easterlies that result in a relatively deep thermocline along the equator, low-latitude connection to the neighboring Pacific and a lack of northward heat export due to the Asian continent. These characteristics shape the Indian Ocean’s air-sea interactions, variability, as well as its impacts and predictability in tropical and extratropical regions on (intra)seasonal, interannual, decadal timescales and beyond. They also make the basin particularly vulnerable to anthropogenic climate change, as well as related extreme weather and climate events, and their impacts for surrounding regions, home to a third of the global population. Advances have recently been made in our understanding of the Indian Ocean’s circulation, interactions with adjacent ocean basins, and its role in regional and global climate. Nonetheless, significant gaps remain in understanding, observing, modeling, and predicting Indian Ocean variability and change across a range of timescales.

This session invites contributions based on observations, modelling, theory, and palaeo proxy reconstructions in the Indian Ocean that focus on recent observed and projected changes in Indian Ocean physical and biogeochemical properties and their impacts on ecological processes, diversity in Indian Ocean modes of variability (e.g., Indian Ocean Dipole, Indian Ocean Basin Mode, Madden-Julian Oscillation) and their impact on predictions, interactions and exchanges between the Indian Ocean and other ocean basins, as well as links between Indian Ocean variability and monsoon systems across a range of timescales. We encourage submissions on weather and climate extremes of societal relevance in the Indian Ocean and surrounding regions, including evaluating climate risks, vulnerability, and resilience.

We also welcome contributions that address research on the Indian Ocean grand challenges highlighted in the IndOOS Decadal Review, and as formulated by CLIVAR, the Sustained Indian Ocean Biogeochemistry and Ecosystem Research (SIBER), the International Indian Ocean Expedition 2 (IIOE-2), findings informed by the Coupled Model Intercomparison Project v6 on past, present and future variability and change in the Indian Ocean climate system, and contributions making use of novel methodologies such as machine learning.

The Southern Ocean around the latitudes of the Antarctic Circumpolar Current is vital to our understanding of the climate system. It is a key region for vertical and lateral exchanges of heat, carbon, and nutrients, with considerable past and potential future global climate implications. The role of the Southern Ocean as a dominant player in heat and carbon exchanges as well as its response to changing atmospheric forcing and increased melting of Antarctic ice masses remains uncertain. Indeed, the sparsity of observations of this system and its inherent sensitivity to small-scale physical processes, which are not fully represented in current Earth system models, result in large climate projection uncertainties. To address these knowledge gaps, the Southern Ocean is currently subject to investigations with increasingly advanced observational platforms, and theoretical, numerical, and machine learning techniques. These efforts are providing deeper insight into the three-dimensional patterns of Southern Ocean change on sub-annual, multi-decadal, and millennial timescales, as well as potential future changes 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, ocean productivity, climate-carbon feedbacks, and ocean-ice-atmosphere interactions. We will also discuss how changes in Southern Ocean heat and carbon transport affect lower latitudes and global climate more generally.

Solicited speaker: Katherine R. Hendry

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? How does the Antarctic Slope Current interact with the continental shelf and connect the basins around the continent? 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 and interactions between ice shelves, sea ice and the ocean. 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 and biological oceanography as well as contributions from the PALMOD project and the SCAR INSTANT program.

This session aims to showcase an exciting diversity of state-of-the-art advances in all aspects of paleoceanography and paleoclimatology. We invite studies ranging across organic and inorganic geochemistry, sedimentology, and paleontology from marine and terrestrial environments, as well as multidisciplinary and modeling studies reaching into the future. We invite contributions that provide insight into the evolution of the Earth on short and long timescales, including how studies of paleoclimate and drivers can inform our current climatic changes and the implications for future Earth.

Today, the Indian, Pacific and Southern Oceans and associated ocean gateways capture the complex intermediate and deep-water return pathways of the global thermohaline circulation. The Indo-Pacific Warm Pool (IPWP) acts as a low latitude heat source for the polar regions and is a crucial part in globally significant climatic systems like the Australasian Monsoon, Intertropical Convergence Zone (ITCZ), El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). This highlights the Indo-Pacific’s importance in deciphering past and future coupled ocean-atmosphere dynamics.
The Cenozoic also sees large reorganisation of the hydrographic and atmospheric fronts across the Southern Hemisphere (SH). These changes have significant consequences for icesheet build-up in Antarctica and ocean-atmosphere carbon cycling, with further implications for surface ocean dynamics and productivity. Characterisation of these fronts using sedimentary records, located in mid-to-high latitudes in the SH allow us to understand the sensitivity and interconnection between Antarctic icesheets and carbon cycle to frontal shifts.
This session explores the role of the Indian, Pacific and Southern Oceans and their gateways in global climate change and as a biogeographic diversity hot spot from the geological past to the present. To understand the Cenozoic evolution of these Oceans and associated low- and high-latitude (especially SH) gateways, we invite submissions on wide-ranging topics including paleoclimatology, palaeoceanography, sedimentology, palaeontology, and data-model comparisons. This session will examine how feedbacks between the IPWP, Australasian hydroclimate and tectonic and/or weathering processes affect the evolution of the global monsoons and the ITCZ. We also encourage marine and/or terrestrial multi-proxy studies, investigating Cenozoic teleconnections of both equatorial Indo-Pacific (e.g., ENSO/IOD) and high latitude SH processes (e.g., variability of hydrographic fronts).

Regional climate is often influenced by or connected to changes in remote locations, a phenomenon known as a teleconnection. Changes in the ocean, sea ice, atmosphere or land conditions in remote locations can trigger atmospheric or oceanic disturbances, which then propagate and influence the climate in one or multiple distant regions. These changes could be periodic modes of variability (such as ENSO, IOD, QBO, AMV, PDV etc.) or a response to anthropogenic forcing (such as the warming Western Tropical Pacific or the North Atlantic Warming Hole etc.). Fleshing out the teleconnections associated with such changes provides us with a clearer understanding of the variations in the climate of a particular region and may also provide a source of predictability. This session invites contributions that focus on this aspect of climate variability and yield new understanding on the origin, dynamics and predictive potential of teleconnections. The studies may be observational or modelling in nature and may be based on paleoclimatic time-scales, the historical period or future scenarios. Research on new methods to diagnose and understand teleconnections is also welcome.

Atmospheric circulation is unquestionably listed among the fundamental causes of weather and climate. The session is dedicated to all aspects of relationships between atmospheric circulation in different spatial scales and climate as well as environmental variables. Contributions concerning theoretical aspects of circulation classifications development and their applications in various tasks (climatological, and environmental), and different scales are particularly welcome as well as submissions on recent climate variability and change studied by tools of synoptic climatology.

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.

In 2015, the UN Sustainable Development Goals and the Paris Agreement on climate recognized the deteriorating resilience of the Earth system, with planetary-scale human impacts constituting a new geological epoch: the Anthropocene. Earth system resilience critically depends on the nonlinear interplay of positive and negative feedbacks of biophysical and increasingly also socio-economic processes. These include dynamics and interactions between the carbon cycle, the atmosphere, oceans, large-scale ecosystems, and the cryosphere, as well as the dynamics and perturbations associated with human activities.

With rising anthropogenic pressures, there is an increasing risk we might be hitting the ceiling of some of the self-regulating feedbacks of the Earth System, and cross tipping points which could trigger large-scale and partly irreversible impacts on the environment, and impact the livelihood of millions of people. Potential domino effects or tipping cascades could arise due to the interactions between these tipping elements and lead to a further decline of Earth resilience. At the same time, there is growing evidence supporting the potential of positive (social) tipping points that could propel rapid decarbonization and transformative change towards global sustainability.

In this session we invite contributions on all topics relating to tipping points in the Earth system, positive (social) tipping, as well as their interaction and domino effects. We are particularly interested in various methodological approaches, from Earth system modelling to conceptual modelling and data analysis of nonlinearities, tipping points and abrupt shifts in the Earth system.

The Arctic Realm is changing rapidly and the fate of the cryosphere, including Arctic sea ice, glaciers and ice caps, is a source of concern. Whereas sea ice variations impact the radiative energy budget, thus playing a role in Arctic amplification, the Greenland Ice Sheet retreat contributes to global sea level rise. Moreover, through various processes linking the atmosphere, ice and ocean, the change in the Arctic realm may modify the atmospheric and ocean circulation at regional to global scales, the freshwater budget of the ocean and deep-water formation as well as the marine and terrestrial ecosystems, including productivity. The processes and feedbacks involved operate on all time scales and it require a range of types of information to understand the processes, drivers and feedbacks involved in Arctic changes, as well as the land-ocean-cryosphere interaction. In this session, we invite contributions from a range of disciplines and across time scales, including observational (satellite and instrumental) data, historical data, geological archives and proxy data, model simulations and forecasts, for the past, present and future climate. The common denominator of these studies will be their focus on a better understanding of mechanisms and feedbacks on short to long time scales that drive Arctic and subarctic changes and their impact on climate, ocean, and environmental conditions, at regional to global scales, including possible links to weather and climate outside the Arctic.

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 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.

Analysis of energy transfers between and within climate components has been at the core of many step changes in the understanding of the climate system. Large-scale atmospheric circulation, hydrological cycle and heat/moisture transports are tightly intertwined. Dynamics and radiative exchanges are linked at the global scale, through the net impact of cloud feedbacks, sea-ice albedo changes, surface absorption by vegetation.

In the Tropics, the zonal mean Hadley circulation determines meridional energy transports, while Rossby and planetary-scale waves modulate the energy exchanges carried by extratropical eddies. In the ocean, the role of Atlantic Meridional Overturning Circulation is essential for the heat budget of continental regions in the Northern Hemisphere: long-term oceanic and sea-ice variability is crucial to understand and predict the dynamics in high latitudes. Observational and model studies have indeed shown that the Arctic is very susceptible to climate change, and climate perturbations in the Arctic likely have wide-spread influence. High-latitude atmosphere, biosphere, oceans and cryosphere have experienced significant changes over the observational era. Hence, advancing the understanding of variability and change, governing mechanisms and global implications, improving predictions and projections of high latitude climate in both hemispheres is highly important for global society.

We invite submissions on the interplay between Earth’s energy exchanges and the general circulation through modeling, theory, and observations, on the forced response and natural variability of the general circulation, understanding present-day climate, past and future changes, impacts of global features and change on regional climate. This session also aims to improve knowledge and representation of the multi-scale mechanisms that control high-latitude climate variability and predictability in both hemispheres from sub-seasonal to multi-decadal and longer time scales. We thus invite contributions on the causes, mechanisms and climate feedbacks associated with the Arctic and Antarctic climate, ocean and sea ice change, including the potential links of the pronounced Arctic amplification to weather and climate outside the Arctic, and teleconnections of high latitude climate with lower latitude climate. We also aim to link climate variability, predictions and projections to potential ecosystem and socio-economic impacts and encourage submissions on this topic.

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.

The polar climate system is strongly affected by interactions between the atmosphere and the cryosphere. Processes that exchange heat, moisture and momentum between land ice, sea ice and the atmosphere, such as katabatic winds, blowing snow, ice melt, polynya formation and sea ice transport, play an important role in local-to-global processes. Atmosphere-ice interactions are also triggered by synoptic weather phenomena such as cold air outbreaks, polar lows, atmospheric rivers, Foehn winds and heatwaves. However, our understanding of these processes is still incomplete. Despite being a crucial milestone for reaching accurate projections of future climate change in Polar Regions, deciphering the interplay between the atmosphere, land ice and sea ice on different spatial and temporal scales, remains a major challenge.

This session aims at showcasing recent research progress and augmenting existing knowledge in polar meteorology and climate and the atmosphere-land ice-sea ice coupling in both the Northern and Southern Hemispheres. It will provide a setting to foster discussion and help identify gaps, tools, and studies that can be designed to address these open questions. It is also the opportunity to convey newly acquired knowledge to the community.

We invite contributions on all observational and numerical modelling aspects of Arctic and Antarctic meteorology and climatology, that address atmospheric interactions with the cryosphere. This may include but is not limited to studies on past, present and future of:
- Atmospheric processes that influence sea-ice (snow on sea ice, sea ice melt, polynya formation and sea ice production and transport) and associated feedbacks,
- The variability of the polar large-scale atmospheric circulation (such as polar jets, the circumpolar trough and storm tracks) and impact on the cryosphere (sea ice and land ice),
- Atmosphere-ice interactions triggered by synoptic and meso-scale weather phenomena such as cold air outbreaks, katabatic winds, extratropical cyclones, polar cyclones, atmospheric rivers, Foehn winds and heatwaves,
- Role of clouds in polar climate and impact on the land ice and sea ice through interactions with radiation,
- Teleconnections and climate indices and their role in land ice/sea ice variability.

This session invites innovative Earth system and climate studies employing geodetic observations and methods. Modern geodetic observing systems have been instrumental in studying a wide range of changes in the Earth’s solid and fluid layers at various spatiotemporal scales. These changes are related to surface processes such as glacial isostatic adjustment, the terrestrial water cycle, ocean dynamics and ice-mass balance, which are primarily due to changes in the climate. To understand the Earth system response to natural climate variability and anthropogenic climate change, different time spans of observations need to be cross-compared and combined with several other datasets and model outputs. Geodetic observables are also often compared with geophysical models, which helps in explaining observations, evaluating simulations, and finally merging measurements and numerical models via data assimilation.



We look forward to contributions that:

1. Utilize geodetic data from diverse geodetic satellites including altimetry, gravimetry (CHAMP, GRACE, GOCE and GRACE-FO), navigation satellite systems (GNSS and DORIS) or remote sensing techniques that are based on both passive (i.e., optical and hyperspectral) and active (i.e., SAR) instruments.

2. Cover a wide variety of applications of geodetic measurements and their combination to observe and model Earth system signals in hydrological, ocean, atmospheric, climate and cryospheric sciences.

3. Show a new approach or method for separating and interpreting the variety of geophysical signals in our Earth system and combining various observations to improve spatiotemporal resolution of Earth observation products.

4. Work on simulations of future satellite mission (such as SWOT and GRACE-2) that may advance climate sciences.

5. Work towards any of the goals of the Inter-Commission Committee on "Geodesy for Climate Research" (ICCC) of the International Association of Geodesy (IAG).



We are committed to promoting gender balance and ECS in our session. With author consent, highlights from this session will be tweeted with a dedicated hashtag during the conference in order to increase the impact of the session.

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 coastal seas and estuaries are also welcome.

Coastal oceanographic processes present important differences with deep water oceanography, resulting in higher prediction errors, where bottom topography in shallow domains exerts a strong control on wave/current/turbulence fields. These fields are modified by many additional factors that include stratification, land boundary conditions and interactions with coastal infrastructure. The strong non-linear interactions (breaking waves, nearshore circulation), the choice of numerical strategy (nested meshes, finite-elements) or the modulations in restricted domains (suspended sediment clouds, vegetation filtering) may also play a critical role in the predictive quality. Coastal observations (in-situ and remote) are therefore necessary to drive and calibrate numerical models, where the advent of new satellite capabilities (e.g. Sentinel resolution and sensors) and new modelling advances (e.g. couplings or unstructured grids) together with enhanced Coastal Observatories, are leading to a qualitative advance of coastal oceanography. Coastal issues become more relevant in a framework of changing climate, since transitional areas are more strongly impacted by climate (e.g. changing domains due to sea-level rise) and therefore more in need of new approaches that include Natural based Solutions.
Because of these reasons, it is timely to discuss recent advances in: a) coastal coupled hydro-morpho-eco modelling at different scales; b) aggregation of in-situ/satellite/numerical data from different sources; c) knowledge-based coastal applications, including the assessment of Nature-based interventions; d) uncertainties in coastal decision-making, framed by an ethical approach and supported by quantitative information. Building upon these challenges, we invite presentations on coastal modelling and coupling, local assimilation, boundary effects or operational coastal predictions with/out interactions with Nature based or traditional interventions. Contributions exploring the potential and currently open issues of non-linear response functions, support from artificial intelligence and big data or uncertainty assessments for coastal applications are also welcome. These and related coastal topics should conform a fruitful session for discussing applications of coastal science to conventional and nature-based interventions under climate change. Please state if you would be interested in submitting your presentation to a peer reviewed special issue in Ocean Science.

Among other stressors, the Mediterranean and Black Seas have recently shown clear signs of climate change, including an increase in sea surface temperature in both basins, salinization of the intermediate and deep waters, a rise in sea level over the last century, and deoxygenation trends. These trends stress the vulnerability of these semi-enclosed and densely populated basins.

The urgent social and economic drivers require targeted improvements in weather, climate, water, oceans, and relevant environmental information and services. The risks associated with climate variability and extreme environmental events can lead to social and economic stresses that require new meteorological, hydrological, oceanographic, and climate services to ensure the safety and security of populations and the development of adaptive economic strategies.

This session is devoted to multidisciplinary scientific advances highlighting environmental trends at different spatial and temporal scales in the Mediterranean and Black Seas. We call for studies that address those threats in the Mediterranean and Black Seas including new approaches in physical and biogeochemical monitoring, ocean modeling, operational oceanography, and downstream product development.

The Paris Agreement on Climate sets the international objective to keep climate warming well below two degrees. This extraordinary challenge requires a dramatic improvement of current scientific capabilities to estimate the budgets and their trends of greenhouse gases (GHG) at regional scale, and how they link up to the global growth rates of the major GHGs (N2O, CH4 and CO2). This session aims to bring together studies to help understand and quantify regional budgets, trends and variability, and drivers of major GHG (N2O, CH4 and CO2) through the analyses of emissions inventories, field and remotely-sensed observations, terrestrial and ocean biogeochemical modeling, and atmospheric inverse modeling. We encourage contributions from the REgional Carbon Cycle Assessment and Processes (RECCAP2), a new global assessment of the Global Carbon Project, as well as studies combining different datasets and approaches at multi-scales from regional to global.

The session gathers multi-disciplinary geoscientific aspects such as dynamics, reactions, and environmental/health consequences of radioactive materials that are massively released accidentally (e.g., Chernobyl and Fukushima nuclear power plant accidents, wide fires, etc.), future potential risk of leakage (e.g., Zaporizhzhia nuclear power plant) and by other human activities (e.g., nuclear tests).

The radioactive materials are known as polluting materials that are hazardous for human society, but are also ideal markers in understanding dynamics and physical/chemical/biological reactions chains in the environment. Therefore, man-made radioactive contamination involves regional and global transport and local reactions of radioactive materials through atmosphere, soil and water system, ocean, and organic and ecosystem, and its relations with human and non-human biota. The topic also involves hazard prediction, risk assessment, nowcast, and countermeasures, , which is now urgent important for the nuclear power plants in Ukraine.

By combining long monitoring data (> halftime of Cesium 137 after the Chernobyl Accident in 1986, 12 years after the Fukushima Accident in 2011, and other events), we can improve our knowledgebase on the environmental behavior of radioactive materials and its environmental/biological impact. This should lead to improved monitoring systems in the future including emergency response systems, acute sampling/measurement methodology, and remediation schemes for any future nuclear accidents.

The following specific topics have traditionally been discussed:
(a) Atmospheric Science (emissions, transport, deposition, pollution);
(b) Hydrology (transport in surface and ground water system, soil-water interactions);
(c) Oceanology (transport, bio-system interaction);
(d) Soil System (transport, chemical interaction, transfer to organic system);
(e) Forestry;
(f) Natural Hazards (warning systems, health risk assessments, geophysical variability);
(g) Measurement Techniques (instrumentation, multipoint data measurements);
(h) Ecosystems (migration/decay of radionuclides).

The session consists of updated observations, new theoretical developments including simulations, and improved methods or tools which could improve observation and prediction capabilities during eventual future nuclear emergencies. New evaluations of existing tools, past nuclear contamination events and other data sets also welcome.

Tsunamis can produce catastrophic damage on vulnerable coastlines, essentially following major earthquakes, landslides, extreme volcanic activity or atmospheric disturbances.
After the disastrous tsunamis in 2004 and 2011, tsunami science has been continuously growing and expanding its scope to new fields of research in various domains, and also to regions where the tsunami hazard was previously underestimated.

The tsunami following the eruption of Hunga Tonga - Hunga Ha'apai in January 2022 provided a new and urging challenge, being an event with an extremely complicated source process and a consequently non-trivial global propagation, posing new questions in terms of modeling, hazard assessment and warning at different scales and evidencing the need for a closer cooperation among different research communities.

The spectrum of topics addressed by tsunami science nowadays ranges from the “classical” themes, such as analytical and numerical modelling of different generation mechanisms (ranging from large subduction earthquakes to local earthquakes generated in tectonically complex environments, from subaerial/submarine landslides to volcanic eruptions and atmospheric disturbances), propagation and run-up, hazard-vulnerability-risk assessment, especially with probabilistic approaches able to quantify uncertainties, early warning and monitoring, to more “applied” themes such as the societal and economic impact of moderate-to-large events on coastal local and nation-wide communities, as well as the present and future challenges connected to the global climate change.

This session welcomes multidisciplinary as well as focused contributions covering any of the aspects mentioned above, encompassing field data, geophysical models, regional and local hazard-vulnerability-risk studies, observation databases, numerical and experimental modeling, real time networks, operational tools and procedures towards a most efficient warning, with the general scope of improving our understanding of the tsunami phenomenon, per se and in the context of the global change, and our capacity to build safer and more resilient communities.