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.
The AMOC is crucial and sensitive part of the global climate system. It transports huge amounts of heat north across the equator into the northern Atlantic. It is the main reason why the Northern Hemisphere is 1 – 2 °C warmer than the Southern Hemisphere (Feulner et al. 2013) and makes Europe’s climate unusually mild for its latitude.
Due to AMOC instabilities, the northern Atlantic region has been the major hotspot of drastic climate changes in Earth’s history, as seen in data from Greenland ice cores and many other sources of paleoclimatic proxy data (Rahmstorf 2002).
The AMOC is expected to weaken strongly in response to human-caused global warming (IPCC 2021). Since Stommel (1961) and Broecker (1987) the risk of the AMOC being destabilised at a tipping point has been much discussed, especially since the emergence of a remarkable cooling patch in the subpolar gyre to the west of the British Isles (Drijfhout et al. 2012, Rahmstorf et al. 2015).
Until recently this has been considered a ‘low probability high impact risk’, to be taken seriously mainly because of the devastating impacts it would have. New research over the past years has changed this viewpoint. Neither a full AMOC shutdown nor a subpolar gyre convection collapse (also with major impacts on society) can be considered ‘low probability’ any more (e.g. Swingedouw et al. 2021, Drijfhout et al. 2025).
This talk will discuss recent scientific developments regarding the risk of AMOC instability.
References
Broecker, W. (1987). Unpleasant surprises in the greenhouse? Nature 328: 123.
Drijfhout, S., J. R. Angevaare, J. Mecking, R. M. van Westen and S. Rahmstorf (2025). Shutdown of northern Atlantic overturning after 2100 following deep mixing collapse in CMIP6 projections. Environmental Research Letters 20(9) doi: 10.1088/1748-9326/adfa3b.
Drijfhout, S., G. J. van Oldenborgh and A. Cimatoribus (2012). Is a Decline of AMOC Causing the Warming Hole above the North Atlantic in Observed and Modeled Warming Patterns? Journal of Climate 25(24): 8373-8379 doi: 10.1175/jcli-d-12-00490.1.
Feulner, G., S. Rahmstorf, A. Levermann and S. Volkwardt (2013). On the origin of the surface air temperature difference between the hemispheres in Earth's present-day climate. Journal of Climate 26(18): 7136-7150 doi: doi:10.1175/JCLI-D-12-00636.1
IPCC (2021). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Geneva, IPCC. 2391 pages.
Rahmstorf, S. (2002). Ocean circulation and climate during the past 120,000 years. Nature 419(6903): 207-214 doi: 10.1038/nature01090.
Rahmstorf, S., J. E. Box, G. Feulner, M. E. Mann, A. Robinson, S. Rutherford and E. J. Schaffernicht (2015). Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation. Nature Climate Change 5(5): 475-480 doi: 10.1038/nclimate2554.
Stommel, H. (1961). Thermohaline convection with two stable regimes of flow. Tellus 13: 224-230.
Swingedouw, D., A. Bily, C. Esquerdo, L. F. Borchert, G. Sgubin, J. Mignot and M. Menary (2021). On the risk of abrupt changes in the North Atlantic subpolar gyre in CMIP6 models. Ann N Y Acad Sci 1504(1): 187-201 doi: 10.1111/nyas.14659.
How to cite: Rahmstorf, S.: AMOC tipping risk reconsidered, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10486, https://doi.org/10.5194/egusphere-egu26-10486, 2026.
A key question for the future ocean is what will happen to the Atlantic Meridional Overturning Circulation (AMOC). In climate models that are run beyond 2100 for a high emission scenario it shuts down in the majority, where the shutdown is preceded by a ceasing of convection in the North Atlantic subpolar gyre (SPG). As some climate models already show a collapse of SPG convection around 2040, it is key to know what this means for the AMOC. What is the interaction between SPG and AMOC? If convection in the SPG stops, is the AMOC bound to shut down as well? Or will other regions or processes take over?
For deep water formation both deep convection in the gyre centre, as well as densification in the boundary current play a role. Climate models do not resolve the SPG boundary current and eddies due to their coarse resolution, meaning key processes for deep water formation are parametrised. I will discuss the relative role of densification in the boundary current and deep convection in the SPG gyre centre for the AMOC in both CMIP6 models and ocean reanalyses. Using causal inference the importance of the two processes for the AMOC is investigated, distinguishing the respective roles of the Labrador and Irminger seas.
Differences between CMIP6 models and reanalyses are discussed, and put in the context of the recent OSNAP results on the relative importance of the eastern and western SPG for the AMOC. This sheds light on the representation of the process of deep water formation that are relevant for the AMOC in climate models, and aids in understanding the impact a collapse of SPG convection would have on the AMOC.
How to cite: Falkena, S. and von der Heydt, A.: The role of the Subpolar Gyre in the future of the AMOC, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8218, https://doi.org/10.5194/egusphere-egu26-8218, 2026.
Western boundary current (WBC) regions play a critical role in air–sea heat exchange, influencing weather patterns and regulating climate. Despite their importance, how the coupled ocean–atmosphere seasonal variability in these regions responds to global warming remains unclear. Using observations (ERA5 and OAFlux) and Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations, we examine long-term trends in the seasonal amplitudes of sea surface temperature (SST) and latent heat flux (LHF) across major WBC systems. Over the past six decades, SST amplitude has significantly decreased, whereas LHF amplitude has increased. This contrast stems from an enhanced seasonal amplitude of air–sea specific humidity difference, driven by a stronger reduction in near-surface air temperature seasonality relative to SST. Future projections suggest that this thermodynamic mechanism will persist over the next four decades, with strong inter-model agreement confirming the robustness of the trend. Unlike previous studies that mainly focused on the climatological modulation of the SST annual cycle by ocean heat advection in WBC regions, our analysis highlights long-term changes in the coupled SST–LHF seasonal coevolution under global warming. These findings reveal that warming climate to some extent alters the seasonal air–sea coupling in WBC regions, with potential consequences for regional climate variability, extreme weather events, and the global surface energy budget.
How to cite: Tong, J., Song, X., Oltmanns, M., and Xie, S.-P.: Enhanced seasonal cycle of air‒sea latent heat flux in western boundary current regions due to global warming, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-157, https://doi.org/10.5194/egusphere-egu26-157, 2026.
Diagnostics from a 1/12 degree resolution ocean model simulation have confirmed that depth-integrated upper-ocean boundary pressure anomalies can be predicted from a simple theory involving wind stress and net meridional flows through the southern boundaries of the Atlantic and Indo-Pacific basins. In particular, the difference between eastern Atlantic and eastern Pacific boundary pressures is mainly determined by wind stress in this model, with the Indo-Pacific overturning playing a significant secondary role. We apply this framework to the analysis of CMIP-6 simulations and find that, for centennial changes, the dominant factor becomes the changing Indo-Pacific overturning (itself related to AMOC changes), and that the resulting boundary pressure changes predict an important proportion of the change in Pacific-Atlantic sea level difference. We also find an amplification mechanism, whereby small changes in deep ocean pressures result in larger sea level changes than would be expected from a simple hydrostatic balance argument.
How to cite: Hughes, C., Gururaj, S., Bingham, R., Blaker, A., Styles, A., Boland, E., and Jones, D.: Ocean boundary pressures link Atlantic-Pacific sea level difference to Indo-Pacific Overturning., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2571, https://doi.org/10.5194/egusphere-egu26-2571, 2026.
A robust basin-wide “fresh-gets-fresher” response in tropical sea surface salinity (SSS) emerges in CMIP projections, with freshening in the Indo-Pacific and salinification in the Atlantic Ocean. Yet large uncertainties persist due to long-standing mean-state biases and inter-model spread in CMIP simulations, limiting confidence in future SSS projections and their underlying mechanisms. By correcting ocean mean-state biases, we show that CMIP models with a strong equatorial cold tongue bias substantially underestimate future western Pacific freshening. Using a bias-corrected ocean model forced by air–sea flux anomalies from multiple CMIP6 models, we disentangle the respective roles of surface freshwater forcing and ocean dynamics. Freshwater flux changes advected by the climatological circulation dominate the basin-scale Pacific–Atlantic salinity contrast, while changes in wind-driven circulation strongly modulate regional SSS anomalies, particularly in the equatorial Indo-Pacific. The balance between these processes varies markedly across CMIP6 forcing sets. Our results demonstrate that improving the representation of the tropical mean state, equatorial winds, and the Walker circulation—together with their projected changes—is essential for reducing uncertainty in CMIP-based projections of future ocean salinity. More broadly, this work highlights how targeted bias correction and process-based analysis can help bridge CMIP limitations and advance robust projections of the future ocean.
How to cite: Pang, S., Lengaigne, M., and Vialard, J.: The role of freshwater flux and wind-driven circulation in shaping future tropical salinity, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5648, https://doi.org/10.5194/egusphere-egu26-5648, 2026.
Coupled Model Intercomparison Project (CMIP) and Ocean Model Intercomparison Project phase 2 (OMIP2) models from the 6th phase of the CMIP group were used in the current study to represent the annual mean biases of hydrographic features. The OMIP2 models are ocean-only simulations, while the CMIP models are coupled ocean-atmosphere-land-sea ice simulations. These models are assessed against the observations in the Tropical Indian Ocean (TIO). This study identified that many of the models from both CMIP and OMIP2 exhibited cold and warm temperature biases at the surface (0-100m) and subsurface (100-300m) on an annual scale, respectively. Overall, the CMIP models were observed to have larger biases than the OMIP2 models. Also, strong positive biases of salinity were identified in the south-eastern Arabian Sea (AS) and the western Bay of Bengal than in other regions of TIO. In addition, a deeper thermocline was identified in the northern AS and Seychelles-Chagos Thermocline Ridge region in CMIP and OMIP2 models compared to observations, which was predominant in the CMIP models than in the OMIP2 models. This deeper thermocline is associated with subsurface warm temperature biases. Brunt-Väisälä frequency revealed weaker stratification from surface to 100m with a peak at 80m. Further, vertical shear currents revealed strong shear bias at the top 40m, that can result in vertical mixing, which is chiefly accountable for the biases of temperatures and salinities. The heat and salt transport analysis at different straits in the TIO suggested positive northward and negative southward transport. Positive transport occurred during the post-monsoon season, while negative transport occurred during other seasons. SST-based upwelling index analysis revealed strong upwelling signals during summer months in all individual models for all regions. However, strengthened upwelling has been identified in the CMIP models than in OMIP2 models due to strong winds over the upwelling regions. A strong negative correlation has been identified between surface temperature and windspeed in CMIP models over most of the TIO, suggesting that strong surface wind speeds lead to vertical mixing, which in turn causes further surface cooling.
How to cite: Madhu, B., Vissa, N. K., and Venkata Sai Udaya Bhaskar, T.: Hydrographic features in the Tropical Indian Ocean: Insights from coupled and uncoupled models from the CMIP6 group, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-51, https://doi.org/10.5194/egusphere-egu26-51, 2026.
How to cite: Zhang, Y., Chen, C., Hu, S., Wang, G., McMonigal, K., and Larson, S.: Summer Westerly Wind Intensification Weakens Southern Ocean Seasonal Cycle Under Global Warming, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17945, https://doi.org/10.5194/egusphere-egu26-17945, 2026.
Reliable projections of future wave climate are vital for coastal adaptation, infrastructure planning, and marine renewable energy development. This study introduces a high-resolution spectral wave dataset for the European Atlantic coast, produced through regional downscaling of CMIP6-based climate projections. The dataset was developed using the WRF atmospheric model in combination with two spectral wave models, WAVEWATCH III (WW3) and Simulating WAves Nearshore (SWAN), to generate 3-hourly directional wave spectra at 1,031 offshore locations, spaced at 10 km intervals and situated approximately 50 km from the coastline. The simulations encompass three 30-year periods: a historical baseline (1985–2014) and two future time slices (2030–2059) under the SSP2-4.5 and SSP5-8.5 scenarios. Two datasets are provided: spectral energy densities and integrated wave parameters, both validated and formatted in CF-1.8-compliant NetCDF-4 files. The spectral dataset enables the initialization of new SWAN simulations, facilitating efficient site-specific wave modeling, while the integrated parameters support regional-scale analyses of climate change impacts on wave conditions. The dataset is publicly accessible via the Centre for Environmental Data Analysis (CEDA) repository and constitutes a valuable resource for research, engineering applications, and policy-making in coastal and marine environments.
How to cite: Arguilé-Pérez, B., Costoya, X., Ribeiro, A. S., deCastro, M., Carracedo, P., and Gómez-Gesteira, M.: High-Resolution Wave Climate Projections along the European Atlantic Coast Based on Downscaled CMIP6 Wind Forcing, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11072, https://doi.org/10.5194/egusphere-egu26-11072, 2026.
The ocean is a vast store of anthropogenic and natural carbon, the former from manmade CO2 emissions absorbed at the surface and the latter produced in the interior from biological regeneration. However, for how long this carbon will remain sequestered in the ocean under a warming climate remains poorly constrained. Here, I quantify the impact of climate change on the sequestration efficiency of the ocean by computing the distribution of times and spatial locations at which carbon currently stored in the ocean is exposed to and exchanges with the atmosphere. These novel calculations fully take into account the time-evolving circulation and buffer chemistry of the ocean under a range of emission scenarios. I show that a projected increase in stratification and concomitant slowdown in the global overturning circulation due to global warming lengthens by centuries to thousands of years the time for which carbon remains sequestered. Moreover, this increase in storage time is evident even under low emission, high mitigation scenarios, and is accompanied by a shift in circulation pathways that further enhances the dominance of the Southern Ocean as the location at which the accumulated carbon remerges at the surface. These results highlight the potential long-term impact of global warming-induced changes in the marine carbon cycle on climate.
How to cite: Khatiwala, S.: Climate change increases the sequestration efficiency of the ocean, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4878, https://doi.org/10.5194/egusphere-egu26-4878, 2026.
Based on simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6), projections of marine heatwave (MHW) annual accumulated days (AACday) and intensity (AACintensity) remain highly uncertain, even in regions where anthropogenic signals are expected to emerge. Total projection uncertainty is decomposed into contributions from intermodel differences, internal variability, and emission scenarios. In the near term, internal variability dominates uncertainty in climate-mode-influenced oceans, while intermodel uncertainty prevails elsewhere. From the mid- to long-term, uncertainties associated with both internal variability and intermodel differences decrease nearly globally. Scenario uncertainty remains negligible until becoming evident over tropical oceans in the long term. Anthropogenic signals in AACday (AACintensity) emerge over only 2.2% (1.9%), 16.5% (1.8%), and 43.1% (2.0%) of the global ocean in the near-, mid-, and long-term, respectively, but expand to 32.4% (11.2%), 63.5% (18.4%), and 79.9% (20.7%) when intermodel differences are removed. These results demonstrate that internal variability and model uncertainty substantially delay the detectability of MHW changes, highlighting the importance of reducing model spread to improve future projections of MHW risks.
How to cite: Li, Y. and Jin, C.: Uncertainty Dominance Delays the Emergence of Marine Heatwave Signals in CMIP6 Projections, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11421, https://doi.org/10.5194/egusphere-egu26-11421, 2026.
The Ross Sea is a critical source region for Antarctic Bottom Water (AABW), driven by the export of Dense Shelf Water (DSW) through major submarine troughs. Under a warming climate, reduced sea-ice production and enhanced surface freshening are projected to weaken buoyancy loss on Antarctic shelves. However, how the Ross Sea shelf–slope circulation reorganizes under such significantly altered surface forcing remains poorly understood. Using high-resolution (0.1°) CESM simulations, we examine the response of this circulation to progressive warming and freshening under present-day, doubled (2xCO2), and quadrupled (4xCO2) CO2 conditions. Our results show that as DSW formation declines, shelf waters become increasingly buoyant, with the most pronounced changes occurring on the western shelf. This asymmetric freshening reshapes the cross-shelf density structure and eventually reverses the horizontal density gradient. In the Joides Trough, the traditional two-layer overturning pattern disappears under 4xCO2 forcing; instead, warm Circumpolar Deep Water (CDW) enters along the bottom, establishing a new deep pathway from the slope onto the shelf. Oceanic instability metrics indicate that strengthened lateral density gradients become comparable to, and locally exceed, the stabilizing effect of vertical stratification along the continental slope. We suggest that conditions favorable to symmetric instability may facilitate vertical exchange and support the emergence of this deep inflow, even as the Antarctic Slope Current intensifies. Rather than providing a single deterministic outcome, these findings illustrate a physically consistent scenario for the regime shift in Antarctic shelf-slope exchange, with profound implications for future abyssal ventilation and global ocean heat uptake.
How to cite: Ju, J., Nam, S., Park, T., and Park, J.: A regime shift in Ross Sea shelf-slope circulation and abyssal ventilation under future extreme CO2 forcing conditions, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16402, https://doi.org/10.5194/egusphere-egu26-16402, 2026.
The Antarctic slope current (ASC) is a westward flow around the Antarctic continental shelf. The ASC plays a key role in regulating the heat transport onto the shelf and thereby affects the ice-shelf melt. However, estimating changes in the ASC in response to greenhouse warming and attributing their potential drivers remain uncertain due to a lack of observations and the limitations of high-resolution coupled climate modeling. Previous equilibrium simulations using the ultra-high-resolution Community Earth System Model, comparing present-day (PD) and quadruple CO2 (4×CO2) simulations, showed the strengthening of the ASC in 4×CO2 relative to the PD simulation mainly due to a decrease in salinity. This enhanced freshening was primarily driven by reduced brine rejection associated with sea-ice formation in mainly austral winter-spring and by enhanced precipitation minus evaporation in year-round. To examine transient changes in the ASC and associated freshwater forcings that could not be captured in the equilibrium experiments, we also used Alfred Wegener Institute Climate Model, version 3 (AWI-CM3) coupled climate model with SSP5-8.5 greenhouse gas emission scenario. We analyzed transient experiment with 31 km and 10 km horizontal resolution for atmosphere and ocean, respectively (TCo319). Since the 2020s, the ASC has rapidly strengthened and expanded meridionally. At the same time, salinity and sea ice concentration began to decrease abruptly, and the freshened region also expanded similarly to the ASC. Compared to the historical period (1981–2010), the future period (2071–2100) showed a strengthened ASC, with increased mean temperatures from the surface to 200 m depth confined to the continental slope. Precipitation also increased along the Antarctic coast region and over the continental slope. By using both equilibrium and transient simulations, we better understand future changes in ASC and the mechanisms linking freshwater factors to the ASC change. Our study has important implications for mesoscale ocean circulation, ocean heat exchanges, and marine ecosystems around Antarctica.
How to cite: Kim, M.-H. and Lee, J.-Y.: Effects of freshwater forcing on the Antarctic slope current in a warmer climate using coupled climate model, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11779, https://doi.org/10.5194/egusphere-egu26-11779, 2026.
We conducted high-resolution (1/8°) dynamical downscaling over the North Pacific to produce ocean climate simulations for 1982–2100. The Regional Ocean Modeling System (ROMS) was forced by seven top-ranked CMIP6 global climate models (GCMs) under four SSP scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5), which provided the required forcing fields. Evaluation of sea surface temperature (SST) over the recent 20 years (1995–2014) shows that the ROMS ensemble mean (EM) substantially reduces the warm bias present in the GCM EM, improving the RMSE by 10.1%, with particularly strong improvement in the subpolar region (17.5%). These SST improvements primarily result from a more realistic representation of the Kuroshio, which alleviates the unrealistic overshooting in coarse-resolution GCM simulations, and are accompanied by improved wintertime net surface heat flux (NHF) near the Kuroshio path. Future projections (2081-2100) reveal pronounced differences between the GCM EM and ROMS EM in the subpolar region. Although both EMs project a strengthened and northward-shifted Kuroshio under higher-emission scenarios, the GCM EM exhibits an excessively large poleward shift. As a result, the GCM EM projects exaggerated, scenario-dependent wintertime changes in SST and NHF, which are substantially mitigated in the ROMS EM. These results highlight the importance of high-resolution regional ocean modeling for reducing biases in western boundary current systems and improving the reliability of future ocean climate projections.
How to cite: Lim, K.-G., Oh, S.-G., Lee, S.-T., Jung, J., Kim, B.-G., and Cho, Y.-K.: High-resolution North Pacific climate changes using dynamical downscaling: impact of improved Kuroshio, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3215, https://doi.org/10.5194/egusphere-egu26-3215, 2026.
Posters virtual: Tue, 5 May, 14:00–18:00 | vPoster spot 1a
EGU26-11315 | Posters virtual | VPS20
Surface flux contributions to CMIP6 spread of dynamic sea-level change vary across regions: insights from an ocean-only perturbed forcing ensembleTue, 05 May, 15:03–15:06 (CEST) vPoster spot 1a
Dynamic sea-level change (ΔDSL) is a key process in shaping the pattern of future sea-level rise. CMIP6 models predict a range of ΔDSL under 1% increase of CO2 per year. We analyse this CMIP6 spread into contributions from: 1) surface flux change (dF) and 2) model sensitivity to it (Φ). Specifically, we perturb the pre-industrial simulation of an ocean model with space- and time-varying dF diagnosed from different CMIP6 models (one at a time). The CMIP6 spread is thus decomposed into a flux-driven spread and a residual; the latter is linked to model spread of Φ. We improve upon previous studies by: (a) deriving the perturbed forcing ensemble using an ocean-only setup and (b) comparing it with the CMIP6 ensemble for both variance and correlation. This reveals distinct roles of surface forcing in driving the CMIP6 spread in different regions. In the North Pacific, differences in windstress forcing primarily explain the CMIP6 spread, while in the North Atlantic, differences in model sensitivity are more important. For the latter region, although buoyancy forcing drives a ΔDSL spread there, it correlates poorly with the CMIP6 spread. In the Southern Ocean, differences in forcing and sensitivity are both important for explaining the CMIP6 spread. The surface forcing affects the spread along 40°S via windstress and the spread around the Antarctic via buoyancy flux. In addition to ΔDSL analysed here, the perturbed forcing ensemble can be used to analyse future changes in other ocean variables, such as temperature, salinity and the Atlantic meridional overturning circulation. The full ensemble data is openly available online and can be freely used for future studies.
How to cite: Wu, Q. and Gregory, J.: Surface flux contributions to CMIP6 spread of dynamic sea-level change vary across regions: insights from an ocean-only perturbed forcing ensemble, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11315, https://doi.org/10.5194/egusphere-egu26-11315, 2026.
EGU26-21419 | ECS | Posters virtual | VPS20
Variability of Black Sea Physical Processes from 1950 to 2100Tue, 05 May, 15:15–15:18 (CEST) vPoster spot 1a
Climate change and climate variability have significant effects on atmospheric and oceanic processes, with semi-enclosed basins such as the Black Sea being particularly vulnerable due to their unique physical and chemical structure. In recent decades, the basin has experienced pronounced changes in temperature, salinity, and circulation, with important consequences for its biogeochemical and ecological functioning. Understanding the mechanisms driving these changes and their future evolution is therefore essential. This study investigates the historical and projected variability of key physical processes in the Black Sea over the period 1950-2100 using a high-resolution regional ocean model (NEMO). Temperature, salinity, mixed layer depth, and Cold Intermediate Layer (CIL) dynamics are analyzed, using atmospheric forcings from reanalysis data (ERA5) and a regional climate model (MAR) forced by a global climate model (EC-Earth). Future projections are conducted under two IPCC Shared Socioeconomic Pathways (SSP1-2.6 and SSP5-8.5). The historical simulations (1950-2020) are validated against in situ CTD observations and satellite-derived sea surface temperature and sea surface height, demonstrating good skill in reproducing the observed thermal and haline structure of the basin. Results from the historical simulations show a progressive weakening of the CIL and a shift toward stronger upper sea stratification. Future simulations aim to quantify how different climate change pathways will modify temperature and salinity dynamics. Together, the results provide new insight into the atmospheric drivers controlling Black Sea hydrodynamics and offer projections of regional climate change impacts on this highly sensitive system.
How to cite: Belen, B., Dişa, D., Acar, A. O., Arkın, S., Yücel, M., Fach, B., and Salihoğlu, B.: Variability of Black Sea Physical Processes from 1950 to 2100, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21419, https://doi.org/10.5194/egusphere-egu26-21419, 2026.
