OS - recent papers

The effect of storms on the Antarctic Slope Current and the warm inflow onto the southeastern Weddell Sea continental shelf

Thu, 20 Nov 2025 18:05:47 +0100

The effect of storms on the Antarctic Slope Current and the warm inflow onto the southeastern Weddell Sea continental shelf
Vår Dundas, Kjersti Daae, Elin Darelius, Markus Janout, Jean-Baptiste Sallée, and Svein Østerhus
Ocean Sci., 21, 3069–3088, https://doi.org/10.5194/os-21-3069-2025, 2025
Moored observations confirm that strong ocean surface stress events ("storms'') can increase the speed of the Antarctic Slope Current and the circulation in the Filchner Trough region. Roughly 25 % of the identified storm events also cause an increased southward current speed on the continental shelf. Such enhanced circulation on the shelf increases the likelihood that warm summer inflow reaches the Filchner Ice Front and cavity before it is lost to the atmosphere during winter.

Catalogue of extreme sea levels recorded at tide-gauge station Bakar in the northeastern Adriatic Sea (Mediterranean)

Wed, 19 Nov 2025 18:05:47 +0100

Catalogue of extreme sea levels recorded at tide-gauge station Bakar in the northeastern Adriatic Sea (Mediterranean)
Iva Međugorac, Karla Jambrošić, Domagoj Dolički, Josipa Kuzmić, Jadranka Šepić, Iva Vrkić Seidl, and Goran Gašparac
Ocean Sci., 21, 2929–3001, https://doi.org/10.5194/os-21-2929-2025, 2025
Flooding caused by storm surges in the Adriatic Sea has been increasingly observed. To better understand this rise in occurrence, we compiled a catalogue of 27 major flood events, each analyzed with respect to the governing processes and associated coastal impacts. The analysis is based on ERA5 data and hourly sea levels recorded at Croatia’s oldest tide-gauge station, Bakar, in the period between 1929 and 2022.

Modeling water column gas transformation, migration and atmospheric flux from seafloor seepage

Wed, 19 Nov 2025 18:05:47 +0100

Modeling water column gas transformation, migration and atmospheric flux from seafloor seepage
Knut Ola Dølven, Håvard Espenes, Alfred Hanssen, Muhammed Fatih Sert, Magnus Drivdal, Achim Randelhoff, and Bénédicte Ferré
Ocean Sci., 21, 3031–3054, https://doi.org/10.5194/os-21-3031-2025, 2025
We modeled how gas seeping from the seafloor spreads in the ocean and how much reaches the atmosphere. Using gas-exchange and hydrodynamic models, we estimated gas dissolution, atmospheric release, and 3D concentration fields. Applied to a methane seep offshore Norway, most methane dissolved and much was consumed by microbes, though uncertainties remain due to microbial and mixing assumptions.

Contribution of dark inorganic carbon fixation to bacterial carbon demand in the oligotrophic Southeastern Mediterranean Sea

Wed, 19 Nov 2025 18:05:47 +0100

Contribution of dark inorganic carbon fixation to bacterial carbon demand in the oligotrophic Southeastern Mediterranean Sea
Tom Reich, Natalia Belkin, Guy Sisma-Ventura, Hagar Hauzer, Maxim Rubin-Blum, Ilana Berman-Frank, and Eyal Rahav
Ocean Sci., 21, 3055–3067, https://doi.org/10.5194/os-21-3055-2025, 2025
Dark carbon fixation by chemoautotrophs take a vital part in marine primary productivity. Measured rates can be seen all the way down to the dark layers of the ocean and integrated in our study site come close to the magnitude of photosynthesis. It can also explain about ~ 35 % of the missing organic carbon supply needed by deep microbial communities. By using oceanographic observations and analysis this paper highlights the significant of this overlooked parameter.

ENSO and the Temperature of the North Equatorial Counter Current

Wed, 19 Nov 2025 18:05:47 +0100

ENSO and the Temperature of the North Equatorial Counter Current
David John Webb
Ocean Sci., 21, 3003–3029, https://doi.org/10.5194/os-21-3003-2025, 2025
A modern climate model is used to test a new hypothesis that changes observed during El Niños are, in part, forced by changes in the temperature of the North Equatorial Counter Current. This is a warm current that flows eastwards across the Pacific, a few degrees north of the Equator, close to the Inter-Tropical Convection Zone, a major region of deep atmospheric convection. The test runs show significant El Niño type responses, giving confidence that the hypothesis is correct.

A data-driven wind-to-current response function and application to ocean surface current estimates

Fri, 14 Nov 2025 18:05:47 +0100

A data-driven wind-to-current response function and application to ocean surface current estimates
Clément Ubelmann, J. Thomas Farrar, Bertrand Chapron, Lucile Gaultier, Laura Gomez-Navarro, Marie-Hélène Rio, and Gérald Dibarboure
Ocean Sci., 21, 2915–2928, https://doi.org/10.5194/os-21-2915-2025, 2025
This study models wind-driven ocean currents using observed wind stress and an empirically estimated impulse response function based on drifting buoys. By convolving this function with wind forcing from ERA5, the estimates align well with independent observations across latitudes. Additionally, the response function serves as a valuable indicator of subsurface properties.

Diagnosing the Atlantic Meridional Overturning Circulation in density space is critical in warmer climates

Thu, 13 Nov 2025 18:05:47 +0100

Diagnosing the Atlantic Meridional Overturning Circulation in density space is critical in warmer climates
Fernanda DI Alzira Oliveira Matos, Dmitry Sidorenko, Xiaoxu Shi, Lars Ackermann, Janini Pereira, Gerrit Lohmann, and Christian Stepanek
Ocean Sci., 21, 2895–2914, https://doi.org/10.5194/os-21-2895-2025, 2025
The Atlantic Meridional Overturning Circulation (AMOC) is responsible for about 25 % of the poleward ocean heat transport. Currently, the AMOC strength is mostly calculated in depth space (z-AMOC). However, we argue that, in warmer climates, the AMOC should be calculated in density space (ρ-AMOC). We performed simulations with CO2 forcing of 280 ppmv (PI) and 1120 ppmv of (4xCO2) and find that ρ-AMOC provides more physical and meaningful information about the AMOC in warmer climates.

Impact of internal tides on chlorophyll a distribution and primary production off the Amazon shelf from glider measurements and satellite observations

Tue, 11 Nov 2025 18:05:47 +0100

Impact of internal tides on chlorophyll a distribution and primary production off the Amazon shelf from glider measurements and satellite observations
Amine M'hamdi, Ariane Koch-Larrouy, Alex Costa da Silva, Isabelle Dadou, Carina Regina de Macedo, Anthony Bosse, Vincent Vantrepotte, Habib Micaël Aguedjou, Trung-Kien Tran, Pierre Testor, Laurent Mortier, Arnaud Bertrand, Pedro Augusto Mendes de Castro Melo, James Lee, Marcelo Rollnic, and Moacyr Araujo
Ocean Sci., 21, 2873–2894, https://doi.org/10.5194/os-21-2873-2025, 2025
In the ocean off the Amazon shelf, internal waves caused by tides move water layers up and down and mix them. Using an underwater glider and satellites, we found internal tides redistribute chlorophyll from the deep chlorophyll maximum upward to the surface and downward to depth. Turbulent chlorophyll fluxes supply about 38 % of surface chlorophyll, and total chlorophyll increases by 14–29 % during strong tides, potentially affecting the marine food web.

Estimating oceanic physics-driven vertical velocities in a wind-influenced coastal environment

Tue, 11 Nov 2025 18:05:47 +0100

Estimating oceanic physics-driven vertical velocities in a wind-influenced coastal environment
Maxime Arnaud, Anne Petrenko, Jean-Luc Fuda, Caroline Comby, Anthony Bosse, Yann Ourmières, and Stéphanie Barrillon
Ocean Sci., 21, 2829–2847, https://doi.org/10.5194/os-21-2829-2025, 2025
Measuring oceanic vertical velocities accurately is a challenge in today’s physical oceanography. Our work shows intense wind-induced coastal events involving upward or downward water movements that have been detected using an acoustic current profiler. These data has also been validated with other in situ and satellite observations. A brand new method to identify and filter out biology-induced velocities is also presented, giving an interdisciplinary point of view of such coastal processes.

When storms stir the Mediterranean depths: chlorophyll a response to Mediterranean cyclones

Tue, 11 Nov 2025 18:05:47 +0100

When storms stir the Mediterranean depths: chlorophyll a response to Mediterranean cyclones
Giovanni Scardino, Alok Kushabaha, Mario Marcello Miglietta, Davide Bonaldo, and Giovanni Scicchitano
Ocean Sci., 21, 2849–2872, https://doi.org/10.5194/os-21-2849-2025, 2025
This study investigated how Mediterranean cyclones impact chlorophyll-a dynamics. Using reanalysis data, ARGO floats, and satellite imagery, we found that slow-moving cyclones significantly uplift the deep chlorophyll maximum. Upwelling and air-sea heat exchange were key mechanisms driving this uplift, enhancing nutrient availability and primary productivity. These findings highlight the strong influence of cyclone intensity and movement on biogeochemical processes in the Mediterranean Sea.

On the applicability of linear wave theories to simulations on the mid-latitude β-plane

Thu, 06 Nov 2025 18:05:47 +0100

On the applicability of linear wave theories to simulations on the mid-latitude β-plane
Itamar Yacoby, Hezi Gildor, and Nathan Paldor
Ocean Sci., 21, 2805–2828, https://doi.org/10.5194/os-21-2805-2025, 2025
The paper examines the applicability of known linear wave theories to numerical simulations of two, zonally invariant, fundamental problems of Physical Oceanography: Geostrophic adjustment and Ekman Adjustment. By simulating the problems with a modified version of the Massachusetts Institute of Technology General Circulation Model (MITgcm) we show that neither of the known wave theories can explain the results of the simulations in large and small meridional domains and for long and short times.

Atmospheric cold pools abruptly reverse thermohaline features in the ocean skin layer

Wed, 05 Nov 2025 18:05:47 +0100

Atmospheric cold pools abruptly reverse thermohaline features in the ocean skin layer
Lisa Gassen, Samuel M. Ayim, Leonie Jaeger, Jens Meyerjürgens, Mariana Ribas-Ribas, and Oliver Wurl
Ocean Sci., 21, 2787–2804, https://doi.org/10.5194/os-21-2787-2025, 2025
This study investigates how abrupt weather changes, such as shifts in air temperature, wind speed and precipitation, impact temperature and salinity in the ocean’s skin layer (upper first millimetre). Two events in the harbour of Bremerhaven and one event in the North Sea revealed that the skin layer reacts instantly, with greater temperature changes than those at a depth of 100 cm, underscoring its key role in air-sea interactions and climate dynamics.

Merging of a mesoscale eddy into the Lofoten Vortex in the Norwegian Sea captured by an ocean glider and SWOT observations

Tue, 04 Nov 2025 18:05:47 +0100

Merging of a mesoscale eddy into the Lofoten Vortex in the Norwegian Sea captured by an ocean glider and SWOT observations
Gillian M. Damerell, Anthony Bosse, and Ilker Fer
Ocean Sci., 21, 2763–2785, https://doi.org/10.5194/os-21-2763-2025, 2025
The Lofoten Vortex is an unusual feature in the ocean: a permanent eddy which does not dissipate as most eddies do. We have long thought that other eddies must merge into the vortex in order to maintain its heat content and energetics, but such mergers are very difficult to observe due to their transient, unpredictable nature. For the first time, we have observed a merger using an ocean glider and high-resolution satellite data and can document how the merger affects the properties of the vortex.

Estimates of Atlantic meridional heat transport from spatiotemporal fusion of Argo, altimetry, and gravimetry data

Mon, 03 Nov 2025 18:05:47 +0100

Estimates of Atlantic meridional heat transport from spatiotemporal fusion of Argo, altimetry, and gravimetry data
Francisco M. Calafat, Parvathi Vallivattathillam, and Eleanor Frajka-Williams
Ocean Sci., 21, 2743–2762, https://doi.org/10.5194/os-21-2743-2025, 2025
Understanding how heat moves through the ocean is crucial to predicting future climate change confidently. This requires accurate records of heat transport throughout the ocean, but these are challenging to obtain by direct ocean observation. Here, we combine in situ and satellite-based observations to generate estimates of meridional heat transport for the period 2004–2020 at 3-month resolution across the Atlantic Ocean with improved accuracy compared to existing indirectly inferred estimates.

Effect of double-diffusion processes in the deep ocean on the distribution and dynamics of particulate and dissolved matter: a case study in the Tyrrhenian Sea

Thu, 30 Oct 2025 18:05:47 +0100

Effect of double-diffusion processes in the deep ocean on the distribution and dynamics of particulate and dissolved matter: a case study in the Tyrrhenian Sea
Xavier Durrieu de Madron, Paul Blin, Mireille Pujo-Pay, Vincent Taillandier, and Pascal Conan
Ocean Sci., 21, 2705–2726, https://doi.org/10.5194/os-21-2705-2025, 2025
This study investigated the effects of salt fingering on particle and solute distribution in the Tyrrhenian Sea. Density interfaces associated with thermohaline staircases slow the settling of suspended particles and promote aggregation. This affects the particle size distribution and creates nutrient and oxygen gradients, affecting microbial activity and nutrient cycling. The research highlights the potential role of salt fingers in deep ocean biogeochemical processes.

Cold lenses in the Amundsen Sea: impacts of sea ice formation on subsurface pH and carbon

Thu, 30 Oct 2025 18:05:47 +0100

Cold lenses in the Amundsen Sea: impacts of sea ice formation on subsurface pH and carbon
Daisy D. Pickup, Dorothee C. E. Bakker, Karen J. Heywood, Francis Glassup, Emily M. Hammermeister, Sharon E. Stammerjohn, Gareth A. Lee, Socratis Loucaides, Bastien Y. Queste, Benjamin G. M. Webber, and Patricia L. Yager
Ocean Sci., 21, 2727–2741, https://doi.org/10.5194/os-21-2727-2025, 2025
Autonomous platforms in the Amundsen Sea have allowed for detection of isolated water masses that are colder, saltier and denser than overlying water. They are also associated with a higher dissolved inorganic carbon concentration and lower pH. The water masses, referred to as lenses, could have implications for the transfer of heat and storage of carbon in the region. We hypothesise that they form in surrounding areas that experience intense cooling and sea ice formation in autumn/winter.

Flow structure and mixing near a small river plume front: Winyah Bay, SC, USA

Wed, 29 Oct 2025 18:05:47 +0100

Flow structure and mixing near a small river plume front: Winyah Bay, SC, USA
Christopher Papageorgiou, George Voulgaris, Alexander E. Yankovsky, and Diane Bennett Fribance
Ocean Sci., 21, 2681–2703, https://doi.org/10.5194/os-21-2681-2025, 2025
This study examines the interaction of river and ocean waters in the coastal ocean and how these mix. High resolution field observations of water properties, flow, and turbulence were collected over a period of ~ 4 h. Flow turbulence is responsible for mixing water near the bed and close to the sea surface, but within the freshly discharged waters mixing efficiency appears to be minimal. This is attributed to turbulence not being uniform but concentrated in layers.

Geostrophic circulation and tidal effects in the Gulf of Gabès

Tue, 28 Oct 2025 18:05:47 +0100

Geostrophic circulation and tidal effects in the Gulf of Gabès
Maher Bouzaiene, Antonio Guarnieri, Damiano Delrosso, Ahmad F. Dilmahamod, Simona Simoncelli, and Claudia Fratianni
Ocean Sci., 21, 2643–2662, https://doi.org/10.5194/os-21-2643-2025, 2025
We analyze the geostrophic circulation and tidal effects in the Gulf of Gabès from 30 years of altimetry data (1993–2022) and the outputs of a high-resolution ocean model for the year 2022.

Enhancement of near-inertial waves by cyclonic eddy in the northwestern South China Sea during spring 2022

Tue, 28 Oct 2025 18:05:47 +0100

Enhancement of near-inertial waves by cyclonic eddy in the northwestern South China Sea during spring 2022
Qi'an Chen, Hongzhou Xu, Dongxiao Wang, Bo Hong, Chunlei Liu, Zheyang Zhang, Huichang Jiang, Wei Song, Tong Long, Ling Wang, Sumin Liu, and Rongjie Chen
Ocean Sci., 21, 2631–2642, https://doi.org/10.5194/os-21-2631-2025, 2025
NIWs (near-inertial waves) have horizontal spatial scales of 10–100 km and slow group velocities, making them to interact strongly with mesoscale eddies. In the northwestern SCS (South China Sea), large portion of eddy propagate westward and may interact with local NIWs. In this study, four moorings were deployed in this area and they captured a vivid case of interaction between a cyclonic eddy and NIWs. Our paper provides direct evidence of strong interaction between eddy and NIWs in the northwestern SCS.

Can satellite altimetry observe coastally trapped waves on sub-monthly timescales?

Tue, 28 Oct 2025 18:05:47 +0100

Can satellite altimetry observe coastally trapped waves on sub-monthly timescales?
Marcello Passaro
Ocean Sci., 21, 2663–2679, https://doi.org/10.5194/os-21-2663-2025, 2025
This paper evaluates the capability of satellite altimetry to monitor coastally trapped waves in light of the latest advancements in daily gridded sea level data, including new interpolation schemes, an increased number of missions in orbit, and the incorporation of wide-swath altimetry measurements. The eastern Australian coast serves as a testbed, with validation provided by tide gauges and model data.