Articles | Volume 21, issue 4
https://doi.org/10.5194/os-21-1505-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-21-1505-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Jul 2025
Research article |
| 24 Jul 2025
| 24 Jul 2025
Sargassum spp. accumulation and transport by mesoscale eddies
Rosmery Sosa-Gutierrez
CORRESPONDING AUTHOR
LEGOS, Université de Toulouse, IRD, CNRS, CNES, Toulouse, France
CELAD/Mercator Ocean International, 31400 Toulouse, France
LEGOS, Université de Toulouse, IRD, CNRS, CNES, Toulouse, France
Leo Berline
Aix-Marseille University, Université de Toulon, CNRS/INSU, IRD, MIO UM 110, Mediterranean Institute of Oceanography (MIO), Campus of Luminy, 13288 Marseille, France
Related authors
No articles found.
Maxime Duranson, Léo Berline, Loïc Guilloux, Alice Della Penna, Mark D. Ohman, Sven Gastauer, Cédric Cotte, Daniela Bănaru, Théo Garcia, Maristella Berta, Andrea Doglioli, Gérald Gregori, Francesco D'Ovidio, and François Carlotti
EGUsphere, https://doi.org/10.5194/egusphere-2025-1125, https://doi.org/10.5194/egusphere-2025-1125, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
The zooplankton community was investigated using net sampling across the North Balearic Front at fine resolution. The front mostly acts as a zonal boundary between communities with a copepod dominated community to the north and a more diversified community to the south. The front itself showed lower biovolume and abundances. The main community difference occurred in the 0–100 m layer, while deeper layers were more homogeneous.
Gabriela Martinez-Balbontin, Julien Jouanno, Rachid Benshila, Julien Lamouroux, Coralie Perruche, and Stefano Ciavatta
EGUsphere, https://doi.org/10.5194/egusphere-2025-1246, https://doi.org/10.5194/egusphere-2025-1246, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
This study uses machine learning to predict chlorophyll-a levels, which are important for monitoring marine ecosystems and the carbon cycle. By using forecasts of sea surface temperature, salinity, height, and mixed layer depth, we can make global predictions up to six months ahead in just minutes. Our approach is as accurate or better than traditional methods, while being faster and more resource-efficient.
Sylvain Cailleau, Laurent Bessières, Léonel Chiendje, Flavie Dubost, Guillaume Reffray, Jean-Michel Lellouche, Simon van Gennip, Charly Régnier, Marie Drevillon, Marc Tressol, Matthieu Clavier, Julien Temple-Boyer, and Léo Berline
Geosci. Model Dev., 17, 3157–3173, https://doi.org/10.5194/gmd-17-3157-2024, https://doi.org/10.5194/gmd-17-3157-2024, 2024
Short summary
Short summary
In order to improve Sargassum drift forecasting in the Caribbean area, drift models can be forced by higher-resolution ocean currents. To this goal a 3 km resolution regional ocean model has been developed. Its assessment is presented with a particular focus on the reproduction of fine structures representing key features of the Caribbean region dynamics and Sargassum transport. The simulated propagation of a North Brazil Current eddy and its dissipation was found to be quite realistic.
Peter Brandt, Gaël Alory, Founi Mesmin Awo, Marcus Dengler, Sandrine Djakouré, Rodrigue Anicet Imbol Koungue, Julien Jouanno, Mareike Körner, Marisa Roch, and Mathieu Rouault
Ocean Sci., 19, 581–601, https://doi.org/10.5194/os-19-581-2023, https://doi.org/10.5194/os-19-581-2023, 2023
Short summary
Short summary
Tropical upwelling systems are among the most productive ecosystems globally. The tropical Atlantic upwelling undergoes a strong seasonal cycle that is forced by the wind. Local wind-driven upwelling and remote effects, particularly via the propagation of equatorial and coastal trapped waves, lead to an upward and downward movement of the nitracline. Turbulent mixing results in upward supply of nutrients. Here, we review the different physical processes responsible for biological productivity.
Roy Dorgeless Ngakala, Gaël Alory, Casimir Yélognissè Da-Allada, Olivia Estelle Kom, Julien Jouanno, Willi Rath, and Ezinvi Baloïtcha
Ocean Sci., 19, 535–558, https://doi.org/10.5194/os-19-535-2023, https://doi.org/10.5194/os-19-535-2023, 2023
Short summary
Short summary
Surface heat flux is the main driver of the heat budget in the Senegal, Angola, and Benguela regions but not in the equatorial region. In the Senegal and Benguela regions, freshwater flux governs the salt budget, while in equatorial and Angola regions, oceanic processes are the main drivers. Results from numerical simulation show the important role of mesoscale advection for temperature and salinity variations in the mixed layer. Nonlinear processes unresolved by observations play a key role.
Sarah Berthet, Julien Jouanno, Roland Séférian, Marion Gehlen, and William Llovel
Earth Syst. Dynam., 14, 399–412, https://doi.org/10.5194/esd-14-399-2023, https://doi.org/10.5194/esd-14-399-2023, 2023
Short summary
Short summary
Phytoplankton absorbs the solar radiation entering the ocean surface and contributes to keeping the associated energy in surface waters. This natural effect is either not represented in the ocean component of climate models or its representation is simplified. An incomplete representation of this biophysical interaction affects the way climate models simulate ocean warming, which leads to uncertainties in projections of oceanic emissions of an important greenhouse gas (nitrous oxide).
Michel Tchilibou, Ariane Koch-Larrouy, Simon Barbot, Florent Lyard, Yves Morel, Julien Jouanno, and Rosemary Morrow
Ocean Sci., 18, 1591–1618, https://doi.org/10.5194/os-18-1591-2022, https://doi.org/10.5194/os-18-1591-2022, 2022
Short summary
Short summary
This high-resolution model-based study investigates the variability in the generation, propagation, and sea height signature (SSH) of the internal tide off the Amazon shelf during two contrasted seasons. ITs propagate further north during the season characterized by weak currents and mesoscale eddies and a shallow and strong pycnocline. IT imprints on SSH dominate those of the geostrophic motion for horizontal scales below 200 km; moreover, the SSH is mainly incoherent below 70 km.
Rainer Kiko, Marc Picheral, David Antoine, Marcel Babin, Léo Berline, Tristan Biard, Emmanuel Boss, Peter Brandt, Francois Carlotti, Svenja Christiansen, Laurent Coppola, Leandro de la Cruz, Emilie Diamond-Riquier, Xavier Durrieu de Madron, Amanda Elineau, Gabriel Gorsky, Lionel Guidi, Helena Hauss, Jean-Olivier Irisson, Lee Karp-Boss, Johannes Karstensen, Dong-gyun Kim, Rachel M. Lekanoff, Fabien Lombard, Rubens M. Lopes, Claudie Marec, Andrew M. P. McDonnell, Daniela Niemeyer, Margaux Noyon, Stephanie H. O'Daly, Mark D. Ohman, Jessica L. Pretty, Andreas Rogge, Sarah Searson, Masashi Shibata, Yuji Tanaka, Toste Tanhua, Jan Taucher, Emilia Trudnowska, Jessica S. Turner, Anya Waite, and Lars Stemmann
Earth Syst. Sci. Data, 14, 4315–4337, https://doi.org/10.5194/essd-14-4315-2022, https://doi.org/10.5194/essd-14-4315-2022, 2022
Short summary
Short summary
The term
marine particlescomprises detrital aggregates; fecal pellets; bacterioplankton, phytoplankton and zooplankton; and even fish. Here, we present a global dataset that contains 8805 vertical particle size distribution profiles obtained with Underwater Vision Profiler 5 (UVP5) camera systems. These data are valuable to the scientific community, as they can be used to constrain important biogeochemical processes in the ocean, such as the flux of carbon to the deep sea.
Léo Berline, Andrea Michelangelo Doglioli, Anne Petrenko, Stéphanie Barrillon, Boris Espinasse, Frederic A. C. Le Moigne, François Simon-Bot, Melilotus Thyssen, and François Carlotti
Biogeosciences, 18, 6377–6392, https://doi.org/10.5194/bg-18-6377-2021, https://doi.org/10.5194/bg-18-6377-2021, 2021
Short summary
Short summary
While the Ionian Sea is considered a nutrient-depleted and low-phytoplankton biomass area, it is a crossroad for water mass circulation. In the central Ionian Sea, we observed a strong contrast in particle distribution across a ~100 km long transect. Using remote sensing and Lagrangian simulations, we suggest that this contrast finds its origin in the long-distance transport of particles from the north, west and east of the Ionian Sea, where phytoplankton production was more intense.
Pierre Damien, Julio Sheinbaum, Orens Pasqueron de Fommervault, Julien Jouanno, Lorena Linacre, and Olaf Duteil
Biogeosciences, 18, 4281–4303, https://doi.org/10.5194/bg-18-4281-2021, https://doi.org/10.5194/bg-18-4281-2021, 2021
Short summary
Short summary
The Gulf of Mexico deep waters are relatively poor in phytoplankton biomass due to low levels of nutrients in the upper layers. Using modeling techniques, we find that the long-living anticyclonic Loop Current eddies that are shed episodically from the Yucatan Channel strongly shape the distribution of phytoplankton and, more importantly, stimulate their growth. This results from the contribution of multiple mechanisms of physical–biogeochemical interactions discussed in this study.
Julien Jouanno, Rachid Benshila, Léo Berline, Antonin Soulié, Marie-Hélène Radenac, Guillaume Morvan, Frédéric Diaz, Julio Sheinbaum, Cristele Chevalier, Thierry Thibaut, Thomas Changeux, Frédéric Menard, Sarah Berthet, Olivier Aumont, Christian Ethé, Pierre Nabat, and Marc Mallet
Geosci. Model Dev., 14, 4069–4086, https://doi.org/10.5194/gmd-14-4069-2021, https://doi.org/10.5194/gmd-14-4069-2021, 2021
Short summary
Short summary
The tropical Atlantic has been facing a massive proliferation of Sargassum since 2011, with severe environmental and socioeconomic impacts. We developed a modeling framework based on the NEMO ocean model, which integrates transport by currents and waves, and physiology of Sargassum with varying internal nutrient quota, and considers stranding at the coast. Results demonstrate the ability of the model to reproduce and forecast the seasonal cycle and large-scale distribution of Sargassum biomass.
Julien Jouanno and Xavier Capet
Ocean Sci., 16, 1207–1223, https://doi.org/10.5194/os-16-1207-2020, https://doi.org/10.5194/os-16-1207-2020, 2020
Short summary
Short summary
The dynamical balance of the Antarctic Circumpolar Current and its implications on the functioning of the world ocean are not fully understood and poorly represented in global circulation models. In this study, the sensitivities of an idealized Southern Ocean (SO) storm track are explored with a set of eddy-rich numerical simulations. We show that the classical partition between barotropic and baroclinic modes is sensitive to current–topography interactions in the mesoscale range of 10–100 km.
Marie-Hélène Radenac, Julien Jouanno, Christine Carine Tchamabi, Mesmin Awo, Bernard Bourlès, Sabine Arnault, and Olivier Aumont
Biogeosciences, 17, 529–545, https://doi.org/10.5194/bg-17-529-2020, https://doi.org/10.5194/bg-17-529-2020, 2020
Short summary
Short summary
Satellite data and a remarkable set of in situ measurements show a main bloom of microscopic seaweed, the phytoplankton, in summer and a secondary bloom in December in the central equatorial Atlantic. They are driven by a strong vertical supply of nitrate in May–July and a shorter and moderate supply in November. In between, transport of low-nitrate water from the west explains most nitrate losses in the sunlit layer. Horizontal eddy-induced processes also contribute to seasonal nitrate removal.
Lala Kounta, Xavier Capet, Julien Jouanno, Nicolas Kolodziejczyk, Bamol Sow, and Amadou Thierno Gaye
Ocean Sci., 14, 971–997, https://doi.org/10.5194/os-14-971-2018, https://doi.org/10.5194/os-14-971-2018, 2018
Short summary
Short summary
The currents along the West African seaboard are poorly known. Based on a carefully evaluated numerical simulation the present study describes these currents in the sector 8–20°N and the physical processes that drive them. Prevailing northward flow with two intensification periods per year is identified. Both local and distant coastal winds (blowing as far as thousands of kilometers away in the Gulf of Guinea) contribute to the circulation in this sector.
Julien Jouanno, Olga Hernandez, and Emilia Sanchez-Gomez
Earth Syst. Dynam., 8, 1061–1069, https://doi.org/10.5194/esd-8-1061-2017, https://doi.org/10.5194/esd-8-1061-2017, 2017
Anna Belcher, Morten Iversen, Sarah Giering, Virginie Riou, Stephanie A. Henson, Leo Berline, Loic Guilloux, and Richard Sanders
Biogeosciences, 13, 4927–4943, https://doi.org/10.5194/bg-13-4927-2016, https://doi.org/10.5194/bg-13-4927-2016, 2016
Short summary
Short summary
We address the imbalance between the supply and loss of organic carbon to the upper layer of the ocean by measuring a previously poorly quantified term: particle-associated microbial respiration of in situ particles. We find rates that are too low to account for the missing sink of carbon and suggest instead that zooplankton drive the transformation of large fast-sinking particles into slow-sinking and suspended particles. This apparent loss may help explain imbalances in the carbon budget.
Julien Jouanno, Xavier Capet, Gurvan Madec, Guillaume Roullet, and Patrice Klein
Ocean Sci., 12, 743–769, https://doi.org/10.5194/os-12-743-2016, https://doi.org/10.5194/os-12-743-2016, 2016
Short summary
Short summary
The aim of this study is to clarify the role of the Southern Ocean storms on interior mixing and meridional overturning circulation. A periodic and idealized configuration of the NEMO model has been designed to represent the key physical processes of a zonal portion of the Southern Ocean. Challenging issues concerning how numerical models are able to represent interior mixing forced by high-frequency winds are exposed and discussed, particularly in the context of the overturning circulation.
F. Roullier, L. Berline, L. Guidi, X. Durrieu De Madron, M. Picheral, A. Sciandra, S. Pesant, and L. Stemmann
Biogeosciences, 11, 4541–4557, https://doi.org/10.5194/bg-11-4541-2014, https://doi.org/10.5194/bg-11-4541-2014, 2014
Related subject area
Approach: Remote Sensing | Properties and processes: Mesoscale to submesoscale dynamics
Advances in surface water and ocean topography for fine-scale eddy identification from altimeter sea surface height merging maps in the South China Sea
Enhanced resolution capability of SWOT sea surface height measurements and their application in monitoring ocean dynamics variability
Generation of super-resolution gap-free ocean colour satellite products using data-interpolating empirical orthogonal functions (DINEOF)
Synoptic observation of full mesoscale eddy lifetime and its secondary instabilities in the Gulf of Mexico
Blending 2D topography images from the Surface Water and Ocean Topography (SWOT) mission into the altimeter constellation with the Level-3 multi-mission Data Unification and Altimeter Combination System (DUACS)
Estimating ocean currents from the joint reconstruction of absolute dynamic topography and sea surface temperature through deep learning algorithms
Integrating wide-swath altimetry data into Level-4 multi-mission maps
Monitoring the coastal–offshore water interactions in the Levantine Sea using ocean color and deep supervised learning
Multiple timescale variations in fronts in the Seto Inland Sea, Japan
MAESSTRO: Masked Autoencoders for Sea Surface Temperature Reconstruction under Occlusion
Deep learning for the super resolution of Mediterranean sea surface temperature fields
Impact of surface and subsurface-intensified eddies on sea surface temperature and chlorophyll a in the northern Indian Ocean utilizing deep learning
Regional mapping of energetic short mesoscale ocean dynamics from altimetry: performances from real observations
Ocean 2D eddy energy fluxes from small mesoscale processes with SWOT
Xiaoya Zhang, Lei Liu, Jianfang Fei, Zhijin Li, Zexun Wei, Zhiwei Zhang, Xingliang Jiang, Zexin Dong, and Feng Xu
Ocean Sci., 21, 1033–1045, https://doi.org/10.5194/os-21-1033-2025, https://doi.org/10.5194/os-21-1033-2025, 2025
Short summary
Short summary
Our research evaluated the precision of mapping the ocean's surface with combined data from a couple of satellites, focusing on dynamic aspects revealed by sea level changes. The results show that 2DVAR (two-dimensional variation), a new mapping product, aligns more closely and with less error with the most advanced satellite observations than a widely used mapping product called AVISO (Archiving, Validation, and Interpretation of Satellite Oceanographic). The results suggest that 2DVAR detects minor ocean movements better, making it more valuable and reliable for ocean dynamic study.
Yong Wang, Shengjun Zhang, and Yongjun Jia
Ocean Sci., 21, 931–944, https://doi.org/10.5194/os-21-931-2025, https://doi.org/10.5194/os-21-931-2025, 2025
Short summary
Short summary
The distance-weighted averaging method was used to calculate the along-orbit sea surface height (SSH) wavenumber spectra of four satellites and to evaluate the along-track resolution capability of the four satellites. The results show that the resolution of Surface Water and Ocean Topography (SWOT) in the Kuroshio region is 25 km, which is twice the resolution of conventional satellites. A parameter was defined using the cross-power-spectrum approach and used to analyse the global ocean.
Aida Alvera-Azcárate, Dimitry Van der Zande, Alexander Barth, Antoine Dille, Joppe Massant, and Jean-Marie Beckers
Ocean Sci., 21, 787–805, https://doi.org/10.5194/os-21-787-2025, https://doi.org/10.5194/os-21-787-2025, 2025
Short summary
Short summary
This work presents an approach for increasing the spatial resolution of satellite data and interpolating gaps due to cloud cover, using a method called DINEOF (data-interpolating empirical orthogonal functions). The method is tested on turbidity and chlorophyll-a concentration data in the Belgian coastal zone and the North Sea. The results show that we are able to improve the spatial resolution of these data in order to perform analyses of spatial and temporal variability in coastal regions.
Charly de Marez
EGUsphere, https://doi.org/10.5194/egusphere-2025-1592, https://doi.org/10.5194/egusphere-2025-1592, 2025
Short summary
Short summary
Oceanic eddies are giant swirling currents that help transport heat, nutrients, and pollutants across the ocean. However, their full life cycle has never been observed in detail. Using new satellite data, we tracked an intense eddy in the Gulf of Mexico, describing its life cycle from birth to dissipation. Our observations reveal small scale turbulence surrounding it and interactions with other structures that shape its evolution and decay, validating decades of numerical studies.
Gerald Dibarboure, Cécile Anadon, Frédéric Briol, Emeline Cadier, Robin Chevrier, Antoine Delepoulle, Yannice Faugère, Alice Laloue, Rosemary Morrow, Nicolas Picot, Pierre Prandi, Marie-Isabelle Pujol, Matthias Raynal, Anaelle Tréboutte, and Clément Ubelmann
Ocean Sci., 21, 283–323, https://doi.org/10.5194/os-21-283-2025, https://doi.org/10.5194/os-21-283-2025, 2025
Short summary
Short summary
The Surface Water and Ocean Topography (SWOT) mission delivers unprecedented swath-altimetry products. In this paper, we describe how we extended the Level-3 algorithms to handle SWOT’s unique swath-altimeter data. We also illustrate and discuss the benefits, relevance, and limitations of Level-3 swath-altimeter products for various research domains.
Daniele Ciani, Claudia Fanelli, and Bruno Buongiorno Nardelli
Ocean Sci., 21, 199–216, https://doi.org/10.5194/os-21-199-2025, https://doi.org/10.5194/os-21-199-2025, 2025
Short summary
Short summary
Ocean surface currents are routinely derived from satellite observations of the sea level, allowing regional- to global-scale synoptic monitoring. In order to overcome the theoretical and instrumental limits of this methodology, we exploit the synergy of multi-sensor satellite observations. We rely on deep learning, physics-informed algorithms to predict ocean currents from sea surface height and sea surface temperature observations. Results are validated by means of in situ measurements.
Maxime Ballarotta, Clément Ubelmann, Valentin Bellemin-Laponnaz, Florian Le Guillou, Guillaume Meda, Cécile Anadon, Alice Laloue, Antoine Delepoulle, Yannice Faugère, Marie-Isabelle Pujol, Ronan Fablet, and Gérald Dibarboure
Ocean Sci., 21, 63–80, https://doi.org/10.5194/os-21-63-2025, https://doi.org/10.5194/os-21-63-2025, 2025
Short summary
Short summary
The Surface Water and Ocean Topography (SWOT) mission provides unprecedented swath altimetry data. This study examines SWOT's impact on mapping systems, showing a moderate effect with the current nadir altimetry constellation and a stronger impact with a reduced one. Integrating SWOT with dynamic mapping techniques improves the resolution of satellite-derived products, offering promising solutions for studying and monitoring sea-level variability at finer scales.
Georges Baaklini, Julien Brajard, Leila Issa, Gina Fifani, Laurent Mortier, and Roy El Hourany
Ocean Sci., 20, 1707–1720, https://doi.org/10.5194/os-20-1707-2024, https://doi.org/10.5194/os-20-1707-2024, 2024
Short summary
Short summary
Understanding the flow of the Levantine Sea surface current is not straightforward. We propose a study based on learning techniques to follow interactions between water near the shore and further out at sea. Our results show changes in the coastal currents past 33.8° E, with frequent instances of water breaking away along the Lebanese coast. These events happen quickly and sometimes lead to long-lasting eddies. This study underscores the need for direct observations to improve our knowledge.
Menghong Dong and Xinyu Guo
Ocean Sci., 20, 1527–1546, https://doi.org/10.5194/os-20-1527-2024, https://doi.org/10.5194/os-20-1527-2024, 2024
Short summary
Short summary
We employed a gradient-based algorithm to identify the position and intensity of the fronts in a coastal sea using sea surface temperature data, thereby quantifying their variations. Our study provides a comprehensive analysis of these fronts, elucidating their seasonal variability, intra-tidal dynamics, and the influence of winds on the fronts. By capturing the temporal and spatial dynamics of these fronts, our understanding of the complex oceanographic processes within this region is enhanced.
Edwin Goh, Alice Yepremyan, Jinbo Wang, and Brian Wilson
Ocean Sci., 20, 1309–1323, https://doi.org/10.5194/os-20-1309-2024, https://doi.org/10.5194/os-20-1309-2024, 2024
Short summary
Short summary
An AI model was used to fill in missing parts of sea temperature (SST) maps caused by cloud cover. We found masked autoencoders can recreate missing SSTs with less than 0.2 °C error, even when 80 % are missing. This is 5000 times faster than conventional methods tested on a single central processing unit. This can enhance our ability in monitoring global small-scale ocean fronts that affect heat, carbon, and nutrient exchange in the ocean. The method is promising for future research.
Claudia Fanelli, Daniele Ciani, Andrea Pisano, and Bruno Buongiorno Nardelli
Ocean Sci., 20, 1035–1050, https://doi.org/10.5194/os-20-1035-2024, https://doi.org/10.5194/os-20-1035-2024, 2024
Short summary
Short summary
Sea surface temperature (SST) is an essential variable to understanding the Earth's climate system, and its accurate monitoring from space is essential. Since satellite measurements are hindered by cloudy/rainy conditions, data gaps are present even in merged multi-sensor products. Since optimal interpolation techniques tend to smooth out small-scale features, we developed a deep learning model to enhance the effective resolution of gap-free SST images over the Mediterranean Sea to address this.
Yingjie Liu and Xiaofeng Li
Ocean Sci., 19, 1579–1593, https://doi.org/10.5194/os-19-1579-2023, https://doi.org/10.5194/os-19-1579-2023, 2023
Short summary
Short summary
The study developed a deep learning model that effectively distinguishes between surface- and subsurface-intensified eddies in the northern Indian Ocean by integrating sea surface height and temperature data. The accurate distinction between these types of eddies provides valuable insights into their dynamics and their impact on marine ecosystems in the northern Indian Ocean and contributes to understanding the complex interactions between eddy dynamics and biogeochemical processes in the ocean.
Florian Le Guillou, Lucile Gaultier, Maxime Ballarotta, Sammy Metref, Clément Ubelmann, Emmanuel Cosme, and Marie-Helène Rio
Ocean Sci., 19, 1517–1527, https://doi.org/10.5194/os-19-1517-2023, https://doi.org/10.5194/os-19-1517-2023, 2023
Short summary
Short summary
Altimetry provides sea surface height (SSH) data along one-dimensional tracks. For many applications, the tracks are interpolated in space and time to provide gridded SSH maps. The operational SSH gridded products filter out the small-scale signals measured on the tracks. This paper evaluates the performances of a recently implemented dynamical method to retrieve the small-scale signals from real SSH data. We show a net improvement in the quality of SSH maps when compared to independent data.
Elisa Carli, Rosemary Morrow, Oscar Vergara, Robin Chevrier, and Lionel Renault
Ocean Sci., 19, 1413–1435, https://doi.org/10.5194/os-19-1413-2023, https://doi.org/10.5194/os-19-1413-2023, 2023
Short summary
Short summary
Oceanic eddies are the structures carrying most of the energy in our oceans. They are key to climate regulation and nutrient transport. We prepare for the Surface Water and Ocean Topography mission, studying eddy dynamics in the region south of Africa, where the Indian and Atlantic oceans meet, using models and simulated satellite data. SWOT will provide insights into the structures smaller than what is currently observable, which appear to greatly contribute to eddy kinetic energy and strain.
Cited articles
Andrade-Canto, F. and Beron-Vera, F. J.: Do eddies connect the tropical Atlantic Ocean and the Gulf of Mexico?, Geophys. Res. Lett., 49, e2022GL099637, https://doi.org/10.1029/2022GL099637, 2022.
Andrade-Canto, F., Beron-Vera, F. J., Goni, G. J., Karrasch, D., Olascoaga, M. J., and Triñanes, J.: Carriers of Sargassum and mechanism for coastal inundation in the Caribbean Sea, Phys. Fluids, 34, 016602, https://doi.org/10.1063/5.0079055, 2022.
Antonio-Martínez, F., Henaut, Y., Vega-Zepeda, A., Cerón-Flores, A. I., Raigoza-Figueras, R., Cetz-Navarro, N. P., and Espinoza-Avalos, J.: Leachate effects of pelagic Sargassum spp. on larval swimming behavior of the coral Acropora palmata, Sci. Rep., 10, 3910, https://doi.org/10.1038/s41598-020-60864-z, 2020.
Beron-Vera, F. J.: Nonlinear dynamics of inertial particles in the ocean: From drifters and floats to marine debris and Sargassum, Nonlin. Dynam., 103, 1–26, 2021.
Beron-Vera, F. J., Olascoaga, M. J., Haller, G., Farazmand, M., Triñanes, J., and Wang, Y.: Dissipative inertial transport patterns near coherent Lagrangian eddies in the ocean, Chaos, 25, 087412, https://doi.org/10.1063/1.4928693, 2015.
Brach, L., Deixonne, P., Bernard, M.-F., Durand, E., Desjean, M.-C., Perez, E., van Sebille, E., and ter Halle, A.: Anticyclonic eddies increase accumulation of microplastic in the North Atlantic subtropical gyre, Mar. Pollut. Bull., 126, 191–196, https://doi.org/10.1016/j.marpolbul.2017.10.077, 2018.
Chaigneau, A., Eldin, G., and Dewitte, B.: Eddy activity in the four major upwelling systems from satellite altimetry, (1992–2007), Prog. Oceanogr., 83, 117–123, https://doi.org/10.1016/j.pocean.2009.07.012, 2009.
Chen, G., Hou, Y., and Chu, X.: Mesoscale eddies in the South China Sea: Mean properties, spatiotemporal variability, and impact on thermohaline structure, J. Geophys. Res., 116, C06018, https://doi.org/10.1029/2010JC006716, 2011.
D'Asaro, E. A., Shcherbina, A. Y., Klymak, J. M., Molemaker, J., Novelli, G., Guigand, C. M., Haza, A. C., Haus, B. K., Ryan, E. H., Jacobs, G. A., Huntley, H. S., Laxague, N. J. M., Chen, S., Judt, F., McWilliams, J. C., Barkan, R., Kirwan, A. D., Poje, A. C., and Özgökmen, T. M.: Ocean convergence and the dispersion of flotsam, P. Natl. Acad. Sci. USA, 115, 1162–1167, https://doi.org/10.1073/pnas.1718453115, 2018.
Descloitres, J., Minghelli, A., Steinmetz, F., Chevalier, C., Chami, M., and Berline, L.: Revisited Estimation of Moderate Resolution Sargassum Fractional Coverage Using Decametric Satellite Data (S2/MSI), Remote Sens., 13, 5106, https://doi.org/10.3390/rs13245106, 2021.
Ernst, P. A., Subrahmanyam, B., Trott, C. B., and Chaigneau, A.: Characteristics of submesoscale eddy structures within mesoscale eddies in the Gulf of Mexico from 1/48° ECCO estimates, Front. Mar. Sci., 10, 1181676, https://doi.org/10.3389/fmars.2023.1181676, 2023.
Esposito, G., Berta, M., Centurioni, L., Lodise, J., Ozgokmen, T., Poulain, P.-M., and Griffa, A.: Submesoscale vorticity and divergence in the Alboran Sea: Scale and depth dependence, Front. Mar. Sci., 8, 843, https://doi.org/10.3389/fmars.2021.678304, 2021.
EU Copernicus Marine Service Product: Global Ocean Gridded L 4 Sea Surface Heights And Derived Variables Reprocessed Copernicus Climate Service, Mercator Ocean International [data set], https://doi.org/10.48670/moi-00145, 2024.
Gaube, P., McGillicuddy, D. J., Chelton, D. B., Behrenfeld, M. J., and Strutton, P. G.: Regional variations in the influence of mesoscale eddies on near-surface chlorophyll, J. Geophys. Res.-Oceans, 119, 8195–8220, https://doi.org/10.1002/2014JC010111, 2014.
Gower, J. F. R. and King, S. A.: Distribution of floating Sargassum in the Gulf of Mexico and the Atlantic Ocean mapped using MERIS, Int. J. Remote Sens., 32, 1917–1929, https://doi.org/10.1080/01431161003639660, 2011.
Gower, J., Young, E., and King, S.: Satellite images suggest a new Sargassum source region in 2011, Remote Sens. Lett., 4, 764–773, 2013.
Hendy, I. W., Woolford, K., Vincent-Piper, A., Burt, O., Schaefer, M., Cragg, S. M., Sanchez-Navarro, P., and Ragazzola, F.: Climate-driven golden tides are reshaping coastal communities in Quintana Roo, Mexico, Clim. Change Ecol., 2, 100033, https://doi.org/10.1016/j.ecochg.2021.100033, 2021.
Huang, M., Liang, X., Zhu, Y., Liu, Y., and Weisberg, R. H.: Eddies connect the tropical Atlantic Ocean and the Gulf of Mexico, Geophys. Res. Lett., 48, e2020GL091277, https://doi.org/10.1029/2020GL091277, 2021.
Jouanno, J., Sheinbaum, J., Barnier, B., Molines, J.-M., Debreu, L., and Lemarié, F.: The mesoscale variability in the caribbean sea. part i: Simulations and characteristics with an embedded model, Ocean Model., 23, 82–101, https://doi.org/10.1016/j.ocemod.2008.04.002, 2008.
Jouanno, J., Morvan, G., Berline, L., Benshila, R., Aumont, O., Sheinbaum, J., and Ménard, F.: Skillful seasonal forecast of Sargassum proliferation in the Tropical Atlantic, Geophys. Res. Lett., 50, e2023GL105545, https://doi.org/10.1029/2023GL105545, 2023.
Langmuir, I.: Surface motion of water induced by wind, Science, 87, 119–123, 1938.
Lévy, M., Franks, P. J., and Smith, K. S.: The role of submesoscale currents in structuring marine ecosystems, Nat. Commun., 9, 4758, https://doi.org/10.1038/s41467-018-07059-3, 2018.
McGillicuddy Jr., D. J.: Mechanisms of physical-biological-biogeochemical interaction at the oceanic mesoscale, Annu. Rev. Mar. Sci., 8, 125–159, https://doi.org/10.1146/annurev-marine-010814-015606, 2016.
Nencioli, F., Dong, C., Dickey, T., Washburn, L., and McWilliams, J. C.: A vector geometry-based eddy detection algorithm and its application to a high-resolution numerical model product and high-frequency radar surface velocities in the Southern California Bight, J. Atmos. Ocean. Tech., 27, 564–579, https://doi.org/10.1175/2009JTECHO725.1, 2010.
Ody, A., Thibaut, T., Berline, L., Changeux, T., André, J.-M., Chevalier, C., Blanfuné, A., Blanchot, J., Ruitton, S., Stiger-Pouvreau, V., Connan, S., Grelet, J., Aurelle, D., Guéné, M., Bataille, H., Bachelier, C., Guillemain, D., Schmidt, N., Fauvelle, V., Guasco, S., and Ménard, F.: From in situ to satellite observations of pelagic Sargassum distribution and aggregation in the Tropical North Atlantic Ocean, Plos ONE, 14, e0222584, https://doi.org/10.1371/journal.pone.0222584, 2019.
Okubo, A.: Horizontal dispersion of floatable particles in vicinity of velocity singularities such as convergences, Deep-Sea Res., 17, 445–454, https://doi.org/10.1016/0011-7471(70)90059-8, 1970.
Pegliasco, C., Chaigneau, A., and Morrow, R.: Main eddy vertical structures observed in the four major Eastern Boundary Upwelling Systems, J. Geophys. Res.-Oceans, 120, 6008–6033, 2015.
Pegliasco, C., Chaigneau, A., Morrow, R., and Dumas, F.: Detection and tracking of mesoscale eddies in the Mediterranean Sea: A comparison between the Sea Level Anomaly and the Absolute Dynamic Topography fields, Adv. Space Res., 68, 401–419, https://doi.org/10.1016/j.asr.2020.03.039, 2021.
Provenzale, A.: Transport by coherent barotropic vortices, Annu. Rev. Fluid Mech., 31, 55–93, https://doi.org/10.1146/annurev.fluid.31.1.55, 1999.
Richardson, P. L.: Caribbean Current and eddies as observed by surface drifters, Deep-Sea Res. Pt. II, 52, 429–463, 2005.
Rodríguez-Martínez, R. E., Reali, M. Á. G., Torres-Conde, E. G., and Bates, M. N.: Temporal and spatial variation in hydrogen sulfide (H2S) emissions during holopelagic Sargassum spp. decomposition on beaches, Environ. Res., 247, 118235, https://doi.org/10.1016/j.envres.2024.118235, 2024.
Rosellón-Druker, J., McAdam-Otto, L., Suca, J. J., Seary, R., Gaytán-Caballero, A., Escobar-Briones, E., Hazen, E., and Muller-Karger, F.: Local ecological knowledge and perception of the causes, impacts and effects of Sargassum massive influxes: a binational approach, Ecosyst. People, 19, 2253317, https://doi.org/10.1080/26395916.2023.2253317, 2023.
Sosa-Gutiérrez, R., Pallàs-Sanz, E., Jouanno, J., Chaigneau, A., Candela, J., and Tenreiro, M.: Erosion of the subsurface salinity maximum of the loop current eddies from glider observations and a numerical model, J. Geophys. Res.-Oceans, 125, e2019JC015397, https://doi.org/10.1029/2019JC015397, 2020.
Sosa-Gutierrez, R., Jouanno, J., Berline, L., Descloitres, J., and Chevalier, C.: Impact of tropical cyclones on pelagic Sargassum, Geophys. Res. Lett., 49, e2021GL097484, https://doi.org/10.1029/2021GL097484, 2022.
Sosa-Gutierrez, R., Jouanno, J., and Berline, L.: Sargassum accumulation and transport by mesoscale eddies [Data set], Zenodo [data set], https://doi.org/10.5281/zenodo.14816717, 2025.
Sun, Y., Wang, M., Liu, M., Li, Z. B., Chen, Z., and Huang, B.: Continuous Sargassum monitoring across the Caribbean Sea and Central Atlantic using multi-sensor satellite observations, Remote Sens. Environ., 309, 114223, https://doi.org/10.1016/j.rse.2024.114223, 2024.
Van Tussenbroek, B. I., Arana, H. A. H., Rodríguez-Martínez, R. E., Espinoza-Avalos, J., Canizales-Flores, H. M., González-Godoy, C. E., Barba-Santos, M. G., Vega-Zepeda, A., and Collado-Vides, L.: Severe impacts of brown tides caused by Sargassum spp. on near-shore Caribbean seagrass communities, Mar. Pollut. Bull., 122, 272–281, https://doi.org/10.1016/j.marpolbul.2017.06.057, 2017.
Vic, C., Hascoët, S., Gula, J., Huck, T., and Maes, C.: Oceanic mesoscale cyclones cluster surface Lagrangian material, Geophys. Res. Lett., 49, e2021GL097488, https://doi.org/10.1029/2021GL097488, 2022.
Wang, M. and Hu, C.: Mapping and quantifying Sargassum distribution and coverage in the Central Western Atlantic using MODIS observations, Remote Sens. Environ., 183, 350–367, https://doi.org/10.1016/j.rse.2016.04.019, 2016.
Wang, M., Hu, C., Cannizzaro, J., English, D., Han, X., Naar, D., Lapointe, B., Brewton, R., and Hernandez, F.: Remote sensing of Sargassum biomass, nutrients, and pigments, Geophys. Res. Lett., 45, 12359–12367, 2018.
Wang, M., Hu, C., Barnes, B. B., Mitchum, G., Lapointe, B., and Montoya, J. P.: The great Atlantic Sargassum belt, Science, 365, 83–87, https://doi.org/10.1126/science.aaw7912, 2019.
Weiss, J.: The dynamics of enstrophy transfer in 2-dimensional hydrodynamics, Physica D, 48, 273–294, https://doi.org/10.1016/0167-2789(91)90088-Q, 1991.
Zhong, Y., Bracco, A., and Villareal, T. A.: Pattern formation at the ocean surface: Sargassum distribution and the role of the eddy field, Limnol. Oceanogr.: Fluids Environ., 2, 12–27, https://doi.org/10.1215/21573689-1573372, 2012.
Short summary
Since 2010, pelagic Sargassum spp. blooms have increased in several tropical Atlantic regions, causing socioeconomic and ecosystem impacts. Offshore structuration of Sargassum by mesoscale dynamics may influence transport and growth. Sargassum stays afloat, constantly interacting with currents, waves, winds, and mesoscale eddies. We find that anticyclones and cyclones effectively trap Sargassum throughout its propagation, with a greater tendency for cyclones to accumulate Sargassum.
Since 2010, pelagic Sargassum spp. blooms have increased in several tropical Atlantic regions,...
