{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,25]],"date-time":"2026-01-25T08:46:32Z","timestamp":1769330792322,"version":"3.49.0"},"reference-count":57,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,20]],"date-time":"2024-09-20T00:00:00Z","timestamp":1726790400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Laoshan Laboratory Science and Technology Innovation Projects","award":["LSKJ202201406-3"],"award-info":[{"award-number":["LSKJ202201406-3"]}]},{"name":"Laoshan Laboratory Science and Technology Innovation Projects","award":["2023YFB3907704"],"award-info":[{"award-number":["2023YFB3907704"]}]},{"name":"Laoshan Laboratory Science and Technology Innovation Projects","award":["LSKJ202400203"],"award-info":[{"award-number":["LSKJ202400203"]}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["LSKJ202201406-3"],"award-info":[{"award-number":["LSKJ202201406-3"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2023YFB3907704"],"award-info":[{"award-number":["2023YFB3907704"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["LSKJ202400203"],"award-info":[{"award-number":["LSKJ202400203"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Laoshan Laboratory Science and Technology Innovation Projects","award":["LSKJ202201406-3"],"award-info":[{"award-number":["LSKJ202201406-3"]}]},{"name":"Laoshan Laboratory Science and Technology Innovation Projects","award":["2023YFB3907704"],"award-info":[{"award-number":["2023YFB3907704"]}]},{"name":"Laoshan Laboratory Science and Technology Innovation Projects","award":["LSKJ202400203"],"award-info":[{"award-number":["LSKJ202400203"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Conventional altimetry has greatly advanced our understanding of mesoscale eddies but falls short in studying fine-scale eddies (&lt;150 km). The newly launched Surface Water and Ocean Topography (SWOT) altimeter, however, with its unprecedented high-resolution capabilities, offers new opportunities to observe these fine-scale eddies. In this study, we use SWOT data to explore these previously elusive fine-scale eddies in the Kuroshio Extension. During SWOT\u2019s fast sampling phase from 29 May 2023 to 10 July 2023, we identified an average of 4.5 fine-scale eddies within each 120 km wide swath. Cyclonic eddies, which are slightly more frequent than the anticyclonic ones (ratio of 1.16), have a similar mean radius of 23.4 km. However, cyclonic eddies exhibit higher amplitudes, averaging 3.5 cm compared to 2.8 cm for anticyclonic eddies. In contrast to the mesoscale eddies detected by conventional altimeters, the fine-scale eddies revealed by SWOT are characterized by smaller sizes and weaker amplitudes. This study offers a preliminary view of fine-scale eddy characteristics from space, highlighting SWOT\u2019s potential to advance our understanding of these dynamic processes. Nonetheless, it also emphasizes the necessity for comprehensive analysis to fully exploit the satellite\u2019s capabilities in monitoring and interpreting complex eddy behaviors.<\/jats:p>","DOI":"10.3390\/rs16183488","type":"journal-article","created":{"date-parts":[[2024,9,20]],"date-time":"2024-09-20T07:38:57Z","timestamp":1726817937000},"page":"3488","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Fine-Scale Eddies Detected by SWOT in the Kuroshio Extension"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1636-4776","authenticated-orcid":false,"given":"Tianshi","family":"Du","sequence":"first","affiliation":[{"name":"Laoshan Laboratory, Qingdao 266237, China"}]},{"given":"Zhao","family":"Jing","sequence":"additional","affiliation":[{"name":"Laoshan Laboratory, Qingdao 266237, China"},{"name":"Physical Oceanography Laboratory, Ocean University of China, Qingdao 266100, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.pocean.2011.01.002","article-title":"Global Observations of Nonlinear Mesoscale Eddies","volume":"91","author":"Chelton","year":"2011","journal-title":"Prog. Oceanogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"L15605","DOI":"10.1029\/2008GL034736","article-title":"Submesoscale Activity over the Argentinian Shelf","volume":"35","author":"Capet","year":"2008","journal-title":"Geophys. Res. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1539","DOI":"10.1175\/2010JPO4353.1","article-title":"The Role of Mesoscale Eddies in the Rectification of the Southern Ocean Response to Climate Change","volume":"40","author":"Farneti","year":"2010","journal-title":"J. Phys. Oceanogr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"795","DOI":"10.1029\/2018EA000492","article-title":"Ocean-Scale Interactions from Space","volume":"6","author":"Klein","year":"2019","journal-title":"Earth Space Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1146\/annurev.fluid.40.111406.102139","article-title":"Ocean Circulation Kinetic Energy: Reservoirs, Sources, and Sinks","volume":"41","author":"Ferrari","year":"2009","journal-title":"Annu. Rev. Fluid Mech."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1126\/science.1252418","article-title":"Oceanic Mass Transport by Mesoscale Eddies","volume":"345","author":"Zhang","year":"2014","journal-title":"Science"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3294","DOI":"10.1038\/ncomms4294","article-title":"Global Heat and Salt Transports by Eddy Movement","volume":"5","author":"Dong","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1126\/science.1208897","article-title":"The Influence of Nonlinear Mesoscale Eddies on Near-Surface Oceanic Chlorophyll","volume":"334","author":"Chelton","year":"2011","journal-title":"Science"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"14","DOI":"10.5670\/oceanog.2010.02","article-title":"Eddy Dynamics From Satellite Altimetry","volume":"23","author":"Fu","year":"2010","journal-title":"Oceanography"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"C11025","DOI":"10.1029\/2011JC007134","article-title":"Vertical Structure of Mesoscale Eddies in the Eastern South Pacific Ocean: A Composite Analysis from Altimetry and Argo Profiling Floats","volume":"116","author":"Chaigneau","year":"2011","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3990","DOI":"10.1002\/2015JC011371","article-title":"Eddy Properties in the Western Mediterranean Sea from Satellite Altimetry and a Numerical Simulation","volume":"121","author":"Escudier","year":"2016","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1007\/s11707-014-0478-z","article-title":"The Most Typical Shape of Oceanic Mesoscale Eddies from Global Satellite Sea Level Observations","volume":"9","author":"Wang","year":"2015","journal-title":"Front. Earth Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3677","DOI":"10.1002\/grl.50736","article-title":"Universal Structure of Mesoscale Eddies in the Ocean","volume":"40","author":"Zhang","year":"2013","journal-title":"Geophys. Res. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"You, Z., Liu, L., Bethel, B.J., and Dong, C. (2022). Feature Comparison of Two Mesoscale Eddy Datasets Based on Satellite Altimeter Data. Remote Sens., 14.","DOI":"10.3390\/rs14010116"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"8195","DOI":"10.1002\/2014JC010111","article-title":"Regional Variations in the Influence of Mesoscale Eddies on Near-Surface Chlorophyll","volume":"119","author":"Gaube","year":"2014","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e2020JC016670","DOI":"10.1029\/2020JC016670","article-title":"Large Mesoscale Eddies in the Western Arctic Ocean from Satellite Altimetry Measurements","volume":"126","author":"Kubryakov","year":"2021","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e2023JC019701","DOI":"10.1029\/2023JC019701","article-title":"Eddy Tracking from In Situ and Satellite Observations","volume":"128","author":"Erickson","year":"2023","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5164","DOI":"10.3390\/rs6065164","article-title":"Statistical Characteristics of Mesoscale Eddies in the North Pacific Derived from Satellite Altimetry","volume":"6","author":"Cheng","year":"2014","journal-title":"Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"19477","DOI":"10.1029\/2000JC900063","article-title":"Global High-Resolution Mapping of Ocean Circulation from TOPEX\/Poseidon and ERS-1 and -2","volume":"105","author":"Ducet","year":"2000","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4910","DOI":"10.1002\/2015JC010904","article-title":"Mesoscale Resolution Capability of Altimetry: Present and Future","volume":"121","author":"Dufau","year":"2016","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7220","DOI":"10.1029\/2018JC014140","article-title":"Up to What Extent Can We Characterize Ocean Eddies Using Present-Day Gridded Altimetric Products?","volume":"123","author":"Amores","year":"2018","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5318","DOI":"10.1002\/2015JC010889","article-title":"Dominant Role of Eddies and Filaments in the Offshore Transport of Carbon and Nutrients in the California Current System","volume":"120","author":"Nagai","year":"2015","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.1007\/s10236-017-1089-5","article-title":"Benchmarking the Mesoscale Variability in Global Ocean Eddy-Permitting Numerical Systems","volume":"67","author":"Cipollone","year":"2017","journal-title":"Ocean. Dyn."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1175\/JTECH-D-13-00109.1","article-title":"On the Transition from Profile Altimeter to Swath Altimeter for Observing Global Ocean Surface Topography","volume":"31","author":"Fu","year":"2014","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1109\/JPROC.2010.2043031","article-title":"The Surface Water and Ocean Topography Mission: Observing Terrestrial Surface Water and Oceanic Submesoscale Eddies","volume":"98","author":"Durand","year":"2010","journal-title":"Proc. IEEE"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"e2023GL107652","DOI":"10.1029\/2023GL107652","article-title":"The Surface Water and Ocean Topography Mission: A Breakthrough in Radar Remote Sensing of the Ocean and Land Surface Water","volume":"51","author":"Fu","year":"2024","journal-title":"Geophys. Res. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Morrow, R., Fu, L.-L., Ardhuin, F., Benkiran, M., Chapron, B., Cosme, E., d\u2019Ovidio, F., Farrar, J.T., Gille, S.T., and Lapeyre, G. (2019). Global Observations of Fine-Scale Ocean Surface Topography with the Surface Water and Ocean Topography (SWOT) Mission. Front. Mar. Sci., 6.","DOI":"10.3389\/fmars.2019.00232"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"d\u2019Ovidio, F., Pascual, A., Wang, J., Doglioli, A.M., Jing, Z., Moreau, S., Gr\u00e9gori, G., Swart, S., Speich, S., and Cyr, F. (2019). Frontiers in Fine-Scale In Situ Studies: Opportunities during the SWOT Fast Sampling Phase. Front. Mar. Sci., 6.","DOI":"10.3389\/fmars.2019.00168"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"20160117","DOI":"10.1098\/rspa.2016.0117","article-title":"Submesoscale Currents in the Ocean","volume":"472","author":"McWilliams","year":"2016","journal-title":"Proc. R. Soc. A."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"e2024GL110000","DOI":"10.1029\/2024GL110000","article-title":"Submesoscale Eddies Detected by SWOT and Moored Observations in the Northwestern Pacific","volume":"51","author":"Zhang","year":"2024","journal-title":"Geophys. Res. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"18491","DOI":"10.1029\/91JC01834","article-title":"Mean Flow and Variability in the Kuroshio Extension from Geosat Altimetry Data","volume":"96","author":"Qiu","year":"1991","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1007\/s10872-015-0283-7","article-title":"Oceanic Fronts and Jets around Japan: A Review","volume":"71","author":"Kida","year":"2015","journal-title":"J. Oceanogr."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"499","DOI":"10.1007\/s10872-014-0270-4","article-title":"Climatological Mean Features and Interannual to Decadal Variability of Ring Formations in the Kuroshio Extension Region","volume":"71","author":"Sasaki","year":"2015","journal-title":"J. Oceanogr."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2090","DOI":"10.1175\/JPO2807.1","article-title":"Variability of the Kuroshio Extension Jet, Recirculation Gyre, and Mesoscale Eddies on Decadal Time Scales","volume":"35","author":"Qiu","year":"2005","journal-title":"J. Phys. Oceanogr."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"8548","DOI":"10.1029\/2018JC014196","article-title":"Oceanic Eddy Characteristics and Generation Mechanisms in the Kuroshio Extension Region","volume":"123","author":"Ji","year":"2018","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6653","DOI":"10.1029\/2018JC014081","article-title":"Decadal Variability of Eddy Characteristics and Energetics in the Kuroshio Extension: Unstable Versus Stable States","volume":"123","author":"Yang","year":"2018","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1339","DOI":"10.1175\/JPO-D-18-0159.1","article-title":"Mesoscale SST Dynamics in the Kuroshio\u2013Oyashio Extension Region","volume":"49","author":"Jing","year":"2019","journal-title":"J. Phys. Oceanogr."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"G\u00f3mez-Navarro, L., Cosme, E., Sommer, J.L., Papadakis, N., and Pascual, A. (2020). Development of an Image De-Noising Method in Preparation for the Surface Water and Ocean Topography Satellite Mission. Remote Sens., 12.","DOI":"10.3390\/rs12040734"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Tr\u00e9boutte, A., Carli, E., Ballarotta, M., Carpentier, B., Faug\u00e8re, Y., and Dibarboure, G. (2023). KaRIn Noise Reduction Using a Convolutional Neural Network for the SWOT Ocean Products. Remote Sens., 15.","DOI":"10.3390\/rs15082183"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"e2024JC021086","DOI":"10.1029\/2024JC021086","article-title":"Seasonal and Fortnight Variations in Internal Solitary Waves in the Indonesian Seas from the SWOT Measurements","volume":"129","author":"Qiu","year":"2024","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1181","DOI":"10.1175\/JTECH-D-14-00019.1","article-title":"A New Sea Surface Height\u2013Based Code for Oceanic Mesoscale Eddy Tracking","volume":"31","author":"Mason","year":"2014","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1175\/JTECH-D-18-0119.1","article-title":"On the Spatial Scales to Be Resolved by the Surface Water and Ocean Topography Ka-Band Radar Interferometer","volume":"36","author":"Wang","year":"2019","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1675","DOI":"10.1175\/JPO-D-18-0058.1","article-title":"On the Seasonal Eddy Variability in the Kuroshio Extension","volume":"48","author":"Yang","year":"2018","journal-title":"J. Phys. Oceanogr."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1175\/1520-0469(1971)028<1087:GT>2.0.CO;2","article-title":"Geostrophic Turbulence","volume":"28","author":"Charney","year":"1971","journal-title":"J. Atmos. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1017\/S0022112095000012","article-title":"Surface Quasi-Geostrophic Dynamics","volume":"282","author":"Held","year":"1995","journal-title":"J. Fluid Mech."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Ma, C., Guo, X., Zhang, H., Di, J., and Chen, G. (2020). An Investigation of the Influences of SWOT Sampling and Errors on Ocean Eddy Observation. Remote Sens., 12.","DOI":"10.3390\/rs12172682"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1175\/JPO-D-15-0188.1","article-title":"Reconstructability of Three-Dimensional Upper-Ocean Circulation from SWOT Sea Surface Height Measurements","volume":"46","author":"Qiu","year":"2016","journal-title":"J. Phys. Oceanogr."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1409","DOI":"10.1175\/JTECH-D-12-00032.1","article-title":"Using High-Resolution Altimetry to Observe Mesoscale Signals","volume":"29","author":"Pujol","year":"2012","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1175\/JTECH-D-14-00152.1","article-title":"Dynamic Interpolation of Sea Surface Height and Potential Applications for Future High-Resolution Altimetry Mapping","volume":"32","author":"Ubelmann","year":"2015","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1047","DOI":"10.1007\/s10236-017-1073-0","article-title":"Using a Dynamical Advection to Reconstruct a Part of the SSH Evolution in the Context of SWOT, Application to the Mediterranean Sea","volume":"67","author":"Morrow","year":"2017","journal-title":"Ocean. Dyn."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"e2019JC015878","DOI":"10.1029\/2019JC015878","article-title":"Increasing the Space\u2013Time Resolution of Mapped Sea Surface Height From Altimetry","volume":"125","author":"Archer","year":"2020","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1593","DOI":"10.1175\/JTECH-D-20-0030.1","article-title":"Dynamic Mapping of Along-Track Ocean Altimetry: Performance from Real Observations","volume":"37","author":"Ballarotta","year":"2020","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1175\/JTECH-D-20-0104.1","article-title":"Mapping Altimetry in the Forthcoming SWOT Era by Back-and-Forth Nudging a One-Layer Quasigeostrophic Model","volume":"38","author":"Guillou","year":"2021","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_54","first-page":"1","article-title":"Blending 2D Topography Images from SWOT into the Altimeter Constellation with the Level-3 Multi-Mission DUACS System","volume":"2024","author":"Dibarboure","year":"2024","journal-title":"EGUsphere"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1175\/JPO-D-17-0169.1","article-title":"Seasonality in Transition Scale from Balanced to Unbalanced Motions in the World Ocean","volume":"48","author":"Qiu","year":"2018","journal-title":"J. Phys. Oceanogr."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"2271","DOI":"10.1175\/JPO-D-18-0272.1","article-title":"Some Expectations for Submesoscale Sea Surface Height Variance Spectra","volume":"49","author":"Callies","year":"2019","journal-title":"J. Phys. Oceanogr."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1067","DOI":"10.5194\/os-12-1067-2016","article-title":"DUACS DT2014: The New Multi-Mission Altimeter Data Set Reprocessed over 20 Years","volume":"12","author":"Pujol","year":"2016","journal-title":"Ocean Sci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/18\/3488\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:00:40Z","timestamp":1760112040000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/18\/3488"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,20]]},"references-count":57,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2024,9]]}},"alternative-id":["rs16183488"],"URL":"https:\/\/doi.org\/10.3390\/rs16183488","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,20]]}}}