{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,19]],"date-time":"2026-05-19T00:03:07Z","timestamp":1779148987622,"version":"3.51.4"},"reference-count":53,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2022,3,31]],"date-time":"2022-03-31T00:00:00Z","timestamp":1648684800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42106008"],"award-info":[{"award-number":["42106008"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41730535"],"award-info":[{"award-number":["41730535"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["2020M681968"],"award-info":[{"award-number":["2020M681968"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004731","name":"Zhejiang Provincial Natural Science Foundation","doi-asserted-by":"publisher","award":["LY21D060001"],"award-info":[{"award-number":["LY21D060001"]}],"id":[{"id":"10.13039\/501100004731","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The large discrepancy between Eulerian and Lagrangian work motivates us to examine the leakage of Eulerian eddies and quantify the contribution of coherent eddy transport in the South China Sea (SCS). In this study, Lagrangian particles with a resolution of 1\/32\u00b0 are advected by surface geostrophic currents derived from satellite observations spanning 23 years, and two types of methods are employed to identify sea surface height (SSH) eddies and Lagrangian coherent structures. SSH eddies are proven to be highly leaky during their lifetimes, with more than 80% of the original water leaking out of the eddy interior. As a result of zonal and meridional eddy propagation, the leaked water exhibits a spatial pattern of asymmetry relative to the eddy center. The degree of eddy leakage is found to be independent of several eddy parameters including the nonlinearity parameter U\/c, which has been commonly used to assess eddy coherency. Finally, the Lagrangian coherent structures in the SCS are diagnosed and the associated coherent eddy diffusivity is calculated. It is found that coherent eddies contribute to less than 5% of the total eddy material transport in both zonal and meridional directions. These findings suggest that previous studies based on the Eulerian framework significantly overestimate the contribution of coherent eddy transport in the SCS.<\/jats:p>","DOI":"10.3390\/rs14071690","type":"journal-article","created":{"date-parts":[[2022,3,31]],"date-time":"2022-03-31T21:34:29Z","timestamp":1648762469000},"page":"1690","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Diagnostics of Coherent Eddy Transport in the South China Sea Based on Satellite Observations"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6945-1393","authenticated-orcid":false,"given":"Tongya","family":"Liu","sequence":"first","affiliation":[{"name":"State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8531-6834","authenticated-orcid":false,"given":"Yinghui","family":"He","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoming","family":"Zhai","sequence":"additional","affiliation":[{"name":"School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6119-4676","authenticated-orcid":false,"given":"Xiaohui","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310000, China"},{"name":"Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1146\/annurev.fluid.36.050802.122121","article-title":"Vertical mixing, energy, and the general circulation of the oceans","volume":"36","author":"Wunsch","year":"2004","journal-title":"Annu. Rev. Fluid Mech."},{"key":"ref_2","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_3","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_4","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1029\/2000RG000084","article-title":"The dynamics of ocean heat transport variability","volume":"39","author":"Jayne","year":"2001","journal-title":"Rev. Geophys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1038\/ngeo2289","article-title":"Eddy transport as a key component of the Antarctic overturning circulation","volume":"7","author":"Thompson","year":"2014","journal-title":"Nat. Geosci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"eaav5014","DOI":"10.1126\/sciadv.aav5014","article-title":"Ocean mesoscale mixing linked to climate variability","volume":"5","author":"Busecke","year":"2019","journal-title":"Sci. Adv."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"753","DOI":"10.1007\/s10872-008-0063-8","article-title":"Recent progress in studies of the South China Sea circulation","volume":"64","author":"Liu","year":"2008","journal-title":"J. Oceanogr."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Zheng, Q., Hu, J., Ho, C.-R., and Xie, L. (2020). Advances in Research of Regional Oceanography of the South China Sea: Overview, World Scientific Publishing Company.","DOI":"10.1142\/9789811206917_0001"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1029\/2010JC006716","article-title":"Mesoscale eddies in the South China Sea: Mean properties, spatiotemporal variability, and impact on thermohaline structure","volume":"116","author":"Chen","year":"2011","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4906","DOI":"10.1029\/2018JC014054","article-title":"A New Assessment of Mesoscale Eddies in the South China Sea: Surface Features, Three-Dimensional Structures, and Thermohaline Transports","volume":"123","author":"He","year":"2018","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"6761","DOI":"10.1038\/s41598-017-07059-1","article-title":"Antisymmetry of oceanic eddies across the Kuroshio over a shelfbreak","volume":"7","author":"Liu","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_12","first-page":"2329","article-title":"Eddy-induced Heat Transport in the South China Sea","volume":"51","author":"Ding","year":"2021","journal-title":"J. Phys. Oceanogr."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1146\/annurev-fluid-010313-141322","article-title":"Lagrangian coherent structures","volume":"47","author":"Haller","year":"2015","journal-title":"Annu. Rev. Fluid Mech."},{"key":"ref_14","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_15","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_16","doi-asserted-by":"crossref","unstructured":"Wang, G., Su, J., and Chu, P. (2003). Mesoscale eddies in the South China Sea observed with altimeter data. Geophys. Res. Lett., 30.","DOI":"10.1029\/2003GL018532"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Xiu, P., Chai, F., Shi, L., Xue, H., and Chao, Y. (2010). A census of eddy activities in the South China Sea during 1993\u20132007. J. Geophys. Res. Ocean., 115.","DOI":"10.1029\/2009JC005657"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Hu, J., Gan, J., Sun, Z., Zhu, J., and Dai, M. (2011). Observed three-dimensional structure of a cold eddy in the southwestern South China Sea. J. Geophys. Res. Ocean., 116.","DOI":"10.1029\/2010JC006810"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.dsr.2015.01.007","article-title":"Three-dimensional properties of mesoscale eddies in the South China Sea based on eddy-resolving model output","volume":"99","author":"Lin","year":"2015","journal-title":"Deep Sea Res. Part I: Oceanogr. Res. Pap."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5937","DOI":"10.1038\/srep05937","article-title":"Mesoscale eddies transport deep-sea sediments","volume":"4","author":"Zhang","year":"2014","journal-title":"Sci. Rep."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.dsr.2011.11.006","article-title":"Heat, salt and volume transports by eddies in the vicinity of the Luzon Strait","volume":"61","author":"Wang","year":"2011","journal-title":"Deep Sea Res. Part I Oceanogr. Res. Pap."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1175\/JPO-D-16-0185.1","article-title":"Anticyclonic Eddy Sheddings from Kuroshio Loop and the Accompanying Cyclonic Eddy in the Northeastern South China Sea","volume":"47","author":"Zhang","year":"2017","journal-title":"J. Phys. Oceanogr."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e2020EF001857","DOI":"10.1029\/2020EF001857","article-title":"How Much Heat and Salt Are Transported Into the South China Sea by Mesoscale Eddies?","volume":"9","author":"Yang","year":"2021","journal-title":"Earth\u2019s Futur."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/0011-7471(70)90059-8","article-title":"Horizontal dispersion of floatable particles in the vicinity of velocity singularities such as convergences","volume":"17","author":"Okubo","year":"1970","journal-title":"Deep Sea Res. Oceanogr. Abstr."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/0167-2789(91)90088-Q","article-title":"The dynamics of enstrophy transfer in two-dimensional hydrodynamics","volume":"48","author":"Weiss","year":"1991","journal-title":"Phys. D Nonlinear Phenom."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"564","DOI":"10.1175\/2009JTECHO725.1","article-title":"A Vector Geometry\u2013Based Eddy Detection Algorithm and Its Application to a High-Resolution Numerical Model Product and High-Frequency Radar Surface Velocities in the Southern California Bight","volume":"27","author":"Nencioli","year":"2010","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1175\/JPO-D-17-0102.1","article-title":"Transport by Lagrangian Vortices in the Eastern Pacific","volume":"48","author":"Abernathey","year":"2018","journal-title":"J. Phys. Oceanogr."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.physd.2005.10.007","article-title":"Definition and properties of Lagrangian coherent structures from finite-time Lyapunov exponents in two-dimensional aperiodic flows","volume":"212","author":"Shadden","year":"2005","journal-title":"Phys. D Nonlinear Phenom."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.dsr.2008.07.014","article-title":"Comparison between Eulerian diagnostics and finite-size Lyapunov exponents computed from altimetry in the Algerian basin","volume":"56","year":"2009","journal-title":"Deep Sea Res. Part I Oceanogr. Res. Pap."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1017\/jfm.2016.151","article-title":"Defining coherent vortices objectively from the vorticity","volume":"795","author":"Haller","year":"2016","journal-title":"J. Fluid Mech."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Haller, G., and Beron-Vera, F.J. (2013). Coherent Lagrangian vortices: The black holes of turbulence. J. Fluid Mech., 731.","DOI":"10.1017\/jfm.2013.391"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4072","DOI":"10.1002\/2015GL064089","article-title":"Coherent water transport across the South Atlantic","volume":"42","author":"Wang","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"8869","DOI":"10.1029\/2019JC015576","article-title":"Quantifying Eulerian Eddy Leakiness in an Idealized Model","volume":"124","author":"Liu","year":"2019","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_34","first-page":"67a-12-gbf23121","article-title":"MITgcm documentation","volume":"19","author":"Adcroft","year":"2018","journal-title":"Release Checkp."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1002\/jgrc.20066","article-title":"Global surface eddy diffusivities derived from satellite altimetry","volume":"118","author":"Abernathey","year":"2013","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5185","DOI":"10.1002\/2016GL068842","article-title":"Interannual variability of winter eddy patterns in the eastern South China Sea","volume":"43","author":"He","year":"2016","journal-title":"Geophys. Res. Lett."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"e2020JC016556","DOI":"10.1029\/2020JC016556","article-title":"Revisit the Vertical Structure of the Eddies and Eddy-Induced Transport in the Leeuwin Current System","volume":"126","author":"He","year":"2021","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"150028","DOI":"10.1038\/sdata.2015.28","article-title":"A daily global mesoscale ocean eddy dataset from satellite altimetry","volume":"2","author":"Faghmous","year":"2015","journal-title":"Sci. Data"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Zhang, W., Wolfe, C.L.P., and Abernathey, R. (2019). Role of Surface-Layer Coherent Eddies in Potential Vorticity Transport in Quasigeostrophic Turbulence Driven by Eastward Shear. Fluids, 5.","DOI":"10.3390\/fluids5010002"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1291","DOI":"10.1007\/s10236-011-0426-3","article-title":"Identification of different types of Kuroshio intrusion into the South China Sea","volume":"61","author":"Nan","year":"2011","journal-title":"Ocean Dyn."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"726","DOI":"10.1175\/2007JPO3868.1","article-title":"Winter Eddy Genesis in the Eastern South China Sea due to Orographic Wind Jets","volume":"38","author":"Wang","year":"2008","journal-title":"J. Phys. Oceanogr."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3113","DOI":"10.1007\/s00382-015-2756-1","article-title":"Interannual-to-decadal variability and trends of sea level in the South China Sea","volume":"46","author":"Cheng","year":"2015","journal-title":"Clim. Dyn."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1175\/1520-0485(1998)028<0433:GVOTFB>2.0.CO;2","article-title":"Geographical variability of the first baro-clinic Rossby radius of deformation","volume":"28","author":"Chelton","year":"1998","journal-title":"J. Phys. Oceanogr."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1007\/s13131-020-1678-x","article-title":"Statistical analysis of mesoscale eddy propagation velocity in the South China Sea deep basin","volume":"39","author":"Huang","year":"2020","journal-title":"Acta Oceanol. Sin."},{"key":"ref_45","unstructured":"Reynolds, O. (1903). The Sub-Mechanics of the Universe, University Press."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1535","DOI":"10.1175\/2011JPO4601.1","article-title":"The Evolution and Propagation of Quasigeostrophic Ocean Eddies","volume":"41","author":"Early","year":"2011","journal-title":"J. Phys. Oceanogr."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.ocemod.2018.07.001","article-title":"Identifying Lagrangian coherent vortices in a mesoscale ocean model","volume":"130","author":"Tarshish","year":"2018","journal-title":"Ocean Model."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.pocean.2008.02.002","article-title":"Statistics from Lagrangian observations","volume":"77","author":"LaCasce","year":"2008","journal-title":"Prog. Oceanogr."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1566","DOI":"10.1175\/JPO-D-11-0205.1","article-title":"Estimating Suppression of Eddy Mixing by Mean Flows","volume":"42","author":"Klocker","year":"2012","journal-title":"J. Phys. Oceanogr."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1881","DOI":"10.1175\/1520-0469(1984)041<1881:RDLAND>2.0.CO;2","article-title":"Relative Dispersion: Local and Nonlocal Dynamics","volume":"41","author":"Bennett","year":"1984","journal-title":"J. Atmos. Sci."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"7413","DOI":"10.1002\/2015JC011047","article-title":"Southern Ocean eddy phenomenology","volume":"120","author":"Frenger","year":"2015","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1175\/JPO-D-16-0256.1","article-title":"Elevated Mixing in the Periphery of Mesoscale Eddies in the South China Sea","volume":"47","author":"Yang","year":"2017","journal-title":"J. Phys. Oceanogr."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"837","DOI":"10.5194\/os-13-837-2017","article-title":"A modelling study of eddy-splitting by an island\/seamount","volume":"13","author":"Yang","year":"2017","journal-title":"Ocean Sci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/7\/1690\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:47:43Z","timestamp":1760136463000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/7\/1690"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,31]]},"references-count":53,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2022,4]]}},"alternative-id":["rs14071690"],"URL":"https:\/\/doi.org\/10.3390\/rs14071690","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,3,31]]}}}