{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:11:43Z","timestamp":1760130703634,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2023,8,31]],"date-time":"2023-08-31T00:00:00Z","timestamp":1693440000000},"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":["42192552","41775053","42022033","2019YFC1510001"],"award-info":[{"award-number":["42192552","41775053","42022033","2019YFC1510001"]}],"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":["42192552","41775053","42022033","2019YFC1510001"],"award-info":[{"award-number":["42192552","41775053","42022033","2019YFC1510001"]}],"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":["42192552","41775053","42022033","2019YFC1510001"],"award-info":[{"award-number":["42192552","41775053","42022033","2019YFC1510001"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Key Research and Development Program of China","award":["42192552","41775053","42022033","2019YFC1510001"],"award-info":[{"award-number":["42192552","41775053","42022033","2019YFC1510001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>A satellite altimeter measures sea surface height (SSH) along the nadir track. Multiple satellite altimeters have been in orbit, and the measurements been merged for mapping mesoscale eddies of ~100 km in size in the oceans. The capability of the mapped SSH for resolving mesoscale eddies depends on mapping algorithms. A two-dimensional variational (2DVAR) algorithm was implemented to generate mapped SSH at a grid size of 1\/12\u00b0 in the South China Sea. A range of comparisons were performed between the mapped SSH and the commonly used AVISO (Archiving, Validation, and Interpretation of Satellite Oceanographic satellite data) mapped SSH data product at a grid size of 1\/8\u00b0 and 1\/4\u00b0. The effective resolution, which represents the spatial scale that the data can resolve, was examined. The effective resolution of the mapped SSH using the 2DVAR algorithm is approximately 100 km, while it is 250 km with the 1\/8\u00b0 and 1\/4\u00b0 AVISO data products. The difference in the effective resolution results from the difference in the background state and thus the background error. The result suggests that the effective resolution of the mapped data could be increased by choosing a background state so that the associated errors could have a smaller decorrelation length scale.<\/jats:p>","DOI":"10.3390\/rs15174275","type":"journal-article","created":{"date-parts":[[2023,8,31]],"date-time":"2023-08-31T11:41:18Z","timestamp":1693482078000},"page":"4275","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Key Factors for Improving the Resolution of Mapped Sea Surface Height from Multi-Satellite Altimeters in the South China Sea"],"prefix":"10.3390","volume":"15","author":[{"given":"Lei","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Atmosphere and Ocean Sciences, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China"},{"name":"College of Meteorology and Oceanology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Xiaoya","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Meteorology and Oceanology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Jianfang","family":"Fei","sequence":"additional","affiliation":[{"name":"College of Meteorology and Oceanology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Zhijin","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Atmosphere and Ocean Sciences, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China"},{"name":"Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, CA 90095, USA"}]},{"given":"Wenli","family":"Shi","sequence":"additional","affiliation":[{"name":"Army Academy of Artillery and Air Defense, Nanjing 211131, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4334-3882","authenticated-orcid":false,"given":"Huizan","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Meteorology and Oceanology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Xingliang","family":"Jiang","sequence":"additional","affiliation":[{"name":"Department of Atmosphere and Ocean Sciences, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China"}]},{"given":"Ze","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Meteorology and Oceanology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Xianyu","family":"Lv","sequence":"additional","affiliation":[{"name":"College of Meteorology and Oceanology, National University of Defense Technology, Changsha 410073, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e2020JC016560","DOI":"10.1029\/2020JC016560","article-title":"Reconstructing Ocean Surface Current Combining Altimetry and Future Spaceborne Doppler Data","volume":"126","author":"Ubelmann","year":"2021","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"789","DOI":"10.5194\/os-17-789-2021","article-title":"The new CNES-CLS18 global mean dynamic topography","volume":"17","author":"Mulet","year":"2021","journal-title":"Ocean Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2937","DOI":"10.1002\/2016JC011716","article-title":"A global surface drifter data set at hourly resolution","volume":"121","author":"Elipot","year":"2016","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/j.asr.2021.01.022","article-title":"Altimetry for the future: Building on 25 years of progress","volume":"68","author":"Abdalla","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1038\/s41586-022-05326-4","article-title":"Ocean currents show global intensification of weak tropical cyclones","volume":"611","author":"Wang","year":"2022","journal-title":"Nature"},{"key":"ref_6","first-page":"1","article-title":"100 Years of Progress in Ocean Observing Systems","volume":"59","author":"Davis","year":"2018","journal-title":"Meteorol. Monogr."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.1175\/JTECH-D-17-0153.1","article-title":"Estimating the Velocity and Transport of Western Boundary Current Systems: A Case Study of the East Australian Current near Brisbane","volume":"35","author":"Zilberman","year":"2018","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_8","unstructured":"Warren, B., and Wunsch, C. (1981). Evolution of Physical Oceanoaraphy, MIT Press."},{"key":"ref_9","first-page":"43","article-title":"A global high-resolution ocean wave model improved by assimilating the satellite altimeter significant wave height","volume":"70","author":"Yu","year":"2018","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_10","first-page":"1297","article-title":"Satellite Altimetry Over Oceans and Land Surfaces","volume":"123","author":"Detlef","year":"2019","journal-title":"Aeronaut. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2019JC015878","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_12","doi-asserted-by":"crossref","first-page":"1888","DOI":"10.1360\/TB-2020-0197","article-title":"Development and evaluation of a new merged sea surface height product from multi-satellite altimeters","volume":"65","author":"Liu","year":"2020","journal-title":"Chin. Sci. Bull."},{"key":"ref_13","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_14","unstructured":"Chelton, D., Dibarboure, G., Pujol, M.I., Taburet, G., and Schlax, M.G. (2014). The Spatial Resolution of AVISO Gridded Sea Surface Height Fields, OSTST. Available online: https:\/\/meetings.aviso.altimetry.fr\/fileadmin\/user_upload\/tx_ausyclsseminar\/files\/29Red0900-1_OSTST_Chelton.pdf."},{"key":"ref_15","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_16","doi-asserted-by":"crossref","first-page":"C06018","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."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2121","DOI":"10.1029\/2003GL018532","article-title":"Mesoscale eddies in the South China Sea observed with altimeter data","volume":"30","author":"Wang","year":"2003","journal-title":"Geophys. Res. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.rse.2015.12.006","article-title":"Estimating background error covariance parameters and assessing their impact in the OSTIA system","volume":"176","author":"Bovis","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.asr.2020.03.039","article-title":"Detection and tracking of mesoscale eddies in the Mediterranean Sea: A comparison between the Sea Level Anomaly and the Absolute Dynamic Topography fields","volume":"68","author":"Pegliasco","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Jiang, X., Liu, L., Li, Z., Liu, L., Sian, K.T.C.L., and Dong, C. (2022). A Two-Dimensional Variational Scheme for Merging Multiple Satellite Altimetry Data and Eddy Analysis. Remote Sens., 14.","DOI":"10.3390\/rs14133026"},{"key":"ref_21","unstructured":"Taburet, G., Pujol, M., and SL-TAC Team (2023, April 05). QUID for Sea Level TAC DUACS Products. Available online: https:\/\/catalogue.marine.copernicus.eu\/documents\/QUID\/CMEMS-SL-QUID-008-032-068.pdf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.5194\/os-15-1091-2019","article-title":"On the resolutions of ocean altimetry maps","volume":"15","author":"Ballarotta","year":"2019","journal-title":"Ocean Sci."},{"key":"ref_23","first-page":"259","article-title":"Placement of Observations for Variational Data Assimilation: Application to Burgers\u2019 Equation and Seiche Phenomenon","volume":"Volume IV","author":"Park","year":"2021","journal-title":"Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications"},{"key":"ref_24","unstructured":"JPL MUR MEaSUREs Project (2015). GHRSST Level 4 MUR Global Foundation Sea Surface Temperature Analysis, Version 4.1, PO.DAAC."},{"key":"ref_25","unstructured":"Lumpkin, R., and Centurioni, L. (2022, March 30). Global Drifter Program Quality-Controlled 6-Hour Interpolated Data from Ocean Surface Drifting Buoys. NOAA National Centers for Environmental Information. Dataset, Available online: https:\/\/www.aoml.noaa.gov\/phod\/gdp\/."},{"key":"ref_26","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."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"723","DOI":"10.1002\/qj.49712555417","article-title":"Construction of correlation functions in two and three dimensions","volume":"125","author":"Gaspari","year":"1999","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1035","DOI":"10.1002\/fld.4253","article-title":"Spectral characteristics of background error covariance and multiscale data assimilation","volume":"82","author":"Li","year":"2016","journal-title":"Int. J. Numer. Methods Fluids"},{"key":"ref_29","unstructured":"Daley, R. (1991). Cambridge Atmospheric and Space Science Series, Cambridge University Press."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1175\/JPO-D-14-0032.1","article-title":"Satellite Observations of mesoscale Eddy-Induced Ekman Pumping","volume":"45","author":"Gaube","year":"2015","journal-title":"J. Phys. Oceanogr."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.dsr.2012.08.005","article-title":"The observed signature of mesoscale eddies in sea surface temperature and the associated heat transport","volume":"70","author":"Hausmann","year":"2012","journal-title":"Deep. Sea Res. Part I Oceanogr. Res. Pap."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1002\/2014JC010308","article-title":"Spatial structure and temporal variability of the zonal flow in the Luzon Strait (Article)","volume":"120","author":"Zhang","year":"2015","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_33","first-page":"146","article-title":"Statistical characterization of sea surface temperature over mesoscale eddies in the south China sea","volume":"50","author":"Liu","year":"2020","journal-title":"Period. Ocean. Univ. China"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"232","DOI":"10.3389\/fmars.2019.00232","article-title":"Global Observations of Fine-Scale Ocean Surface Topography with the Surface Water and Ocean Topography (SWOT) Mission","volume":"6","author":"Morrow","year":"2019","journal-title":"Front. Mar. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4838","DOI":"10.1029\/2018JC014869","article-title":"An Observing System Simulation Experiment for Ocean State Estimation to Assess the Performance of the SWOT Mission: Part 1\u2014A Twin Experiment","volume":"124","author":"Li","year":"2019","journal-title":"J. Geophys. Res. Ocean."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/17\/4275\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:43:41Z","timestamp":1760129021000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/17\/4275"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,31]]},"references-count":35,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2023,9]]}},"alternative-id":["rs15174275"],"URL":"https:\/\/doi.org\/10.3390\/rs15174275","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2023,8,31]]}}}