{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:19:52Z","timestamp":1760235592586,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2021,8,30]],"date-time":"2021-08-30T00:00:00Z","timestamp":1630281600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003711","name":"Ministry of Science and Technology","doi-asserted-by":"publisher","award":["109-2221-E-006-101, 108-2611-M-012-002","108-2917-I-006-012"],"award-info":[{"award-number":["109-2221-E-006-101, 108-2611-M-012-002","108-2917-I-006-012"]}],"id":[{"id":"10.13039\/501100003711","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100013864","name":"NOAA Research","doi-asserted-by":"publisher","award":["MOU-2020-078\/12015\/NPS-21-400-2778"],"award-info":[{"award-number":["MOU-2020-078\/12015\/NPS-21-400-2778"]}],"id":[{"id":"10.13039\/100013864","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>A network of high-frequency radars (HFRs) has been deployed around Taiwan. The wide-area data coverage is dedicated to revealing near real-time sea-surface current information. This paper investigates three primary objectives: (1) describing the seasonal current synoptic variability; (2) determining the influence of wind forcing; (3) describing the tidal current field pattern and variability. Sea surface currents derived from HFR data include both geostrophic components and wind-driven components. This study explored vector complex correlations between the HFR time series and wind, which was sufficient to identify high-frequency components, including an Ekman balance among the surface currents and wind. Regarding the characteristics of mesoscale events and the tidal field, a year-long high-resolution surface dataset was utilized to observe the current\u2013eddy\u2013tide interactions over four seasons. The harmonic analysis results derived from surface currents off of northeastern Taiwan during 2013 are presented. The results agree well with the tidal parameters estimated from tide-gauge station observations. The analysis shows that this region features a strong, mixed, mainly semidiurnal tide. Continued monitoring by a variety of sensors (e.g., satellite and HFR) would improve the understanding of the circulation in the region.<\/jats:p>","DOI":"10.3390\/rs13173438","type":"journal-article","created":{"date-parts":[[2021,8,31]],"date-time":"2021-08-31T22:58:15Z","timestamp":1630450695000},"page":"3438","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Observations of Surface Currents and Tidal Variability Off of Northeastern Taiwan from Shore-Based High Frequency Radar"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8625-7146","authenticated-orcid":false,"given":"Yu-Ru","family":"Chen","sequence":"first","affiliation":[{"name":"Institute of Ocean Technology and Marine Affairs, National Cheng Kung University, Tainan 701, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2525-7473","authenticated-orcid":false,"given":"Jeffrey D.","family":"Paduan","sequence":"additional","affiliation":[{"name":"Department of Oceanography, Naval Postgraduate School\u2014NPS, Monterey, CA 93943, USA"}]},{"given":"Michael S.","family":"Cook","sequence":"additional","affiliation":[{"name":"Department of Oceanography, Naval Postgraduate School\u2014NPS, Monterey, CA 93943, USA"}]},{"given":"Laurence Zsu-Hsin","family":"Chuang","sequence":"additional","affiliation":[{"name":"Institute of Ocean Technology and Marine Affairs, National Cheng Kung University, Tainan 701, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2534-1173","authenticated-orcid":false,"given":"Yu-Jen","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Marine Science, Naval Academy, Kaohsiung 813, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1023\/A:1007892819134","article-title":"Taiwan Current (Kuroshio) and impinging eddies","volume":"55","author":"Yang","year":"1999","journal-title":"J. Oceanogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1085","DOI":"10.1016\/S0967-0645(03)00011-0","article-title":"Upper-ocean currents around Taiwan","volume":"50","author":"Liang","year":"2003","journal-title":"Deep Sea Res. Part II Top. Stud. Oceanogr."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1146\/annurev-marine-121211-172315","article-title":"High-frequency radar observations of ocean surface currents","volume":"5","author":"Paduan","year":"2013","journal-title":"Annu. Rev. Mar. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"49","DOI":"10.5670\/oceanog.1997.21","article-title":"Mapping surface currents in Monterey Bay with CODAR-type HF radar","volume":"10","author":"Paduan","year":"1997","journal-title":"Oceanography"},{"key":"ref_5","first-page":"67","article-title":"A study on the homogeneity of tides around coasts of Taiwan","volume":"5","author":"Lee","year":"2005","journal-title":"J. Mar. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1007\/s10872-010-0020-1","article-title":"Seasonal variations of the surface currents in the Tsushima Strait","volume":"66","author":"Yoshikawa","year":"2010","journal-title":"J. Oceanogr."},{"doi-asserted-by":"crossref","unstructured":"Yoshikawa, Y., and Masuda, A. (2009). Seasonal variations in the speed factor and deflection angle of the wind-driven surface flow in the Tsushima Strait. J. Geophys. Res. Oceans, 114.","key":"ref_7","DOI":"10.1029\/2009JC005632"},{"unstructured":"Fang, Y.C., Wang, J., and Yang, Y.J. (2012, January 17\u201319). Surface Current Measurement Using HF-Radar off Northeastern Taiwan: Preliminary Result and Validation. Proceedings of the 1st Ocean Radar Conference for Asia, Seoul, Korea.","key":"ref_8"},{"doi-asserted-by":"crossref","unstructured":"Chen, Y.-W., Yang, Y.J., and Wang, J. (2014, January 7\u201310). A study on data filling from incomplete dataset of HF radar measured ocean currents\u2014A case study of the flow field Northeast of Taiwan: Data filling from incomplete ocean currents dataset. Proceedings of the OCEANS 2014, Taipei, Taiwan.","key":"ref_9","DOI":"10.1109\/OCEANS-TAIPEI.2014.6964466"},{"unstructured":"Picot, N., Case, K., Desai, S., Vincent, P., and Bronner, E. (2003). AVISO and PODAAC User Handbook. IGDR and GDR Jason Products, Jet Propulsion Laboratory, California Institute of Technology.","key":"ref_10"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4305","DOI":"10.1002\/jgrc.20323","article-title":"Seasonal to interannual variations in the intensity and central position of the surface Kuroshio east of Taiwan","volume":"118","author":"Hsin","year":"2013","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1007\/BF02123503","article-title":"Circulation of the East China Sea, a numerical study","volume":"46","author":"Chao","year":"1990","journal-title":"J. Oceanogr."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3240","DOI":"10.1002\/jgrc.20220","article-title":"Evaluating the use of high-frequency radar coastal currents to correct satellite altimetry","volume":"118","author":"Roesler","year":"2013","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_14","first-page":"PO54F-3322","article-title":"Improvements and Advances to the Cross-Calibrated Multi-Platform (CCMP) Ocean Vector Wind Analysis (V2. 0 release)","volume":"2016","author":"Scott","year":"2016","journal-title":"Am. Geophys. Union"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4355","DOI":"10.1029\/JC088iC07p04355","article-title":"Eddy kinetic energy in the North Atlantic from surface drifters","volume":"88","author":"Richardson","year":"1983","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/s12040-012-0258-7","article-title":"Evaluation of OSCAR ocean surface current product in the tropical Indian Ocean using in situ data","volume":"122","author":"Sikhakolli","year":"2013","journal-title":"J. Earth Syst. Sci."},{"doi-asserted-by":"crossref","unstructured":"Reyes Suarez, N.C., Cook, M.S., Ga\u010di\u0107, M., Paduan, J.D., Drago, A., and Cardin, V. (2019). Sea Surface Circulation Structures in the Malta-Sicily Channel from Remote Sensing Data. Water, 11.","key":"ref_17","DOI":"10.3390\/w11081589"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1512","DOI":"10.1175\/2009JPO4013.1","article-title":"Anisotropic response of surface currents to the wind in a coastal region","volume":"39","author":"Kim","year":"2009","journal-title":"J. Phys. Oceanogr."},{"doi-asserted-by":"crossref","unstructured":"Kohut, J.T., Glenn, S.M., and Paduan, J.D. (2006). Inner shelf response to tropical storm Floyd. J. Geophys. Res. Oceans, 111.","key":"ref_19","DOI":"10.1029\/2003JC002173"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"20669","DOI":"10.1029\/96JC01663","article-title":"Remotely sensed surface currents in Monterey Bay from shore-based HF radar (Coastal Ocean Dynamics Application Radar)","volume":"101","author":"Paduan","year":"1996","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1175\/1520-0485(1976)006<0238:EVONTO>2.0.CO;2","article-title":"Ekman veering observed near the ocean bottom","volume":"6","author":"Kundu","year":"1976","journal-title":"J. Phys. Oceanogr."},{"doi-asserted-by":"crossref","unstructured":"Kohut, J.T., Glenn, S.M., and Chant, R.J. (2004). Seasonal current variability on the New Jersey inner shelf. J. Geophys. Res. Oceans, 109.","key":"ref_22","DOI":"10.1029\/2003JC001963"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.dsr2.2008.08.007","article-title":"Methodology for a regional tidal model evaluation, with application to central California","volume":"56","author":"Rosenfeld","year":"2009","journal-title":"Deep Sea Res. Part II Top. Stud. Oceanogr."},{"doi-asserted-by":"crossref","unstructured":"de Beurs, K.M., and Henebry, G.M. (2010). Spatio-temporal statistical methods for modelling land surface phenology. Phenological Research, Springer.","key":"ref_24","DOI":"10.1007\/978-90-481-3335-2_9"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1016\/S0098-3004(02)00013-4","article-title":"Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE","volume":"28","author":"Pawlowicz","year":"2002","journal-title":"Comput. Geosci."},{"unstructured":"Britannica, T. (2021, August 27). Harmonic Analysis. Available online: https:\/\/www.britannica.com\/science\/harmonic-analysis.","key":"ref_26"},{"doi-asserted-by":"crossref","unstructured":"Scharffenberg, M.G., and Stammer, D. (2010). Seasonal variations of the large-scale geostrophic flow field and eddy kinetic energy inferred from the TOPEX\/Poseidon and Jason-1 tandem mission data. J. Geophys. Res. Oceans, 115.","key":"ref_27","DOI":"10.1029\/2008JC005242"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"193","DOI":"10.4236\/ojms.2015.52016","article-title":"Characteristics of tides in the Red Sea region, a numerical model study","volume":"5","author":"Madah","year":"2015","journal-title":"Open J. Mar. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.csr.2013.09.008","article-title":"Observed tidal currents on the continental shelf off the west coast of India","volume":"69","author":"Subeesh","year":"2013","journal-title":"Cont. Shelf Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1917","DOI":"10.1175\/JPO-D-15-0006.1","article-title":"Long-period tides in an atmospherically driven, stratified ocean","volume":"45","author":"Ponte","year":"2015","journal-title":"J. Phys. Oceanogr."},{"key":"ref_31","first-page":"132","article-title":"Analysis of fortnightly and monthly tides","volume":"LIX","author":"Crawford","year":"1982","journal-title":"Int. Hydrogr. Rev."},{"unstructured":"Schureman, P. (1958). Manual of Harmonic Analysis and Prediction of Tides, US Government Printing Office.","key":"ref_32"},{"unstructured":"Stewart, R.H. (2008). Introduction to Physical Oceanography, Texas A&M University.","key":"ref_33"},{"unstructured":"Lin, S.F., Yang, Y.J., and Tang, T.Y. (2005, January 1\u20132). Coastal Tidal Current Phenomena on Northern Taiwan. Proceedings of the 27th Ocean Engineering Conference, Taichung, Taiwan.","key":"ref_34"},{"unstructured":"Dietrich, G., and Kalle, K. (1957). General Oceanography, An Introduction; Interscience Pub.","key":"ref_35"},{"unstructured":"Courtier, A. (1939). Classification of tides in four types. Int. Hydrogr. Rev., Available online: https:\/\/journals.lib.unb.ca\/index.php\/ihr\/article\/download\/27428\/1882520184.","key":"ref_36"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"103","DOI":"10.2307\/1351368","article-title":"Tidal wave characteristics of Chesapeake Bay","volume":"5","author":"Hicks","year":"1964","journal-title":"Chesap. Sci."},{"unstructured":"Dai, C.F. (2018). Regional Oceanography of Taiwan Version II, National Taiwan University Press.","key":"ref_38"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/17\/3438\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:55:33Z","timestamp":1760165733000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/17\/3438"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,8,30]]},"references-count":38,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["rs13173438"],"URL":"https:\/\/doi.org\/10.3390\/rs13173438","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,8,30]]}}}