{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,8]],"date-time":"2026-02-08T05:36:30Z","timestamp":1770528990924,"version":"3.49.0"},"reference-count":22,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2018,8,15]],"date-time":"2018-08-15T00:00:00Z","timestamp":1534291200000},"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":["41706193"],"award-info":[{"award-number":["41706193"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Internal dynamical processes play a critical role in hurricane intensity variability. However, our understanding of internal storm processes is less well established, partly because of fewer observations. In this study, we present an analysis of the hurricane double-eye structure imaged by the RADARSAT-2 cross-polarized synthetic aperture radar (SAR) over Hurricane Bertha (2008). SAR has the capability of hurricane monitoring because of the ocean surface roughness induced by surface wind stress. Recently, the C-band cross-polarized SAR measurements appear to be unsaturated for the high wind speeds, which makes SAR suitable for studies of the hurricane internal dynamic processes, including the double-eye structure. We retrieve the wind field of Hurricane Bertha (2008), and then extract the closest axisymmetric double-eye structure from the wind field using an idealized vortex model. Comparisons between the axisymmetric model extracted wind field and SAR observed winds demonstrate that the double-eye structure imaged by SAR is relatively axisymmetric. Associated with airborne measurements using a stepped-frequency microwave radiometer, we investigate the hurricane internal dynamic process related to the double-eye structure, which is known as the eyewall replacement cycle (ERC). The classic ERC theory was proposed by assuming an axisymmetric storm structure. The ERC internal dynamic process of Hurricane Bertha (2008) related to the symmetric double-eye structure here, which is consistent with the classic theory, is observed by SAR and aircraft.<\/jats:p>","DOI":"10.3390\/rs10081292","type":"journal-article","created":{"date-parts":[[2018,8,15]],"date-time":"2018-08-15T10:40:07Z","timestamp":1534329607000},"page":"1292","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Symmetric Double-Eye Structure in Hurricane Bertha (2008) Imaged by SAR"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4984-3925","authenticated-orcid":false,"given":"Guosheng","family":"Zhang","sequence":"first","affiliation":[{"name":"Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS B2Y 4A2, Canada"}]},{"given":"William","family":"Perrie","sequence":"additional","affiliation":[{"name":"Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS B2Y 4A2, Canada"}]}],"member":"1968","published-online":{"date-parts":[[2018,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1146\/annurev-fluid-010816-060022","article-title":"Recent developments in the fluid dynamics of tropical cyclones","volume":"49","author":"Montgomery","year":"2017","journal-title":"Annu. Rev. Fluid Mech."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3406","DOI":"10.1175\/MWR-D-15-0066.1","article-title":"Satellite and aircraft observations of the eyewall replacement cycle in Typhoon Sinlaku (2008)","volume":"143","author":"Sanabia","year":"2015","journal-title":"Monthly Weather Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1175\/JAS-3377.1","article-title":"Reexamining the near-core radial structure of the tropical cyclone primary circulation: Implications for vortex resiliency","volume":"62","author":"Mallen","year":"2005","journal-title":"J. Atmos. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3829","DOI":"10.1175\/MWR-D-11-00034.1","article-title":"Intensity and structure changes during hurricane eyewall replacement cycles","volume":"139","author":"Sitkowski","year":"2011","journal-title":"Mon. Weather Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1175\/WAF-D-14-00121.1","article-title":"Hurricane wind\u2013pressure relationship and eyewall replacement cycles","volume":"30","author":"Kossin","year":"2015","journal-title":"Weather Forecast."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1079","DOI":"10.1175\/1520-0469(2001)058<1079:TDRITK>2.0.CO;2","article-title":"Two distinct regimes in the kinematic and thermodynamic structure of the hurricane eye and eyewall","volume":"58","author":"Kossin","year":"2001","journal-title":"J. Atmos. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1175\/1520-0434(2003)018<0032:GDWPIH>2.0.CO;2","article-title":"GPS dropwindsonde wind profiles in hurricanes and their operational implications","volume":"18","author":"Franklin","year":"2003","journal-title":"Weather Forecast."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1175\/BAMS-D-11-00211.1","article-title":"Tropical cyclone morphology from spaceborne synthetic aperture radar","volume":"94","author":"Li","year":"2013","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"491","DOI":"10.5589\/m03-020","article-title":"Characterization of hurricane eyes in RADARSAT-1 images with wavelet analysis","volume":"29","author":"Du","year":"2003","journal-title":"Can. J. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1743","DOI":"10.1109\/TGRS.2016.2631663","article-title":"A hurricane morphology and sea surface wind vector estimation model based on C-band cross-polarization SAR imagery","volume":"55","author":"Zhang","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1002\/2015JC011044","article-title":"Rain effects on the hurricane observations over the ocean by C-band Synthetic Aperture Radar","volume":"121","author":"Zhang","year":"2016","journal-title":"J. Geophys. Res."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Zhang, G., and Perrie, W. (2018). Dual-Polarized Backscatter Features of Surface Currents in the Open Ocean during Typhoon Lan (2017). Remote Sens., 10.","DOI":"10.3390\/rs10060875"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1676","DOI":"10.1002\/2017GL076988","article-title":"Effects of asymmetric secondary eyewall on tropical cyclone evolution in Hurricane Ike (2008)","volume":"45","author":"Zhang","year":"2018","journal-title":"Geophys. Res. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"7186","DOI":"10.1109\/TGRS.2014.2308839","article-title":"A hurricane tangential wind profile estimation method for C-band cross-polarization SAR","volume":"52","author":"Zhang","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1175\/1520-0469(1982)039<0395:CEWSWM>2.0.CO;2","article-title":"Concentric eye walls, secondary wind maxima, and the evolution of the hurricane vortex","volume":"39","author":"Willoughby","year":"1982","journal-title":"J. Atmos. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1175\/1520-0469(1982)039<0378:TROBHT>2.0.CO;2","article-title":"The response of balanced hurricanes to local sources of heat and momentum","volume":"3","author":"Shapiro","year":"1982","journal-title":"J. Atmos. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1884","DOI":"10.1175\/MWR-D-12-00115.1","article-title":"A new parametric tropical cyclone tangential wind profile model","volume":"141","author":"Wood","year":"2013","journal-title":"Mon. Weather Rev."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5820","DOI":"10.1109\/TGRS.2013.2293143","article-title":"Wind speed retrieval from VH dual-polarization RADARSAT-2 SAR images","volume":"52","author":"Shen","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4766","DOI":"10.1109\/TGRS.2017.2699622","article-title":"A hurricane wind speed retrieval model for C-band RADARSAT-2 cross-polarization ScanSAR images","volume":"55","author":"Zhang","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2887","DOI":"10.1109\/TGRS.2014.2366433","article-title":"Tropical cyclone winds retrieved from C-band cross-polarized synthetic aperture radar","volume":"53","author":"Horstmann","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3940","DOI":"10.1175\/JAS-D-15-0004.1","article-title":"Synthesis of vortex Rossby waves. Part I: Episodically forced waves in the inner waveguide","volume":"72","author":"Cotto","year":"2015","journal-title":"J. Atmos. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3758","DOI":"10.1175\/2009MWR2850.1","article-title":"Western North Pacific typhoons with concentric eyewalls","volume":"137","author":"Kuo","year":"2009","journal-title":"Mon. 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