Abstract
Mesoscale eddies exist almost everywhere in the ocean and play important roles in the ocean circulation of the world. These eddies may cause sound spread singular regions and bring great influences to the upwater ship and underwater aircraft. Due to the lack of hydrographic survey datasets, study of mesoscale eddies has been greatly restricted. Fortunately, satellite altimeter provided an effective way to study mesoscale eddies. An automatic detection algorithm is introduced to detect mesoscale eddies of specific intensity and spatial/temporal scale based on satellite sea surface height (SSH) data and the algorithm is applied in a strong eddy activity region: the South China Sea and the Northwest Pacific. The algorithm includes four steps. The first step is preprocessing of the SSH image, which includes elimination of error SSH data and interpolation. The second step is to detect suspected mesoscale eddies from preprocessed SSH images by dynamic threshold adjustment and morphological method, and the suspected mesoscale eddy detection includes two procedures: suspected mesoscale eddy core region detection and suspected mesoscale eddy brim extraction. The third step is to pick out mesoscale eddies satisfied with specified criteria from suspected mesoscale eddies. The criteria include three items, that is, intensity criterion, spatial scale, criterion and temporal scale criterion. The last step is algorithm performance analysis and verification. The algorithm has the capability of adaptive parameter adjustment, and can extract mesoscale eddies of interested intensity and spatial/temporal scale. The paper can provide a basis for analyzing space-time characteristics of mesoscale eddy in the South China Sea and the Northwest Pacific.
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References
Chelton D B, Schlax M G, Samelson R M. 2011. Global observations of nonlinear mesoscale eddies. Prog Oceanogr, 91: 167–216
Cheng X H, Qi Y Q, Wang W H. 2005. Seasonal and internanual variabilities of mesoscale eddies in South China Sea. J Trop Oceanogr, 24: 51–59
Durand M, Fu L L, Lettenmaier D P, et al. 2010. The surface water and ocean topography mission: Observing terrestrial surface water and oceanic submesoscale eddies. Proc IEEE, 98: 766–779
Fernandes A, Nascimento S. 2006. Automatic water eddy detection in SST maps using random ellipse fitting and vectorial fields for image segmentation. DS’06 Proceedings of the 9th international conference on Discovery Science, Springer-Verlag Berlin Heidelberg. 4265: 77–88. doi: 10.1007/1189331811
Fu L L, Chelton D B, Le Traon P Y. 2010. Eddy dynamics from satellite altimetry. Oceanography, 23: 14–25
Gairola R M, Basu S, Pandey P C. 2001. Eddy detection over Southern Indian Ocean using TOPEX/POSEIDON altimeter data. Mar Geod, 24: 107–121
Gründlingh M L. 1995. Tracking eddies in the southeast Atlantic and Southwest Indian Oceans with TOPEX/Poseidon. J Geophys Res, 100: 24977–24986
Guan B X, Yuan Y C. 2006. Overview of studies on some eddies in the China Seas and their adjacent seas: The South China Sea and the region east of Taiwan (in Chinese). Acta Oceanol Sin, 28: 1–16
Hwang C, Chen S A. 2001. Circulations and eddies over the South China Sea derived from TOPEX/Poseidon altimeter data. J Geophys Res, 105: 23943–23965
Hwang C, Wu C R, Kao R. 2004. TOPEX/Poseidon observations of mesoscale eddies over the Subtropical Countercurrent: Kinematic characteristics of an anticyclonic eddy and a cyclonic eddy. J Geophys Res, 109: C08013, doi: 10.1029/2003JC002026
Ji G R, Chen X, Huo Y Z, et al. 2002. An automatic detection method of the marine meso-scale eddy in remote sensing image (in Chinese). Oceanol Et Limnol Sin, 33: 139–144
Lan J, Yu F, Bao Y. 2005. Multi-eddy structure in the Southern South China Sea. Adv Mar Sci, 23: 408–413
Li J X, Zhang R, Chen Y D, et al. 2011. Ocean mesoscale eddy modeling and its application in studying the effect on underwater acoustic propagation. Mar Sci Bull, 30: 37–46
Lin P F, Wang F, Chen Y L. 2007. Temproal and spatial variation characteristics on eddies in the South China Sea (in Chinese). Acta Oceanol Sin, 29: 14–22
Nichol D G. 1987. Autonomous extraction of an eddy-like structure from infrared images of the ocean. IEEE Trans Geosci Remote Sens, 25: 28–34
Peckingpaugh S H, Holyer R J. 1994. Circle detection for extracting eddy size and position from satellite imagery of the ocean. IEEE Trans Geosci Remote Sens, 32: 267–273
Roemmich D, Gilson J. 2001. Eddy transport of heat and thermocline waters in the North Pacific: A key to interannual/decadal climate variability. J Phys Oceanogr, 31: 675–687
Wang G H, Su J L, Chu P C. 2003. Mesoscale eddies in the South China Sea observed with altimeter data. Geophys Res Lett, 30: 2121
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Zhang, C., Xi, X., Liu, S. et al. A mesoscale eddy detection method of specific intensity and scale from SSH image in the South China Sea and the Northwest Pacific. Sci. China Earth Sci. 57, 1897–1906 (2014). https://doi.org/10.1007/s11430-014-4839-y
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DOI: https://doi.org/10.1007/s11430-014-4839-y