The most typical shape of oceanic mesoscale eddies from global satellite sea level observations

doi:10.1007/s11707-014-0478-z

Front. Earth Sci.

2015, Vol. 9

Issue (2) : 202-208 https://doi.org/10.1007/s11707-014-0478-z

RESEARCH ARTICLE

The most typical shape of oceanic mesoscale eddies from global satellite sea level observations

Zifei WANG¹,Qiuyang LI¹,Liang SUN^1,^2,^*(

),Song LI¹,Yuanjian YANG^1,³,Shanshan Liu^1,²

1. Key Laboratory of the Atmospheric Composition and Optical Radiation, CAS, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
2. State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, State Oceanic Administration, HangZhou 310012, China
3. Key Laboratory of Atmospheric Sciences and Satellite Remote Sensing of Anhui Province, Anhui Institute of Meteorological Sciences, Hefei 230031, China

Download: PDF(787 KB) HTML
Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks

Abstract

In this research, we normalized the characteristics of ocean eddies by using satellite observation of the Sea Level Anomaly (SLA) data to determine the most typical shape of ocean eddies. This normalization is based on modified analytic functions with nonlinear optimal fitting. The most typical eddy is the Taylor vortex (~50%), which exhibits a Gaussian-shaped exp(-r²) SLA and a vorticity distribution of (1-r²)exp(-r²) as a function of the normalized radii r. The larger the amplitude of the eddy, the more likely the eddy is to be Gaussian-shaped. Furthermore, approximately 40% of ocean eddies are combinations of two Gaussian eddies with different parameters, but the composition of these types of eddies is more like a quadratic eddy than a Gaussian one. Only a small portion of oceanic eddies are pure quadratic eddies (<10%) with the same vorticity distribution as a Rankine vortex. We concluded that the Taylor vortex is a good approximation of the typical shape of ocean eddies.

Keywords sea level anomaly ocean eddies Taylor vortex typical shape

Corresponding Author(s): Liang SUN

Online First Date: 17 December 2014 Issue Date: 30 April 2015

Cite this article:

Zifei WANG,Liang SUN,Song LI, et al. The most typical shape of oceanic mesoscale eddies from global satellite sea level observations[J]. Front. Earth Sci., 2015, 9(2): 202-208.

URL:

https://academic.hep.com.cn/fesci/EN/10.1007/s11707-014-0478-z
https://academic.hep.com.cn/fesci/EN/Y2015/V9/I2/202

Fig.1 (a) A typical Gaussian eddy profile (squares) and fitting profile (curve) with A = ?35.1 cm, L_e= 62.8 km, B = 7.4 cm and x₀= ?19.1 km. (b) The profiles of the direct normalization (triangles) and the optimal normalization (circles) are shown, and the curve is the profile from the normalized Gaussian function.

Fig.2 (a) A typical Gaussian eddy profile with A = 21 cm, L_e = 60.4 km, B = 1.8 cm and x₀= 1.8 km. (b) Probability density function distribution of the normalized SLA shape for Gaussian eddies.

Fig.3 (a) A typical quadratic eddy with A = 61.8 cm, L_e= 92.6 km, B = ?17.7 cm, and x₀= 2.2 km; (b) Probability density function distribution of the normalized SLA shape for quadratic eddies.

Fig.4 The rest type of eddies. (a) A combination eddy consisting of two Gaussian eddies (left: A = 45 cm, L_e = 132.2 km, B = ?10.3 cm and x₀= 0.65 km; right: A = 18.5 cm, L_e = 121.3 km, B = 16.46 cm and x₀= 7.24 km). (b) Probability density function distribution of the normalized SLA shape of Gaussian eddies.

Fig.5 Numbers of eddies per map and ratios of the different types of eddies.

Fig.6 (a) Distribution of B and A of the eddies. (b) Mean and standard deviation of B vs. A. (c) The distribution of x₀ and L_e of the eddies. (d) Mean and standard deviation of x₀ vs. L_e.

1	Chaigneau A, Gizolme A, Grados C (2008). Mesoscale eddies off Peru in altimeter records: identification algorithms and eddy spatio-temporal patterns. Prog Oceanogr, 79(2-4): 106-119 https://doi.org/10.1016/j.pocean.2008.10.013
2	Chaigneau A, Le Texier M, Eldin G, Grados C, Pizarro O (2011). Vertical structure of mesoscale eddies in the eastern South Pacific Ocean: A composite analysis from altimetry and Argo profiling floats. Journal of Geophysical Research: Oceans, 116(C11): C11025 https://doi.org/10.1029/2011JC007134
3	Chelton D B, Gaube P, Schlax M G, Early J J, Samelson R M (2011b). The influence of nonlinear mesoscale eddies on near surface oceanic Chlorophyll. Science, 334(6054): 328-332 https://doi.org/10.1126/science.1208897
4	Chelton D B, Schlax M G, Samelson R M (2011a). Global observations of nonlinear mesoscale eddies. Prog Oceanogr, 91(2): 167-216 https://doi.org/10.1016/j.pocean.2011.01.002
5	Chelton D B, Schlax M G, Samelson R M, de Szoeke R A (2007). Global observations of large oceanic eddies. Geophys Res Lett, 34(15): L15606 https://doi.org/10.1029/2007GL030812
6	Dong C, Lin X, Liu Y, Nencioli F, Chao Y, Guan Y, Chen D, Dickey T, McWilliams J C (2012). Three-dimensional oceanic eddy analysis in the Southern California Bight from a numerical product. J Geophys Res, 117: C00H14 https://doi.org/10.1029/2011JC007354
7	Dong C, McWilliams J C, Liu Y, Chen D (2014). Global heat and salt transports by eddy movement. Nature Communications, 5: 3294
8	Ducet N, Le Traon P Y, Reverdin G (2000), Global high resolution mapping of ocean circulation from TOPEX/Poseidon and ERS-1 and -2, J. Geophys. Res., 105, 19,477-19,478 https://doi.org/10.1029/2000JC900063
9	Early J J, Samelson R M, Chelton D B (2011). The evolution and propagation of quasigeostrophic ocean eddies. J Phys Oceanogr, 41(8): 1535-1555 https://doi.org/10.1175/2011JPO4601.1
10	Hu J, Gan J, Sun Z, Zhu J, Dai M (2011). Observed three-dimensional structure of a cold eddy in the southwestern South China Sea. J Phys Oceanogr, 116: C05016 https://doi.org/10.1029/2010JC006810
11	Isern-Fontanet J, Garcia-Ladona E, Font J (2003). Identification of marine eddies from altimetric maps. J Atmos Ocean Technol, 20(5): 772-778 https://doi.org/10.1175/1520-0426(2003)20<772:IOMEFA>2.0.CO;2
12	Li Q Y, Sun L, Liu S S, Xian T, Yan Y F (2014). A new mononuclear eddy identification method with simple splitting strategies. Remote Sensing Letters, 5 (1): 65-72 https://doi.org/10.1080/2150704X.2013.872814
13	Ponte R M, Wunsch C, Stammer D (2007). Spatial Mapping of Time-Variable Errors in Jason-1 and TOPEX/Poseidon Sea Surface Height Measurements. J Atmos Ocean Technol, 24(6): 1078-1085 https://doi.org/10.1175/JTECH2029.1
14	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(3): 675-687 https://doi.org/10.1175/1520-0485(2001)031<0675:ETOHAT>2.0.CO;2
15	Sun L (2011). A typhoon-like vortex solution of incompressible 3D inviscid flow. Theor Appl Mech Lett, 1(4): 042003 https://doi.org/10.1063/2.1104203
16	Wu J Z, Ma H Y, Zhou M D (2006). Vorticity and Vortex Dynamics. Berlin-Heidelberg: Springer-Verlag. XIV, 776 p., 291 illus
17	Yang G, Wang F, Li Y, Lin P (2013). Mesoscale eddies in the northwestern subtropical Pacific Ocean: Statistical characteristics and three‐dimensional structures. Journal of Geophysical Research: Oceans, 118(4): 1906-1923
18	Zhang Z G, Zhang Y, Wang W, Huang R X (2013). Universal structure of mesoscale eddies in the ocean. Geophys Res Lett, 40(14): 3677-3681 https://doi.org/10.1002/grl.50736

Viewed

Full text

Abstract

Cited

Shared

Discussed