Abstract
A theoretical analysis of the principal oceanic ring parameters (tangential and angular velocities, shape function, horizontal and vertical scale of the ring) is described. The theoretical model consists of a reduced gravity model of the lens-like vortices with solid body rotation. The application of this approach is tested by comparison with data from the North Brazil Current Rings Experiment and remote sensing data. Specifically, we used the data corresponding to the surfaceintensified North Brazil Current ring (R-3) surveyed in February–March 1999, using direct velocity and hydrographical measurements. The theoretical model was used for evaluating the geometrical structure of the surface-intensified rings that produce remarkable signals in satellite data. The principal ring parameters from the model were compared with those from satellite data (altimetry and drifter information), which were estimated by using the method of minimization of the multivariable objective functions. Although the proposed model is linear in its conception, a good agreement was observed between the model and the primary characteristics of the observed rings. The model, however, allows for improvement in its assumptions, since its application is rather limited to intense ocean rings.
Similar content being viewed by others
References
Castelão GP, Johns WE (2011) Sea surface structure of North Brazil Current ring derived from shipboard and moored acoustic Doppler current profiler observations. J Geophys Res 116:C01010. doi:10.1029/2010JC006575
Cruz Gómez RC, Bulgakov SN (2007) Remote sensing observations of the coherent and non-coherent ring structures in the vicinity of Lesser Antilles. Annales Geophysicae 25(2):331–340
Cruz Gómez RC (2010) Interacción de los Giros de la Corriente Norte de Brasil con los estrechos de las Antillas. Ph.D. Thesis, Universidad Nacional Autónoma de México, 114 p
Didden N, Schott F (1993) Eddies in the North Brazil Current retroflexion region observed by GEOSAT altimetry. J Geophys Res — Oceans 98:20121–20131
Fonseca CA, Goni GJ, Johns WE, Campos EJ (2004) Investigation of the North Brazil Current retroflection and North Countercurrent variability. Geophys Res Lett 31:L21304. doi:10.1029/2004GL02005
Fratantoni DM, Johns WE, Townsend TL (1995) Rings of the North Brazil Current: their structure and behaviour inferred from observations and a numerical simulation. J Geophys Res — Oceans 100(C6):10633–10654
Fratantoni DM, Glikson DA (2002) North Brazil Current ring generation and evolution observed with SeaWiFS. J Phys Oceanogr 32:1058–1074
Fratantoni DM, Richardson PL (2006) The evolution and demise of North Brazil Current Rings. J Phys Oceanogr 36(7):1241–1264
Garraffo ZD, Johns WE, Chassignet EP, Goni GJ (2003) North Brazil Current rings and transport of southern waters in a high resolution numerical simulation of the North Atlantic. In: Goni GJ, Malanotte-Rizzoli P (eds) Interhemispheric water exchange in the Atlantic Ocean. Elsevier Ocean Series 68, pp 375–410
Garzoli SL, Ffield A, Yao Q (2003) North Brazil Current Rings and the variability in the latitude of retroflection. In: Goni GJ, Malanotte-Rizzoli P (eds) Interhemispheric water exchange in the Atlantic Ocean. Elsevier Ocean Series 68, pp 357–373
Goni GJ, Johns WE (2001) A census of North Brazil Current rings observed from T/P altimetry: 1992–1998. Geophys Res Lett 28(4):1–4
Goni GJ, Johns WE (2003) Synoptic study of warm rings in the North Brazil Current retroflection region using satellite altimetry. In: Goni GJ, Malanotte-Rizzoli P (eds) Interhemispheric water exchange in the Atlantic Ocean. Elsevier Ocean Series 68, pp 335–356
Hansen D, Poulain PM (1996) Quality control and interpolation of WOCE-TOGA drifter data. J Atmos Ocean Tech 13:900–909
Holton JR (1992) An introduction to dynamic meteorology, 3rd edn. Academic Press, 511 p
Jochumsen K, Rhein M, Hüttl-Kabus S, Böning CW (2010) On the propagation and decay of North Brazil Current rings. J Geophys Res 115:C10004. doi:10.1029/2009JC006042
Johns WE, Lee TN, Schott FA, Zantopp R, Evans RH (1990) The North Brazil Current retroflection: Seasonal structure and eddy variability. J Geophys Res 95:22103–22120
Johns WE, Lee TN, Beardsley RC, Candela J, Limeburner R, Castro B (1998) Annual cycle and variability of the North Brazil Current. J Phys Oceanogr 28(1):103–128
Johns WE, Zantopp RJ, Goni GJ (2003) Cross-gyre transport by North Brazil Current rings. In: Goni GJ, Malanotte-Rizzoli P (eds) Interhemispheric water exchange in the Atlantic Ocean. Elsevier Ocean Series 68, pp 411–441
Kloosterziel RC, van Heijst GJF (1991) An experimental study of unstable barotropic vortices in a rotating fluid. J Fluid Mech 223:1–24
Lagarias JC, Reeds JA, Wright MH, Wright PE (1998) Convergence properties of the Nelder-Mead simplex method in low dimensions. Siam J Optimiz 9(1):112–147
Lumpkin R, Garzoli SL (2005) Near-surface circulation in the Tropical Atlantic ocean. Deep-Sea Res I 52(3):495–518
Lumpkin R, Pazos M (2007) Measuring surface currents with SVP drifters: the instrument, its data and some recent results. In: Griffa A, Kirwan AD, Mariano AJ, Ozgokmen T, Rossby T (eds) Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics. Cambridge Univ Press, pp 39–67
Nof D (1981) On the β-induced movement of isolated baroclinic eddies. J Phys Oceanogr 11:1662–1672
Olson DB (1991) Rings in the ocean. Annu Rev Earth Planet Sci 19:283–311
Richardson PL, Hufford GE, Limeburner R, Brown WS (1994) North Brazil Current retroflection eddies. J Geophys Res 99:5081–5093
Richardson PL (2005) Caribbean Current and eddies as observed by surface drifters. Deep-Sea Res II 52:429–463
Simmons HL, Nof D (2002) The squeezing of eddies through gaps. J Phys Oceanogr 32:314–335
Skiba YN (2000) On the normal mode instability of harmonic waves on a sphere. Geophys Astrophys Fluid Dyn 92(1–2):115–127
Skiba YN (2002) On the spectral problem in the linear stability study of flows on a sphere. J Math Anal Appl 270(1):165–180
Snyder JP (1987) Map projections-A working manual. US Government Printing Office, Washington, US Geological Survey professional Paper 1395, Supersedes USGS Bulletin 1532, 383 p
Valcke S, Verron J (1997) Interaction of baroclinic isolated vortices: The dominant effect of shielding. J Phys Ocean 27:524–541
Wilson DW, Johns WE, Garzoli SL (2002) Velocity structure of North Brazil Current rings. Geophys Res Lett 29(8):1273. doi:10.1029/2001GL013869
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Cruz-Gómez, R., Salcedo-Castro, J. Analysis of horizontal and vertical ring structure based on analytical model and satellite data: Application to the North Brazil Current Rings. Ocean Sci. J. 48, 161–172 (2013). https://doi.org/10.1007/s12601-013-0013-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12601-013-0013-2