World Library  

Add to Book Shelf
Flag as Inappropriate
Email this Book

Surface Signature of Mediterranean Water Eddies in the Northeastern Atlantic: Effect of the Upper Ocean Stratification : Volume 8, Issue 6 (01/11/2012)

By Bashmachnikov, I.

Click here to view

Book Id: WPLBN0004020622
Format Type: PDF Article :
File Size: Pages 13
Reproduction Date: 2015

Title: Surface Signature of Mediterranean Water Eddies in the Northeastern Atlantic: Effect of the Upper Ocean Stratification : Volume 8, Issue 6 (01/11/2012)  
Author: Bashmachnikov, I.
Volume: Vol. 8, Issue 6
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Publication Date:
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications


APA MLA Chicago

Bashmachnikov, I., & Carton, X. (2012). Surface Signature of Mediterranean Water Eddies in the Northeastern Atlantic: Effect of the Upper Ocean Stratification : Volume 8, Issue 6 (01/11/2012). Retrieved from

Description: Institute of Oceanography of the Faculty of Sciences of the University of Lisbon (OI-FCUL), Campo Grande, 1749-016, Lisbon, Portugal. Meddies, intra-thermocline eddies of Mediterranean water, can often be detected at the sea surface as positive sea-level anomalies. Here we study the surface signature of several meddies tracked with RAFOS floats and AVISO altimetry.

While pushing its way through the water column, a meddy raises isopycnals above. As a consequence of potential vorticity conservation, negative relative vorticity is generated in the upper layer. During the initial period of meddy acceleration after meddy formation or after a stagnation stage, a cyclonic signal is also generated at the sea-surface, but mostly the anticyclonic surface signal follows the meddy.

Based on geostrophy and potential vorticity balance, we present theoretical estimates of the intensity of the surface signature. It appears to be proportional to the meddy core radius and to the Coriolis parameter, and inversely proportional to the core depth and buoyancy frequency. This indicates that surface signature of a meddy may be strongly reduced by the upper ocean stratification. Using climatic distribution of the stratification intensity, we claim that the southernmost limit for detection in altimetry of small meddies (with radii on the order of 10–15 km) should lie in the subtropics (35–45° N), while large meddies (with radii of 25–30 km) could be detected as far south as the northern tropics (25–35° N). Those results agree with observations.

Surface signature of Mediterranean water eddies in the Northeastern Atlantic: effect of the upper ocean stratification

Flierl, G. R.: Rossby-wave radiation from a strongly nonlinear warm eddy, J. Phys. Oceanogr., 14, 47–58, 1984.; Aiki, H. and Yamagata, T.: A numerical study on the successive formation of Meddy-like lenses, J. Geophys. Res., 109, C06020, doi:10.1029/2003JC001952, 2004.; Arbic, B. K., Scott, R. B., Chelton, D. B., Richman, J. G., and Shriver, J. F.: Effects of stencil width on surface ocean geostrophic velocity and vorticity estimation from gridded satellite altimeter data, J. Geophys. Res., 117, C03029, doi:10.1029/2003JC001952, 2012; Armi, L., Hebert, D., Oakey, N., Price, J. F., Richardson, P. L., Rossby, H. T., and Ruddick, B.: The history and decay of a Mediterranean salt lens, Nature, 333, 649–651, 1988.; Flierl, G. R.: Particle motions in large-amplitude wave fields, Geophys. Astro. Fluid, 18, 39–74, 1981.; Armi, L., Hebert, D., Oakey, N., Price, J. F., Richardson, P. L., Rossby, H. T., and Ruddick, B.: Two Years in the Life of a Mediterranean Salt Lens, J. Phys. Oceanogr., 19, 354–370, 1989.; AVISO altimeter products, produced by Ssalto/Duacs and distributed by Aviso, with support from CNES, available at: (last access: 1 November 2011), 2011.; Bashmachnikov, I., Machin, F., Mendonca, A., and Martins, A.: In-situ and remote sensing signature of meddies east of the Mid-Atlantic ridge, J. Geophys. Res., 114, C05018, doi:10.1029/2008JC005032, 2009a.; Bashmachnikov, I., Mohn, C., Pelegrí, J. L., Martins, A., Machín, F., Jose, F., and White, M.: Interaction of Mediterranean water eddies with Sedlo and Seine seamounts, Subtropical Northeast Atlantic, Deep-Sea Res. Pt. II, 56: 2593–2605, 2009b.; Bashmachnikov, I., Boutov, D., Dias, J., Aguiar, A., and Monteiro, J. H.: Surface signature of a meddy while interacting with the Azores current, in: Geophysical Research Abstracts, Vol. 14/ EGU General Assembly, Vienna, Austria, 24–27 April 2012, EGU2012-6152-1, 2012.; Bower, A. S., Armi, L., and Ambar, I.: Lagrangian observations of meddy formation during a Mediterranean Undercurrent Seeding Experiment, J. Phys. Oceanogr., 27, 2545–2575, 1997.; Carton, X. J., Flierl, G. R., and Polvani, L. M.: The generation of tripoles from unstable axisymmetric isolated vortex structures, Europhys. Lett., 9, 339–344, 1989.; Carton, X., Cherubin, L., Paillet, J., Morel, Y., Serpette, A., and Le Cann, B.: Meddy coupling with deep cyclone in the gulf of Cadiz, J. Marine Sys., 32, 13–42, 2002.; Carton, X., Daniault, N., Alves, J., Cherubin, L., and Ambar, I.: Meddy dynamics and interaction with neighboring eddies southwest of Portugal: Observations and modelling, J. Geophys. Res., 115, C06017, doi:10.1029/2009JC005646, 2010.; Chavanne, C. P. and Klein, P.: Can oceanic submesoscale processes be observed with satellite altimetry? Geophys. Res. Lett., 37, L22602, doi:10.1029/2010GL045057, 2010.; Fu, L.-L. and Cazenave, A. (Eds.): Satellite Altimetry and Earth Sciences - A Handbook of Techniques and Applications, International Geophysics Series 69, Academic Press, London, 1–463, 2001.; Hebert, D. L.: A Mediterranean salt lens, Ph.D. thesis, Dalhousie University, Halifax, Nova Scotia, April, 187 pp., 1988.; Hebert, D., Oakey, N., and Ruddick, B.: Evolution of a Mediterranean salt lens: scalar properties, J. Phys. Oceanogr., 20, 1468–1483, 1990.; Isern-Fontanet, J., Garcia-Ladona, E., and Font, J.: Identification of marine eddies from altimetric maps, J. Atmos. Oceanic Technol., 20, 772–778, 2003.; Käse, R. H., Beckmann, A., and Hinrichsen, H. H.: Observational evidence of salt lens formation in the Iberian basin, J. Geophys. Res., 94, 4905–4912, 1989.; Legras, B. an


Click To View

Additional Books

  • Effect of Variable Winds on Current Stru... (by )
  • An Empirical Stochastic Model of Sea-sur... (by )
  • An Eddy Resolving Tidal-driven Model of ... (by )
  • Metrological Traceability of Oceanograph... (by )
  • Seismic Imaging of a Thermohaline Stairc... (by )
  • An Estimate of the Sunda Shelf and the S... (by )
  • Annual Cycles of Chlorophyll-A, Non-alga... (by )
  • Mesoscale Variability of Water Masses in... (by )
  • Spatio-temporal Variability of Micro-, N... (by )
  • Exchange Across the Shelf Break at High ... (by )
  • Forecasting the Mixed-layer Depth in the... (by )
  • How Does Ocean Ventilation Change Under ... (by )
Scroll Left
Scroll Right


Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.