Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
van Sebille , E.; van Leeuwen, Peter Jan (2007)
Publisher: American Meteorological Society
Languages: English
Types: Article
The adiabatic transit time of wave energy radiated by an Agulhas ring released in the South Atlantic Ocean to the North Atlantic Ocean is investigated in a two-layer ocean model. Of particular interest is the arrival time of baroclinic energy in the northern part of the Atlantic, because it is related to variations in the meridional overturning circulation. The influence of the Mid-Atlantic Ridge is also studied, because it allows for the conversion from barotropic to baroclinic wave energy and the generation of topographic waves. Barotropic energy from the ring is present in the northern part of the model basin within 10 days. From that time, the barotropic energy keeps rising to attain a maximum 500 days after initiation. This is independent of the presence or absence of a ridge in the model basin. Without a ridge in the model, the travel time of the baroclinic signal is 1300 days. This time is similar to the transit time of the ring from the eastern to the western coast of the model basin. In the presence of the ridge, the baroclinic signal arrives in the northern part of the model basin after approximately 10 days, which is the same time scale as that of the barotropic signal. It is apparent that the ridge can facilitate the energy conversion from barotropic to baroclinic waves and the slow baroclinic adjustment can be bypassed. The meridional overturning circulation, parameterized in two ways as either a purely barotropic or a purely baroclinic phenomenon, also responds after 1300 days. The ring temporarily increases the overturning strength. Th presence of the ridge does not alter the time scales.\ud
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Anderson, D., and P. Rowlands, 1976: The role of inertia-gravity and planetary waves in the response of a tropical ocean to the incidence of an equatorial Kelvin wave on a meridional boundary. J. Mar. Res., 34, 295-312.
    • Andersson, H., and G. Veronis, 2004: Thermohaline circulation in a two-layer model with sloping boundaries and a mid-ocean ridge. Deep-Sea Res. I, 51, 93-106.
    • Barnier, B., 1988: A numerical study of the Mid-Atlantic Ridge on nonlinear first-mode baroclinic Rossby waves generated by seasonal winds. J. Phys. Oceanogr., 18, 417-433.
    • Beismann, J., R. Käse, and J. Lutjeharms, 1999: On the influence of submarine ridges on translation and stability of Agulhas rings. J. Geophys. Res., 104, 7897-7906.
    • Boebel, O., J. Lutjeharms, C. Schmid, W. Zenk, T. Rossby, and C. Barron, 2003: The Cape Cauldron, a regime of turbulent inter-ocean exchange. Deep-Sea Res. II, 50, 57-86.
    • Broecker, W., 1997: Thermohaline circulation, the Achilles heel of our climate system: Will man-made CO2 upset the current balance. Science, 278, 1582-1588.
    • Bryden, H., H. Longworth, and S. Cunningham, 2005: Slowing of the Atlantic meridional overturning circulation at 25°N. Nature, 438, 655-657.
    • Cessi, P., and P. Otheguy, 2003: Oceanic teleconnections: Remote response to decadal wind forcing. J. Phys. Oceanogr., 33, 1604-1617.
    • Clark, P., N. Pisias, T. Stocker, and A. Weaver, 2002: The role of the thermohaline circulation in abrupt climate change. Nature, 415, 863-869.
    • De Ruijter, W., A. Biastoch, S. Drijfhout, J. Lutjeharms, R. Matano, T. Pichevin, P. J. Van Leeuwen, and W. Weijer, 1999: Indian-Atlantic interocean exchange: Dynamics, estimation and impact. J. Geophys. Res., 104, 20 885-20 910.
    • --, H. Ridderinkhof, and M. Schouten, 2005: Variability of the southwest Indian Ocean. Philos. Trans. Roy. Soc. London A, 363, 63-76.
    • De Steur, L., P. J. Van Leeuwen, and S. Drijfhout, 2004: Tracer leakage from modelled Agulhas rings. J. Phys. Oceanogr., 34, 1387-1399.
    • Drijfhout, S., C. Katsman, L. De Steur, P. Van der Vaart, P. J. Van Leeuwen, and C. Veth, 2003: Modeling the initial, fast sea-surface height decay of Agulhas Ring “Astrid.” Deep-Sea Res. II, 50, 299-319.
    • Ganachaud, A., and C. Wunsch, 2000: Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature, 408, 453-456.
    • Gordon, A., 1986: Interocean exchange of thermocline water. J. Geophys. Res., 91, 5037-5046.
    • Johnson, H., and D. Marshall, 2002a: Localization of abrupt change in the North Atlantic thermohaline circulation. Geophys. Res. Lett., 29, 1083, doi:10.1029/2001GL014140.
    • --, and --, 2002b: A theory for the surface Atlantic response to thermohaline variability. J. Phys. Oceanogr., 32, 1121- 1132.
    • Kamenkovitch, V., Y. Leonov, D. Nechaev, D. Byrne, and A. Gordon, 1996: On the influence of bottom topography on the Agulhas eddy. J. Phys. Oceanogr., 26, 892-912.
    • Knorr, G., and G. Lohmann, 2003: Southern Ocean origin for the resumption of Atlantic thermohaline circulation during deglaciation. Nature, 424, 532-536.
    • Kowalik, Z., and T. Murty, 1993: Numerical Modelling of Ocean Dynamics. Advanced Series on Ocean Engineering, Vol. 5, World Scientific, 496 pp.
    • Liu, Z., L. Wa, and E. Baler, 1999: Rossby wave-coastal Kelvin wave interaction in the extratropics. Part I: Low-frequency adjustment in a closed basin. J. Phys. Oceanogr., 29, 2382- 2404.
    • Longuet-Higgins, M., 1965: The response of a stratified ocean to stationary or moving wind-systems. Deep-Sea Res., 12, 923- 973.
    • Lutjeharms, J., 1996: The exchange of water between the South Indian and South Atlantic Oceans. The South Atlantic: Present and Past Circulation, G. Wefer et al., Eds., SpringerVerlag, 125-162.
    • Mesinger, F., and A. Arakawa, 1976: Numerical methods used in atmospheric models. GARP Publications, World Meteorological Organization, 71 pp.
    • Nof, D., 1983: On the migration of isolated eddies with application to Gulf Stream rings. J. Mar. Res., 41, 399-425.
    • Peeters, F., R. Acheson, G. Brummer, W. De Ruijter, R. Schneider, G. Ganssen, E. Ufkes, and D. Kroon, 2004: Vigorous exchange between the Indian and Atlantic Oceans at the end of the past five glacial periods. Nature, 430, 661-665.
    • Primeau, F., 2002: Long Rossby wave basin-crossing time and the resonance of low-frequency basin modes. J. Phys. Oceanogr., 32, 2652-2665.
    • Rahmstorf, S., 1996: On the freshwater forcing and transport of the Atlantic thermohaline circulation. Climate Dyn., 12, 799- 811.
    • --, and A. Ganopolsky, 1999: Long-term global warming scenarios computed with an efficient coupled climate model. Climatic Change, 43, 353-367.
    • Saenko, O., J. Gregory, A. Weaver, and M. Eby, 2002: Distinguishing the influence of heat, freshwater, and momentum fluxes on ocean circulation and climate. J. Climate, 15, 3686- 3697.
    • Schmitz, W., Jr., 1995: On the interbasin-scale thermohaline circulation. Rev. Geophys., 33, 151-173.
    • Schouten, M., W. De Ruijter, P. J. Van Leeuwen, and J. Lutjeharms, 2000: Translation, decay and splitting of Agulhas rings in the southeastern Atlantic Ocean. J. Geophys. Res., 105, 21 913-21 925.
    • Tailleux, R., 2004: A WKB analysis of the surface signature and vertical structure of long extratropical baroclinic Rossby waves over topography. Ocean Modell., 6, 191-219.
    • --, and J. McWilliams, 2000: Acceleration, creation, and depletion of wind-driven, baroclinic Rossby waves over an ocean ridge. J. Phys. Oceanogr., 30, 2186-2213.
    • Tang, C., 1979: Development of radiation fields and baroclinic eddies in a -plane. J. Fluid Mech., 93, 379-400.
    • Van Aken, H., A. Van Veldhoven, C. Veth, W. De Ruijter, P. J. Van Leeuwen, S. Drijfhout, C. Whittle, and M. Rouault, 2003: Observations of a young Agulhas ring, Astrid, during MARE in March 2000. Deep-Sea Res. II, 50, 167-195.
    • Wang, L., and C. Koblinsky, 1994: Influence of mid-ocean ridges on Rossby waves. J. Geophys. Res., 99, 25 143-25 153.
    • Weijer, W., W. De Ruijter, H. Dijkstra, and P. J. Van Leeuwen, 1999: Impact of interbasin exchange on the Atlantic overturning circulation. J. Phys. Oceanogr., 29, 2266-2284.
    • --, --, A. Sterl, and S. Drijfhout, 2002: Response of the Atlantic overturning circulation to South Atlantic sources of buoyancy. Global Planet. Change, 34, 293-311.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article