Intercomparing drifts from RAFOS and profiling floats in the deep western boundary current along the Mid-Atlantic Ridge


  • Francisco Machín Departamento de Física, Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria
  • Uwe Send Forschungsbereich: Ozeanzirkulation und Klima, Physikalische Ozeanographie II, Leibnitz-Institut für
  • Walter Zenk Forschungsbereich: Ozeanzirkulation und Klima, Physikalische Ozeanographie II, Leibnitz-Institut für



cycling float, APEX, RAFOS, Lagrangian, Deep Western Boundary Current (DWBC)


The Lagrangian nature of cycling floats is evaluated in the framework defined by the Deep Western Boundary Current of the Mid-Atlantic Ridge. In a statistical approach, speeds and drifts are estimated for an APEX cycling float and compared with the velocities inferred from a park ensemble of four eddy-resolving RAFOS floats. They were deployed at the same location and ballasted for drifting at the same mission depth. Displacement errors induced by geostrophic shear and wind forced currents are analyzed. We observe that the velocity estimated from the RAFOS floats is not statistically different from the velocity estimated from the APEX float. Likewise, the initial separation between the cycling float and a simultaneously deployed RAFOS float has been studied in terms of the turbulent diffusivity. Though the performance of this study in comparable cases without a mean current field may be limited, these oceanic observations support exploiting the Lagrangian nature of the cycling floats.


Download data is not yet available.


Böhme, L. and U. Send. – 2005. Objective analyses of hydrographic data for referencing profiling float salinities in highly variable environments. Deep-Sea Res. II, 52(3-4): 651-664. doi:10.1016/j.dsr2.2004.12.014

Bower, A., B. L. Cann, T. Rossby, W. Zenk, W.J. Gould, K. Speer, P. Richardson, M. Prater and H.-M. Zhang. – 2002. Directly measured mid-depth circulation in the northeast North Atlantic Ocean. Nature, 419: 603-607. doi:10.1038/nature01078 PMid:12374975

Davis, R., J. Sherman and J. Dufour. – 2001. Profiling ALACEs and other advances in autonomous subsurface floats. J. Atmos. Oceanic Technol., 18: 982-993. doi:10.1175/1520-0426(2001)018<0982:PAAOAI>2.0.CO;2

Davis, R., D. Webb, L. Regier and J. Dufour. – 1992. The autonomous lagrangian circulation explorer (ALACE). J. Atmos. Oceanic Technol., 9: 264-285. doi:10.1175/1520-0426(1992)009<0264:TALCE>2.0.CO;2

Davis, R. and W. Zenk. – 2001. Subsurface lagrangian observations during the 1990s. In: J. Gould, G. Siedler and J. Church (eds.) Ocean Circulation and Climate (Observing and Modeling the Global Ocean), pp. 123-139. Academic Press, San Diego.

Faure, V. and K. Speer. – 2005. Labrador Sea Water circulation in the Northern North Atlantic Ocean . Deep-Sea Res. II, 52(3-4): 565-581. doi:10.1016/j.dsr2.2004.12.004

Fleischmann, U., H. Hildebrandt, A. Putzka and R. Bayer. – 2001. Transport of newly ventilated deep water from Iceland Basin to the Westeuropean Basin. Deep-Sea Res. I, 48: 1793-1819. doi:10.1016/S0967-0637(00)00107-2

Gould, W.J. – 2005. From Swallow floats to Argo–the development of neutrally buoyant floats. Deep-Sea Res. II, 52(3-4): 529-543. doi:10.1016/j.dsr2.2004.12.005

Ichikawa, Y., Y. Takatsuki, K. Mizuno, N. Shikama and K. Takeuchi. – 2001. Estimation of drifting velocity and error at parking depth for Argo float. Report of Japan Marine Science and Technology Center, 44: 81-90.

Krauss, W. – 1986. The North Atlantic Current. J. Geophys. Res., 91: 5061-5074. doi:10.1029/JC091iC04p05061

Ledwell, J., A. Watson and C. Law. – 1998. Mixing of a tracer in the pycnocline. J. Geophys. Res., 103(C10): 21499-21529. doi:10.1029/98JC01738

Loaec, G., N. Cortes, M. Menzel and J. Moliera. – 2002. Provor: A hydrographic profiler based on marvor technology.

Paillet, J., M. Arhan and M. McCartney. – 1998. Spreading of Labrador Sea Water in the eastern North Atlantic. J. Geophys. Res., 103(C7): 10223-10239. doi:10.1029/98JC00262

Park, J., K. Kim and W. Crawford. – 2004. Inertial currents estimated from surface trajectories of Argo floats. Geophys. Res. Lett., 31(13), 10.1029/2004GL020191. doi:10.1029/2004GL020191

Rossby, T., D. Dorson and J. Fontaine. – 1986. The RAFOS system. J. Atmos. Oceanic Technol., 3(4): 672-679. doi:10.1175/1520-0426(1986)003<0672:TRS>2.0.CO;2

Schmidt, C., R. Molinari and S. Garzoli. – 2001. New observations of the intermediate depth circulation in the Tropical Atlantic. J. Mar. Res., 59: 281-312. doi:10.1357/002224001762882664

Schott, F., J. Meincke, G. Meinecke, S. Neuer and W. Zenk. – 2000. North Atlantic 1999, Cruise No. 45, 18 May – 4 November 1999. Meteor–Berichte 00-4, Universität Hamburg.

Smith, N., R. Bailey, O. Alves, T. Delcroix, K. Hanawa, E. Harrison, B. Keeley, G. Meyers, B. Molinari and D. Roemmich. – 2001. The upper ocean thermal network. In: C.J. Koblinsky and N.R. Smith (eds.), Observing the Ocean in the 21st Century, pp. 259-284. Melbourne.

Speer, K., W.J. Gould and J. LaCasce. – 1999. Year-long float trajectories in the Labrador Sea Water of the eastern North Atlantic Ocean. Deep-Sea Res. II, 46: 165-179. doi:10.1016/S0967-0645(98)00103-9

Wong, A., G.C. Johnson and W.B. Owens. – 2003. Delayedmode calibration of autonomous CTD profiling float salinity data by theta-S climatology. J. Atmos. Oceanic Technol., 20(2): 308-318. doi:10.1175/1520-0426(2003)020<0308:DMCOAC>2.0.CO;2

Zenk, W., A. Pinck, S. Becker and P. Tiller. – 2000. The float park: a new tool for a cost-effective collection of lagrangian time series with dual release RAFOS floats. J. Atmos. Oceanic Technol., 17(10): 1439-1443. doi:10.1175/1520-0426(2000)017<1439:TFPANT>2.0.CO;2




How to Cite

Machín F, Send U, Zenk W. Intercomparing drifts from RAFOS and profiling floats in the deep western boundary current along the Mid-Atlantic Ridge. scimar [Internet]. 2006Mar.30 [cited 2023Dec.10];70(1):1-8. Available from:




Most read articles by the same author(s)