A statistical description of the mean circulation and eddy variability in the northwestern Atlantic using SOFAR floats

Abstract Velocity data obtained from trajectories of SOFAR floats launched as part of several experiments carried out in the Northwest Atlantic during the last two decades are used to give a statistical description of the mean Gulf Stream and its recirculation. The distribution of eddy variability in the region is also presented. A mean Gulf Stream which bifurcates between 55° and 45°W to feed the North Atlantic Current and a southern recirculation can be clearly identified. A weak interior Sverdrup flow is also suggested. The spatial distribution of eddy variability is consistent with previous descriptions, showing a maximum near the Gulf Stream.

[1]  C. Wunsch,et al.  Space and time scales of mesoscale motion in the western North Atlantic , 1977 .

[2]  P. Richardson.  Average velocity and transport of the Gulf Stream near 55W , 1985 .

[3]  C. Iselin.  A study of the circulation of the western North Atlantic , 1936 .

[4]  L. V. Worthington.  On the North Atlantic Circulation , 1977 .

[5]  M. Kennelly,et al.  Gulf Stream Recirculation Experiment (GUSREX) and line experiment SOFAR float data, 1980-1982 , 1984 .

[6]  W. Owens.  A Synoptic and Statistical Description of the Gulf Stream and Subtropical Gyre Using SOFAR Floats , 1984 .

[7]  R. Thompson.  Observations of Rossby waves near site D1 , 1977 .

[8]  W. Owens,et al.  Gulf Stream recirculation experiment - Part II , 1989 .

[9]  S. Riser,et al.  The Western North Atlantic - A Lagrangian Viewpoint , 1983 .

[10]  P. Richardson,et al.  Nine-year trajectory of a SOFAR float in the southwestern North Atlantic , 1988 .

[11]  A. Bower.  A Simple Kinematic Mechanism for Mixing Fluid Parcels across a Meandering Jet , 1991 .

[12]  N. Fofonoff,et al.  Current Variability near the Southeast Newfoundland Ridge , 1985 .

[13]  E. D. Brown,et al.  The Local Dynamics of Eddies in the Western North Atlantic , 1983 .

[14]  Peter Cornillon,et al.  The Effect of the New England Seamounts on Gulf Stream Meandering as Observed from Satellite IR Imagery , 1986 .

[15]  A. Bradley,et al.  North Atlantic Subtropical Gyre: SOFAR Floats Tracked by Moored Listening Stations. , 1981, Science.

[16]  G. W. Snedecor.  Statistical Methods , 1964 .

[17]  R. Pickart,et al.  The northern recirculation gyre of the gulf Stream , 1986 .

[18]  H. W. Hill,et al.  Current System South and East of the Grand Banks of Newfoundland , 1980 .

[19]  P. Richardson.  A vertical section of eddy kinetic energy through the Gulf Stream system , 1983 .

[20]  W. Owens,et al.  Site L SOFAR float experiment, 1982-1985 , 1987 .

[21]  S. Riser,et al.  Mesoscale motions near the deep western boundary of the North Atlantic , 1978 .

[22]  W. Schmitz.  Eddy kinetic energy in the deep western North Atlantic , 1976 .

[23]  W. Owens.  A Statistical Description of the Vertical and Horizontal Structure of Eddy Variability on the Edge of the Gulf Stream Recirculation , 1985 .

[24]  J. Reid.  On the middepth circulation and salinity field in the North Atlantic Ocean , 1978 .

[25]  W. Schmitz.  Weakly depth-dependent segments of the North Atlantic circulation , 1980 .

[26]  S. Riser,et al.  Quasi-Lagrangian structure and variability of the subtropical western North Atlantic circulation , 1983 .

[27]  D. Webb,et al.  The spatial and temporal evolution of a cluster of SOFAR floats in the POLYMODE local dynamics experiment (LDE) , 1986 .

[28]  J. W. Schmitz.  Abyssal eddy kinetic energy in the North Atlantic , 1984 .

[29]  J. Bendat,et al.  Measurement and Analysis of Random Data , 1968 .

[30]  Russ E. Davis,et al.  Observing the general circulation with floats , 1991 .

[31]  D. Webb,et al.  A quasi-Lagrangian study of mid-ocean variability using long range SOFAR floats , 1976 .