|dc.contributor.author||Rossby, H. Thomas||
|dc.contributor.author||Voorhis, Arthur D.||
|dc.contributor.author||Webb, Douglas C.||
|dc.description||Also published as Journal of Marine Research, 1975, Volume 33, No . 3, pp. 355-382||en_US||
|dc.description.abstract||Twenty neutrally buoyant SOFAR floats were used in the Mid-Ocean Dynamics Experiment
(MODE) to study the structure and variability of the deep ocean currents. The floats were clustered
so that the pattern of motions could be resolved (mapping and pattern recognition). A number
of float trajectories are shown and the very individual character of their signature is emphasized.
Some floats remain nearly stationary for a year whereas others will cover hundreds of kilometers
to the south or west in just a few months. Superposition of all trajectories in the spaghetti diagram
is shown to reveal considerable organization of the "eddy" field in the MODE area and is thought
to be caused by the near presence of the Blake-Bahama Outer Ridge to the west. There is considerable
asymmetry to the float dispersal with floats rapidly scattering to the south and west, but
not to the north and east even though the r .m.s. velocities are a factor 3 to 6 times greater than
the mean drift.
The evolution and dispersal of the float cluster is illustrated in a set of figures in each of which
a 12 day segment of all float trajectories is displayed. At times their mobility and relative motion
is shown to be associated with onset of sudden swirls and regions of large horizontal shear, features
that are not evident from the analysis of individual trajectories.
Cluster averages of the float velocities and kinetic energy, computed weekly and plotted as a
function of time, show substantial variability. Much better averages are obtained by limiting the
cluster to floats within a geographical region. As the spaghetti diagram indicates and the following
paper discusses in more detail there exist substantial geographical variations in the average kinetic
energy levels. These may be in some way caused topographically by the close proximity to the
continental margin. Whatever the reason they caution us to reexamine the notion that the scale
of variation of the second order eddy statistics is large compared to the eddies themselves, at
least in the MODE-I area.
Ten floats also contained a system to record the local pressure, temperature and vertical currents.
The pressure and temperature yield data concerning low frequency vertical displacements and the
vertical current meters measure the internal wave sea state which is shown to be remarkably constant.||en_US||
|dc.description.sponsorship||Prepared for the Office of Naval Research under
Contracts N00014-66-C-0241; NR 083-004 ( WHOI), N00014-67-A-0097-001 (Yale University) and NSF
Grants GX-30220 (WHOI), GX-30416 (Yale University) .||en_US||
|dc.publisher||Woods Hole Oceanographic Institution||en_US||
|dc.relation.ispartofseries||WHOI Technical Reports||en_US||
|dc.subject||Mid-Ocean Dynamics Experiment (MODE)||
|dc.title||A quasi-Lagrangian study of mid-ocean variability using long range SOFAR floats||en_US||