Publikationsdatum:
2022-05-26
Beschreibung:
Also published as: Journal of Geophysical Research 84 (1979): 7727-7741
Beschreibung:
A cyclonic Gulf Stream ring, Allen, was followed over its life from September 1976 to April 1977 in
the region north of Bermuda. Conductivity, temperature, and depth; expendable bathythermograph; and
velocity profile measurements were made in Allen, and over the last 5 months of its life, satellite buoys
were used to track continuously its movement. The measurements indicate that in December 1976 Allen
split into two rings, a large one, Allen, and a small one, Arthur. Arthur moved rapidly eastward and coalesced
with the Gulf Stream near the New England seamounts. Allen moved in a large clockwise loop; at
the end of February 1977 it became attached to the Gulf Stream and reformed into a modified ring,
smaller in size and faster in rotation . At the end of April 1977 the modified ring coalesced with the Gulf
Stream and disappeared as it was advected downstream in the stream. The principal results of this study
are that (I) the New England Seamount chain was a major influence in the genesis of Allen and on the
trajectories of nearby rings; (2) while a free eddy, months after its formation, Allen evolved into a bi
modal or peanut-shaped structure; (3) the bimodal structure ultimately bifurcated, spawning a new isolated
eddy, denoted as Arthur, and a modified remnant, Allen; (4) the velocity field of Allen involved the
whole water column, with bottom velocities of 10-15 em s- 1; (5) the barotropic velocity at the center of
Allen (6 cm s-1 to NNW) was about equal to its translation velocity (4 cm s-1 to NW); (6) especially
energetic inertial motions were seen at the center of Allen, and these may play a role in enhancing the
stirring of water properties; (7) Allen survived several close encounters or entrainments with the Gulf
Stream, proving that such encounters can be nonfatal to a ring; (8) the encounters appear to result in injections
(exchanges) of water (momentum, heat, etc.) into the rings at an estimate rate of 106 m3 s-1 per
ring; and (9) the behavior of Allen and Arthur was in contrast to the results of some other studies which
have shown that rings generally drift slowly and passively southwestward.
Beschreibung:
Prepared for the Office of Naval Research under Contract
N000 14-74-C-0262; NR 083-004 and for the National Science
Foundation under Grants OCE 76-82059, DES 74-02783, and
OCE 76-24605.
Schlagwort(e):
Eddies
;
Oceanographic buoys
Repository-Name:
Woods Hole Open Access Server
Materialart:
Technical Report
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