Tm. Joyce et al., Zonal circulation in the NW Atlantic and Caribbean from a meridional WorldOcean Circulation Experiment hydrographic section at 66 degrees W, J GEO RES-O, 106(C10), 2001, pp. 22095-22113
A World Ocean Circulation experiment Hydrographic Program section along 66
degreesW in the North Atlantic was made in 1997. In addition to the usual v
ariables (hydrographic and tracer) measured in WOCE onetime sections, we ma
de lowered acoustic doppler current profiler (LADCP) measurements at nearly
all of the stations. The section closed off a portion of the western North
Atlantic to the west of the line, making a closed volume for constraining
the circulation. In addition, the deep portions of the Caribbean do not com
municate with the rest of the basin. By combining mass, silica, and LADCP i
nformation as constraints an inverse calculation obtained reveals a strong
eastward transport in the Gulf Stream bounded by westward flowing water on
either side. Within these energetic flows we see evidence for recently vent
ilated Classical Labrador Sea Water, which has not reached the Deep Western
Boundary Current north of Puerto Rico in any significant amounts. Within t
he Caribbean our major new finding is a deep cyclonic circulation below sil
l depth in excess of 100 times the inflow of deep Atlantic water through th
e major deep sill: the Anegada-Jungfern Passage. The signature of the deep
Atlantic source water is most prominent in CFCs and both a bottom and mid-d
epth maximum are present in the Caribbean to the south of Puerto Rico. Off
the coast of Venezuela, however, only the deeper CFC maximum is found. For
the entire section the net overturning circulation, heat flux, and freshwat
er fluxes are all consistent with expectations based on water mass formatio
n and air-sea exchanges to the west of our section, but the annual mean air
-sea fluxes of heat and freshwater from Comprehensive Ocean-Atmosphere Data
Sets appear somewhat too small in comparison with our single-section resul
t.