Instead, they found that the flow in the upper layers of the Caribbean was westward everywhere except along the coast of Venezuela. Based on the observations of Pillsbury , Model provided the first description of the inflow through all of the Caribbean passages. He found that of the 28 Sv flowing into the Caribbean, 24 Sv flowed in through the Lesser Antilles passages.
As Johns et al. However, some of the studies that sampled the transport through individual passages in the eastern Caribbean Metcalf ; Stalcup and Metcalf ; and Brooks were relatively short and affected by significant tidal and synoptic variability Johns et al. Thus, there has been considerable debate over the actual amount of water transported into the Caribbean through different areas.
Gordon obtained geostrophic transports of Sv through the eastern Caribbean and less than 5 Sv of inflow through Windward Passage. This suggested that most of the water entered the Caribbean through the southern Lesser Antilles passages Johns et al.
Worthington , on the other hand, estimated 20 Sv through the Caribbean and 10 Sv through Windward Passage. Still another estimate came from Roemich , who used inverse calculations to find a transport of about 22 Sv through Windward Passage Johns et al. After reanalyzing the Stalcup and Metcalf data, Schmitz and Richardson concluded that 22 Sv of the Florida Current transport came from the southern Lesser Antilles passages, while 7 Sv could be attributed to Windward Passage further north Johns et al.
Johns et al. After reviewing the available observations, they concluded that the area most in need of study is Windward Passage, since estimates there ranged from 3 to 9 Sv. The current is significantly influenced by freshwater discharges from the Amazon and Orinoco Rivers Morrison and Smith In fact, the Amazon River is the largest point source of fresh water entering the ocean, adding anywhere from 0.
Thus, the possibility exists for the variability in riverine contributions to affect the regional circulation Morrison and Smith In support of this view, most of the drifters that Limeburner et al. The origin of the water can be determined by examining its unique temperature, salinity, and dissolved oxygen signature; South Atlantic waters are less saline and have more dissolved oxygen than do North Atlantic waters of the same density Wilson The circulation pattern of the North Atlantic gyre suggests that South Atlantic water is likely to enter the Caribbean mostly through the southern passages.
Wust analyzed historical hydrographic data and found this to be the case, but more recent surveys through the southern passages found waters of North Atlantic origin Mazeika et al. This suggests that the amount of South Atlantic water flowing into the Caribbean may have a strong time dependence Wilson Roemmich studied the amounts of water leaving the western Caribbean and the amounts of water entering through the eastern Caribbean and the Windward Passage.
Within the southernmost portion of this area, they observed two different flow patterns. Underneath this flow, there was an eastward flow with a subsurface maximum near the coast of Venezuela. Caribbean Surface Water is found in the upper 50 m of the water column. It is relatively fresh, with salinity values of The circulation in the Caribbean experiences much variation in both space and time, some of it in the form of mesoscale eddies and meanders.