Velocity structure and transport in the Windward Islands Passages

Direct observations of velocity and transport in the passages between the Intra‐Americas Sea and the Atlantic Ocean, 1984–1996

“…Their mean transport for the six transects which had full-depth coverage (some of which were included in the present study) was -4.7 _+ 1.6 Sv to the bottom of the passage, which is located at ---900-m depth. The observed velocity structure described by Wilson and Johns [1997] is in good agreement with that from the present study (Figures 10 and 11), but the transport is lower, as our average transport through Grenada Passage was -4.9 _+ 1.9 Sv for the upper 200 m alone. Our value is -4.1 Sv if the anomalously high transport observed during one particular cruise is discarded.…”

“…They used data collected in 1970 by Stalcup and Metcalf [1972] to examine the flow between the islands of the Lesser Antilles and arrived at an estimate of the transport distribution based on the limited data available at that time. More recently, Wilson and Johns [1997] conducted a comprehensive study of the inflow to the eastern Caribbean during the Windward Islands Passages Program. Using a cable-lowered acoustic Doppler current profiler (ADCP), they were able to obtain enough direct observations of transport and velocity structure in the southern passages over several years to more closely examine the mean inflow and its variability.…”

Decadal- to interannual-scale source water variations in the Caribbean Sea recorded by Puerto Rican coral radiocarbon

“…The results of the mixing model ( Figure 6) are intriguing because they indicate that the proportion of water from equatorial sources versus northern subtropical sources bathing southwestern Puerto Rico changes on interannual to decadal time scales as hypothesized by Wilson and Johns (1997). It must be noted that the low 14 C, equatorially sourced, water is a mixture of North Atlantic and South Atlantic water, and is not a pure South Atlantic signal.…”

“…Hydrographic surveys of the Caribbean inflow have found that the inflow to the Caribbean comes from 1) primarily South Atlantic origins (Wust 1964), ostensibly in part from MOC return flow, or 2) from primarily North Atlantic origins (Mazeika et al 1983;Metcalf et al 1971;Parr 1937), ostensibly driven by Sverdrup transport. These conflicting results lead Wilson and Johns (1997) to conclude that the amount of water coming into the Caribbean from the South and North Atlantic may be variable with time.…”

On the world ocean circulation. Volume I, Some global features/North Atlantic circulation

“…However, the North Brazil Current System and lately the Caribbean passages have been studied extensively in recent years (Brown et al, 1992;da Silveira et al, 1994;Johns et al, 1990;Richardson, 1994;Richardson et al, 1994;Schott et al, 1995;SR9l;Wilson and Johns, 1996;Wilson et aL., 1994), so that a clearer picture is emerging. One schematic of the upper level currents at low latitudes in the North Atlantic is shown in Figure 1-74.…”