Recent current measurements in the tropical eastern North Atlantic reproduce the components of the large scale flow field. However, the observations as well as the 1/12°‐FLAME model computations indicate that a lot of eddy scale variability is superimposed on the mean flow field. Despite of the disturbance by variability the signature of the Guinea Dome is well present. In November 2002 the Guinea Dome transport from direct observations was about 2.8 Sv above σθ = 25.8 kg/m3 and 4 Sv between σθ = 25.8 and 27.1 kg/m3. The oxygen minimum in the shadow zone comprises the central water and the Antarctic Intermediate Water (AAIW) layers and is located between the equatorial current system and the North Equatorial Current. The North Equatorial Counter‐ and Undercurrents at 3° to 6°N are major oxygen sources for the central water layer of the low‐oxygen regions in the northeastern tropical Atlantic. A second, northern North Equatorial Countercurrent (nNECC) band exists at 8° to 10°N. The nNECC carries oxygen rich water from the southern hemisphere eastward but with an admixture of water from the northern hemisphere. A float at 200 m depth was spreading eastward in the North Equatorial Undercurrent (NEUC), at 28°W it shifted northward into the nNECC, and then was trapped in the Guinea Dome region for more than 3 years. The model indicates the region 22° to 32°W as the area of exchange between the NECC/NEUC and the nNECC bands. In the AAIW layer the northern Intermediate Countercurrent acts as oxygen source for the oxygen minimum zone.

[1] A major pathway of the Atlantic meridional overturning circulation (MOC) is the warm inflow into the Caribbean Sea. The transport and the contribution of water from the South Atlantic is calculated from observations (ADCP data and hydrography) and compared to the results of the 1 12°F LAME model. The model and the observations show high consistency in the strength of the mean total inflow and its range of variability as well as in the general distribution of water from South Atlantic origin. The measurements give an annual mean South Atlantic Water (SAW) transport into the Caribbean of 9.3 Sv with high variability. This estimate has to be regarded as a lower bound since the present method (using temperature and salinity data) cannot identify the SAW included in the North Equatorial Current (NEC), which recirculated and was transformed in the interior tropical Atlantic. The model transport reproduces the observational values rather closely, with an annual mean inflow of 8.6 Sv and similar high variability. Closer inspection of the SAW pathways in the model suggest that the additional contribution by the NEC-pathway is only about 2 Sv. The model results confirm the relative importance of the MOC pathways suggested by observations: the Caribbean inflow seems to be the main pathway (63%) for the warm and central water (s q < 27.1 kg m À3 ), whereas for the intermediate water a larger fraction (59%) is transported northward at the eastern side of the Lesser Antilles.

[1] A suite of basin-scale models of the thermohaline and wind-driven circulation in the Atlantic Ocean is used to study the mechanisms of decadal variability in the shallow subtropical-tropical cells (STCs). The emphasis is on the spatial patterns of the transport anomalies in the tropical thermocline, particularly their manifestation in the equatorial current system and on the relative role of changes in the deep meridional overturning cell (MOC) associated with variations in the formation of Labrador Sea Water (LSW) in the subpolar North Atlantic. Using wind stress and heat flux variations based on NCEP/ NCAR-reanalysis products, the variability of the zonally integrated STC transports is similar to that obtained in a recent regional model study, corroborating the role of both the southern and northern STC in supporting wind-driven transport anomalies of O(2 Sv) near the equator. Sensitivity experiments indicate that changes in subarctic MOC transports associated with the strong variability in LSW formation during the last decades contributed a signal of O(0.3 Sv) to the upper-layer equatorial transports. Whereas the local wind-driven variability clearly dominates on interannual-decadal timescales and is confined to depths down to 150 m, the weak MOC-related signal is primarily reflected in an interdecadal modulation of the STC transports. While a strong part in the STC's transport anomalies is associated with the western boundary current (NBC), there is an important contribution also by weaker, interior ocean flow anomalies which tend to counteract the variability of the NBC.