Deep circulation in the tropical North Atlantic

Atlantic meridional overturning circulation at 14.5° N and 24.5° N during 1989/1992 and 2013/2015: volume, heat and freshwater fluxes

“…7±9.6 Sv in 1989 and -17.9±8.0 Sv in 2013, which is in agreement with the previous estimates ranging from -16 to -27 Sv in the tropical North Atlantic (Speer and McCartney, 1991;Molinari et al, 1992;Friedrichs and Hall, 1993). Different from Friedrichs and Hall (1993), we found that the northward recirculation occurred both at the western flank of the MAR, and directly to the east of the southward core along the continental slope. At Regarding the deep water formation as a primary driver of the AMOC, the long-term variability observed at lower latitudes might be related to changes in the export rate of deep waters in the subpolar North Atlantic.…”

“…5c) Molinari et al (1992), which is calculated by using repeated cruise sections between 14.5° N and the equator. Friedrichs and Hall (1993) have 5 shown that at 8° N in the Atlantic, 27 Sv were transported southward within the DWBC along the continental slope, which was accompanied by a northward recirculation of 16 Sv primarily along the western flank of the MAR. They further schematically showed that the whole tropical North Atlantic adopted such a circulation pattern.…”

“…Note that the uncertainties of the freshwater fluxes were estimated following Friedrichs and Hall (1993) as the amount of freshwater flux change due to an assumed salinity uncertainty of 0.2 psu in the western boundary at each section. This assumption is based on the fact that the freshwater flux is very sensitive to the transport-weighted salinity in the western 20 boundary ( ! )…”

Sediment <sup>231</sup>Pa/<sup>230</sup>Th as a recorder of the rate of the Atlantic meridional overturning circulation: insights from a 2-D model

“…2). The Atlantic Meridional Overturning Circulation (AMOC) is initiated by the formation of 20.5 Sv of North Atlantic Deep Water (NADW) (Friedrichs and Hall, 1993;Macdonald, 1998;Talley et al, 2003) Xp's = particulate concentrations (dpm.m -3 ). P X = production rates from U decay (dpm.m -3 .y Water from this homogeneous region is then transported horizontally to the south at different rates (Fig.…”

Modelling the Dynamics of Abyssal Equator-Crossing Currents

“…ocean. While While part part of of this this flow flow recirculates recirculates within within the the Brazil Brazil Basin, Basin, remaining remaining in in the the southern southern hemisphere, hemisphere, part part of of the the flow flow is is observed observed to to cross cross the the equator equator into into the the northern northern hemisphere hemisphere (DeMadron (DeMadron & & Weatherly, Weatherly, 1994;1994;Friedrichs Friedrichs & & Hall, Hall, 1993). 1993.…”