AOML_observational program

1. North Brazil Current Experiment:

The North Brazil Current is a major western boundary current in the tropical Atlantic that transports upper ocean waters northward across the equator. It plays a dual role, first in closing the wind-driven equatorial gyre bounded on the south by the South Equatorial Current (SEC) and on the north by the North Equatorial Countercurrent (NECC), and second in providing a conduit for cross-equatorial transport of South Atlantic upper ocean waters as part of the Atlantic meridional overturning cell (MOC). The NBC separates sharply from the coast at 6-7N and curves back on itself (retroflects) to feed NECC. During this retroflection phase the pinch off large anticyclonic current rings. more

Surface current in the tropical Atlantic across high density XBT line AX08. Gustavo Goni and Molly O. Baringer.

Abstract: Three temperature sections that cross the tropical Atlantic obtained from high density XBT transects are used to identify the major upper ocean currents and to compute their water mass transports. The dynamic heights are computed using the XBT temperature profiles with salinity derived from historical T-S relationships. The values of dynamic height estimated from altimeter data used in conjunction with climatological dynamic height fields are within 3 to 4 cm of the XBT-derived values. The error in XBT-derived dynamic height introduced by using historical T-S relationships instead of actual salinity values are estimated using profiling float salinity profiles and are of the order of 1.5 cm. The structure exhibited in the dynamic height and altimeter-derived sea height fields do not reveal all the components of the upper ocean current system, making the temperature sections presented here critical for computing transports and investigating the temporal and spatial variability of the upper ocean dynamics in the tropical Atlantic.

Large-scale SST distributions drive the response of the climate in the tropical Atlantic sector, and even over land areas as distant as the southern and eastern Unites States. In spite of its importance, no dynamical model has successfully predicted Atlantic SST one-to-several seasons in advance. more