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Interannual to decadal changes in the western boundary circulation in the Atlantic at 11°S
Author(s) -
Hummels Rebecca,
Brandt Peter,
Dengler Marcus,
Fischer Jürgen,
Araujo Moacyr,
Veleda Doris,
Durgadoo Jonathan V.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl065254
Subject(s) - oceanography , boundary current , eddy , climatology , water mass , geology , north atlantic deep water , subtropics , current (fluid) , gulf stream , shutdown of thermohaline circulation , mooring , ocean current , thermohaline circulation , circulation (fluid dynamics) , geography , meteorology , physics , turbulence , biology , thermodynamics , fishery
Abstract The western boundary current system off Brazil is a key region for diagnosing variations of the Atlantic meridional overturning circulation (AMOC) and the southern subtropical cell. In July 2013 a mooring array was installed off the coast at 11°S similar to an array installed between 2000 and 2004 at the same location. Here we present results from two research cruises and the first 10.5 months of moored observations in comparison to the observations a decade ago. Average transports of the North Brazil Undercurrent and the Deep Western Boundary Current (DWBC) have not changed between the observational periods. DWBC eddies that are predicted to disappear with a weakening AMOC are still present. Upper layer changes in salinity and oxygen within the last decade are consistent with an increased Agulhas leakage, while at depths water mass changes are likely related to changes in the North Atlantic as well as tropical circulation changes.