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Dynamics of Deep Ocean Eastern Boundary Currents
Author(s) -
Yang Xiaoting,
Tziperman Eli,
Speer Kevin
Publication year - 2020
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 - 10.1029/2019gl085396
Subject(s) - boundary current , geology , ocean current , deep sea , current (fluid) , stratification (seeds) , boundary (topology) , oceanography , ocean dynamics , climatology , boundary layer , ocean general circulation model , vorticity , potential vorticity , vortex , general circulation model , meteorology , climate change , geography , mechanics , physics , seed dormancy , mathematical analysis , botany , germination , mathematics , dormancy , biology
The long‐standing paradigm for the large‐scale time‐averaged ocean circulation in the world oceans includes intensified currents at the western boundary, and a much slower interior flow elsewhere. However, poleward deep boundary currents in the eastern limits of the deep South Pacific, Atlantic, and Indian Oceans have been observed repeatedly at 2‐ to 4‐km depth. They carry up to a third of the total deep ocean transports, implying a significant role in climate, yet their dynamics are still not well understood. Here we develop a theoretical understanding for these currents, using a hierarchy of realistic and idealized models, focusing on the South Pacific Ocean. The deep eastern boundary current there is shown to be driven by a traditional interior balance together with a narrow boundary layer scale near the eastern boundary, which exists only when stratification and topography are both included. A simplified semianalytical vorticity model is developed for the deep eastern boundary current.