Antarctic bottom and lower circumpolar deep water circulation in the eastern Indian Ocean
Sloyan, Bernadette M.
MetadataShow full item record
Net northward transport below γn > 28.1 kgm−3 (≈3200 m) into the Perth Basin of between 4.4 and 5.8 Sv is estimated from a year-long current meter mooring array between the Broken and Naturaliste Plateaus. Northward transport of between 2.0 and 2.5 Sv of Antarctic Bottom Water (γn >28.2 kgm−3), that must upwell within the southern region of the Perth Basin, results in an area-averaged diapycnal velocity and diffusivity of w*=2.5− 3.1× 10−6 ms−1 and κ = 13−15×10−4 m2s−1, respectively. Diffusivity estimates for the Perth Basin are several times larger than area averaged mixing estimates for the abyssal subtropical South Atlantic and Pacific Oceans. However, the dissipation of turbulent kinetic energy required to maintain the abyssal mixing in the Perth basin, ε=O(10−9 Wkg−1), is similar to that required in the South Atlantic Ocean. The area-averaged diffusivity in the Perth Basin does not require unreasonable energy dissipation rates as this ocean basin is only weakly stratified. The abyssal diffuvisity of the Perth Basin results from intense mixing at the basin boundary and in the basin interior over rough topography. The complex bathymetry and low abyssal stratification suggests that the Indian Ocean, for a given energy dissipation, may support a larger meridional overturning circulation than other subtropical basins.
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): C02006, doi:10.1029/2005JC003011.
Suggested CitationJournal of Geophysical Research 111 (2006): C02006
Showing items related by title, author, creator and subject.
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean Menezes, Viviane V.; Macdonald, Alison M.; Schatzman, Courtney (American Association for the Advancement of Science, 2017-01-25)Southern Ocean abyssal waters, in contact with the atmosphere at their formation sites around Antarctica, not only bring signals of a changing climate with them as they move around the globe but also contribute to that ...
Multidecadal Indian Ocean variability linked to the Pacific and implications for preconditioning Indian Ocean dipole events Ummenhofer, Caroline C.; Biastoch, Arne; Böning, Claus W. (American Meteorological Society, 2017-02-15)The Indian Ocean has sustained robust surface warming in recent decades, but the role of multidecadal variability remains unclear. Using ocean model hindcasts, characteristics of low-frequency Indian Ocean temperature ...
Counts of Mysidacea species collected during the International Indian Ocean Expeditions (IIOE) aboard multiple cruises in the Indian Ocean from 1962-1965 (IIOE project) Nair, Vijayalakshmi R. (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-11-01)Counts of Mysidacea species collected during the International Indian Ocean Expeditions (IIOE) in the Indian Ocean. Mysidacea were collected by several ships that took part in the IIOE from 1962 to 1965. Though collections ...