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Advection and diffusion of Indonesian Throughflow Water within the Indian Ocean South Equatorial Current
Author(s) -
Gordon Arnold L.,
Ma Shubin,
Olson Donald B.,
Hacker Peter,
Ffield Amy,
Talley Lynne D.,
Wilson Douglas,
Baringer Molly
Publication year - 1997
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 - 10.1029/97gl01061
Subject(s) - throughflow , isopycnal , thermocline , oceanography , deep ocean water , geology , boundary current , water mass , ocean general circulation model , ocean surface topography , monsoon , advection , ocean gyre , western hemisphere warm pool , subtropical indian ocean dipole , thermohaline circulation , ocean heat content , ocean current , subtropics , pacific ocean , climate change , physics , fishery , biology , soil science , general circulation model , thermodynamics
Warm, low salinity Pacific water weaves through the Indonesian Seas into the eastern boundary of the Indian Ocean. The Indonesian Throughflow Water (ITW) adds freshwater into the Indian Ocean as it spreads by the advection and diffusion within the Indian Ocean's South Equatorial Current (SEC). The low salinity throughflow trace, centered along 12°S, stretches across the Indian Ocean, separating the monsoon dominated regime of the northern Indian Ocean from the more typical subtropical stratification to the south. ITW is well represented within the SEC thermocline, extending with concentrations above 80% of initial characteristics from the sea surface to 300‐m within the eastern half of the Indian Ocean, with 60% concentration reaching well into the western Indian Ocean. The ITW transport within the SEC varies from 4 to 12 × 10 6 m³ sec −1 , partly in response to variations of the injection rate at the eastern boundary and to the likelihood of a zonally elongated recirculation cell between the Equatorial Counter Current and the SEC within the Indian Ocean. Lateral mixing disperses the ITW plume meridionally with an effective isopycnal mixing coefficient of 1.1 to 1.6 × 10 4 m²sec −1 .