Indian Ocean Subtropical Mode Water: its water characteristics and spatial distribution
We have improved a basic description (water characteristics and spatial distribution) of the Indian Ocean Subtropical Mode Water (IOSTMW) using an isopycnally averaged three-dimensional hydrographic dataset. Two mode waters and corresponding wintertime mixed layer depth maxima were observed north of...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2010-01-01
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| Series: | Ocean Science |
| Online Access: | http://www.ocean-sci.net/6/41/2010/os-6-41-2010.pdf |
| Summary: | We have improved a basic description (water characteristics and spatial distribution) of the Indian Ocean Subtropical Mode Water (IOSTMW) using an isopycnally averaged three-dimensional hydrographic dataset. Two mode waters and corresponding wintertime mixed layer depth maxima were observed north of the subtropical front (STF) in the South Indian Ocean: IOSTMW (within 25.8–26.2 &sigma;<sub>&theta;</sub>) in the region of 28–45&deg; E and another subtropical mode water in the subtropical gyre (within 26.4–26.7 &sigma;<sub>&theta;</sub>) in the 60–80&deg; E longitudinal band. Through careful examination of the spatial distribution and water characteristics of a core in the layer of minimum vertical temperature gradient (LMVTG), we identified that a mass of LMVTG corresponds to IOSTMW. The average water characteristics of the IOSTMW during approximately 1960–2004 were 16.54 &plusmn; 0.49 &deg;C, 35.51 &plusmn; 0.04 psu and 26.0 &plusmn; 0.1 &sigma;<sub>&theta;</sub>. The IOSTMW distribution area was estimated to be 25–50&deg; E, 27–38&deg; S. The formation region and approximate water characteristics of the second subtropical mode water were also estimated. Its probable formation region was 37–42&deg; S, 60–80&deg; E and north of the STF, with approximate water characteristics of 12.84 &plusmn; 0.57 &deg;C, 35.17 &plusmn; 0.11 psu and 26.57 &plusmn; 0.04 &sigma;<sub>&theta;</sub>. |
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| ISSN: | 1812-0784 1812-0792 |