www.ocean-sci.net/6/41/2010/ doi:10.5194/os-6-41-2010 © Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License. Indian Ocean Subtropical Mode Water: its water characteristics and spatial distribution Department of Geophysics, Tohoku University, Sendai, Japan Abstract. 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 σθ) in the region of 28–45° E and another subtropical mode water in the subtropical gyre (within 26.4–26.7 σθ) in the 60–80° 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 ± 0.49 °C, 35.51 ± 0.04 psu and 26.0 ± 0.1 σθ. The IOSTMW distribution area was estimated to be 25–50° E, 27–38° S. The formation region and approximate water characteristics of the second subtropical mode water were also estimated. Its probable formation region was 37–42° S, 60–80° E and north of the STF, with approximate water characteristics of 12.84 ± 0.57 °C, 35.17 ± 0.11 psu and 26.57 ± 0.04 σθ. Final Revised Paper (PDF, 10687 KB) Discussion Paper (OSD) Citation: Tsubouchi, T., Suga, T., and Hanawa, K.: Indian Ocean Subtropical Mode Water: its water characteristics and spatial distribution, Ocean Sci., 6, 41-50, doi:10.5194/os-6-41-2010, 2010. Bibtex EndNote Reference Manager XML |
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