Abstract
Based on HYbrid Coordinate Ocean Model (HYCOM) assimilation and observations, we analyzed seasonal variability of the salinity budget in the southeastern Arabian Sea (AS) and the southern part of the Bay of Bengal (BOB), as well as water exchange between the two basins. Results show that fresh water flux cannot explain salinity changes in salinity budget of both regions. Oceanic advection decreases salinity in the southeastern AS during the winter monsoon season and increases salinity in the southern BOB during the summer monsoon season. In winter, the Northeast Monsoon Current (NMC) carries fresher water from the BOB westward into the southern AS; this westward advection is confined to 4°–6°N and the upper 180 m south of the Indian peninsula. Part of the less saline water then turns northward, decreasing salinity in the southeastern AS. In summer, the Southwest Monsoon Current (SMC) advects high-salinity water from the AS eastward into the BOB, increasing salinity along its path. This eastward advection of high-salinity water south of the India Peninsula extends southward to 2°N, and the layer becomes shallower than in winter. In addition to the monsoon current, the salinity difference between the two basins is important for salinity advection.
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References
Antonov J I, Locarnini R A, Boyer T P et al. 2006. World Ocean Atlas 2005, Volume 2: Salinity. S. Levitus, Ed. NOAA Atlas NESDIS 62, U.S. Government Printing Office, Washington D C. 182p.
Bleck R. 2002. An oceanic general circulation model framed in hybrid isopycnic-Cartesian coordinates. Ocean Modeling, 4(1): 55–88.
Bruce J G, Johnson G D R, Kindle J C. 1994. Evidence for eddy formation in the eastern Arabian Sea during the northeast monsoon. J. Geophys. Res., 99(C4): 7 651–7 664, http://dx.doi.org/10.1029/94JC00035.
Bruce J G, Kindle J C, Kantha L H et al. 1998. Recent observations and modeling in the Arabian Sea Laccadive High region. J. Geophys. Res., 103(C4): 7 593–7 600, http://dx.doi.org/10.1029/97JC03219.
Chassignet E P, Hurlburt H E, Metzger E J et al. 2009. U.S. GODAE: global ocean prediction with the HYbrid Coordinate Ocean Model (HYCOM). Oceanography, 22(2): 48–59.
Christensen J H, Hewitson B, Busuioc A et al. 2007. Regional Climate Projections. In: Solomon S, Qin D, Manning M eds. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
Cummings J A. 2005. Operational multivariate ocean data assimilation. Quart. J. Royal Met. Soc., Part C, 131(613): 3 583–3 604, http://dx.doi.org/10.1256/qj.05.105.
Cutler A N, Swallow J C. 1984. Surface currents of the Indian Ocean (to 25°S, 100°E). IOS Tech. Rep. 187, Inst of Oceanogr. Sci., Wormley, England.
Feng M, Hacker P, Lukas R. 1998. Upper ocean heat and salt balances in response to a westerly wind burst in the western equatorial Pacific during TOGA COARE. J. Geophys. Res., 103(C5): 10 289–10 311.
Fox D N, Teague W J, Barron C N et al. 2002. The Modular Ocean Data Assimilation System (MODAS). J. Atmos. Ocean. Technol., 19(2): 240–252.
Gopalakrishna V V, Johnson Z, Salgaonkar G et al. 2005. Observed variability of sea surface salinity and thermal inversions in the Lakshadweep Sea during contrast monsoons. Geophys. Res. Lett., 32: L18605, http://dx.doi.org/10.1029/2005GL023280.
Halliwell G R, Bleck R, Chassignet E P. 1998. Atlantic Ocean simulations performed using a new hybrid-coordinate ocean model. EOS, Fall 1998 AGU Meeting.
Halliwell G R, Bleck R, Chassignet E P et al. 2000. Mixed layer model validation in Atlantic ocean simulations using the Hybrid Coordinate Ocean Model (HYCOM). EOS, 80, OS304.
Halliwell G R. 2002. HYCOM Overview. http://hycom.org/hycom/overview. Accessed on 2011-6-1.
Han W, McCreary J P. 2001. Modeling salinity distributions in the Indian Ocean. J. Geophys. Res., 106(C1): 859–877.
Jensen T G. 2001. Arabian Sea and Bay of Bengal exchange of salt and tracers in an ocean model. Geophys. Res. Lett., 28(20): 3 967–3 970, http://dx.doi.org/10.1029/2001GL013422.
Jensen T G. 2003. Cross-equatorial pathways of salt and tracers from the northern Indian Ocean: modelling results. Deep-Sea Res. II, 50(12–13): 2 111–2 127.
Masumoto Y, Hase H, Kuroda Y et al. 2005. Intraseasonal variability in the upper layer currents ob-served in the eastern equatorial Indian Ocean. Geophys. Res. Lett., 32: L02607, http://dx.doi.org/10.1029/2004GL021896.
Murty V S N, Sarma Y V B, Rao D P et al. 1992. Water characteristics, mixing and circulation in the Bay of Bengal during southwest monsoon. Journal of Marine Research, 50(2): 207–228.
Prasanna Kumar S, Narvekar J, Kumar A et al. 2004. Intrusion of the Bay of Bengal water into the Arabian Sea during winter monsoon and associated chemical and biological response. Geophys. Res. Lett., 31: L15304, http://dx.doi.org/10.1029/2004GL020247.
Rao R R, Sivakumar R. 1999. On the possible mechanisms of the evolution of a mini-warm pool during the pre-summer monsoon season and the genesis of onset vortex in the southeastern Arabian Sea. Q. J. R. Meteorol. Soc., 125: 787–809.
Rao R R, Sivakumar R. 2003. Seasonal variability of sea surface salinity and salt budget of the mixed layer of the north Indian Ocean. J. Geophys. Res., 108(C1): 3 009, http://dx.doi.org/10.1029/2001JC000907.
Schmitt R W.1995. The ocean component of the global water cycle. Reviews of Geophysics, 33: 1 395–1 409.
Schott F, Reppin J, Fischer J. 1994. Currents and transports of the Monsoon Current south of Sri Lanka. J. Geophys. Res., 99(C12): 25 127–25 141, http://dx.doi.org/10.1029/94JC02216.
Schott F, McCreary J P. 2001. The monsoon circulation of the Indian Ocean. Prog. Oceanogr., 51(1): 1–123, http://dx.doi.org/10.1016/S0079-6611(01)00083-0.
Sengupta D, Senan R, Goswami B N. 2001. Origin of intraseasonal variability of circulation in the tropical central In-dian Ocean. Geophys. Res. Lett., 28: 1 267–1 270.
Sengupta D, Senan R, Goswami B N. 2007. Intraseasonal variability of equatorial Indian Ocean zonal currents. J. Clim., 20: 3 036–3 055.
Shankar D, Shetye S R. 1997. On the dynamics of the Lakshadweep high and low in the southeastern Arabian Sea. J. Geophys. Res., 102(C6): 12 551–12 567.
Shenoi S S C, Shankar D, Shetye S R. 1999. On the sea surface temperature high in the Lakshadweep Sea before the onset of the southwest monsoon. J. Geophys. Res., 104(C7): 15 703–15 712, http://dx.doi.org/10.1029/1998JC900080.
Shetye S R, Gouveia A D, Shankar D et al. 1996. Hydrography and circulation in the western Bay of Bengal during the northeast monsoon. J. Geophys. Res., 101(C6): 14 011–14 025, http://dx.doi.org/10.1029/95JC03307.
Shetye S R, Gouveia A D, Shenoi S S C et al. 1991. The coastal current off western India during the northeast monsoon. Deep Sea Res., 38(12): 1 517–1 529, http://dx.doi.org/10.1016/0198-0149(91)90087-V.
Suryanarayana A, Murty V S N, Rao D P. 1993. Hydrography and circulation of the Bay of Bengal during early winter. Deep — Sea Res., 40(1): 205–217, http://dx.doi.org/10.1016/0967-0637(93)90061-7.
Vinayachandran P N, Yamagata T. 1998. Monsoon response of the sea around Sri Lanka: eneration of thermal domes and anti-cyclonic vortices. J. Phys. Oceanogr., 28(10): 1 946–1 960.
Zhang Y, Xu H, Du Y et al. 2009. Seasonal variability of salinity budget in the southeastern Arabian Sea. Journal of Tropical Oceanology, 28(5): 66–74. (in Chinese with English abstract)
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Supported by the National Basic Research Program of China (973 Program) (No. 2010CB950300), the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q11-02), the National Basic Research Program of China (973 Program) (No. 2012CB955603), and the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-BR-04)
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Zhang, Y., Du, Y. Seasonal variability of salinity budget and water exchange in the northern Indian Ocean from HYCOM assimilation. Chin. J. Ocean. Limnol. 30, 1082–1092 (2012). https://doi.org/10.1007/s00343-012-1284-7
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DOI: https://doi.org/10.1007/s00343-012-1284-7