Numerical Investigation of Bidirectional Mode-1 and Mode-2 Internal Solitary Wave Generation from North and South of Batti Malv Island, Nicobar Islands, India

N. Jithendra Raju Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India

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Mihir K. Dash Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India

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Prasad Kumar Bhaskaran Department of Ocean Engineering and Naval Architecture, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India

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P. C. Pandey Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India

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Abstract

Strong bidirectional internal solitary waves (ISWs) generate from a shallow channel between Car Nicobar and Chowra Islands of Nicobar Islands, India, and propagate toward the Andaman Sea (eastward) and Bay of Bengal (westward). Batti Malv Island separates this shallow channel into two ridges, north of Batti Malv (NBM) and south of Batti Malv (SBM). First, this study identifies the prominent mode-1 and mode-2 ISWs emerging from NBM and SBM using synthetic aperture radar images and then explores their generation mechanism(s) using a nonlinear, unstructured, and nonhydrostatic model, SUNTANS. During spring tide, flow over NBM is supercritical with respect to mode-1 internal wave. Model simulations reveal that mode-1 ISWs are generated at NBM by a “lee wave mechanism” and propagate both in the east and west directions depending on the tidal phases. However, the flow over SBM is subcritical with respect to mode-1 internal wave. The bidirectional propagating mode-1 ISWs evolve from a long-wave disturbance induced by “upstream influence.” But, during spring tide, with an increased tidal flow over SBM, it is observed that the westward propagating ISWs are formed by a dispersed hydraulic jump observed over the ridge. Moreover, the bidirectional mode-2 waves from SBM are generated by a lee wave mechanism. An energy budget comparison reveals that the region surrounding NBM is efficient in radiating low-mode baroclinic energy (0.98 GW), while SBM is highly efficient in converting barotropic to baroclinic energy (4.1 GW).

Supplemental information related to this paper is available at the Journals Online website: https://doi.org/10.1175/JPO-D-19-0182.s1.

© 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Mihir K. Dash, mihir@coral.iitkgp.ac.in

Abstract

Strong bidirectional internal solitary waves (ISWs) generate from a shallow channel between Car Nicobar and Chowra Islands of Nicobar Islands, India, and propagate toward the Andaman Sea (eastward) and Bay of Bengal (westward). Batti Malv Island separates this shallow channel into two ridges, north of Batti Malv (NBM) and south of Batti Malv (SBM). First, this study identifies the prominent mode-1 and mode-2 ISWs emerging from NBM and SBM using synthetic aperture radar images and then explores their generation mechanism(s) using a nonlinear, unstructured, and nonhydrostatic model, SUNTANS. During spring tide, flow over NBM is supercritical with respect to mode-1 internal wave. Model simulations reveal that mode-1 ISWs are generated at NBM by a “lee wave mechanism” and propagate both in the east and west directions depending on the tidal phases. However, the flow over SBM is subcritical with respect to mode-1 internal wave. The bidirectional propagating mode-1 ISWs evolve from a long-wave disturbance induced by “upstream influence.” But, during spring tide, with an increased tidal flow over SBM, it is observed that the westward propagating ISWs are formed by a dispersed hydraulic jump observed over the ridge. Moreover, the bidirectional mode-2 waves from SBM are generated by a lee wave mechanism. An energy budget comparison reveals that the region surrounding NBM is efficient in radiating low-mode baroclinic energy (0.98 GW), while SBM is highly efficient in converting barotropic to baroclinic energy (4.1 GW).

Supplemental information related to this paper is available at the Journals Online website: https://doi.org/10.1175/JPO-D-19-0182.s1.

© 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Mihir K. Dash, mihir@coral.iitkgp.ac.in

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  • Alpers, W., H. Wang-Chen, and L. Hock, 1997: Observation of internal waves in the Andaman Sea by ERS SAR. Proc. IGARSS’97: IEEE Int. Geoscience and Remote Sensing Symp., Denver, CO, IEEE, 15181520, https://doi.org/10.1109/IGARSS.1997.608926.

    • Crossref
    • Export Citation
  • Armi, L., 1986: The hydraulics of two flowing layers with different densities. J. Fluid Mech., 163, 2758, https://doi.org/10.1017/S0022112086002197.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Baines, P. G., 1984: A unified description of two-layer flow over topography. J. Fluid Mech., 146, 127167, https://doi.org/10.1017/S0022112084001798.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bourgault, D., P. S. Galbraith, and C. Chavanne, 2016: Generation of internal solitary waves by frontally forced intrusions in geophysical flows. Nat. Commun., 7, 13606, https://doi.org/10.1038/ncomms13606.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Buijsman, M., Y. Kanarska, and J. McWilliams, 2010: On the generation and evolution of nonlinear internal waves in the south China sea. J. Geophys. Res., 115, C02012, https://doi.org/10.1029/2009JC005275.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Codiga, D. L., 2011: Unified tidal analysis and prediction using the UTide Matlab functions. Tech. Rep. 2011-01, Graduate School of Oceanography, University of Rhode Island Narragansett, 59 pp., ftp://www.po.gso.uri.edu/pub/downloads/codiga/pubs/2011Codiga-UTide-Report.pdf.

  • Cummins, P. F., and L. Armi, 2010: Upstream internal jumps in stratified sill flow: Observations of formation, evolution, and release. J. Phys. Oceanogr., 40, 14191426, https://doi.org/10.1175/2010JPO4435.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cummins, P. F., L. Armi, and S. Vagle, 2006: Upstream internal hydraulic jumps. J. Phys. Oceanogr., 36, 753769, https://doi.org/10.1175/JPO2894.1.

  • Da Silva, J., M. Buijsman, and J. Magalhaes, 2015: Internal waves on the upstream side of a large sill of the mascarene ridge: A comprehensive view of their generation mechanisms and evolution. Deep-Sea Res. I, 99, 87104, https://doi.org/10.1016/j.dsr.2015.01.002.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Farmer, D. M., and J. D. Smith, 1980: Tidal interaction of stratified flow with a sill in knight inlet. Deep-Sea Res., 27A, 239254, https://doi.org/10.1016/0198-0149(80)90015-1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Farmer, D. M., and R. A. Denton, 1985: Hydraulic control of flow over the sill in observatory inlet. J. Geophys. Res., 90, 90519068, https://doi.org/10.1029/JC090iC05p09051.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Farmer, D. M., and L. Armi, 1999: The generation and trapping of solitary waves over topography. Science, 283, 188190, https://doi.org/10.1126/science.283.5399.188.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fringer, O., M. Gerritsen, and R. Street, 2006: An unstructured-grid, finite-volume, nonhydrostatic, parallel coastal ocean simulator. Ocean Modell., 14, 139173, https://doi.org/10.1016/j.ocemod.2006.03.006.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grimshaw, R., and K. Helfrich, 2018: Internal solitary wave generation by tidal flow over topography. J. Fluid Mech., 839, 387407, https://doi.org/10.1017/jfm.2018.21.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hibiya, T., 1986: Generation mechanism of internal waves by tidal flow over a sill. J. Geophys. Res., 91, 76977708, https://doi.org/10.1029/JC091iC06p07697.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Holleman, R., O. Fringer, and M. Stacey, 2013: Numerical diffusion for flow-aligned unstructured grids with application to estuarine modeling. Int. J. Numer. Methods Fluids, 72, 11171145, https://doi.org/10.1002/fld.3774.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jackson, C. R., J. C. Da Silva, and G. Jeans, 2012: The generation of nonlinear internal waves. Oceanography, 25, 108123, https://doi.org/10.5670/oceanog.2012.46.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jensen, T. G., J. Magalhães, H. W. Wijesekera, M. Buijsman, R. Helber, and J. Richman, 2020: Numerical modelling of tidally generated internal wave radiation from the Andaman sea into the Bay of Bengal. Deep-Sea Res. II, 172, 104710, https://doi.org/10.1016/J.DSR2.2019.104710.

    • Search Google Scholar
    • Export Citation
  • Jithin, A., P. Francis, A. Unnikrishnan, and S. Ramakrishna, 2019: Modeling of internal tides in the western Bay of Bengal: Characteristics and energetics. J. Geophys. Res. Oceans, 124, 87208746, https://doi.org/10.1029/2019JC015319.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kang, D., and O. Fringer, 2012: Energetics of barotropic and baroclinic tides in the monterey bay area. J. Phys. Oceanogr., 42, 272290, https://doi.org/10.1175/JPO-D-11-039.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lai, Z., C. Chen, G. W. Cowles, and R. C. Beardsley, 2010: A nonhydrostatic version of FVCOM: 2. Mechanistic study of tidally generated nonlinear internal waves in Massachusetts bay. J. Geophys. Res., 115, C12049, https://doi.org/10.1029/2010JC006331.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Magalhaes, J., and J. da Silva, 2018: Internal solitary waves in the Andaman Sea: New insights from SAR imagery. Remote Sens., 10, 861, https://doi.org/10.3390/rs10060861.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Maxworthy, T., 1979: A note on the internal solitary waves produced by tidal flow over a three-dimensional ridge. J. Geophys. Res., 84, 338346, https://doi.org/10.1029/JC084iC01p00338.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mellor, G. L., and T. Yamada, 1982: Development of a turbulence closure model for geophysical fluid problems. Rev. Geophys., 20, 851875, https://doi.org/10.1029/RG020i004p00851.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mohanty, S., A. Rao, and G. Latha, 2018: Energetics of semidiurnal internal tides in the Andaman Sea. J. Geophys. Res. Oceans, 123, 62246240, https://doi.org/10.1029/2018JC013852.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Osborne, A., and T. Burch, 1980: Internal solitons in the Andaman Sea. Science, 208, 451460, https://doi.org/10.1126/science.208.4443.451.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Raju, N. J., M. K. Dash, S. P. Dey, and P. K. Bhaskaran, 2019: Potential generation sites of internal solitary waves and their propagation characteristics in the Andaman Sea: A study based on MODIS true-colour and SAR observations. Environ. Monit. Assess., 191, 809, https://doi.org/10.1007/s10661-019-7705-8.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rayson, M. D., G. N. Ivey, N. L. Jones, and O. B. Fringer, 2018: Resolving high-frequency internal waves generated at an isolated coral atoll using an unstructured grid ocean model. Ocean Modell., 122, 6784, https://doi.org/10.1016/j.ocemod.2017.12.007.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shimizu, K., and K. Nakayama, 2017: Effects of topography and Earth’s rotation on the oblique interaction of internal solitary-like waves in the Andaman Sea. J. Geophys. Res. Oceans, 122, 74497465, https://doi.org/10.1002/2017JC012888.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sindhu, B., I. Suresh, A. Unnikrishnan, N. Bhatkar, S. Neetu, and G. Michael, 2007: Improved bathymetric datasets for the shallow water regions in the Indian Ocean. J. Earth Syst. Sci., 116, 261274, https://doi.org/10.1007/s12040-007-0025-3.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Udaya Bhaskar, T., M. Ravichandran, and R. Devender, 2007: An operational objective analysis system at INCOIS for generation of Argo value added products. Tech. Rep. INCOIS-MOG-ARGO-TR-04-2007, Indian National Centre for Ocean Information, 29 pp., http://moeseprints.incois.gov.in/3554/1/INCOIS-MOG-ARGO-TR-04-2007.pdf.

  • Vitousek, S., and O. B. Fringer, 2011: Physical vs. numerical dispersion in nonhydrostatic ocean modeling. Ocean Modell., 40, 7286, https://doi.org/10.1016/j.ocemod.2011.07.002.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wall, M., L. Putchim, G. Schmidt, C. Jantzen, S. Khokiattiwong, and C. Richter, 2015: Large-amplitude internal waves benefit corals during thermal stress. Proc. Roy. Soc., 282, 20140650, https://doi.org/10.1098/RSPB.2014.0650.

    • Search Google Scholar
    • Export Citation
  • Wijeratne, E., P. Woodworth, and D. Pugh, 2010: Meteorological and internal wave forcing of seiches along the Sri Lanka coast. J. Geophys. Res., 115, C03014, https://doi.org/10.1029/2009JC005673.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wijesekera, H., W. Teague, E. Jarosz, D. Wang, H. Fernando, and Z. Hallock, 2019: Internal tidal currents and solitons in the southern Bay of Bengal. Deep-Sea Res. II, 168, 104587, https://doi.org/10.1016/J.DSR2.2019.05.010.

    • Search Google Scholar
    • Export Citation
  • Wolfram, P. J., and O. B. Fringer, 2013: Mitigating horizontal divergence “checker-board” oscillations on unstructured triangular C-grids for nonlinear hydrostatic and nonhydrostatic flows. Ocean Modell., 69, 6478, https://doi.org/10.1016/j.ocemod.2013.05.007.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, Z., O. Fringer, and S. Ramp, 2011: Three-dimensional, nonhydrostatic numerical simulation of nonlinear internal wave generation and propagation in the south China sea. J. Geophys. Res., 116, C05022, https://doi.org/10.1029/2010JC006424.

    • Crossref
    • Search Google Scholar
    • Export Citation
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