An Intrathermocline Eddy and a tropical cyclone in the Bay of Bengal

Article English OPEN
Gordon, Arnold L. ; Shroyer, Emily ; Murty, V. S. N. (2017)
  • Publisher: Nature Publishing Group
  • Journal: Scientific Reports, volume 7 (issn: 2045-2322, eissn: 2045-2322)
  • Related identifiers: doi: 10.1038/srep46218, pmc: PMC5388918
  • Subject: Article

The Bay of Bengal, subjected to monsoonal forcing and tropical cyclones, displays a complex field of ocean eddies. On 5 December 2013 a sub-surface vortex or Intrathermocline Eddy (ITE) composed of water characteristic of the Andaman Sea was observed within the thermocline of the western Bay of Bengal. We propose that the ITE was the product of Tropical Cyclone Lehar interaction on 27 November 2013 with a westward propagating surface eddy from the eastern Bay of Bengal. While Lehar’s interaction with the ocean initially removes heat from the upper layers of the eddy, air-sea flux is limited as the deeper portions of the eddy was subducted into the stratified thermocline, inhibiting further interaction with the atmosphere. The ITE core from 30 to 150 m is thus isolated from local air-sea fluxes by strong stratification at the mixed layer base, and its periphery is stable to shear instability, suggestive of longevity and the ability to carry water far distances with minimal modification.
  • References (28)
    28 references, page 1 of 3

    Alam M., Hossain A. & Shafee S. Frequency of Bay of Bengal Cyclonic Storms and Depression crossing different coastal zones. Int. J. Climatol. 23, 1119–1125 (2003).

    Gordon A. L., Shroyer E. L., Mahadevan A., Sengupta D. & Freilich M. Bay of Bengal: 2013 northeast monsoon upper-ocean circulation. Oceanography 29(2), 82–91, http://dx.doi.org/10.5670/oceanog.2016.41 (2016)

    Chelton D. B., Schlax M. G. & Samelson R. M. Global observations of nonlinear mesoscale eddies. Progress in Oceanography 91, 167–216, doi: 10.1016/j.pocean.2011.01.002 (2011).

    Kostianoy A. G. & Belkin I. M. A survey of observations on intrathermocline eddies in the world ocean. In Mesoscale/Synoptic Coherent Structures in Geophysical Turbulence eds. Nihoul and Jamart, Elsevier, pages 821–841 (1991).

    Riser S. C., Owens W. B., Rossby H. T. & Ebbesmeyer C. C. The structure, dynamics, and origin of a small-scale lens of water in the western North Atlantic thermocline. J. Phys. Oceanogr. 16, 572– 590 (1986).

    Gordon A. L.. Japan/East Sea Intra-thermocline Eddies. J. Phys. Oceanogr.32(6) 1960–1974 (2002).

    Nauw J. J., van Aken H. M., Lutjeharms J. R. E. & de Ruijter W. P. M. Intrathermocline eddies in the Southern Indian Ocean. J. Geophys. Res. 111, C03006, doi: 10.1029/2005JC002917 (2006).

    Hormazabal S.. Intrathermocline eddies in the coastal transition zone off central Chile (31–41°S). J. Geophys. Res. Oceans 118, 4811–4821, doi: 10.1002/jgrc.20337 (2013).

    Ou H. W. & Gordon A. L. Subduction along a mid-ocean front and the generation of intra-thermocline eddies: a theoretical study. J. Phy. Oceanogr. 32, 1960–1974 (2002).

  • Metrics
    No metrics available
Share - Bookmark