Climate Dynamics

, Volume 51, Issue 9–10, pp 3405–3420 | Cite as

Evidence of organized intraseasonal convection linked to ocean dynamics in the Seychelles–Chagos thermocline ridge

  • Joseph M. D’Addezio
  • Bulusu Subrahmanyam


The Madden–Julian oscillation (MJO) is the dominant driver of intraseasonal variability across the equatorial domain of the global ocean with alternating wet and dry bands that propagate eastward primarily between 5°N and 5°S. Past research has shown that MJOs impact the surface and subsurface variability of the Seychelles–Chagos thermocline ridge (SCTR) (55°E–65°E, 5°S–12°S) located in the southwest tropical Indian Ocean (SWTIO), but investigations of how SWTIO internal dynamics may play an important role in producing MJO events remain limited. This study uses Argo, in conjunction with several remote sensing and reanalysis products, to demonstrate that SWTIO oceanic dynamics, particularly barrier layer formation and near surface heat buildup, may be associated with MJO genesis between August and December of most years between 2005 and 2013. A total of eight SWTIO specific MJO events are observed, all occurring between August and December. Four of the eight events are correlated with positive SWTIO total heat content (THC) and barrier layer thickness (BLT) interannual anomalies. Two others formed over the SWTIO during times when only one of the variables was at or above their seasonal average, while two additional events occurred when both variables experienced negative interannual anomalies. Lacking complete 1:1 correlation between the hypothesized oceanic state and the identified SWTIO MJO events, we conclude that additional work is required to better understand when variability in key oceanic variables plays a primary role in regional MJO genesis or when other factors, such as atmospheric variability, are the dominate drivers.


Seychelles–Chagos thermocline ridge MJO SWTIO BLT 



This work is supported by the Office of Naval Research (ONR) Award #N00014-15-1-2591 awarded to BS. JMD is supported by the Naval Research Laboratory Cooperative Agreement BAA-N00173-03-73-13-01 awarded to The University of Southern Mississippi. NOAA interpolated outgoing longwave radiation (OLR) data were obtained from Argo temperature and salinity data were obtained from the Asia Pacific Data-Research Center (APDRC) ( Merged TRMM data were obtained from NASA Goddard Space Flight Center ( ECMWF ERA-Interim data used in this study/project have been provided by ECMWF/have been obtained from the ECMWF data server The authors would like to thank the anonymous reviewers and the editor whose comments significantly contributed to the improvement of this paper.


  1. Annamalai H, Liu P, Xie SP (2004) Southwest Indian Ocean SST variability: Its local effect and remote influence on Asian Monsoons. J Climatol 18:4150–4167. CrossRefGoogle Scholar
  2. Balaguru K, Change P, Saravanan R,. Leung LR, Xue Z et al (2012) Ocean barrier layers’ effect on tropical cyclone intensification. Proc Nat Acad Sci 109:14343–14347. CrossRefGoogle Scholar
  3. Bessafi M, Wheeler MC (2005) Modulations of South Indian ocean tropical cyclones by the Madden–Julian oscillation and convectively coupled equatorial waves. Mon Wea Rev 134:638–656CrossRefGoogle Scholar
  4. Chowdary JS, Gnanaseelan C (2007) Basin-wide warming of the Indian Ocean during ElGoogle Scholar
  5. Chowdary JS, Gnanaseelan C, Xie SP (2009) Westward propagation of barrier layer formation in the 2006–07 Rossby wave event over the tropical southwest Indian Ocean. Geophys Res Lett 36:1–5. CrossRefGoogle Scholar
  6. D’Addezio JM, Subrahmanyam B (2016) The role of salinity on the interannual variability of the Seychelles–Chagos thermocline ridge. Remote Sens Environ 180:178–192. CrossRefGoogle Scholar
  7. Dee DP, Uppala SM, Simmons AJ et al (2011) The ERA-Interim reanalysis: configuration and performance of the data assimilation system. QJR Meteorol Soc 137:553–597. CrossRefGoogle Scholar
  8. Dijkstra HA (2008) Dynamical oceanography. Springer, Berlin, p 276Google Scholar
  9. Drushka K, Sprintall J, Gille ST (2014) Subseasonal variations in salinity and barrier-layer thickness in the eastern equatorial Indian Ocean. J Geophys Res 119:805–823. CrossRefGoogle Scholar
  10. Duvel JP, Roca R, Vialard J (2004) Ocean mixed layer temperature variations induced by intraseasonal convective perturbations over the Indian Ocean. J Atmos Sci 61:1004–1023CrossRefGoogle Scholar
  11. Felton CS, Subrahmanyam B, Murty VSN, Shriver JF (2014) Estimation of the barrier layer thickness in the Indian Ocean using Aquarius Salinity. J Geophys Res Oceans. CrossRefGoogle Scholar
  12. Godfrey JS, Lindstrom EJ (1989) The heat budget of the equatorial western Pacific surface mixed layer. J Geophys Res 94:8007–8017CrossRefGoogle Scholar
  13. Grunseich G, Subrahmanyam B, Wang B (2013) The Madden–Julian oscillation detected in Aquarius salinity observations. Geophys Res Lett 40:5461–5466. CrossRefGoogle Scholar
  14. Halkides DJ, Waliser DE, Lee T et al (2015) Quantifying the processes controlling intraseasonal mixed-layer temperature variability in the tropical Indian Ocean. J Geophys Res 120:692–715. CrossRefGoogle Scholar
  15. Harrison DE, Vecchi G (2001) January 1999 Indian Ocean cooling event. Geophys Res Lett 28:3717–3720CrossRefGoogle Scholar
  16. Helber RW, Kara AB, Richman JG et al (2012) Temperature versus salinity gradients below the ocean mixed layer. J Geophys Res 117:1–19. CrossRefGoogle Scholar
  17. Hendon HH (2000) Impact of air-sea coupling on the Madden–Julian oscillation in a general circulation model. J Atmos Sci 57:3939–3952CrossRefGoogle Scholar
  18. Hermes JC, Reason CJC (2008) Annual cycle of the South Indian Ocean (Seychelles–Chagos) thermocline ridge in a regional ocean model. J Geophys Res 113:1–10. CrossRefGoogle Scholar
  19. Huang B, Kinter JL III (2002) Interannual variability in the tropical Indian Ocean. J Geophys Res 107:1–23. CrossRefGoogle Scholar
  20. Huffman GJ, Adler RF, Bolvin DT et al (2007) The TRMM multi-satellite precipitation analysis: Quasi-global multi-year, combined sensor precipitation estimates at fine scale. J Hydrometeorol 8:38–55CrossRefGoogle Scholar
  21. Huffman GJ, Adler RF, Bolvin DT et al (2010) The TRMM multi-satellite precipitation analysis (TMPA). In: Hossain F, Gebremichael M (eds) Satellite rainfall applications for surface hydrology, Chap. 1. Springer, Düsseldorf, pp 3–22CrossRefGoogle Scholar
  22. Inness PM, Slingo JM (2003) Simulation of the Madden–Julian oscillation in a coupled general circulation model. Part I: comparison with observations and an atmosphere-only GCM. J Clim 16:345–364CrossRefGoogle Scholar
  23. Izumo T, de Boyer Montégut C, Luo JJ et al (2008) The role of the western Arabian Sea upwelling in Indian monsoon rainfall variability. J Clim 21:5603–5623. CrossRefGoogle Scholar
  24. Jayakumar A, Gnanaseelan (2012) Anomalous intraseasonal events in the thermocline ridge region of the Southern Tropical Indian Ocean and their regional impacts. J Geophys Res 117:1–16. CrossRefGoogle Scholar
  25. Jayakumar A, Vialard J, Lengaigne M et al (2011) Processes controlling the surface temperature signature of the Madden–Julian Oscillation in the thermocline ridge of the Indian Ocean. Clim Dyn 37:2217–2234. CrossRefGoogle Scholar
  26. Liebmann B, Smith CA (1996) Description of a complete (interpolated) outgoing longwave radiation dataset. Bull Am Meteorol Soc 77:1275–1277Google Scholar
  27. Madden RA, Julian PR (1972) Description of global-scale circulation cells in the tropics with a 40–50 day period. J Atmos Sci 29:1109–1123CrossRefGoogle Scholar
  28. Masumoto Y, Meyers G (1998) Forced Rossby waves in the southern tropical Indian Ocean. J Geophys Res 103::589–27602CrossRefGoogle Scholar
  29. Moteki Q (2015) Equatorially antisymmetric features in the intuition process of the Madden–Julian Oscillation Observed in late October during CINDY2011. J Meteorol Soc Japan 93:59–79. CrossRefGoogle Scholar
  30. Niño and Indian Ocean dipole years. Int J Climatol 27:1421–1438. CrossRefGoogle Scholar
  31. Nyadjro ES, Subrahmanyam B, Murty VSN, Shriver JF (2012) The role of salinity on the dynamics of the Arabian Sea mini warm pool. J Geophys Res 117:1–12. CrossRefGoogle Scholar
  32. Schott FA, McCreary JP (2001) The monsoon circulation of the Indian Ocean. Prog Oceanogr 51:1–123CrossRefGoogle Scholar
  33. Seo H, Subramanian AC, Miller AJ, Cavanaugh NR (2014) Coupled impacts of the diurnal cycle of sea surface temperature on the Madden–Julian Oscillation. J Clim 27:8422–8443. CrossRefGoogle Scholar
  34. Shinoda T, Jensen TG, Flatau M et al (2013) Large-scale oceanic variability associated with the Madden–Julian Oscillation during the CINDY/DYNAMO Field Campaign from Satellite Observations. Remote Sens 5:2072–2092. CrossRefGoogle Scholar
  35. Takayabu YN, Iguchi T, Kachi M et al (1999) Abrupt termination of the 1997–1998 El Niño in response to a Madden–Julian Oscillation. Nature 402: 279–282. CrossRefGoogle Scholar
  36. Tozuka T, Yokoi T, Yamagata T (2010) A modeling study of interannual variations in the Seychelles Dome. J Geophys Res 115:1–14. CrossRefGoogle Scholar
  37. Vialard J, Delecluse P (1998) An OGCM study for the TOGA decade. Part II: barrier-layer formation and variability. J Phys Oceanography 28:1089–1106CrossRefGoogle Scholar
  38. Vialard J, Foltz GR, McPhaden MJ et al (2008) Strong Indian Ocean sea surface temperature signals associated with the Madden–Julian Oscillation in late 2007 and early 2008. Geophys Res Lett 35:1–5. CrossRefGoogle Scholar
  39. Vialard J, Duvel JP, McPhaden MJ, Bouruet-Aubertot P et al (2009a) Cirene: air-sea interactions in the Seychelles–Chagos thermocline ridge region. Bull Am Meteor Soc 90:45–61CrossRefGoogle Scholar
  40. Vialard J, Shenoi SSC, McCreary JP et al (2009b) Intraseasonal response of the northern Indian Ocean coastal waveguide to the Madden–Julian Oscillation. Geophys Res Lett 36:1–5. CrossRefGoogle Scholar
  41. Vinayachandran PN, Murty VSN, Babu VR (2002) Observations of barrier layer formation in the Bay of Bengal during summer monsoon. J Geophys Res 107:1–9. CrossRefGoogle Scholar
  42. Webber BGM, Matthews AJ, Heywood KJ (2010) A dynamical ocean feedback mechanism for the Madden–Julian Oscillation. QJR Meteorol Soc 136:740–754. CrossRefGoogle Scholar
  43. Webber BGM, Stevens DP, Matthews AJ, Heywood KJ (2012a) Dynamical ocean forcing of the Madden–Julian oscillation at lead times of up to five months. J Clim 25:2824–2842. CrossRefGoogle Scholar
  44. Webber BGM, Matthews AJ, Heywood KJ, Stevens DP (2012b) Ocean Rossby waves as a triggering mechanism for primary Madden–Julian events. QJR Meteorol Soc 138:154–527. CrossRefGoogle Scholar
  45. Wheeler MC, Hendon HH (2004) An all-season real-time multivariate MJO index: development of an index for monitoring and prediction. Mon Wea Rev 132:1917–1932CrossRefGoogle Scholar
  46. Wheeler MC, Hendon HH, Cleland S et al (2009) Impacts of the Madden–Julian oscillation on Australian rainfall and circulation. J Clim 22:1482–1498. CrossRefGoogle Scholar
  47. Xie SP, Annamalai H, Schott FA, McCreary JP Jr (2002) Structure and mechanism of South Indian Ocean climate variability. J Clim 15:864–878CrossRefGoogle Scholar
  48. Yoneyama K, Zhang C, Long CN (2013) Tracking pulses of the Madden–Julian oscillation. Bull Am Meteor Soc 94:1871–1891. CrossRefGoogle Scholar
  49. Zhang C (2005) Madden–Julian oscillation. Rev Geophys 43:1–36. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Division of Marine Science, School of Ocean Science and TechnologyThe University of Southern MississippiHattiesburgUSA
  2. 2.School of the Earth, Ocean, and EnvironmentUniversity of South CarolinaColumbiaUSA

Personalised recommendations