Skip to main content
Log in

Three-type MJO initiation processes over the Western Equatorial Indian Ocean

  • Published:
Advances in Atmospheric Sciences Aims and scope Submit manuscript

Abstract

Thirty strong Madden-Julian Oscillation (MJO) events in boreal winter 1982–2001 are selected to investigate the triggering processes of MJO convection over the western equatorial Indian Ocean (IO). These MJO events are classified into three types, according to their dynamic and thermodynamic precursor signals in situ. In Type I, a remarkable increase in low-level moisture occurs, on average, 7 days prior to the convection initiation. This low-level moistening is mainly due to the advection of the background mean moisture by easterly wind anomalies over the equatorial IO. In Type II, lower-tropospheric ascending motion anomalies develop, on average, 4 days prior to the initiation. The cause of this ascending motion anomaly is attributed to the anomalous warm advection, set up by a suppressed MJO phase in the equatorial IO. In Type III, there are no clear dynamic and thermodynamic precursor signals in situ. The convection might be triggered by energy accumulation in the upper layer associated with Rossby wave activity fluxes originated from the midlatitudes.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Bladé, I., and D. L. Hartmann, 1993: Tropical intraseasonal oscillations in a simple nonlinear model. J. Atmos. Sci., 50, 2922–2939, doi: 10.1175/1520-0469(1993)050<2922:TIOIAS>2.0.CO;2.

    Article  Google Scholar 

  • Gill, A. E., 1980: Some simple solutions for heat-induced tropical circulation. Quart. J. Roy. Meteor. Soc., 106, 447–462, doi: 10.1002/qj.49710644905.

    Article  Google Scholar 

  • Hendon, H. H., 1988: A simple model of the 40–50 day oscillation. J. Atmos. Sci., 45, 569–584, doi: 10.1175/1520-0469(1988)045<0569:ASMOTD>2.0.CO;2.

    Article  Google Scholar 

  • Holton, J., 2004: An Introduction to Dynamic Meteorology. 4th ed., Academic Press, 535 pp.

    Google Scholar 

  • Hsu, H.-H., B. J. Hoskins, and F.-F. Jin, 1990: The 1985/86 intraseasonal oscillation and the role of the extratropics. J. Atmos. Sci., 47, 823–839, doi: 10.1175/1520-0469(1990)047<0823:TIOATR>2.0.CO;2.

    Article  Google Scholar 

  • Hsu, P.-C., and T. Li, 2012: Role of the boundary layer moisture asymmetry in causing the eastward propagation of the Madden-Julian oscillation. J. Climate, 25, 4914–4931, doi: 10.1175/JCLI-D-11-00310.1.

    Article  Google Scholar 

  • Hu, Q., and D. A. Randall, 1994: Low-frequency oscillations in radiative-convective systems. J. Atmos. Sci., 51, 1089–1099, doi: 10.1175/1520-0469(1994)051<1089:LFOIRC>2.0.CO;2.

    Article  Google Scholar 

  • Jiang, X.-A., and T. Li, 2005: Reinitiation of the boreal summer intraseasonal oscillation in the tropical Indian Ocean. J. Climate, 18, 3777–3795, doi: 10.1175/JCLI3516.1.

    Article  Google Scholar 

  • Kemball-Cook, S. R., and B. C. Weare, 2001: The onset of convection in the Madden-Julian oscillation. J. Climate, 14, 780–793, doi: 10.1175/1520-0442(2001)014<0780:TOOCIT>2.0.CO;2.

    Article  Google Scholar 

  • Kiladis, G. N., and K. M. Weickmann, 1992: Circulation anomalies associated with tropical convection during northern winter. Mon. Wea. Rev., 120, 1900–1923, doi: 10.1175/1520-0493(1992)120<1900:CAAWTC>2.0.CO;2.

    Article  Google Scholar 

  • Knutson, T. R., and K. M. Weickmann, 1987: 30–60 day atmospheric oscillations: Composite life cycles of convection and circulation anomalies. Mon. Wea. Rev., 115, 1407–1436, doi: 10.1175/1520-0493(1987)115<1407:DAOCLC>2.0.CO;2.

    Article  Google Scholar 

  • Lau, K.-M., and P. H. Chan, 1985: Aspects of the 40–50 day oscillation during the northern winter as inferred from outgoing longwave radiation. Mon. Wea. Rev., 113, 1889–1909, doi: 10.1175/1520-0493(1985)113<1889:AOTDOD>2.0.CO;2.

    Article  Google Scholar 

  • Lau, K.-M., and L. Peng, 1987: Origin of low-frequency (intraseasonal) oscillations in the tropical atmosphere. Part I: Basic theory. J. Atmos. Sci., 44, 950–972, doi: 10.1175/1520-0469(1987)044<0950:OOLFOI>2.0.CO;2.

    Article  Google Scholar 

  • Li, T., F. Tam, X. H. Fu, T. J. Zhou, and W. J. Zhu, 2008: Causes of the intraseasonal SST variability in the tropical Indian Ocean. Atmos. Oceanic Sci. Lett., 1, 18–23.

    Google Scholar 

  • Liebmann, B., and C. A. Smith, 1996: Description of a complete (interpolated) outgoing longwave radiation dataset. Bull. Amer. Meteor. Soc., 77, 1275–1277.

    Google Scholar 

  • Lindzen, R. S., and S. Nigam, 1987: On the role of sea surface temperature gradients in forcing low-level winds and convergence in the tropics. J. Atmos. Sci., 44, 2418–2436, doi: 10.1175/1520-0469(1987)044<2418:OTROSS>2.0.CO;2.

    Article  Google Scholar 

  • Ling, J., C. D. Zhang, and P. Bechtold, 2013: Large-scale distinctions between MJO and Non-MJO convective initiation over the tropical Indian Ocean. J. Atmos. Sci., 70, 2696–2712, doi: 10.1175/JAS-D-13-029.1.

    Article  Google Scholar 

  • Matthews, A. J., 2000: Propagation mechanisms for the Madden-Julian Oscillation. Quart. J. Roy. Meteor. Soc., 126, 2637–2651, doi: 10.1002/qj.49712656902.

    Article  Google Scholar 

  • Matthews, A. J., 2008: Primary and successive events in the Madden-Julian oscillation. Quart. J. Roy. Meteor. Soc., 134, 439–453, doi: 10.1002/qj.224.

    Article  Google Scholar 

  • Matthews, A. J., and G. N. Kiladis, 1999: The tropicalextratropical interaction between high-frequency transients and the Madden-Julian oscillation. Mon. Wea. Rev., 127, 661–677, doi: 10.1175/1520-0493(1999)127<0661:TTEIBH>2.0.CO;2.

    Article  Google Scholar 

  • Pan, L.-L., and T. Li, 2008: Interactions between the tropical ISO and midlatitude low-frequency flow. Climate Dyn., 31, 375–388, doi: 10.1007/s00382-007-0272-7.

    Article  Google Scholar 

  • Ray, P., C. D. Zhang, J. Dudhia, and S. S. Chen, 2009: A numerical case study on the initiation of the Madden-Julian oscillation. J. Atmos. Sci., 66, 310–331, doi: 10.1175/2008JAS2701.1.

    Article  Google Scholar 

  • Rui, H. L., and B. Wang, 1990: Development characteristics and dynamic structure of tropical intraseasonal convection anomalies. J. Atmos. Sci., 47, 357–379, doi: 10.1175/1520-0469(1990)047<0357:DCADSO>2.0.CO;2.

    Article  Google Scholar 

  • Saha, S., and Coauthors, 2006: The NCEP climate forecast system. J. Climate, 19, 3483–3517, doi: 10.1175/JCLI3812.1.

    Article  Google Scholar 

  • Seo, K. H., and K. Y. Kim, 2003: Propagation and initiation mechanisms of the Madden-Julian oscillation. J. Geophys. Res., 108, 4384, doi: 10.1029/2002JD002876.

    Article  Google Scholar 

  • Straub, K. H., 2012: MJO initiation in the real-time multivariate MJO index. J. Climate, 26, 1130–1151, doi: 10.1175/JCLID-12-00074.1.

    Article  Google Scholar 

  • Takaya, K., and H. Nakamura, 2001: A formulation of a phaseindependent wave-activity flux for stationary and migratory quasigeostrophic eddies on a zonally varying basic flow. J. Atmos. Sci., 58, 608–627, doi: 10.1175/1520-0469(2001)058<0608:AFOAPI>2.0.CO;2.

    Article  Google Scholar 

  • Uppala, S. M., and Coauthors, 2005: The ERA-40 re-analysis. Quart. J. Roy. Meteor. Soc., 131, 2961–3012, doi: 10.1256/qj.04.176.

    Article  Google Scholar 

  • Wang, B., and T. M. Li, 1994: Convective interaction with boundary-layer dynamics in the development of a tropical intraseasonal system. J. Atmos. Sci., 51, 1386–1400, doi: 10.1175/1520-0469(1994)051<1386:CIWBLD>2.0.CO;2.

    Article  Google Scholar 

  • Wang, L., K. Kodera, and W. Chen, 2012: Observed triggering of tropical convection by a cold surge: Implications for MJO initiation. Quart. J. Roy. Meteor. Soc., 138, 1740–1750, doi: 10.1002/qj.1905.

    Article  Google Scholar 

  • Yanai, M., S. Esbensen, and J.-H. Chu, 1973: Determination of bulk properties of tropical cloud clusters from large-scale heat and moisture budgets. J. Atmos. Sci., 30, 611–627, doi: 10.1175/1520-0469(1973)030<0611:DOBPOT>2.0.CO;2.

    Article  Google Scholar 

  • Zhao, C. B., T. Li, and T. J. Zhou, 2013: Precursor signals and processes associated with MJO initiation over the Tropical Indian Ocean. J. Climate, 26, 291–370, doi: 10.1175/JCLID-12-00113.1.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Tim Li.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mei, S., Li, T. & Chen, W. Three-type MJO initiation processes over the Western Equatorial Indian Ocean. Adv. Atmos. Sci. 32, 1208–1216 (2015). https://doi.org/10.1007/s00376-015-4201-0

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00376-015-4201-0

Key words

Navigation