Climate Dynamics

, Volume 45, Issue 1–2, pp 175–184

Non-stationary and non-linear influence of ENSO and Indian Ocean Dipole on the variability of Indian monsoon rainfall and extreme rain events

  • Jagdish Krishnaswamy
  • Srinivas Vaidyanathan
  • Balaji Rajagopalan
  • Mike Bonell
  • Mahesh Sankaran
  • R. S. Bhalla
  • Shrinivas Badiger
Article

DOI: 10.1007/s00382-014-2288-0

Cite this article as:
Krishnaswamy, J., Vaidyanathan, S., Rajagopalan, B. et al. Clim Dyn (2015) 45: 175. doi:10.1007/s00382-014-2288-0

Abstract

The El Nino Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are widely recognized as major drivers of inter-annual variability of the Indian monsoon (IM) and extreme rainfall events (EREs). We assess the time-varying strength and non-linearity of these linkages using dynamic linear regression and Generalized Additive Models. Our results suggest that IOD has evolved independently of ENSO, with its influence on IM and EREs strengthening in recent decades when compared to ENSO, whose relationship with IM seems to be weakening and more uncertain. A unit change in IOD currently has a proportionately greater impact on IM. ENSO positively influences EREs only below a threshold of 100 mm day−1. Furthermore, there is a non-linear and positive relationship between IOD and IM totals and the frequency of EREs (>100 mm day−1). Improvements in modeling this complex system can enhance the forecasting accuracy of the IM and EREs.

Keywords

Dynamic linear models Generalised additive models La Nina Western Ghats Indo-Gangetic plain 

Supplementary material

382_2014_2288_MOESM1_ESM.pdf (4.6 mb)
Supplementary material 1 (PDF 4,664 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Jagdish Krishnaswamy
    • 1
  • Srinivas Vaidyanathan
    • 2
  • Balaji Rajagopalan
    • 3
  • Mike Bonell
    • 4
  • Mahesh Sankaran
    • 5
    • 6
  • R. S. Bhalla
    • 2
  • Shrinivas Badiger
    • 1
  1. 1.Ashoka Trust for Research in Ecology and the Environment (ATREE)BangaloreIndia
  2. 2.Foundation for Ecological Research, Advocacy and Learning (FERAL)VillupuramIndia
  3. 3.Department of Civil, Environmental and Architectural Engineering and Co-operative Institute for Research in Environmental SciencesUniversity of ColoradoBoulderUSA
  4. 4.Centre for Water Law, Policy and Sciences Under the Auspices of UNESCOUniversity of DundeeDundeeScotland, UK
  5. 5.Ecology and Evolution GroupNational Centre for Biological Sciences, TIFRBangaloreIndia
  6. 6.School of BiologyUniversity of LeedsLeedsUK

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