Increasing trend of synoptic activity and its relationship with extreme rain events over central India

R. S. Ajayamohan, William J. Merryfield, Viatcheslav V. Kharin

Research output: Contribution to journalArticle


The nature of the increasing frequency of extreme rainfall events (ERE) in central India is investigated by relating their occurrence to synoptic activity. Using a long record of the paths and intensities of monsoon synoptic disturbances, a synoptic activity index (SAI) is defined whose interannual variation correlates strongly with that in the number of ERE, demonstrating a strong connection between these phenomena. SAI furthermore shows a rising trend that is statistically indistinguishable from that in ERE, indicating that the increasing frequency of ERE is likely attributable to a rising trend in synoptic activity. This synoptic activity increase results from a rising trend in relatively weak low pressure systems (LPS), and it outweighs a declining trend in stronger LPS.

Original languageEnglish (US)
Pages (from-to)1004-1013
Number of pages10
JournalJournal of Climate
Issue number4
StatePublished - Feb 1 2010


ASJC Scopus subject areas

  • Atmospheric Science

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