Revisiting the ENSO-monsoon relationship

El Nino and Southern Oscillation (ENSO) has been considered as the most important driver of the interannual variation of Indian summer monsoon rainfall (ISMR) with higher propensity for drought (excess) seasons during the occurrence of El Nino (La Nina). Recently, it was reported that this classical ENSO-Indian monsoon relationship has been weakened during the second half of the twentieth century. Weakening of the walker circulation over the Indo-Pacific region, increase of the surface temperature in Eurasia and strengthening of the link between ISMR and Indian Ocean Dipole were attributed as the cause for the weakening of ISMR-ENSO relationship. However, in the recent decades, even the moderate El Niños, such as in 2002 and 2009 were accompanied by the worst droughts. Here, we revisit the variation in the ENSO-ISMR relationship and show that this relationship has been strengthened again after 2000. The strengthening of ENSO - Indian monsoon relationship in the recent decades is accompanied by the strengthening of the Walker circulation and the cooling of surface temperature in Eurasia during the preceding winter. In addition to ENSO, Equatorial Indian Ocean Oscillation (EQUINOO) also has been found to be influencing the inter annual variation of ISMR. In the epoch, when ENSO-ISMR relationship has weakened, ENSO-EQUINOO relationship was stronger and in the recent decades, this relationship is weakening again. Thus, the varying ENSO/EQUINOO-ISMR relationship could be part of decadal variability.