This is the final version. It is currently under embargo. It was first published by Wiley at http://onlinelibrary.wiley.com/doi/10.1002/2015GL063826/full.Two types of El Niño events are distinguished by sea surface temperature (SST) anomalies
centered in the central or eastern equatorial Pacific. The Central Pacific El Niño events (CP-El Niño) are
more highly correlated with weakening of the central Indian Summer Monsoon and linked to decadal Pacific
climate variability. We present a 50 year, subannually resolved speleothem δ18O record from northeast India
that exhibits a significant correlation with northern Pacific decadal variability and central equatorial Pacific
SSTs. Accordingly, we suggest that δ18O time series in similar northeast Indian speleothems are effective tools
for investigating preinstrumental changes in Pacific climate, including changes in El Niño dynamics. In
contrast to central India, rainfall amounts in northeast India are relatively unaffected by El Niño. However,
back trajectory analysis indicates that during CP-El Niño events moisture transport distance to northeast India
is reduced, suggesting that variations in moisture transport primarily control δ18O in the region.This work was supported through the BanglaPIRE project (NSF OISE-0968354), an award from the Vanderbilt International Office to JLO and SFMB, and awards from the Cave Research Foundation and the Geological Society of America to CGM. SFMB received financial support from the Schweizer National Fond (SNF), Sinergia grant CRSI22 132646/1