Modern and sub-fossil corals suggest reduced temperature variability in the eastern pole of the Indian Ocean Dipole during the medieval climate anomaly

Abstract We present two 40 year records of monthly coral Sr/Ca ratios from the eastern pole Indian Ocean Dipole. A modern covers period 1968 to 2007. sub-fossil derives medieval climate anomaly (MCA) and spans 1100–1140 ad . The SST variability in strong correlation is also found between IOD index. with ENSO asymmetric: shows a moderate El Niño weak La Niña. large interannual variability. Extreme events cause cooling > 3 °C (1994, 1997) or ~ 2 (2006). In total, indicates 32 warm/cool events, 16 cool warm events. MCA 24 14 10 Only one event could be comparable positive Dipole 2006. seasonal cycle reduced (< 50% modern) skewness data lower. This suggests deeper thermocline associated Niña-like mean state Indo-Pacific during MCA.