An annually laminated stalagmite record of the changes in Thailand monsoon rainfall over the past 387 years and its relationship to IOD and ENSO

Northern Thailand is the most flood-prone region in Thailand during the Indian Ocean Dipole (IOD) and El Niño-Southern Oscillation (ENSO) events. An annual growth rate profile covering the period from 1622 to 2008 AD was derived from the laminated stalagmite NJ-0901 from this area. By comparing stalagmite NJ-0901 to a contemporaneous stalagmite from the same cave and correlating the growth rate of NJ-0901 with meteorological data from the most recent 100 years, the stalagmite record proved to be a paleoclimate proxy of Thailand monsoon (TM) rainfall. This is the first annually laminated speleothem record that has been traced back four centuries. This record provided a long-term perspective and a valuable insight into TM rainfall and allowed us to investigate variations in the monsoon activity that was associated with IOD and ENSO. Our results indicate that both IOD and ENSO are significant climate modes that impact TM rainfall, but the effect of the interaction IOD and ENSO on TM rainfall remains unclear.