Final Report Summary - ASIAN MONSOON (The Impact of Climate Change on the Southeast Asian Monsoon)
Although we sampled at sub-annual resolution, the magnitude of the signal is not large enough to capture intra-annual climate variability. However, comparison of the oxygen isotopes in northern Laos with the Pacific decadal oscillations (PDO) and the Southern oscillation index (SOI) indicates that the highest values in the speleothem record coincide with a period of sustained positive PDO overlaping with two strong ENSO events. In addition, the Lao speleothem record shows similarities with the monsoon variability captured in Chinese speleothems, suggesting that the climate in Indochina is coupled on inter-annual timescales to large-scale atmospheric circulation in the Pacific Ocean. We are refining the chronology in order to attempt to develop a quantitative reconstruction of past precipitation based on comparisons with other stalagmites situated along the same moisture transport pathway.
The insights gained from this study will have socio-economical implications by improving our understanding of factors controlling monsoon variability in this area, and therefore our ability to understand future climate changes in this area. Furthermore, by providing a record of monsoon variability that overlaps with, and extends beyond the instrumental records will allow an assessment of the full range of natural climate variability in Indochina.