This project will compile existing palaeoclimate data across Southeast Asia and produce new speleothem-based (stalagmite) records from Thailand to reconstruct the shifting extent, strength and variability of the various Asian monsoon sub-systems through time. These reconstructions will be compared to synthesized archaeological, historical, and palaeoenvironmental datasets to unravel the influence of climate change on agricultural and societal developments.
The project
This project will utilize uranium-series dating and stable-isotope analysis of speleothems to produce a network of precisely-dated, ultra-high-resolution palaeoclimate data. This will provide reconstructions of local climatic conditions in several key regions, which reveal past changes in effective-moisture
(precipitation-evaporation) and monsoon precipitation on seasonal-to-millennial timescales. By synthesizing these records with existing palaeoclimate data across Southeast Asia and climate-model simulations, the extent, strength and variability of the Asian monsoon subsystems will be reconstructed so that their influences on, and responses to, the global climate system can be assessed. This knowledge will contextualize recent climate change within a much longer history of climate evolution and inform predictions on the impacts of future climate change. To achieve this, the project has four primary objectives:
- Utilize state-of-the-art speleothem analysis to produce high-resolution multi-proxy palaeoclimate data that is chronologically well-constrained in study regions across Thailand.
- Synthesize and statistically examine these new records, and existing records, to establish the extent, strength and variability of the Asian monsoon sub-systems across Mainland Southeast Asia, and changes in the seasonality of precipitation, over the Holocene.
- Combine the monsoon reconstructions with climate model simulations to examine their shifting relationships with other aspects of the global climate system.
- Examine these datasets in the context of established climate events – such as the Bølling-Allerød, Younger Dryas, Green Sahara, and Little Ice Age – to determine their impact in Mainland Southeast Asia and mechanisms for propagation of these events globally.
The produced palaeoclimate history will be compared to archaeological, historical, and palaeoenvironmental datasets synthesized in the The agricultural history of East and Southeast Asia project to explore the influence of climate change on agricultural and societal developments.
Publications
Jacobson, M.J., Chawchai, S., Scholz, D., Riechelmann, D.F.C., Vonhof, H., Holmgren, K., et al., Speleothem records from western Thailand reveal a rapid response of the Indian Summer Monsoon to the Younger Dryas Termination. Quaternary Science Reviews 330: 108597. https://doi.org/10.1016/j.quascirev.2024.108597
