My listeners will be led on a true interdisciplinary scientific journey that starts in a Sumatran cave, makes a pit stop in carbonate mineralogy with the use of lasers and thin sections, goes on retreat with meteorological data analysis and climate models, and eventually reaches its destination in the form of a unique 16,000 year-long record of hydroclimate variability from the eastern Indian Ocean.
Abrupt changes in North Atlantic ocean circulation are known to have affected the strength of rainfall around the globe since the Last Glacial Maximum, 20,000 years ago. However, there is still much uncertainty around the precipitation response of the Indo-Pacific Warm Pool (IPWP) region to abrupt climate changes. Many studies suggest a southward shift in the equatorial rain belt in the IPWP region during phases of reduced ocean circulation, however, existing proxies have seasonal biases and conflicting responses, making it difficult to determine the true extent of North Atlantic forcing in this climatically important region.
I will present a precisely-dated, high-resolution climate reconstruction based on stable isotope and trace element measurements in an aragonite-calcite speleothem from central Sumatra. This represents the western-most speleothem record from the IPWP region and exhibits a North Atlantic forcing signal very different to existing speleothem records from the region.