P2C2: A Network of Paleo-Monsoon Rainfall Stations in Southeast Asia to Investigate Atmospheric Circulation Changes over the Past Four Centuries

University Of Southern California, Los Angeles CA

Investigators

Abstract

Funding is provided to support the development and calibration of a method for reconstructing rainwater delta Oxygen-18 from cellulose extracted from the annual rings of trees that grow throughout Thailand. The researchers will measure delta Oxygen-18 tree cellulose from Khasi pine and Merkus pine trees as a means to reconstruct annual to subannual records of atmospheric precipitation at sites across Southeast (SE) Asia. The researchers hypothesize that the increased moisture from the Indian Ocean is a response to the expansion of the continental monsoon trough eastward over SE Asia. To test this hypothesis, the researchers will extend the data base of Pine delta Oxygen-18 to sites across SE Asia in order to map the spatial pattern of precipitation delta Oxygen-18 variability. The project offers the promise of helping opening tropical tree-rings to climate analysis. This is important because, at present, tropical tree cannot be used as a reliable paleoclimate archive because they do not lay down visible seasonal tree rings as do higher latitude specimens. Developing an isotopic technique for tropical trees would be a transformative breakthrough in climate analysis.