Collaborative Research: P2C2: Water Isotopes in Peat Mosses as Proxies for Understanding Climate and Atmospheric Circulation Changes in Southern Patagonia

Brown University, Providence RI

Investigators

Abstract

This award to Lehigh and Brown Universities will develop and test a powerful technique to reconstruct atmospheric circulation patterns and moisture trajectories using two water isotopes from peat mosses. The research will generate important climate records that will potentially transform our understanding of climate dynamics of the last 1000 years in the relatively understudied southern hemisphere. This approach is also applicable over longer time scales in this geographic regions, as well as other places Sphagnum moss can be found. The new climate records from under-studied southern Patagonia will provide a benchmark data set with which to evaluate the climate models that are used for projecting future climate change. The project will train graduate and undergraduate students at both institutions in the application of a state-of-art technology in innovative interdisciplinary research. This award will use isotope records to document and understand climate and atmospheric circulation changes in the last millennium using a novel dual water isotope approach and systematic modern calibration from single species peat mosses (Sphagnum) as preserved in peat bogs in southernmost Patagonia (southern South America). The investigators will carry out calibration sampling and analysis to span large latitude and precipitation gradients in southern Patagonia. The isotope records will be derived from the existing peat cores at Lehigh University. In addition to using oxygen and hydrogen isotope time series from cellulose and lipids for ?conventional? paleoclimate interpretations, the team will explore the use of derived deuterium excess (delta-excess) as a tracer for moisture source region conditions and moisture trajectories. This innovative use of dual (O and D) isotopes would provide powerful information regarding past atmospheric circulation and mechanisms of observed climate changes.