GC21F-05
A 3000 year lake sediment record of local and synoptic Indian summer monsoon variability from the southeastern Tibetan Plateau
Tuesday, 15 December 2015: 09:20
3003 (Moscone West)
Broxton W Bird1, Pratigya J Polissar2, Yanbin Lei3, Tandong Yao4, Bruce Finney5, Daniel Bain6, David P Pompeani6, Byron A Steinman7 and Lonnie G Thompson8, (1)Indiana University Purdue University Indianapolis, Earth Sciences, Indianapolis, IN, United States, (2)Lamont-Doherty Earth Observato, Nyack, NY, United States, (3)Institute of Tibetan Plateau Research, CAS, Beijing, China, (4)ITP Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, (5)Idaho State University, Pocatello, ID, United States, (6)University of Pittsburgh Pittsburgh Campus, Pittsburgh, PA, United States, (7)University of Minnesota Duluth, Duluth, MN, United States, (8)Byrd Polar Research Center, The Ohio State University, Columbus, OH, United States
Abstract:
The ways in which Indian summer monsoon (ISM) precipitation responded during the Medieval Climate Anomaly (MCA; 1000-800 cal yr B.P.) and Little Ice Age (LIA; 550-150 cal yr B.P.) is not clear based on the available data. Some records suggest increased precipitation during the MCA, while the LIA has been identified as a period of aridity. Others records, however, show little evidence for coherent hydroclimate variability during these events. Refinement of current models of monsoonal dynamics during the MCA and LIA is needed in order to better constrain the relationship between temperature and hydroclimate variability, as well as to refine the global expression of the MCA and LIA. This need is underscored by recent changes in the ISM that may be related to anthropogenic warming trends. As part of this effort, we present new leaf wax hydrogen isotope from Badi Namco, a small alpine lake located in the monsoon dominated southern Tibetan Plateau. Combined with sedimentological and geochemical data, these new isotope results are used to evaluate the hypothesis that the MCA and LIA were minor hydroclimate events on the Tibetan plateau that were superimposed on lower frequency ISM variations forced largely by Indo-Pacific sea surface temperature changes during at least the last 3000 years.
