HR: 09:15h
AN: PP41C-06    [Abstracts]
TI: Possible Solar Forcing of Late Holocene Indian Monsoon Rainfall
AU: * Sinha, A
EM: asinha@csudh.edu
AF: California State University Dominguez Hills, 1000 E. Victoria Street, Carson, CA 92555 United States
AU: Cannariato, K
EM: cannaria@usc.edu
AF: University of Southern California, 3651 Trousdale Parkw, Los Angeles, CA 90089 United States
AU: Stott, L
EM: stott@usc.edu
AF: University of Southern California, 3651 Trousdale Parkw, Los Angeles, CA 90089 United States
AU: Cheng, H
EM: cheng021@umn.edu
AF: University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 United States
AU: Edwards, L
EM: edwar001@umn.edu
AF: University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 United States
AB: Nearly one-quarter of the world's population is affected by the seasonal rainfall brought by the Southwest Indian Summer Monsoon. Meteorological records and historical accounts document repeated episodes of drought on inter-annual to decadal time scales. As recently as the late 1960s, 1.5 million people in India died when the monsoon failed for three consecutive years. Recent climate model simulations indicate that multi-decadal monsoon failures may be possible. Our work investigates this longer-term variability of the Indian Monsoon using the oxygen isotope composition of stalagmites collected from caves throughout India. We have generated a high-resolution (~1-10 yr), absolute dated, oxygen isotope record covering the last 1400 yr from a stalagmite collected from Dandak Cave located in central-eastern India. The record reveals multi-decadal to century-scale intervals of anomalously heavy oxygen isotope values that we interpret as periods of reduced monsoon rainfall. During the Medieval Warm Period the monsoon was generally stronger (fewer shorter intervals of reduced rainfall) while during the Little Ice Age it was generally weaker (more frequent and longer intervals of reduced rainfall). We also note a striking resemblance between our monsoon rainfall record and the residual Δ¹⁴C record. If the variations in the Δ¹⁴C record are related to changes in solar luminosity, our record suggests a possible causal link between reduced (enhanced) monsoon precipitation and lower (higher) solar luminosity. Our results from a core monsoon region of India appear to corroborate studies from other regions suggesting solar forcing of Indian/Asian Monsoon variability on decadal to centennial time scales.
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4914 Continental climate records
DE: 4958 Speleothems
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005