title: 1,500 year quantitative reconstruction of winter precipitation in the Pacific Northwest.
abstract: Multiple paleoclimate proxies are required for robust assessment of past hydroclimatic conditions. Currently, estimates of drought variability over the past several thousand years are based largely on tree-ring records. We produced a 1,500-y record of winter precipitation in the Pacific Northwest using a physical model-based analysis of lake sediment oxygen isotope data. Our results indicate that during the Medieval Climate Anomaly (MCA) (900-1300 AD) the Pacific Northwest experienced exceptional wetness in winter and that during the Little Ice Age (LIA) (1450-1850 AD) conditions were drier, contrasting with hydroclimatic anomalies in the desert Southwest and consistent with climate dynamics related to the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). These findings are somewhat discordant with drought records from tree rings, suggesting that differences in seasonal sensitivity between the two proxies allow a more compete understanding of the climate system and likely explain disparities in inferred climate trends over centennial timescales.
authors: Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, SRCC Room 200, Pittsburgh, PA 15260-3332, USA. bas56@psu.edu
authors: Byron A
authors: BA
authors: Steinman
authors: Mark B
authors: MB
authors: Abbott
authors: Michael E
authors: ME
authors: Mann
authors: Nathan D
authors: ND
authors: Stansell
authors: Bruce P
authors: BP
authors: Finney
mesh_terms: D002980:Climate; D003198:Computer Simulation; D019015:Geologic Sediments / Q000032:analysis*; D049668:History, 15th Century; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049691:History, Medieval; D006813:Humidity; D060106:Lakes; D016014:Linear Models; D013058:Mass Spectrometry; D008962:Models, Theoretical; D015205:Northwestern United States; D010101:Oxygen Consumption; D011891:Rain; D012621:Seasons; D013696:Temperature; D014961:X-Ray Diffraction