2.3
Climate variability since a.d. 1736 as expressed in an ice core from the Saint Elias Mountain Range in northwestern North America
G. W. K. Moore, University of Toronto, Toronto, ON, Canada; and G. Holdsworth and K. Alverson
Spatially correlated precipitation anomalies are an important consequence of recurring and persistent large-scale wave-like patterns in the atmosphere. These patterns known as teleconnections are recognized as a naturally occurring low frequency component of the global climate system. Several extratropical regions, including the Northeast Pacific Ocean and western North America (PNA), exhibit such precipitation anomalies that are the result of teleconnections excited by the El-Nino Southern Oscillation (ENSO) cycle. Here we present an annually resolved record of extra-tropical climate variability covering the period 1736-1985 from an ice core obtained in the Saint Elias Mountains of the Yukon. The Mount Logan site located in the center of the region with the most significant extra-tropical ENSO signature has the potential to provide valuable information on extra-tropical climate variability in the pre-instrumental era. The net snow accumulation time series derived from the core exhibits periodic transitions between statistically significant correlation and anti-correlation with various instrumental and reconstructed ENSO indices. As we shall show, we are now in a period where there may be a transition in the correlation characteristics of the extra-tropical response to ENSO events.
Session 2, Observed Climate Variability and Change: Proxy Records (Parallel with Session 1)
Monday, 15 January 2001, 10:30 AM-2:45 PM
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