LONG-TERM RELATIONSHIPS BETWEEN RECONSTRUCTED SEASONAL MASS BALANCE AT PEYTO GLACIER, CANADA, AND PACIFIC SEA SURFACE TEMPERATURES

Abstract

Tree-ring based mass balance reconstructions developed for Peyto Glacier, Alberta, Canada are compared with measured conditions in the Pacific Ocean over the last century and, using reconstructions of Pacific climate indices, over the past ?300 years, at interannual and decadal-interdecadal timescales. Tree-ring reconstructed winter balance totals at Peyto Glacier in La NiNa, negative Pacific Decadal Oscillation (PDO) and La NiNa/negative PDO years significantly exceed those in El NiNo, positive PDO and El NiNo/positive PDO years, respectively. The same phase pairings of reconstructed summer mass balance do not differ significantly. These findings confirm those seen in the measured mass balance records and shorter (100 years) tree-ring and instrumental climate record-based reconstructions, suggesting similar relationships have existed over the past ?300 years. Maps showing the regression of Pacific sea surface temperatures (SSTs) on the seasonal mass balance series indicates that both winter and, albeit more weakly, summer mass balance series are related to ENSO-like patterns of SST variability in the Pacific Ocean at both interannual and interdecadal timescales.