Two centuries of coherent decadal climate variability across the Pacific North American region

Abstract

The decadal variability of the Pacific Ocean and North American hydroclimate are subjects of immediate concern for society, yet the length of the instrumental record limits full mechanistic understanding of this variability. Here we introduce a 178 year, seasonally resolved coral oxygen isotopic record from Clarion Island (18°N, 115°W), a sampling a subtropical region that is strongly influenced by the decadal-scale fluctuations of the North Pacific Gyre Oscillation and a region that serves as a critical locus for the communication of climate anomalies with the tropics. This Mexican Pacific coral record is highly correlated to coral records from the central tropical Pacific and tree ring records from western North America. Significant changes in the amplitude of oceanic decadal variability in the early nineteenth century are mirrored in the drought reconstructions in western North America. The spatial manifestation of this relationship was relatively invariant, despite notable changes in the climatic mean state.