The Northwestern Pacific corals unravel the NPGO/Victoria Mode-related temperature back to the 19th century

Abstract

Abstract The atmospheric and oceanic phenomena in the Pacific Ocean, such as the North Pacific Gyre Oscillation (NPGO) and the Victoria Mode (VM), have significant implications for global climate change patterns. Although the relationship between surface temperature changes in the Central Pacific warming pool (CPW-ST), NPGO and VM has recently attracted attention, the historical relationships over the centuries remain unknown due to limited instrumental observations. Here, we present a long-term NPGO/VM-related temperature variability based on the Northwestern Pacific coral proxy from 1798 to 2014 AD. The coral skeletal Sr/Ca-inferred temperature record matched the CPW-ST time series, revealing extra-tropical propagation of NPGO/VM-related temperature variation from the central Pacific through an ocean-atmosphere bridge. Furthermore, we identified distinct negative NPGO/low-temperature phases in the late 1840s and during the 1860s-1900s and a positive NPGO/high-temperature phase in the 2000s-2010s. Additionally, a significant correlation between CPW-ST and high-frequency NPGO/VM variability was observed in the past 200 years. Our coral record indicates that the relationship lasted until the 1930s, except from the 1970s to the 1990s, and has strengthened from the 2000s to the present. The coral-based temperature record from the Northwestern Pacific provides important insights into the historical spatiotemporal changes in NPGO/VM-related temperature variability.