| 04 Sep 2025
The Northwest Pacific corals unravel the NPGO/Victoria Mode-related temperature back to the 19th century
Abstract. 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 variability through their linkage with temperature variability in the Central Pacific (CP). The NPGO and VM manifest as sea surface height and basin-wide sea surface temperature anomaly patterns, respectively, in the North Pacific. Although recent studies have drawn attention to their connections with surface temperature anomalies in the CP, their historical interactions remain poorly understood due to limited instrumental observations. Here, we present a long-term reconstruction of NPGO/VM-related temperature variability based on a coral Sr/Ca temperature proxy from the Northwest Pacific, covering the period from 1798 to 2014 Common Era. This reconstruction contributes to a better spatiotemporal understanding of historical interactions among NPGO, VM, and surface temperature anomalies in the CP over the past two centuries. The coral-inferred temperature record closely aligns with surface temperature variability in the CP, indicating the extra-tropical propagation of NPGO/VM-related temperature variations from the CP via an ocean-atmosphere bridge. Our reconstruction identifies pronounced negative-NPGO/cool-temperature phases in the late 1840s and during the 1860s–1900s, and a positive-NPGO/warm-temperature phase during the 2000s–2010s. We also find a significant correlation between surface temperature anomalies in the CP and interannual to decadal NPGO/VM variability throughout the past 200 years. This relationship lasted from the early 20th century until 2014, with the exception of the period from the 1970s to the 1990s, and strengthened from the 2000s onward. Given the strong linkage between the NPGO and the surface temperature anomalies in the CP, as well as the projected increase in CP-centred climate variability under future warming scenarios, the prominence of the NPGO in the North Pacific and beyond is expected to intensify.
