Article Open access Feng Jiang , Richard Seager & Mark A. Cane Nature Communications 15 , Article number: 8291 (2024) Cite this article Metrics Abstract The eastern tropical Pacific has defied the global warming trend. There has been a debate about whether this observed trend is forced or natural (i.e., the Interdecadal Pacific Oscillation; IPO) and this study shows that there are two patterns, one that oscillates along with the IPO, and one that is emerging since the mid-1950s, herein called the Pacific Climate Change (PCC) pattern. Here we show these have distinctive and distinguishable atmosphere-ocean signatures. While the IPO features a meridionally broad wedge-shaped SST pattern, the PCC pattern is marked by a narrow equatorial cooling band. These different SST patterns are related to distinct wind-driven ocean dynamical processes. We further show that the recent trends during the satellite era are a combination of IPO and PCC. Our findings set a path to distinguish climate change signals from internal variability through the underlying dynamics of each. Introduction The sea surface temperature (SST) trends over 1980 to 2022, and the longer period of 1958 to 2022, are shown in Fig. 1a, b . We will show that the former is largely the well-known pattern of the long-studied Interdecadal Pacific Oscillation (IPO; see Methods for a definition) and the latter is a pattern that we will call the Pacific Climate Change (PCC) pattern. We further show that the ocean dynamics associated with the two patterns are distinct. The SST trend (°C per decade) based on HadISST during ( a ) 1980–2022 and ( b ) 1958–2022. Dots in ( a , b ) indicate the trend exceeding the 95% confidence level. c Timeseries of raw (black dashed lines) and 15-year running mean (red solid lines) annual-mean SST anomalies in the […]