Climate models struggle to simulate observed North Pacific jet trends, even accounting for tropical Pacific sea surface temperature trends

Patterson, M. ORCID: https://orcid.org/0000-0002-9484-8410 and O'Reilly, C. H. ORCID: https://orcid.org/0000-0002-8630-1650 (2025) Climate models struggle to simulate observed North Pacific jet trends, even accounting for tropical Pacific sea surface temperature trends. Geophysical Research Letters, 52 (4). e2024GL113561. ISSN 1944-8007 doi: 10.1029/2024GL113561

Abstract/Summary

We show that the wintertime (December‐January‐February) North Pacific jet in ERA5 has shiftednorthwards over the satellite‐era (1979–2023) at a faster rate than any of the state‐of‐the‐art coupled climatemodels used in this study. Differences in tropical sea surface temperature (SST) trends can only partially explainthe discrepancy in jet trends between models and observations and a small minority of simulations forced withobserved SSTs match the magnitude of the observed jet trend. However, analysis of longer‐term jet variability inreanalysis suggests that the jet trend has not clearly emerged from multi‐decadal internal climate variability.Consequently, it is unclear whether the difference in observed and modeled jet trends arises due to differingresponses to anthropogenic forcing or overly weak long‐term internal variability in models. These results haveimportant implications for future climate projections for North America and motivate further research into theunderlying causes of long‐term jet trends.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/120956
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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