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Abstract The evolution of the spatial pattern of ocean surface warming affects global radiative feedback, yet different climate models provide varying estimates of future patterns. Paleoclimate data, especially from past warm periods, can help constrain future equilibrium warming patterns. By analyzing marine temperature records spanning the past 10 million years with a regression‐based technique that removes temporal dimensions, we extract long‐term ocean warming patterns and quantify relative sea surface temperature changes across the global ocean. This analysis revealed a distinct pattern of amplified warming that aligns with equilibrated model simulations under high CO₂conditions, yet differs from the transient warming pattern observed over the past 160 years. This paleodata‐model comparison allows us to identify models that better capture fundamental aspects of Earth's warming response, while suggesting how ocean heat uptake and circulation changes modify the development of warming patterns over time. By combining this paleo‐ocean warming pattern with equilibrated model simulations, we characterized the likely evolution of global ocean warming as the climate system approaches equilibrium. 

Extreme precipitation events are driven by complex multiscale atmospheric dynamic interactions, fuelled by available moisture. They are expected to intensify with climate change, posing increasing risks to human communities and ecosystems. However, current low-resolution climate models struggle to accurately represent key extreme precipitation-generating phenomena, limiting our ability to generate robust and reliable future projections. Here we present an ensemble of climate simulations with a 10-to-25-km resolution and an improved representation of mesoscale convective systems to assess future changes in daily extreme precipitation and its drivers. Our high-resolution simulations more realistically capture the observed spatial distribution and intensity of daily extreme precipitation over the historical period than the 100-km resolution counterparts. In a future scenario with high carbon dioxide emissions, daily extreme precipitation over land could increase by about 41% by 2100, mainly as a result of increased mesoscale moisture convergence. The impact of this dynamical contribution to extreme precipitation is underestimated by a factor of three in the low-resolution model. These results highlight the crucial role of high-resolution climate modelling in constraining future extremes and informing more effective climate risk assessments and adaptation strategies. 

Abstract Extreme sea-level events, such as those caused by tropical cyclones (TCs), pose significant risks to coastal areas. However, the current generation of climate models struggles to simulate these events due to coarse resolution. By comparing high-resolution (HR) and low-resolution (LR) Community Earth System Model simulations with tide gauge and altimeter data along the US. Gulf of Mexico (GoM) coast, we find that HR better represents both mean dynamic sea level (DSL) and daily mean extreme DSL (EDSL) statistics. In contrast, LR significantly underestimates the strength of EDSL mainly due to its deficiency in simulating strong TCs. Both observations and HR show larger daily mean EDSL on the western Gulf coast than on the eastern side, highlighting the need for HR climate simulations to improve coastal resilience planning. 

Abstract The Kuroshio Extension (KE) exhibits significant decadal variations, particularly following the 1976/77 Pacific climate regime shift. Robust ocean–atmosphere interactions over the KE imply a potential key role in basin-scale climate variability. Recent studies suggest that North Pacific Oscillation (NPO)-like atmospheric teleconnections from the central tropical Pacific dominantly influence KE decadal variability through oceanic Rossby waves. However, this relationship varies on interdecadal time scales and only achieves statistical significance after the regime shift. This study utilizes outputs from an unprecedented 500-yr preindustrial control simulation conducted with an eddy-resolving coupled general circulation model to explore the potential and mechanisms of natural variability–induced interdecadal modulation. When the entire simulation period is divided into five segments, a relationship between the KE and the central tropical Pacific, resembling that after the regime shift, is found during the segment marked by the strongest decadal variability in the central tropical Pacific and the NPO. These variabilities enhance each other by positive feedback on decadal time scale via the Pacific meridional mode triggered by air–sea interaction. As the westerly jet migrates southward over the eastern North Pacific during this period, the southern lobe of the NPO also expands southward, likely providing a favorable background condition for its active interaction with the tropics. In contrast, the relationship is absent in other periods, likely due to weaker and less persistent tropical variability, differences in the location of atmospheric teleconnections, and/or influences of the Kuroshio large meander. These findings suggest that the interdecadal modulation of the KE may occur independently of anthropogenic forcing. Significance StatementAtmospheric teleconnections from the central tropical Pacific have been suggested to drive the decadal variability of the Kuroshio Extension, particularly after the 1976/77 climate regime shift. This study analyzes a 500-yr preindustrial simulation from a high-resolution coupled model, revealing a possible interdecadal modulation of this relationship due to natural variability. The observed relationship emerges during a simulation period characterized by strong decadal variability in the central tropical Pacific and the North Pacific atmosphere. They enhance each other via air–sea interaction, suggesting a positive feedback operating on decadal time scales. During this period, anomalous atmospheric circulation over the eastern North Pacific expands southward, associated with a southward-shifted westerly jet, providing a favorable background condition. 

Abstract Mesoscale sea surface temperature (SST) variability influences the marine atmosphere boundary layer (MABL), affecting near‐surface winds and turbulent heat fluxes. This study examines precipitation response to mesoscale SST forcing using satellite observations, ERA5 reanalysis, and high‐ and low‐resolution climate models. The results show that high‐resolution models produce a precipitation response to mesoscale SST consistent with satellite observations and ERA5. However, partitioning ERA5 and model precipitation into resolved and parameterized convective components reveals that even in high‐resolution models, the simulated mesoscale SST‐precipitation relationship is shaped by the characteristics of convective parameterization. Further, the precipitation response to SST is strongly dependent on the background SST and SST variability in coupled models. Further analysis of ERA5 and high‐resolution simulations shows a vertical velocity response extending to 500 hPa. However, the reliance on convective parameterizations introduces uncertainties about whether high‐resolution models accurately capture these effects. 

Abstract Understanding and predicting “droughts” in wind and solar power availability can help the electric grid operator planning and operation toward deep renewable penetration. We assess climate models' ability to simulate these droughts at different horizontal resolutions, ∼100 and ∼25 km, over Western North America and Texas. We find that these power droughts are associated with the high/low pressure systems. The simulated wind and solar power variabilities and their corresponding droughts during historical periods are more sensitive to the model bias than to the model resolution. Future climate simulations reveal varied future change of these droughts across different regions. Although model resolution does not affect the simulation of historical droughts, it does impact the simulated future changes. This suggests that regional response to future warming can vary considerably in high‐ and low‐resolution models. These insights have important implications for adapting power system planning and operations to the changing climate. 

Abstract Emerging high‐resolution global ocean climate models are expected to improve both hindcasts and forecasts of coastal sea level variability by better resolving ocean turbulence and other small‐scale phenomena. To examine this hypothesis, we compare annual to multidecadal coastal sea level variability over the 1993–2018 period, as observed by tide gauges and as simulated by two identically forced ocean models, at (LR) and (HR) horizontal resolution. Differences between HR and LR, and misfits with tide gauges, are spatially coherent at regional alongcoast scales. Resolution‐related improvements are largest in, and near, marginal seas. Near attached western boundary currents, sea level variance is several times greater in HR than LR, but correlations with observations may be reduced, due to intrinsic ocean variability. Globally, in HR simulations, intrinsic variability comprises from zero to over 80% of coastal sea level variance. Outside of eddy‐rich regions, simulated coastal sea level variability is generally damped relative to observations. We hypothesize that weak coastal variability is related to large‐scale, remotely forced, variability; in both HR and LR, tropical sea level variance is underestimated by 50% relative to satellite altimetric observations. Similar coastal dynamical regimes (e.g., attached western boundary currents) exhibit a consistent sensitivity to horizontal resolution, suggesting that these findings are generalizable to regions with limited coastal observations. 

Abstract Jiang et al. (2023),https://doi.org/10.1029/2023gl103777argue that the apparent impact of the equatorial Atlantic on El Niño‐Southern Oscillation (ENSO) is a statistical artifact, and that the 6‐month lead correlation reported in previous studies stems from early developing ENSO events driving the equatorial Atlantic zonal mode (AZM) in boreal summer and maturing in winter. Closer examination, however, reveals that most AZM events develop too early to be driven by developing ENSO, and that the influence of decaying ENSO events has to be considered too. Thus, while early developing ENSO events may play a role, they do not fully explain observed AZM behavior. Our aim is not to argue for or against an AZM influence on ENSO, but rather to show that Jiang et al.’s analysis is insufficient to resolve this issue. More analysis will be needed for a deeper understanding of Atlantic‐Pacific interaction. 

Abstract We investigate the role of ocean heat transport (OHT) in driving the decadal variability of the Arctic climate by analyzing the pre‐industrial control simulation of a high‐resolution climate model. While the OHT variability at 65°N is greater in the Atlantic, we find that the decadal variability of Arctic‐wide surface temperature and sea ice area is much better correlated with Bering Strait OHT than Atlantic OHT. In particular, decadal Bering Strait OHT variability causes significant changes in local sea ice cover and air‐sea heat fluxes, which are amplified by shortwave feedbacks. These heat flux anomalies are regionally balanced by longwave radiation at the top of the atmosphere, without compensation by atmospheric heat transport (Bjerknes compensation). The sensitivity of the Arctic to changes in OHT may thus rely on an accurate representation of the heat transport through the Bering Strait, which is difficult to resolve in coarse‐resolution ocean models.