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Abstract Marine heatwaves have become more frequent and intense under anthropogenic warming, posing increasing threats to marine ecosystems and coastal societies, necessitating a better understanding of their mechanism and predictability. Here we show how ocean dynamics modulate marine heatwaves globally by comparing dynamic and slab ocean climate model simulations. We discover that ocean dynamics significantly promote marine heatwave intensity and duration in mid-to-high latitude oceans, as well as the eastern tropical Pacific where marine heatwaves are inherently linked to extreme El Niño events. Our mixed-layer heat budget analysis unravels that heat accumulation during marine heatwave episodes is strongly influenced by vertical mixing and horizontal transport processes, so that warm sea surface temperature extremes in dynamic ocean differ in magnitude and evolution rhythm from those in slab ocean. We further find robust multi-year potential predictability of marine heatwave in the North Atlantic with a dynamic ocean, owing primarily to the predictability of the Atlantic Meridional Overturning Circulation. Our findings emphasize the irreplaceable role of oceanic dynamics in marine heatwave evolution and predictability, with important implications for future climate extreme prediction and adaptation strategies. 

Abstract Observations reveal Antarctic sea ice expansion and Southern Ocean surface cooling trends from 1979 to 2014, whereas climate models mostly simulate the opposite. Here I use historical ensemble simulations with multiple climate models to show that sea-ice natural variability enables the models to simulate an Antarctic sea ice expansion during this period under anthropogenic forcings. Along with sea-ice expansion, Southern Ocean surface and subsurface temperatures up to 50^oS, as well as lower tropospheric temperatures between 60^oS and 80^oS, exhibit significant cooling trends, all of which are consistent with observations. Compared to the sea-ice decline scenario, Antarctic sea ice expansion brings tropical precipitation changes closer to observations. Neither the Southern Annular Mode nor the Interdecadal Pacific Oscillation can fully explain the simulated Antarctic sea ice expansion over 1979–2014, while the sea-ice expansion is closely linked to surface meridional winds associated with a zonal wave 3 pattern. 

Abstract El Niño/Southern Oscillation variability has conspicuous impacts on ecosystems and severe weather. Here, we probe the effects of anthropogenic aerosols and greenhouse gases on El Niño/Southern Oscillation variability during the historical period using a broad set of climate models. Increased aerosols significantly amplify El Niño/Southern Oscillation variability primarily through weakening the mean advection feedback and strengthening the zonal advection and thermocline feedbacks, as linked to a weaker annual cycle of sea surface temperature in the eastern equatorial Pacific. They prevent extreme El Niño events, reduce interannual sea surface temperature skewness in the tropical Pacific, influence the likelihood of El Niño/Southern Oscillation events in April and June and allow for more El Niño transitions to Central Pacific events. While rising greenhouse gases significantly reduce El Niño/Southern Oscillation variability via a stronger sea surface temperature annual cycle and attenuated thermocline feedback. They promote extreme El Niño events, increase SST skewness, and enlarge the likelihood of El Niño/Southern Oscillation peaking in November while inhibiting Central Pacific El Niño/Southern Oscillation events. 

Abstract The Southern Ocean Meridional Overturning Circulation (MOC) has intensified in recent decades, yet the interplay between its Eulerian and eddy components under future warming remains uncertain. Using ensemble climate simulations, here we show that the Eulerian-mean MOC shifts poleward under high-emission scenarios during the twenty-first century, with compensating eddy-induced MOC sustaining a uniformly intensified residual overturning. This response is less pronounced under low-emission scenarios with climate mitigation. Likewise, a poleward-shifted Eulerian-mean MOC occurred during the Mid-Pliocene Warm Period, but with weaker, broader eddy compensation, leading to non-uniform intensified residual overturning. Across past and future warming climates, the eddy-induced MOC is primarily modulated by surface heat flux changes at lower latitudes and by freshwater flux changes at higher latitudes over the Southern Ocean. The buoyancy forcing changes drive northward Antarctic upwelling, promoting Antarctic bottom water formation. Along with MOC changes, ventilation intensifies in the lower latitudes of the Southern Ocean as related to the subduction branch, especially during the past warm period. 

Abstract Most oceans over the globe have experienced surface warming during the past century, but the subpolar Atlantic is quite otherwise. The sea surface temperature cooling trend to the south of Greenland, known as the North Atlantic Warming Hole, has raised debate over whether it is driven by the slowing of the Atlantic Meridional Overturning Circulation. Here we use observations as a benchmark and climate models as a tool to demonstrate that only models simulating a weakened historical Atlantic overturning can broadly reproduce the observed cooling and freshening in the warming hole region. This, in turn, indicates that the realistic Atlantic overturning slowed between 1900 and 2005, at a rate of −1.01 to −2.97 Sv century⁻¹(1 Sv = 10⁶ m³ s⁻¹), according to a sea-surface-temperature-based fingerprint index estimate. Particularly, the Atlantic overturning slowdown causes an oceanic heat transport divergence across the subpolar North Atlantic, which, while partially offset by enhanced ocean heat uptake, results in cooling over the warming hole region. 

Abstract Arctic sea ice has undergone non-monotonic changes since the middle of the last century. Here, we investigate the cause of this behavior by isolating and quantifying the effects of anthropogenic aerosols, well-mixed greenhouse gases, and biomass burning on sea ice dynamics through climate model simulations. We find minimal changes in Arctic sea ice from 1956 to 1980, which largely reflect a balance between the warming effect of greenhouse gases and the cooling effect of aerosols. This balance, however, is disrupted in subsequent decades. Both sea ice area and volume exhibit marked declines between 1981 and 2005, owing primarily to intensified warming by greenhouse gases and a shift in aerosols’ role from mitigating to exacerbating sea ice loss. Our sea ice volume budget analysis demonstrates that sea ice changes since 1956 are mostly driven by thermodynamic processes: greenhouse gases significantly promote surface melting, whereas aerosols and biomass burning diminish surface melting by reducing surface shortwave radiation during boreal summer. From 1956–1980 to 1981–2005, the transitional effects of aerosols are associated with increased bottom ice melting and decreased bottom ice formation, which are primarily driven by changes in the Atlantic meridional overturning circulation. 

The Collaboration for Astronomy Signal Processing and Electronic Research (CASPER) toolflow is a widely used framework for designing and implementing digital signal processing systems, particularly in the field of radio astronomy. It provides a set of tools and libraries that enable researchers to create custom hardware and software solutions for processing astronomical data. The CASPER toolflow has been instrumental in the development of Field-Programmable Gate Array (FPGA)-based digital instruments for various radio telescopes, enabling for real-time data processing and analysis. However, the current frontend tool that CASPER uses for high-level FPGA design is based on Model Composer integrated into MATLAB/Simulink, which is a proprietary software. In this paper, we introduce Scilab as a new frontend tool for the CASPER toolflow. Scilab is an open-source software platform for numerical computation and data visualization, which offers a similar environment to MATLAB/Simulink for designing CASPER blocks, generating FPGA Intellectual Property (IP) cores, and simulating Digital Signal Processing (DSP) systems. We present our implementation of Scilab in the CASPER toolflow and demonstrate its capabilities by developing an FPGA-based spectrometer on a RFSoC4[Formula: see text] × [Formula: see text]2, a commonly used CASPER platform well suited to radio astronomy applications. We have also developed Scilab support for other CASPER compatible platforms. Our results show that Scilab can successfully be used as an alternate frontend for CASPER-based designs. 

Aiming to interrogate the possibility of heteronuclear B–C one-electron σ-bonding, we have prepared a naphthalene-based platform ([5]+) decorated at its peri-positions by a carbenium and a boryl unit separated by a B–C distance of 2.994(4) Å. Reduction of this cationic platform by one electron affords a radical (5•) with a shortened B–C distance of 2.874(3) Å, suggesting the onset of B–C one-electron bonding. This radical, which was also characterized by EPR spectroscopy, undergoes a second reduction, affording a borate ([5]−) with a long, polar covalent B–C bond of 1.793(8) Å. These compounds have been structurally, spectroscopically, and computationally investigated, shedding light on the polarization and weakness of the B–C bond of 5•, which is best described as a noncovalent one-electron B···C triel bond rather than a covalent one-electron σ-bond. 

Atomic vacancies in oxides induce deviations from ideal stoichiometry, critically influencing their functional properties in applications such as energy storage-conversion, catalysis, and electronic devices. The dynamic behavior of these vacancies as main mass transport mediums to exchange chemical species with surroundings under operating conditions is central to oxide redox reactions running with the Mars-van Krevelen (MvK) mechanism; yet in-situ atomic-scale monitoring of the vacancy dynamics and vacancy-induced secondary defects within oxides remains challenging due to both their rapid transport kinetics at buried subsurface/interface and characterization difficulties, arising from the insulating nature of bulk oxides and the spatial-resolution requirement in reaction conditions. These challenges hinder precise defect engineering for the performance optimization of functional oxides. In this review, recent advancements in tracking oxygen vacancy and vacancy-induced secondary defects dynamics in oxides, including surface steps, cation vacancies, interfacial dislocations, ledges, and interfaces, have been summarized. The dynamic interconversion of defects and their synergistic effects on surface/subsurface/interface evolution are mainly discussed. The aim of this review is to enhance understanding of defect dynamics and their pivotal role in modulating structural dynamics and surface reaction reactivity, which is highly relevant to the catalyst activity/selectivity/stability evaluation of functional oxide catalysts for electroreduction and catalytic oxidation reactions. Finally, strategies to control buried subsurface and interfacial defects (interface engineering) through tailored surface reactions are proposed, offering new pathways to customize the performance of advanced oxide-based materials.