Matched-field processing is highly sensitive to environmental mismatch, yet most robust formulations emphasize static uncertainties more than time-evolving environmental forcing. This study examines a representative low-frequency shallow-water scenario in which wind-driven mixed-layer deepening reshapes the upper-ocean sound-speed profile and perturbs modal horizontal wavenumbers, producing accumulated phase errors, ambiguity-surface distortion, and systematic range bias. To organize these effects beyond a single operating point, a conditional modal phase-spread analysis is introduced to show how wind-driven degradation depends jointly on wind state, propagation range, frequency, and source depth relative to the mixed layer. A physics-coupled particle filter (PC-PF) is then proposed, in which wind speed is treated as a dynamic hidden state and estimated jointly with source range through an embedded reduced-order environmental model. Broadband numerical experiments are used to assess mechanism and tracking performances. For the representative storm-evolution scenario considered here, a conventional static-model broadband Bartlett processor develops kilometer-scale range errors, whereas the proposed PC-PF substantially reduces the root mean square error and preserves track continuity. The formulation is intended as a reduced-order, acoustically informed framework for dynamic environmental adaptation in time-varying conditions.

In this study, we reconstructed the North Atlantic Ocean temperature field by combining an interpretable deep learning framework with multi-source satellite data, including sea surface temperature (SST), sea surface height (SSH), sea level anomaly (SLA), sea surface wind field (SSW), and SST gradient (GRAD). The optimal model configuration achieved a root mean square error (RMSE) of 0.49 °C. This study extends the SHapley Additive exPlanations (SHAP) method to spatial, temporal, and vertical dimensions to systematically analyze the model’s error sources and feature contributions. The results show that the reconstruction error is concentrated in regions with large physical gradients, such as the thermocline and Gulf Stream, exhibiting a significant seasonal bias pattern. SHAP analysis reveals a clear vertical transition in feature importance that SST dominates at all depths with a relative contribution of 34.60%. The contributions of SSW and GRAD were mainly concentrated at the sea surface, whereas the contributions of SSH and SLA began to increase in the lower mixed layer and peaked in the thermocline, becoming crucial in connecting the surface and ocean interior. This study highlights the depth and spatial dependence of feature contributions, providing a physical basis for the future optimization of remote sensing-based ocean temperature reconstruction models.

Abstract Antarctic Intermediate Water (AAIW), occupying a broad region at intermediate depths in the Southern Hemisphere oceans, plays a crucial role in global heat and freshwater redistribution. However, its origin at the sea surface remains a subject of ongoing debate. A recently defined distance metric, which distinguishes similar water parcels, is applied to Argo data to trace the surface origins of the AAIW cores in each ocean basin. By examining the spatial distribution of distances to the AAIW cores, we identify that the Pacific and Atlantic AAIW cores primarily originate from localized surface regions, specifically near the Subantarctic Front in the southeast Pacific and the Falkland Plateau in the southwest Atlantic. Further investigation indicates that through subduction in the deep mixed layer, low-salinity water penetrates to intermediate depths in these regions. North of the subduction sites, water masses primarily circulate within the subtropical gyre in the South Pacific, whereas to the south, they are advected eastward by the Antarctic Circumpolar Current into the Atlantic Ocean. In the Indian Ocean, the AAIW core, distinguished by its relatively low oxygen concentration, originates both from eastward inflow carried by the Antarctic Circumpolar Current from the southeast Pacific and local surface sources near 90°E. Our findings confirm the reliability of the distance metric and emphasize the importance of localized physical processes in the penetration of AAIW into the ocean interior. Significance Statement Antarctic Intermediate Water (AAIW), found in Southern Hemisphere intermediate depths, is essential for global heat and freshwater distribution. Using a newly defined distance metric, it is found that AAIW originates primarily from the Subantarctic Front in the southeast Pacific and the Falkland Plateau in the southwest Atlantic, where low-salinity water subducts into deeper layers. In contrast, the Indian Ocean lacks this direct path, with its AAIW formed by the inflow of AAIW from the Atlantic via the Antarctic Circumpolar Current. These findings improve our understanding of AAIW origins and pathways within the ocean.

Weather specific evaluation of satellite retrieved aerosol optical depth over drylands of the Southwest United States

Self-assembled monolayers based hole-transport layers (HTLs) have endowed inverted perovskite solar cells (PSCs) with dramatically improved photovoltaic performance and scalability. Their molecular ordering however affects the defect passivation in the perovskite buried interface and interfacial charge transfer. Herein, we propose an effective doping mixed SAMs strategy to modulate molecular ordering of SAMs, strengthen the interfacial interactions with perovskite buried surface, and mitigate tensile strain in the perovskite film. Leveraging the solubility and phase compatibility difference during solution-processing of mixed SAMs and perovskite layers, the dopant enriched on top of SAMs surface to form coordination bonding with the perovskite buried interface. The synergistic interfacial engineering enables 23.48% efficiency for 1.68eV bandgap inverted PSCs with over 90% retention after 1500h under 1-sun illumination. Moreover, the strategy was successfully extended to two-terminal monolithic perovskite/silicon tandem solar cells to afford impressive PCEs of 30.18%. Our doping mixed SAMs strategy demonstrates great efficacy for interfacial engineering of wide bandgap perovskite to fabricate efficient perovskite single-junction and tandem solar cells.

Accurate measurement of ammonium (NH4+) and nitrate (NO3-) concentrations in soils is essential for understanding factors that determine nitrogen bioavailability and potential losses to the wider environment. Diffusive gradients in thin-films (DGT) can be used to examine NH4+ and NO3- dynamics in soils, while overcoming some of the limitations faced by conventionally used extraction methods. This study evaluated the effects of temperature, soil type, and moisture content on NH4+ and NO3- dynamics using DGT across two experiments. In the first experiment, NH4+ and NO3- were applied to three South Australian soils and incubated at three moisture contents. Single and mixed binding layer DGT probes were deployed for 12, 24, and 48 h to examine short-term changes in N species concentrations. In the second experiment, NH4+ and NO3- concentrations and transformation rates were monitored in one soil over 42 days following urea application, at three soil moisture contents and two temperatures (15 and 24 °C). Soil type, moisture content, and DGT deployment time affected measured NH4+ and NO3- concentrations in the first experiment. However, the mixed binding layer DGT underestimated concentrations of both species by up to 66%. In the second experiment, DGT-measured NH4-N increased to up to 3044 ± 379 µg L-1 within 3 days under the warmest, wettest treatment, with transformation rates of both N species further influenced by temperature, moisture content, and time after urea application. These dynamics were clearly resolved by DGT, thus demonstrating the technique's potential to provide valuable new insight into soil nitrogen cycling.

This paper examines sustainable development and tribological performance of fly ash reinforced AA8011 aluminium matrix composites by stir casting. Composites with 0, 4, 8 and 12 wt.% fly ash content were made and tested under dry sliding conditions using pin on disc apparatus. The Taguchi L16 orthogonal array with the aid of the multi-response optimization through the use of the Grey Relational Analysis (GRA) was used to analyze wear rate, frictional force, and coefficient of friction (COF). The experimental outcomes indicate that the wear rate was 0.00447-0.00813 mm3/m, 4.84-9.89 N frictional force, 0.228-0.711 Coefficient of Friction (COF). The best parameters were found to be 8 wt.% fly ash, 30 N load, 3m/s sliding velocity and 3200m sliding distance which gave a maximum Grey Relational Grade (GRG) of 0.831. The results of ANOVA showed that applied load had the greatest contribution (48.95%), and then followed by the sliding distance (23.57%), but fly ash content had a smaller but significant contribution (3.12%). The confirmatory test showed that there was a small error of 2.6% in the value of predicted and experimental GRG. SEM analysis revealed the shift towards the severe abrasive wear in the base alloy to the mild oxidative wear with the stable mechanically mixed layer in higher reinforcement level. The research confirms that the wear resistance with the use of fly ash is enhanced, and sustainable development of materials through the effective use of industrial waste is improved.

As metal halide perovskite light-emitting diodes (PeLEDs) rapidly improve in performance, identifying and resolving factors that limit operational stability is paramount. Compounds released by the perovskite as byproducts of interfacial electrochemistry can react with and compromise various LED layers and diminish performance, particularly corroding and degrading metal anodes. In this study, we use a mixed-polymer hole transport layer (a mixture of poly(N,N'-bis-4-butylphenyl-N,N'-bisphenyl)benzidine (polyTPD) and poly(9-vinylcarbazole) (PVK)) to stabilize methylammonium lead iodide-based PeLEDs with Au metal anodes against increasing leakage current under repeated operation and decreased emission intensity under constant driving. We study this layer using a newly developed Au-corrosion-based triiodide detection experiment to determine that our mixed hole transport layer interferes with and inhibits triiodide transport, leading to more stable operation.

Cu-Mg alloy droppers in high-speed railways operate under complex conditions involving corrosion, heat, and mechanical load. However, the synergistic damage evolution mechanisms under such multiphysics coupling remain unclear. This study investigated the tribological behavior of CuMg0.4 alloy using a crossed-cylinder configuration, focusing on the synergistic effects of normal load, precorrosion, and temperature. The results indicate that the higher loads are associated with the formation of a more compact mechanically mixed layer (MML), which corresponds to more stable friction and a lower wear depth. In contrast, precorrosion severely deteriorates frictional stability due to brittle layer fragmentation and subsequent three-body abrasion. Notably, temperature exerted opposite effects on uncorroded and corroded surfaces. For uncorroded substrates, elevated temperatures (90–120 °C) increase wear depth via thermally activated plastic flow. Nevertheless, for precorroded specimens, the elevated temperature promotes a more pronounced tendency for surface reconstruction. The reduced post-wear Cu enrichment, together with the continued detection of O/Cl-containing species on the wear scar, suggests that the fractured corrosion products and wear debris are more readily retained and compacted within the contact zone at the elevated temperature. As a result, the worn surface tends to develop a more continuous and compact tribolayer consistent with MML formation, which is associated with reduced substrate exposure and lower material loss. The surface reconstruction tendency identified in this study provides further insight into the damage evolution of copper alloys under multiphysics coupling.

Dimethyl sulphide (DMS) serves as a key olfactory cue for seabird navigation, yet existing DMS products operate at coarse spatiotemporal resolutions (≥ 25km, monthly) mismatched to the scales of individual movement decisions. We ask (I) whether machine learning can produce biologically relevant, high-resolution DMS estimates across the North Atlantic, and (ii) whether such estimates can be readily integrated with animal tracking data to support ecological interpretation of animal trajectories. Using North Atlantic in-situ DMS observations (2002-2024) and five satellite-data-based environmental predictors (chlorophyll, mixed layer depth, nitrate, sea-surface temperature, and photosynthetically available radiation), we developed a machine-learning-based ensemble model for DMS prediction that achieved strong accuracy (test R2 = 0.88; RMSE = 0.859 µmol m-3), exceeding previously reported performance for basin-scale DMS mapping. To identify the key drivers of the model predictions, we conducted SHAP (SHapley Additive exPlanations) analysis, which revealed that mixed layer depth, nitrate concentration, and chlorophyll were the dominant controlling factors, aligning with established understanding of DMS biogeochemistry. We then produced a spatially continuous, daily 4km DMS dataset for the North Atlantic domain (0-60° N, 80° W-15° E), revealing seasonal cycles, persistent hotspots, and fine-scale gradients not captured by coarse climatologies. Finally, we develop AniDMS, an open-source Python package that automates trajectory annotation with gridded DMS and associated covariates, demonstrated with a Manx shearwater case study. Together, the dataset and the tool enable scalable, hypothesis-driven tests of olfactory navigation of seabirds and provide a transferable framework for integrating high-resolution environmental context into movement ecology.

Surface ozone pollution over the Tibet, China: Characteristics, drivers, and source analysis.

The photoelectric conversion mechanism is the core foundation of photovoltaic devices, determining their ability to convert sunlight into electricity. For hydrothermally deposited Sb2(S,Se)3 solar cells, it is conventionally recognized that gradient-bandgap Sb2(S,Se)3 was thought to form a heterojunction with flat-bandgap CdS for carrier separation/transport. In this study, we uncover a previously unidentified photoelectric conversion mechanism. Annealing is shown to drive selenium diffusion into CdS, resulting in the formation of gradient bandgap Cd(S,Se). The Cd(S,Se) homojunction-based solar cell unexpectedly delivers a short-circuit current density of 1.43 mA cm-2. This reveals that the electron-hole separation is not exclusively occurred at the Sb2(S,Se)3/Cd(S,Se) interface, the Sb2(S,Se)3 and Cd(S,Se) form a "V"-shaped bandgap mixed absorber layer concurrently separates charge carriers with the remaining Cd(S,Se). Additionally, the Na2S4O6 additive significantly improves the heterojunction performance. These findings reshape the understanding of photoelectric conversion mechanism and guide band alignment design in the hydrothermally deposited Sb2(S,Se)3 solar cells.

A novel Subsea Winched Profiling System (SWIPS) was deployed in the Atlantic Water (AW) inflow to the Arctic Ocean north of Svalbard, providing high-resolution, year-round observations of upper ocean hydrography and biogeochemistry. Between July 2022 and July 2023, SWIPS collected 85 vertical profiles from ∼125 m to 10 m depth at 4-day intervals, capturing seasonal transitions and fine-scale variability across open water and ice-covered conditions. The autonomous system provides a sustained Eulerian perspective of upper ocean dynamics, resolving the evolving water mass distribution, seasonal stratification, the deepening of the mixed layer in autumn and winter, and the persistent influence of AW beneath a strongly stratified surface layer. SWIPS captured an under-ice phytoplankton bloom in May 2023, occurring under > 80% sea ice concentrations and preceding the onset of Polar Day by more than one week. During peak bloom periods, satellite-derived chlorophyll concentrations underestimated in-situ values by up to an order of magnitude due to persistent subsurface chlorophyll maxima and ice cover. The profiler also detected two episodes of anomalous winter hydrography during which AW reached the surface and disrupted the expected cold, stratified regime. The hydrographic data and satellite sea surface temperature suggest these events were driven by upstream AW advection from Fram Strait and facilitated localized convection to depths exceeding 100 m, reinforcing the role of remote forcing in shaping local upper ocean and ice conditions. By capturing both gradual seasonal evolution and short-lived anomalies, SWIPS provides critical in-situ observations that complement traditional observational methods and improve understanding of ocean–ice–ecosystem interactions under Arctic amplification.

The influence of dynamical ocean features on seabed-interacting acoustic transmissions was investigated southeast of Malta in the Mediterranean Sea. Waveforms at 610-890 Hz were transmitted to mimic impulse propagation over two fixed paths of 25 and 45 km length. Area conditions included topographically trapped diurnal waves, stochastic internal waves, a 60-m-thick surface mixed layer, and weak mesoscale flows. Many stable arrivals with transmission loss of 57 to 66 dB were observed on the short path. The matched-filter recovered impulse response showed a high degree of temporal coherence over the 5-d-long experiment. Travel times of tracked individual signal peaks showed root mean square variation of 3 ms. Much of this reported travel-time variability results from slowly fluctuating dominance between micromultipaths, rather than time variation of a single steady ray. Spectral analysis of the travel times provided weak evidence of a peak at the diurnal tidal frequency, with no reliable evidence of semidiurnal-band oscillations of arrival peak levels or times. Most rays interact with the seabed, and model simulations with different bottom attenuation coefficients support intuition that seabed properties determine a base-state transmission loss and impulse response in the area, only slightly modified by water column variations.

A DNS study of differential diffusion effects on the ignition of a turbulent NH <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si208.svg" display="inline" id="d1e1506"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> /H <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si260.svg" display="inline" id="d1e1514"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:math> /N <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si260.svg" display="inline" id="d1e1522"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:math> -air mixing layer

Impact of parameterized wind-driven boundary layer turbulence on the development and evolution of submesoscale mixed layer eddies in an idealized front

The reef manta ray (Mobula alfredi) is a highly mobile pelagic marine ray found throughout the tropical and subtropical waters of the Indo-Pacific, but investigation into their behavior and ecology within Papua New Guinea has not been previously undertaken. Furthermore, the home range, dispersal characteristics, and inter-seasonal fine-scale habitat use of this species is limited. To address these data gaps and investigate the vertical and horizontal habitat use of a previously unstudied population, SPLASH10-F-321A pop-off archival satellite tags were used to track ten adult individuals from 4–181 days between 2016–2018 across two distinct monsoonal periods in the Samarai Islands of Milne Bay, southeastern Papua New Guinea. Our findings indicate strong site-attached movement patterns for reef manta rays in this region, with 75% of relocations occurring within ten kilometers of the tagging site. While occasional movements beyond this range were observed, the maximum displacement distance was 86.9 km, and no consistent seasonal differences in horizontal displacement distance were detected. Tagged rays displayed a clear preference for the Samarai Islands and the Papuan Plateau across both monsoons, with shallow bathymetry and elevated chlorophyll-a values driving observed habitat preferences. We found evidence for shifts in vertical occupancy of the water column that corresponded with the mixed layer depth; dives were deeper when the mixed layer depth was shallow, suggesting that reef manta rays can exhibit behaviorally plastic responses to seasonal variations in oceanographic conditions. These findings provide the first insight into the movement ecology of this reef manta ray population that can be used to inform the development of economically valuable manta ray tourism practices and a sustainable management plan in the region.

Photochemistry can convert dissolved organic matter (DOM) to inorganics (mainly CO2) and "new" DOM, hence impacting aquatic carbon cycling. The apparent quantum yields (AQYs) of these photoprocesses usually decrease with increasing wavelength. This study reports exceptions to this paradigm and discusses the biogeochemical implications of this phenomenon. Specifically, we determined the broadband AQYs over ultraviolet-B (UVB), ultraviolet-A (UVA), and visible (VIS) radiations for photomineralization of dissolved organic carbon (DOC) and photobleaching of chromophoric and florescent DOM (CDOM, FDOM) in the freshwater, brackish water, and seawater samples from the Pearl River estuary. UVB-broadband AQYs of DOC photomineralization (AQYDOC) and of CDOM and humic-like FDOM photoleaching were considerably higher than their UVA and VIS counterparts for all three water samples. Surprisingly, the broadband AQYDOC over VIS was significantly higher than that over UVA for the brackish water and seawater samples, contrary to the above-mentioned paradigm. Moreover, exposure of all three water samples to VIS produced protein-like FDOM, while significant losses of this FDOM pool occurred in the presence of UV. Per depth-integrated contributions in the water column, UVB or UVA primarily controlled CDOM and FDOM photobleaching, while VIS dominated DOC photomineralization and protein-like FDOM formation. These results suggest photochemistry may cause CO2 and biolabile DOM accumulations in VIS-dominated sunlit waters below surface mixed layers, contributing to coastal ocean DOM biogeochemical cycling, acidification, and deoxygenation. This shall be a self-intensified process since UV-driven CDOM photobleaching in surface layers reinforces and extends further deeper the VIS-induced subsurface CO2 and biolabile DOM photoproduction.

Glassy carbon (GC) and lignite coal powder surfaces are functionalized-either electrochemically or chemically-with alkylammonium groups. The modified coal powder is then embedded within cellulose acetate asymmetric membranes. The surface functionalization process involves the reduction of 2,6-dimethylbenzene diazonium salt (2,6-DMBD), which generates the 2,6-dimethylphenyl radical. Owing to steric hindrance, this radical does not react directly with the surface; instead, it undergoes a radical crossover reaction with brominated alkylammonium salts, generating alkylammonium radicals that subsequently graft onto GC and coal surfaces. In contrast, the reduction of 4-nitro- and 3,5-dicarboxybenzenediazonium salts produces aryl radicals that bind directly to the coal surface while simultaneously generating alkylammonium radicals. This dual mechanism enables the formation of mixed alkylammonium-aryl layers. On GC, the modification yields a surface layer of alkylammonium groups, as confirmed by cyclic voltammetry using redox probes and by X-ray photoelectron spectroscopy (XPS), particularly through the N 1s signal, which attests to the presence of alkylammonium groups. When coal modified with alkylammonium ions-either alone or in combination with aryl groups-is incorporated into heterogeneous asymmetric membranes, the resulting membranes exhibit enhanced productivity, product flux, and solute separation compared to both unmodified membranes and those modified without ammonium groups.

The precise engineering of surface-bound organic layers remains a central challenge in materials chemistry, particularly for the construction of mixed monolayers with tunable composition. While the electroreduction of diazonium salts produces robust, covalently anchored films, its inherent limitations (poor control over surface coverage and the lack of dynamic molecular exchange) frequently result in uncontrolled multilayer growth, complicating compositional tuning. In this study, we demonstrate that rational molecular design, specifically the incorporation of extended alkyl spacers, overcomes these limitations by enabling controlled coimmobilization of functional and diluent species and by promoting confinement of film growth to the monolayer regime. Using TEMPO as a model redox-active motif, we compare mixed layers derived from diazonium precursors with and without C12 spacers. Electrochemical characterization reveals that the presence of extended linkers suppresses overgrowth and enables predictable tuning of redox unit surface density through adjustment of the functionalization solution composition while influencing the interfacial arrangement of the grafted species. These results establish clear design principles for the controlled assembly of multifunctional organic interfaces and provide new insight into structure-reactivity relationships in diazonium-based surface modification.