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This study investigates the impact of the salinity barrier layer (BL) on the upper ocean response to Super Typhoon Mangkhut (2018) in the western North Pacific. After the passage of Mangkhut, a noticeable increase (∼0.6 psu) in sea surface salinity and a weak decrease (< 1°C) in sea surface temperature (SST) were observed on the right side of the typhoon track. Mangkhut-induced SST change can be divided into the three stages, corresponding to the variations in BL thickness and SST before, during, and after the passage of Mangkhut. During the pre-typhoon stage, SST slightly warmed due to the entrainment of BL warm water, which suppressed the cooling induced by surface heat fluxes and horizontal advection. During the forced stage, SST cooling was controlled by entrainment, and the preexisting BL reduced the total cooling by 0.89°C d−1, thus significantly weakening the overall SST cooling induced by Mangkhut. During the relaxation stage, the SST cooling was primarily caused by the entrainment. Our results indicate that a preexisting BL can limit typhoon-induced SST cooling by suppressing the entrainment of cold thermocline water, which contributed to Mangkhut becoming the strongest typhoon in 2018. [ABSTRACT FROM AUTHOR]

Strong salinity stratification induced by large freshwater fluxes in the northern Bay of Bengal (BOB) results in the formation of a quasi-permanent barrier layer (BL) that covers almost the entire BOB and leads to a unique temperature inversion within the thick BL in winter. In the presence of temperature inversions, the entrainment process at the bottom of the mixed layer (ML) induces warming effects in the ML, but little is known about this. In this paper, we quantify the contribution of the entrainment process to the ML temperature (MLT) in the northern BOB during the winter of 2013 using monthly and daily data from the Ocean General Circulation Model for the Earth Simulator version 2 (OFES2). It is found that the warming effect of the daily entrainment heat flux (EHF), which resolved the high-frequency variations, is 4 orders of magnitude larger than the monthly EHF for most of the wintertime. This significantly enhanced warming effect in daily data offsets up to 87% of the surface cooling induced by net heat flux during wintertime. A further analysis reveals that the larger daily EHF warming effect compared to its monthly counterpart is closely related to the deepened ML, the larger temperature difference within the ML and vertical velocity at the bottom of the ML. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the impact of the ocean barrier layer (BL) on regional ocean dynamics requires the knowledge of BL variability and the factors influencing it. Herein, using SODA reanalysis data sets, we systematically investigate the seasonal variations and formation mechanisms of BLs in the North Indian Ocean (NIO). Our results show that BLs are mainly found in the southeastern Arabian Sea (SEAS), Bay of Bengal (BoB), and the Eastern Equatorial Indian Ocean (EEIO), with the thickest BLs occurring in SEAS and BoB in January, and in EEIO in November. Seasonal BL variability is primarily driven by isothermal layer (IL) modulation. Further budget analysis reveals that the factors affecting seasonality of BL variability through modulating IL differ across the three regions. In the SEAS, BL variability is primarily modulated by ocean vertical processes, notably oceanic planetary waves and Ekman pumping. In the BoB, vertical dynamics, including Ekman pumping and oceanic planetary waves, are the primary determinant of BL variability, while horizontal advection affects the spatial extent of BL. In the EEIO, equatorial upwelling and oceanic planetary waves significantly affect BL variability. These results contribute to a better understanding of regional ocean dynamics and may improve the accuracy of ocean state estimates and representation of BL processes using ocean model simulations. Plain Language Summary: In the upper ocean, the barrier layer (BL) that occurs when the temperature mixing layer (isothermal layer, IL) and the salinity mixing layer (ML) are not coincident, which plays a crucial role in the regional ocean dynamics by modulating ocean surface temperature. This study focuses on understanding the BL in the North Indian Ocean and utilized SODA reanalysis to investigate how the BL changes with the seasons and what causes these changes. Our findings show that the BL is thickest during the winter months—January in the southeastern Arabian Sea (SEAS) and Bay of Bengal (BoB), and November in the Eastern Equatorial Indian Ocean (EEIO). We discovered that the mechanisms by which these regions affect BL changes through the modulation of IL are different. In the SEAS, the BL changes are mostly related to vertical process. In the BoB, ocean vertical processes like Ekman pumping and oceanic planetary waves play a dominant role in BL variability, while horizontal advection serves as a secondary factor. In the EEIO, the BL changes are closely linked to tropical upwelling, with only a weak correlation to horizontal advection. Key Points: The relative contribution of mixed layer and isothermal layer to the barrier layer in the North Indian Ocean is estimatedBarrier layers thickness changes are more closely correlated with isothermal layer depth variations in the North Indian OceanVertical process induced isothermal layer depth variations is the dominant driver for barrier layer thickness variations [ABSTRACT FROM AUTHOR]

Previous studies have confirmed the diverse spatiotemporal characteristics of Atlantic Niño events. Our research further reveals the crucial preparatory role of equatorial western Atlantic barrier layers (BL) and the triggering effect of westerly wind bursts (WWB) on different varieties of Atlantic Niño. Strong easterly winds typically facilitate the formation of thick BL by deepening isothermal layer depth in the western Atlantic through horizontal transport. The existence of BL accumulates the necessary heat for the onset of Atlantic Niño. Additionally, the timing of BL occurrences, the presence of easterly wind anomalies preceding WWB, and the duration of westerly wind anomalies jointly contribute to Atlantic Niño diversity. Persistent westerly wind anomalies following strong easterly winds often lead to Atlantic Niño events lasting over 6 months, while short‐lived events occur when westerly wind anomalies cease shortly after their onset. Plain Language Summary: The tropical Atlantic Ocean experiences significant year‐to‐year climate variability known as Atlantic Niño or Niña, similar to the warm and cold phases of El Niño–Southern Oscillation (ENSO) in the Pacific. Atlantic Niño has a considerable impact on local rainfall and cyclone activity. However, each instance of Atlantic Niño has unique spatiotemporal development characteristics, which can be classified into four varieties. While previous research has demonstrated that distinct preconditions give rise to different varieties of Atlantic Niño events, there hasn't been any investigation into the common factors among them. The salinity stratified isothermal layer between the base of the mixed layer and the top of the thermocline is referred to as the barrier layer (BL), which is a common feature of tropical western Pacific and Atlantic. The BL in the tropical western Pacific has been confirmed to facilitate the accumulation of heat in the upper ocean and can provide favorable thermal conditions for the onset of El Niño events. Our study reveals the key role of BL induced heat accumulation in various Atlantic Niño onsets. This suggests that anomalies of BL can be reliable indicators for predicting the onset of Atlantic Niño events. Key Points: The role of barrier layers in heat buildup is confirmed during the development of the four varieties of Atlantic NiñoThe heat buildup caused by barrier layers, combined with zonal wind events, regulates the diversity of Atlantic NiñoThe sustainability of westerly wind anomalies links to the strength of Atlantic Niño events [ABSTRACT FROM AUTHOR]

The Banda Sea is of crucial importance for the circulation of the world's oceans, as it is part of the connection between the Pacific to the Indian Ocean. One peculiarity of the upper ocean hydrography in the Banda Sea is the occurrence of barrier layers. The regionality and temporal variability of barrier layer thickness (BLT) in the Banda Sea are examined in this study utilizing in‐situ observations and ocean reanalysis output. It is found that a barrier layer occurs in over 90 % of the observational data profiles, and in over 72 % of those profiles, the BLT is shallower than 10 m. Furthermore, we find a seasonal cycle in BLT with a maximum thickness of about 60 m occurring during austral autumn and winter and coinciding with the presence of low saline waters fed by the regional river discharge and rainfall from the Java Sea and Makassar Strait. In addition, we identify the existence of a quasi‐permanent anticyclonic circulation cell in the Banda Sea that may support the trapping of surface freshwater by retention. The anticyclonic circulation is most likely wind‐driven because it coincides with the regional Ekman pumping pattern. Modulation of the anticyclone is via seasonal variability in the wind stress curl which in turn may explain the efficiency of freshwater retention and thus the BLT. The annual mean BLT distribution in the Banda Sea shows a preferential region of thickened barrier layers around 6o‐8oS and 124o‐126oE and resampling the pattern of the monthly mean climatology. Plain Language Summary: The Banda Sea is crucial to the circulation of the world's oceans and atmosphere due to its location within the equatorial regions of the Indonesian Maritime Continent. It links the Pacific and Indian Oceans' circulation via the Indonesian Throughflow and contributes to driving atmospheric conditions via heat and moisture fluxes. Strong salinity‐stratified barrier layers insulate the water exchange between the surface and subsurface. The formation and seasonal variation of barrier layer thickness (BLT) in the Banda Sea are analyzed based on all available observations and ocean reanalysis outputs. Observations show that the Banda Sea has a barrier layer for the most part of the season. The BLT maximum appears during austral winter (June to August) months. The seasonal BLT maximum is attributed to the near‐surface water freshening, which shoals the mixed layer depth (MLD) and deep isothermal layer depth (ILD) maintained by a steady anticyclonic gyre. Other processes, such as wind stress curl‐induced Ekman pumping associated convergence, also modulate its seasonal variability. Key Points: First study estimating barrier layer thickness (BLT) in the Banda Sea using comprehensive observationsA quasi‐permanent barrier layer exists in the Banda Sea with seasonal variation in occurrence and thicknessThe intrusion of low saline waters and anticyclonic circulation are identified as the main mechanisms for creating and modulating the local BLT [ABSTRACT FROM AUTHOR]

The present study investigates the mixed layer variations near mesoscale eddies in the Bay of Bengal (BoB) using satellite altimeter and Argo data. Furthermore, the factors responsible for sea surface variations near mesoscale eddies are analyzed using the mixed layer heat and salinity budgets estimated from Argo profiles. In the diagnostic mixed layer heat budget analysis, the entrainment term is parametrized based on the presence and absence of the barrier layer. The role of inversion and barrier layers on eddy-induced temperature variations is also examined near eddy locations. Results showed that anti-cyclonic eddies deepen mixed layer depth (MLD) and barrier layer thickness (BLT). Whereas, near cyclonic eddies shallower MLD and BLT is evident. However, MLD and BLT variations near mesoscale eddies are prominent during monsoon and winter seasons, respectively. Heat budget analysis near eddy locations depicts that surface heat fluxes and vertical entrainment are the primary factors responsible for temperature variations near mesoscale eddies. Similarly, the salinity budget analysis near eddy locations reveals that horizontal advection (stirring effect) is the predominant processes responsible for the salinity variations. The outcome of the present study is believed to be useful in validating and improving the eddy-resolving ocean models. [ABSTRACT FROM AUTHOR]

Silicon-on-insulator devices are widely utilized in high-performance and high-reliability fields, facing challenges from self-heating effects (SHEs). However, research on the heat dissipation path closely related to SHEs remains incomplete. This paper initiates an in-depth analysis of thermal effects involving the fine structures within the heat dissipation path, using ultrafast pulse I–V measurements combined with thermal simulations. It is found in practical processes that the SHEs of scaled-down devices decreased by 40% rather than increased. Research shows the improvement is attributed to the reduction in the thickness of the buried oxide layer between different generations of processes, and the decrease in thermal sensitivity. Based on the two-stage SHE mechanism, the study clarifies for the first time that the box layer mainly affects first-stage heat dissipation, and the main timescale of impact is about the first 100 ns. In addition, the heat dissipation contact capability can effectively affect the temperature rise of first-stage SHEs. For the first time, we reveal that the TiN barrier layer with low thermal conductivity is the key factor limiting heat dissipation through contact. This study represents the crucial step toward a comprehensive investigation of SHEs, offering substantial support for device modeling. [ABSTRACT FROM AUTHOR]

In order to improve the stability of Bi2Te3-based thermoelectric devices, we attempted to prepare a barrier layer via diffusion welding using Co powder as the barrier materials. The diffusion welding process was conducted at 674 K for a duration of 5 min. The optimal connection was achieved at the interfaces of Co/Bi0.4Sb1.6Te3 and Co/Bi2Te2.7Se0.3. The results showed that the Co/Bi0.4Sb1.6Te3 joint had diffusion thickness of 1.6 µm, contact resistivity of 0.83 µΩ cm2, and bonding strength of 4.86 MPa for the barrier layer. Similarly, the Co/Bi2Te2.7Se0.3 joint had diffusion thickness of 1.6 µm, contact resistivity of 0.75 µΩ cm2, and bonding strength of 3.99 MPa for the barrier layer. The thermoelectric device fabricated through this process exhibited a hot–cold cycle number of 35,000, which was significantly higher than the device with a Ni-based barrier layer under similar experimental conditions. Thus, it indicates that Co is a promising material for the preparation of barrier layers in Bi2Te3-based thermoelectric devices. [ABSTRACT FROM AUTHOR]

In the hydrogen separation membrane, a dense TaTiNbZr amorphous layer was prepared between Pd and Ta to form a Pd/TaTiNbZr/Ta membrane system to prevent the reaction between Pd and Ta at high temperatures. The structural and chemical stability of the Pd/TaTiNbZr/Ta film system at high temperatures were investigated by annealing at 600 °C for 24 h. The high-temperature hydrogen permeation properties of the Pd/TaTiNbZr/Ta film systems were investigated by hydrogen permeation experiments at 600 °C after heat treatment for 6 h. The TaTiNbZr layer was significantly hydrogen-permeable. With the increase in the thickness of the barrier layer, the hydrogen permeability of Pd/TaTiNbZr/Ta decreased, but its hydrogen permeation flux was smaller than that of the highest value of Pd/Ta when it reached the steady state. The presence of the TaTiNbZr layer effectively blocks the interdiffusion between Pd and Ta to form TaPd3, improving the sustained working ability of the Pd/TaTiNbZr/Ta membrane system. The results show that TaTiNbZr is a candidate material for the intermediate layer to improve the high-temperature stability of metal-composite hydrogen separation membranes. [ABSTRACT FROM AUTHOR]

Abstract Previous studies have confirmed the diverse spatiotemporal characteristics of Atlantic Niño events. Our research further reveals the crucial preparatory role of equatorial western Atlantic barrier layers (BL) and the triggering effect of westerly wind bursts (WWB) on different varieties of Atlantic Niño. Strong easterly winds typically facilitate the formation of thick BL by deepening isothermal layer depth in the western Atlantic through horizontal transport. The existence of BL accumulates the necessary heat for the onset of Atlantic Niño. Additionally, the timing of BL occurrences, the presence of easterly wind anomalies preceding WWB, and the duration of westerly wind anomalies jointly contribute to Atlantic Niño diversity. Persistent westerly wind anomalies following strong easterly winds often lead to Atlantic Niño events lasting over 6 months, while short‐lived events occur when westerly wind anomalies cease shortly after their onset.

Carbon fibre reinforced polymer (CFRP) laminates are used in various studies as Li-ion polymer (LiPo) battery packaging. However, their suitability as a packaging material is not well understood. The present study investigates the liquid absorption (water and lithium bis(trifluoromethanesulfonic)imide (LiTFSI) electrolyte immersion tests) and barrier layer properties (water vapour transmission rate (WVTR) and oxygen transmission rate (OTR) tests) of a 200 gsm woven CFRP laminate to assess its suitability as a battery packaging material. This is the first study to show that prolonged immersion in battery electrolyte does not change the mechanical properties of a woven CFRP laminate. Hence, the CFRP laminate may be suitable for structural battery components, such as current collectors and electrodes. However, CFRP should not be used as battery packaging, as OTR and WVTR values of the CFRP laminate were found to be five and one order of magnitudes higher than typical battery pouch materials (i.e. aluminium foil), respectively.

Strong salinity stratification induced by large freshwater fluxes in the northern Bay of Bengal (BOB) results in the formation of a quasi-permanent barrier layer (BL) that covers almost the entire BOB and leads to a unique temperature inversion within the thick BL in winter. In the presence of temperature inversions, the entrainment process at the bottom of the mixed layer (ML) induces warming effects in the ML, but little is known about this. In this paper, we quantify the contribution of the entrainment process to the ML temperature (MLT) in the northern BOB during the winter of 2013 using monthly and daily data from the Ocean General Circulation Model for the Earth Simulator version 2 (OFES2). It is found that the warming effect of the daily entrainment heat flux (EHF), which resolved the high-frequency variations, is 4 orders of magnitude larger than the monthly EHF for most of the wintertime. This significantly enhanced warming effect in daily data offsets up to 87% of the surface cooling induced by net heat flux during wintertime. A further analysis reveals that the larger daily EHF warming effect compared to its monthly counterpart is closely related to the deepened ML, the larger temperature difference within the ML and vertical velocity at the bottom of the ML.

The intra-molecular coupling within multiple units of paramagnetic molecules can produce various effects on molecular spintronics devices (MSD). This paper focuses on double-segmented molecules as the device element to advance understanding of the Impact of internal molecular structure on magnetic tunnel junction-based MSD (MTJMSD). We performed Monte Carlo simulations (MCS) to fill the knowledge gap about the intramolecular coupling role in the magnetic properties of the MTJMSD. This study explored a double-segmented molecule containing two atomic sections, each with a net spin state interacting via Heisenberg exchange coupling within molecules and with ferromagnetic electrodes at different thermal energies, magnetic fields, and coupling strengths. This study also investigated the effect of magnetic field on the double-segmented molecule-based cross-junction-shaped MTJMSD. We also compared the effect of the magnetic field on the mono and double-segmented molecules when connected to two ferromagnetic electrodes. In the strong coupling regime, the intramolecular coupling and molecule coupling with the two ferromagnetic electrodes dominated the MTJMSD response near the molecular junction area. This study provides insight for evaluating the Impact of molecular nanostructure internal connectedness on the integrated MSD. [ABSTRACT FROM AUTHOR]

The barrier layer (BL) significantly impacts the upper ocean circulation and thermodynamic structure by inhibiting the heat and momentum exchange between the mixed layer (ML) and the subsurface layer. There exist sea surface temperature and salinity dipole modes in the tropical Indian Ocean, however, a BL dipole mode has not yet been identified. Using the latest observations and ocean reanalysis, here we show a robust BL dipole mode in the central and eastern equatorial Indian Ocean, which is highly correlated with the Indian Ocean Dipole (IOD) events. Composite analysis shows that the BL thickness anomalies peak in autumn and are much larger during positive IOD events than during negative IOD events. We show that a positive BL dipole phase is characterized by positive BL thickness anomalies in the central equatorial Indian Ocean and negative BL thickness anomalies in the eastern equatorial Indian Ocean, and vice versa for a negative BL dipole phase. During positive IOD events, negative surface salinity anomalies slightly affect the ML depth along the equatorial Indian Ocean. Positive subsurface temperature anomalies deepen the isothermal layer (IL) in the central equatorial Indian Ocean and strong negative subsurface temperature anomalies significantly lift the IL in the eastern equatorial Indian Ocean, controlling the BL thickness anomalies and forming a positive BL dipole pattern. This operates in an opposite direction during negative IOD events. Our study shows a close relationship between the BL dipole and the IOD and has far‐reaching implications for better understanding and predicting the IOD events. Plain Language Summary: The ocean barrier layer (BL) is an intermediate layer of water between the base of the ML and the base of the isothermal layer (IL). The BL acts as a "barrier" to entrainment cooling and vertical mixing between the surface ML and subsurface layer. In the tropical Indian Ocean, whether there is a BL dipole mode co‐existing with the Indian Ocean Dipole (IOD) is still unknown. This study identified a BL dipole mode in the central and eastern equatorial Indian Ocean. During the IOD events, the anomalous zonal currents cause surface salinity anomalies and further impact the ML depth along the equatorial Indian Ocean. Subsurface temperature anomalies associated with equatorial waves and anomalous currents significantly change the IL depth in the central and eastern equatorial Indian Ocean. We show that temperature and salinity anomalies can induce a BL dipole, which is highly correlated and co‐varies with the IOD. This BL can potentially enhance the positive feedback of the IOD by changing the ocean circulation and thermodynamic structure in the upper ocean. This study will be beneficial to better understand the evolution of the IOD. Key Points: A barrier layer (BL) dipole is identified in the central equatorial Indian Ocean and eastern equatorial Indian OceanThe BL dipole is highly correlated and co‐occurs with the Indian Ocean Dipole event, which peaks in autumnThe isothermal layer depth dominates the evolution of the BL thickness along the equatorial Indian Ocean [ABSTRACT FROM AUTHOR]

Benguela Niño events are characterized by strong warm sea surface temperature (SST) anomalies off the Angolan and Namibian coasts. In 1995, the strongest event in the satellite era took place, impacting fish availability in both Angolan and Namibian waters. In this study, we use direct observations, satellite data, and reanalysis products to investigate the impact that the up‐until‐now unnoticed mechanism of freshwater input from Congo River discharge (CRD) and precipitation had on the evolution of the 1995 Benguela Niño. In the onset phase of the event, anomalous rainfall in November/December 1994 at around 6°S, combined with a high CRD, generated a low salinity plume. The plume was advected into the Angola‐Namibia region in the following February/March 1995 by an anomalously strong poleward surface current generated by the relaxation of the southerly winds and shifts in the coastal wind stress curl. The presence of this low surface salinity anomaly of about −2 psu increased ocean stability by generating barrier layers, thereby reducing the turbulent heat loss, since turbulent mixing acted on a weak vertical temperature gradient. A mixed layer heat budget analysis demonstrates that southward advection of Angolan waters drove the warming at the onset, while reduced mixing played the main role at the event's peak. We conclude that a freshwater input contributed to the SST increase in this exceptionally strong event and suggest that this input can influence the SST variability in Angola‐Namibia waters through a combination of high CRD, precipitation, and the presence of a strong poleward surface current. Plain Language Summary: Benguela Niño events are characterized by excessive warming of the sea surface temperature off the Angolan and Namibian coasts. One of the strongest‐ever recorded warm events dates back to 1995, impacting fish availability in both Angolan and Namibian waters. In our research, we investigate if freshwater from rain and from the Congo River could have impacted the evolution of this 1995 Benguela Niño. In the event's early stage, high precipitation and river discharge generated a low salinity pool at the Congo River mouth, which in February/March 1995 was taken to the south by an exceptionally strong surface current, generated by changes in wind strength and direction at the African coast. This low sea surface salinity in a shallow layer in the upper meters of the ocean increased the ocean's stability. As the stabilized waters diminished the usual mixing from the depths below which cools down the surface waters, it contributed to an increase in warming in the surface layer of the ocean. We conclude that the warming of the surface waters in the region was indeed influenced by the combination of high precipitation and high Congo River discharge with a strong surface current toward the south. Key Points: Freshwater input has significantly contributed to the surface warming at the peak of the 1995 Benguela NiñoAnomalously high river discharge and precipitation increased stratification and reduced turbulent heat loss by creating barrier layersCombination of high freshwater input and strong poleward surface current might play a role in temperature variability off Angola [ABSTRACT FROM AUTHOR]

The conditions for the synthesis of mullite-corundum ceramic prepared on the basis of Al2O3 and SiO2 powders were investigated. The composition of mullite-corundum ceramic with Al2O3 < 80 wt.%, which affords the best thermomechanical compatibility with molybdenum, was determined. The possibility of obtaining a composite material based on a mullite-corundum matrix and molybdenum, as well as its use as a barrier layer at the Mo–Si-containing ceramic interface, was confirmed. It was ascertained that the use of a barrier layer substantially reduces the likelihood of thermal stresses arising at the interface between two phases. It is demonstrated that the technological parameters of the process of preparing Al2O3–SiO2 powder mixtures require elaboration in order to increase the thermochemical compatibility of molybdenum with mullite-corundum ceramic. [ABSTRACT FROM AUTHOR]

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The southeastern Indian Ocean is characterized by the warm barrier layer (BL) underlying the cool mixed layer water in austral winter. This phenomenon lasts almost half a year and thus provides a unique positive effect on the upper mixed layer heat content through the entrainment processes at the base of the mixed layer, which has not been well evaluated due to the lack of proper method and dataset. Among various traditional threshold methods, here it is shown that the 5 m fixed depth difference can produce a reliable and accurate estimate of the entrainment heat flux (EHF) in this BL region. The comparison between the daily and monthly EHF warming indicates that the account for high-frequency EHF variability almost doubles the warming effect in the BL period, which can compensate for or even surpass the surface heat loss. This increased warming is a result of stronger relative rate of the mixed layer deepening and larger temperature differences between the mixed layer and its immediate below in the daily-resolving data. The interannual EHF shows a moderately increasing trend and similar variabilities to the Southern Annular Mode (SAM), likely because the mixed layer deepening under the positive SAM trend is accompanied by enhanced turbulent entrainment and thus increases the BL warming. [ABSTRACT FROM AUTHOR]

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The demand for ultra-tight encapsulation solutions with excellent barrier and high conformality properties has increased in recent years. To meet these challenges, thin-film barrier coatings have emerged as a promising solution. In this study, we investigate well-established silicon-based plasma-enhanced chemical vapor deposition (PECVD) and metal oxide atomic layer deposition (ALD) barrier coatings deposited at low temperatures (≤100 °C) regarding their abilities to address high-level 3D encapsulation applications. Various combinations of such layers are evaluated by measuring the water vapor transmission rate (WVTR) and considering the conformality properties. The impact and the benefits of the organic film integration, namely parylene VT4 grade, on the barrier performances is assessed. Among these combinations, parylene-AlOx stack emerges as one of the most effective solutions, obtaining a WVTR of 3.1 × 10−4 g m−2 day−1 at 38 °C and 90% relative humidity conditions. [ABSTRACT FROM AUTHOR]

Graphene nanomaterials improve electrical and thermal conductivity in coatings and enhance barrier properties against diffusive molecular species. Using a two-step process, a superhydrophobic coating with highly effective anti-corrosion properties was obtained using a thiol-ene UV curable thermosetting resin incorporating silica nanoparticles (Si-NP) and graphene oxide (GO). The Si-NP offers a dual-scale roughness structure which leads to superhydrophobicity based on the Cassie-Baxter wetting principle. The GO is a barrier layer for diffusion, dramatically enhancing corrosion resistance efficiency. It also mediates the electron-transfer process between the corrodent environment and the carbon steel substrate. A superhydrophobic property with a highly crosslinked structure offers excellent chemical resistance and adhesion strength promising high environmental durability as coatings. [ABSTRACT FROM AUTHOR]

The effect of the electrolyte composition for hard anodizing of aluminum on the corrosion resistance of the synthesized anodic coatings was studied. The hard anodizing was carried out at temperatures of –4–0°C for 60 min at a current density of 5 A/ dm2. The basic electrolyte was a 20% aqueous solution of H2SO4. Hydrogen peroxide (H2O2) was added to the electrolyte in concentrations of 30; 50; 70 and 100 g/L to determine strong oxidants influence on the characteristics of the anode layers. The concentration of 70 g/L H2O2 in the electrolyte, which ensures the synthesis of the thickest and least porous coating, was optimal. At the initial moment of immersion of anodic coatings synthesized in hydrogen peroxide electrolyte, their corrosion resistance decreases. When peroxide electrolyte concentration increases from 30 to 100 g/L, corrosion currents increase by 30 and 90%, respectively. However, with increasing exposure of coatings in the environment, their corrosion current density decreases more intensively with a decrease in their porosity. After 14 days, no dependence of the coatings corrosion durability on the composition of the electrolyte observed, what indicated a complete closure of the pores. [ABSTRACT FROM AUTHOR]

We report the color conversion performance of amber and red emitting quantum dots (QDs) on InGaN solid-state lighting (SSL) light emitting diode (LED) packages. Spherical quantum well (SQW) architectures (CdS/CdSe1-xSx/CdS) were prepared using a library of thio- and selenourea synthesis reagents and high throughput synthesis robotics. CdS/CdSe1-xSx QDs with narrow luminescence bands were coated with thick CdS shells (thickness = 1.6-7.5 nm) to achieve photoluminescence quantum yields (PLQY) up to 88% at amber and red emission wavelengths (λmax = 600-642 nm, FWHM < 45 nm). The photoluminescence from SQWs encapsulated in silicone and deposited on LED packages was monitored under accelerated aging conditions (oven temperature = 85 °C, relative humidity = 5-85%, blue optical power density = 3-45 W/cm2) by monitoring the red photon output over several hundred hours of continuous operation. The growth of a ZnS shell on the SQW surface increases the stability under long-term operation but also reduces the PLQY, especially of SQWs with thick CdS shells. The results illustrate that the outer ZnS shell layer is key to optimizing the PLQY and the long-term stability of QDs during operation on SSL packages.

SiC, as a representative of the third generation semiconductors, is widely investigated in power devices and sensors. However, ohmic contacts, an important component for signal output of various SiC chips, have always faced challenges with unclear formation mechanism and difficulty to withstand high temperature. To solve such problems, two sets of NPN-type SiC ohmic contact were prepared, including Ti/TaSi2/Pt and Ni/W. Experimental results show that whether ohmic contact can be formed mainly depends on the contact metal. The alloy phase with lower work function is formed after high temperature annealing, which reduces the height and width of the Schottky barrier. For the prepared SiC ohmic contacts, It was demonstrated that the invasion of oxygen atoms cause contacts failure, and incorporation of barrier layer (Ta-based layer) and effective protective layer (Pt layer) determine whether high temperatures can be tolerated. Finally, piezoresistive 4H–SiC pressure sensor chips with dimensions of 3000 μm × 3000 μm × 200 μm were fabricated using the obtained ohmic contacts. Sensor chips output resistance were monitored up to 600 °C in air to show stability of the ohmic contact. The highly stable and high temperature ohmic contact can be applied in a variety of SiC devices.

This work investigates the impact of barrier layer thickness on DC and RF performance of a GaN HEMT device, targeting the low noise high gain application. An optimisation workflow based on the barrier layer thickness and Al mole fraction is presented for improving the RF metrics of a GaN HEMT. AlGaN/GaN HEMTs with a gate length of 400 nm were fabricated with 22% Al content and a barrier layer thickness of 23 and 20 nm, respectively. TCAD simulation studies were carried out for different barrier thickness and Al mole fraction in accordance with the fabricated devices. Increasing the barrier thickness increases the 2-DEG density which increases the maximum drain current and results in a negative shift in the threshold voltage. With a thin barrier layer, the AlGaN/GaN HEMTs exhibit a higher transconductance due to improved gate action. The fabricated devices were investigated with the help of small-signal equivalent circuit, which demonstrate higher capacitances associated with a thin barrier layer. Apart from DC characteristics and small-signal performance, the intrinsic gain (gm/gd ratio), noise performance, and large-signal performance of the device has been investigated which provides a great contribution in creating a design subspace for a specific application (depending on the performance requirement). A thin barrier layer improves the intrinsic gain of the GaN HEMT device by 74% due to a higher transconductance and comparatively lower output conductance values. An increase in Al mole fraction increases the transconductance but is dominated by an increase in the output conductance, which in turn reduces the intrinsic gain of the device. An in-depth analysis is presented by investigating and optimising the trade-offs with barrier layer thickness and Al mole fraction towards the noise performance of the devices at microwave C- and X-band. [ABSTRACT FROM AUTHOR]

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The thickness of interconnect line (THK) in copper interconnect trench plays a crucial role in the performance of integrated circuit, making it an important evaluation parameter in IC manufacturing process. FA/O II as copper chelating agent, potassium citrate (CAK) as accelerator, and 1,2-benzisothiazolin-3-one (BIT) as bacteriostatic agent were added to an oxidant- and corrosion inhibitor-free alkaline slurry for chemical mechanical polishing (CMP) of the barrier layer of copper interconnect, and the effects of their mass fractions in the slurry on the removal rates of Cu and TEOS (tetraethyl orthosilicate) and THK were studied. The results showed that the removal rate ratio of TEOS to Cu influences the THK, and the THK is negatively correlated with the resistance of barrier layer. The removal rate ratio of TEOS to Cu was about 1.7 when the mass fractions of FA/O II, CAK, and BIT in the slurry were 0.8%, 1%, and 0.04%, respectively, the THK was 225 nm, and the resistance of barrier layer was 0.18 Ω, meeting the requirements of industrial production. [ABSTRACT FROM AUTHOR]

In this study, the formation of thin-film barrier coatings based on a highly conductive Bi1.60Er0.4O3 (EDB) solid electrolyte on supporting Ce0.8Sm0.2O1.9 (SDC) electrolyte substrates was implemented for the first time using electrophoretic deposition (EPD). The electrokinetic properties of EDB-based suspensions in a non-aqueous dispersion medium of isopropanol modified with small additions of polyethyleneimine (PEI, 0.26 g/L) and acetylacetone (0.15 g/L), as well as in a mixed isopropanol/acetylacetone (70/30 vol.%) medium, were studied. The dependences of the thickness of the EDB coatings on voltage and deposition time were obtained using deposition on a model Ni foil electrode. Preliminary synthesis of a conductive polypyrrole (PPy) polymer film was used to create surface conductivity on non-conductive SDC substrates. The efficiency of using a modified dispersion medium based on isopropanol to obtain a continuous EDB coating 12 μm thick, sintered at a temperature of 850 °C for 5 h, is shown. The microstructure and morphology of the surface of the EDB coating were studied. A Pt/SDC/EDB/Pt cell was used to characterize the coating's conductivity. The EPD method is shown to be promising for the formation of barrier coatings based on doped bismuth oxide. The developed method can be used for creating cathode barrier layers in SOFC technology. [ABSTRACT FROM AUTHOR]

Abstract For the first time, the processes controlling the variations of mixed layer temperature (MLT) and salinity (MLS) in the Banda Sea are quantified using data from a single Argo float in combination with satellite and reanalysis outputs from August 2017 to August 2019. This augments previous studies that utilized ocean model data only. We document the presence of a barrier layer and quantify the roles of air-sea heat and mass exchanges, horizontal advection, and vertical entrainment in the seasonal variability of MLT and MLS. We find that heat gains and losses at the air-sea interface are the main contributor to the warming and cooling of the MLT. Seasonal changes in MLS are driven by advection of low salinity water rather than freshwater fluxes from precipitation and evaporation. This is particularly the case during the late northwest and monsoon transition period from February to April when low salinity is advected eastward from the Java Sea into the Banda Sea.

It's a critical issue for the successful commercialization of solid oxide fuel cells (SOFCs) to achieve long-term operation and thermal cycling stability without significant degradation. Current work reports an almost-dense, sintering-active and Sr-blocking cathode/electrolyte interface, fabricated through a cost-competitive and scalable method of modifying porous Gadolinia doped Ceria (GDC) barrier layer by in-situ grown GDC nanoparticles. Result show that the robust interface enables improved durability and thermal cycling stability. The hydrothermal modified anode supported cell performance only deteriorates by ∼0.5% after 20 times thermal cycles between 200 and 750 °C, which is more prominent enhancement than ∼16% for pristine cell. The modified symmetric cell shows smaller cathode polarization resistance and well-attached cathode/electrolyte interfaces after ∼1200 h of operation, including 4 times thermal cycles. While the pristine cell shows more obvious area specific resistances increases and the peeled-off cathode layer. It is discussed and concluded that the hydrothermal modified sintering-active barrier layer has contributed mainly to the construction of robust cathode/electrolyte interface, yielding the improved performance and prolonged operation. • Enhanced cathode/electrolyte interfaces construction by modified barrier layer. • Prominently improved durability with no cathode delamination nor Sr migration. • Stable operation over 1000 h and 20 thermal cycles with minimal degradations. [ABSTRACT FROM AUTHOR]

The object of this study is structural formation during the surfacing of steel (iron) on titanium with plasma-sprayed coatings to obtain a butt connection of titanium-steel bimetallic plates. The task to be solved was to devise a technology for applying a barrier layer between titanium and steel to obtain a defect-free butt joint of the edges of bimetallic sheets of carbon steel, clad with a layer of titanium, under conditions of arc or plasma surfacing of carbon steel on titanium. The application of the barrier layer was carried out by plasma spraying of steel wire or iron powder. In this case, a coating with a thickness of 150...750 μm was applied on Grade2 titanium, on which 1–2 mm thick layers of materials similar to the sprayed ones were deposited by arc and plasma deposition. It was established that during spraying with subsequent surfacing of steel wire or iron powder, the main technological factors for eliminating cracks in the resulting compound are the thickness of the sprayed coating and the amount of linear surfacing energy. The thickness of the sprayed coating was selected (at least 400...600 microns) followed by plasma surfacing of ER70S-6 steel wire with a diameter of 1.0 mm or CNPC-Fe200 iron powder with unit energy up to ~200...250 J/mm. A defect-free transition layer from titanium to steel was obtained. It is a continuous layer with a thickness of 50–60 microns, consisting of intermetalides FeTi and FeTi2, as well as a β-phase titanium with an enhanced iron content, which retains certain ductility without cracks and other defects. With the help of the devised approach for connecting titanium-steel bimetallic edges, it is planned to manufacture seam bimetallic pipes for main pipelines to transport oil and gas raw materials extracted from wells. [ABSTRACT FROM AUTHOR]

We have studied the effect of annealing conditions on the formation of nickel particles on a titanium nitride barrier layer produced by atomic layer deposition. The results demonstrate that the nanoparticle size depends on annealing temperature and time. At temperatures above 700°C, annealing for more than 5 min results in coalescence, which leads to particle growth and a decrease in the surface density of the particles. During annealing, nickel diffuses into the titanium nitride and the amount of nickel on the surface decreases. The experimental data agree with results of nanoparticle formation modeling in the hydrodynamic model. We have determined the catalyst–buffer interaction potential and melt viscosity, which demonstrate that, in the case of melting of a thin nickel layer, on the order of a few nanometers in thickness, the metal is similar to a supercooled liquid. Modeling results suggest that, during annealing of a thin metal film/barrier layer couple, the average nanoparticle size is smaller at lower potentials of interaction between the constituent materials of the couple. [ABSTRACT FROM AUTHOR]

The consequences of climate change may directly or indirectly impact the marine biosphere. Although ocean stratification has been recognized as one of the crucial consequences of ocean warming, its impacts on several critical aspects of marine microbes remain largely unknown in the Indian Ocean. Here, we investigate the effects of water stratification, in both surface and subsurface layers, on hydrogeographic parameters and bacterioplankton diversity within the equatorial eastern Indian Ocean (EIO). Strong stratification in the upper 200 m of equatorial EIO was detected with evidential low primary productivity. The vertical bacterioplankton diversity of the whole water columns displayed noticeable variation, with lower diversity occurring in the surface layer than in the subsurface layers. Horizontal heterogeneity of bacterioplankton communities was also in the well-mixed layer among different stations. SAR11 and Prochlorococcus displayed uncharacteristic low abundance in the surface water. Some amplicon sequence variants (ASVs) were identified as potential biomarkers for their specific depths in strongly-stratified water columns. Thus, barriers resulting from stratification are proposed to function as an 'ASV filter' to regulate the vertical bacterioplankton community diversity along the water columns. Overall, our results suggest that the effects of stratification on the structure and diversity of bacterioplankton can extend up to the bathypelagic zone in the strongly-stratified waters of the equatorial EIO. This study provides the first insight into the effect of stratification on the subsurface microbial communities in the equatorial eastern Indian Ocean. [ABSTRACT FROM AUTHOR]

Observations of Argo profiles and TAO/TRITON array confirm the significant seasonality of the barrier layer (BL) and temperature inversion (TI) in the northeastern tropical Pacific (NETP). Statistical result of the occurrence based on the Argo profiles reveals a bimodal variability of the BL, with two peaks in July and October. This bimodal seasonality of BL is attributed to the out‐of‐phase variations of the eastern Pacific fresh and warm pools. The fresh and warm pools both expand westward from May to July, when the Inter‐Tropical Convergence Zone (ITCZ) becomes intense and broad. Heavy rainfall is the dominant contributor to the extension of the fresh and warm pools, leading to a high frequency of thick BL (40%). This frequent thick BL provides a precondition for its another development after August. The fresh pool is stable from August to November, while the warm pool contracts sharply. The cold tongue becomes active due to a prevailing trade wind and horizontal advection transports surface cold water to the northeastern warm pool. This cold advection deepens the isothermal layer and contributes to a frequent TI (30%) and thick BL (46%). The results suggest that the ITCZ rainfall and northward cold advection from equator dominate the upper layer stratification of NETP in summer and autumn, respectively. Plain Language Summary: The marine barrier layer (BL) features strong salinity stratification at the base of a surface mixed layer insulating water exchange between the surface and subsurface. The formation mechanisms of the BL in the northeastern tropical Pacific are analyzed based on the observations of Argo floats and the TAO/TRITON array. The BLs show a bimodal seasonality with two peaks in July and October. The atmospheric forcing leads to extensions of the warm and fresh pools in the summer and causes the BL formation. Temperature inversions (TIs) occur frequently during the boreal autumn, with the surface temperature lower than the subsurface 1.82°C in October. The warm pool contracts sharply during autumn due to the development of the cold tongue, which causes frequent TIs and thickens the BLs. The out‐of‐phase changes in the warm and fresh pools result in bimodal seasonality and different formation mechanisms. Key Points: The bimodal barrier layer seasonality is due to the out‐of‐phase variabilities of the fresh and the warm poolsThe heavy rainfall and equatorial ocean dynamics dominate the upper layer stratification in summer and autumn, respectivelyThe cold transport by the cold tongue deepens the isothermal layer, contributing to the temperature inversion and thick barrier layer [ABSTRACT FROM AUTHOR]

For the first time, the processes controlling the variations of mixed layer temperature (MLT) and salinity (MLS) in the Banda Sea are quantified using data from a single Argo float in combination with satellite and reanalysis outputs from August 2017 to August 2019. This augments previous studies that utilized ocean model data only. We document the presence of a barrier layer and quantify the roles of air-sea heat and mass exchanges, horizontal advection, and vertical entrainment in the seasonal variability of MLT and MLS. We find that heat gains and losses at the air-sea interface are the main contributor to the warming and cooling of the MLT. Seasonal changes in MLS are driven by advection of low salinity water rather than freshwater fluxes from precipitation and evaporation. This is particularly the case during the late northwest and monsoon transition period from February to April when low salinity is advected eastward from the Java Sea into the Banda Sea. [ABSTRACT FROM AUTHOR]

In this paper, a strategy to finely modulate the energy band structure to control the carrier confinement capability of digital alloys (DA) is proposed. Strain analysis shows that As and Sb atoms are exchanged within the AlAsSb DA. The bottom of the corrected potential well is low on the left and high on the right in the growth direction, resulting in a higher band offset of the AlSb potential barrier layer on the left side of the potential well than on the right side. The modulation of the band leads to a higher probability of electron tunneling in DA under the action of an electric field opposite to the growth direction. Conversely, it is difficult for the electrons to tunnel into the lower energy level potential wells. The I â€" V curve of DA shows that the current value under positive bias is significantly smaller than the value under negative bias when the voltage is higher. The measured results correspond perfectly with the modified energy band model, which verifies the feasibility of energy band modulation. This is important for the structural design of DA and the reduction of dark current in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study simulated copper corrosion in a bentonite/groundwater solution, analyzing the kinetics of metal passivation through potentiodynamic polarization, potentiostatic polarization, and electrochemical impedance spectroscopy experiments. Morphological characterization provided insights into corrosion development patterns, and the mechanisms by which bentonite affects copper corrosion were comprehensively elucidated based on the point defect model. The findings revealed that bentonite affects copper corrosion resistance through Donnan exclusion, cation adsorption, and hydrolysis salt effects. At lower potentials, bentonite aids in inhibiting anodic dissolution, reducing the polarization current by approximately 75 % under certain conditions. With increasing bentonite content, the induction time for stable pitting corrosion shortens significantly, down to 10 %, the current surge before breakdown intensifies, and the breakdown potential decreases. When the bentonite volume ratio exceeds 0.5/0.1, the breakdown potential of OFP-Cu/OF-Cu markedly decreases and stabilizes at 0.1/0 V SCE. The microscopic mechanism of pitting corrosion induced by bentonite hydrolysis salts was elucidated using the point defect model, calculating the polarizability of the passive layer/outer layer interface as α = 0.1. The reliability of the cation adsorption and adsorption-desorption mechanisms was confirmed through experimental data fitting, point defect model fitting, and theoretical analysis. [ABSTRACT FROM AUTHOR]

• A dual-layer Cr/FeCrAl coating was deposited on Zry-4 using magnetron sputtering. • The Cr/FeCrAl coating exhibits excellent corrosion resistance in HTHP water. • The Cr/FeCrAl coating on Zry-4 can tolerate 1200 °C steam environment. • The formed Zr(Fe,Cr) 2 layer prevents the Fe-Zr eutectic reaction in LOCA condition. A dual-layer Cr/FeCrAl coating was deposited on zircaloy-4 using magnetron sputtering, and its corrosion performance was investigated under simulated pressurized water reactor (PWR) and high-temperature steam environments. Despite experiencing weight loss in high-temperature and high-pressure water (360 °C/18.6 MPa), the coating developed a durable Fe/Cr composite oxide layer on its surface, effectively mitigating corrosion. In high-temperature steam conditions, a continuous Al 2 O 3 coating formed, providing protection up to 1200 °C for 30 min. Microstructure analysis unveiled the formation of Zr (Fe, Cr) 2 layer, which played a crucial role in preventing Fe indiffusion and the formation of Fe-Zr low melting point eutectic. These findings provide valuable insights into enhancing the corrosion and oxidation resistance of zirconium alloy cladding in extreme environments. [ABSTRACT FROM AUTHOR]

Polymeric materials, including polyethylene terephthalate (PET), are widely used in various fields because of their beneficial properties. Functional films are deposited on these materials through different approaches, such as plasma-enhanced atomic layer deposition (PEALD), to enhance their performance and prolong their life span. However, the inert and thermally fragile nature of most polymers hinders deposition. We developed a strategy for the PEALD of nanoscale Al2O3 films on PET substrates. First, a PET substrate is subjected to alkali treatment, which gives it basic hydrophilicity for the subsequent dopamine modification. After 24 h of dopamine deposition, the substrate shows adequate active sites (phenolic hydroxyl groups), which can chemisorb large amounts of precursor during the initial deposition. The island growth mode was observed during the PEALD processes. We analyzed the detailed chemical components of Al2O3 on alkali-treated PET and dopamine-modified PET. After 100 cycles of deposition, the Al2O3 films on both samples contained much hydrogen. Benefitting from the more active sites, we observed more continuous Al2O3 film on dopamine-modified PET, which exhibited excellent water vapor blocking performance. Our findings suggest that dopamine could act as a ‘bridge’ between polymers and PEALD functional films. [ABSTRACT FROM AUTHOR]

In this work, we investigated the effect of the tungsten nitride (WNx) diffusion barrier layer on the resistive switching operation of the aluminum nitride (AlN) based conductive bridge random access memory. The WNx barrier layer limits the diffusion of Cu ions in the AlN switching layer, hence controlling the formation of metallic conductive filament in the host layer. The device operated at a very low operating voltage with a Vset of 0.6 V and a Vreset of 0.4 V. The spatial and temporal switching variability were reduced significantly by inserting a barrier layer. The worst-case coefficient of variations (σ/µ) for HRS and LRS are 33% and 18%, respectively, when barrier layer devices are deployed, compared to 167% and 33% when the barrier layer is not present. With a barrier layer, the device exhibits data retention behavior for more than 104 s at 120 °C, whereas without a barrier layer, the device fails after 103 s. The device demonstrated synaptic behavior with long-term potentiation/depression (LTP/LTD) for 30 epochs by stimulating with a train of identical optimized pulses of 1 µs duration. [ABSTRACT FROM AUTHOR]

The results of a comprehensive study of the structural-morphological and thermodynamic characteristics of the electrochemical precipitation of Cu in transition holes with a barrier layer of TiN in Si/SiO2 substrates by scanning electron microscopy (SEM) and differential thermal analysis (DTA) are presented. The temperature range that determines the heat resistance of copper (up to 750°C) and the temperature range (up to 886°C) that determines the thermal stability of the composite as a whole, as well as the ability to maintain the chemical composition and ordered structure at elevated temperatures, are found. [ABSTRACT FROM AUTHOR]

The barrier layer (BL) is part of the surface ocean isolated from the local air‐sea exchange processes despite it's great potential to store the heat beneath the mixed layer. The tropical oceans are known for the presence of BL. The interannual variability of the BL of the tropical Indian Ocean is examined in this study with a concomitant analysis of observations and outputs from an ocean general circulation model. The model faithfully reproduces the tropical variability of the dynamics and thermodynamics of the Indian Ocean when compared with observations and other studies. The BL thins (thickens) in the eastern (central‐to‐western) tropical Indian Ocean during the positive phase of the Indian Ocean Dipole Mode (IOD). The individual roles of five major forcing mechanisms on BL‐IOD coupling are examined. The thinning in the east is caused by upward heaving thermocline due to upwelling Kelvin waves during the positive phase of the IOD, causing the isothermal layer to shoal steeper than the mixed layer. The surface freshwater fluxes substantiate the thinning of BL in the east during this time, while the net heat fluxes thin the BL in the entire tropical Indian Ocean. The basin‐wide salinity (temperature) dynamics have widespread and complementary impacts, a BL thickening (thinning) in the equatorial and eastern tropical Indian Ocean during positive IOD years, with the former overwhelming the latter. The thickening of BL in the central‐to‐western tropical Indian Ocean during positive IOD is due to a combined action of salinity and freshwater forcing. The thermocline heaving, temperature and salinity dynamics and buoyancy forcing could explain the net variability of BL in the tropical Indian Ocean almost entirely in the model. The ocean‐only response shows that a BL weakens the shoaling (deepening) of the ocean mixed layer during positive (negative) IOD years in the eastern tropical Indian Ocean. As barrier layers store heat beneath the mixed layer, their role in Indian Ocean weather and climate needs to be examined with coupled model experiments. Plain Language Summary: Barrier layers (BL) are the depth between the isothermal layer and the ocean's mixed layer. The eastern tropical Indian Ocean has a barrier layer for the most part of the year. The year‐to‐year variability of barrier layer thickness (BLT) of the tropical Indian Ocean is studied with the help of an ocean general circulation model. BLT of the eastern tropical Indian Ocean thins by ∼10 m during the positive Indian Ocean Dipole Mode (IOD) years and thickens by a few meters in the western tropical Indian Ocean. The role of ocean dynamics and thermodynamics involving the thermocline, entire Indian Ocean domain salinity & temperature, surface heat and freshwater fluxes were separately identified in the BLT variability. The eastern Indian Ocean thinning of BLT during positive IOD years is caused by the combined action of ocean thermocline dynamics, surface heat fluxes, and freshwater fluxes. From the central to the western tropical Indian Ocean, the thickening of BLT during positive IOD years is due to the combined action of salinity dynamics and freshwater fluxes. The BL weakens MLD's shoaling (deepening) during positive (negative) IOD years in the eastern tropical Indian Ocean. Key Points: Tropical Indian Ocean barrier layer (BL) thickness variability is intimately tied to the Indian Ocean Dipole Mode (IOD)The BL thins (thickens) at eastern (central‐to‐western) tropical Indian Ocean during positive IODThe thermocline heaving, basin‐scale Temperature & Salinity dynamics, and buoyancy forcing explains net variability of BL almost entirely [ABSTRACT FROM AUTHOR]

Time series measurements (2010–2017) from the Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) moorings at 15°N, 90°E and 12°N, 90°E are used to investigate the effect of the seasonal barrier layer (BL) on the mixed-layer heat budget in the Bay of Bengal (BoB). The mixed-layer temperature tendency (∂T/∂t) is primarily controlled by the net surface heat flux that remains in the mixed layer (Q′) from March to October, while both Q′ and the vertical heat flux at the base of the mixed layer (Qh), estimated as the residual of the mixed-layer heat budget, dominate during winter (November–February). An inverse relation is observed between the BL thickness and the mixed-layer temperature (MLT). Based on the estimations at the moorings, it is suggested that when the BL thickness is ⩾25 m, it exerts a considerable influence on ∂T/∂t through the modulation of Qh (warming) in the BoB. The cooling associated with Qh is strongest when the BL thickness is ⩽10 m with the MLT exceeding 29°C, while the contribution from Qh remains nearly zero when the BL thickness varies between 10 m and 25 m. Temperature inversion is evident in the BoB during winter when the BL thickness remains ⩾25 m with an average MLT<28.5°C. Furthermore, Qh follows the seasonal cycle of the BL at these RAMA mooring locations, with r>0.72 at the 95% significance level. [ABSTRACT FROM AUTHOR]

Theories of ocean–atmosphere interaction during a Madden–Julian Oscillation (MJO) are generally based on a thermodynamic model with surface fluxes dictating changes in sea surface temperature. Evidence from a two month ocean glider deployment in early 2019 in the southeast Indian Ocean suggests the impact of mesoscale dynamics on upper-ocean stratification likely affects ocean–atmosphere interaction at MJO scales. Until mid-February, local surface fluxes consistent with a convectively suppressed MJO phase drove near-surface ocean evolution. With the advection of a fresh-core eddy to the glider location in late February, ocean dynamics then becomes an additional driver of this evolution by modulating local stratification and generating a barrier layer of ≈12 m thickness for 10 days. One-dimensional modelling experiments based on the ocean and atmospheric conditions experienced during our sampling period show that the ocean subsurface structure within the eddy induce changes in SST of physical significance for ocean-atmosphere interaction. Moreover, results also suggest that the presence of a thick eddy-induced barrier layer during the MJO suppressed phase modulates the magnitude of temperature anomalies forced by surface fluxes during the following enhanced MJO phase. As eddies are abundant in this area, their dynamics must be considered to correctly represent SST variability for MJO modelling. • Ocean dynamics affect air-sea interaction via a lasting barrier layer induced by fresh-core mesoscale eddy. • The presence of a thick eddy-induced BL modulates SST anomalies forced by surface fluxes during a typical MJO event. • Suggests mesoscale variability as an important ocean dynamic component for inclusion in MJO system modelling. [ABSTRACT FROM AUTHOR]