Horizontal Scale Research Articles

Correction to: Regional differences in cloud characteristics at different depth, intensity and horizontal scale over South Asia during Indian summer monsoon using CloudSat and reanalysis data

Correction to: Regional differences in cloud characteristics at different depth, intensity and horizontal scale over South Asia during Indian summer monsoon using CloudSat and reanalysis data

Characterisation of the spatial variability of underconsolidated Singapore Marine Clay using random field theory

ABSTRACT This paper characterised the spatial variability of Singapore Kallang Formation Marine Clays using piezocone penetration test (CPT) data from the Marina South area. Both vertical and horizontal scales of fluctuation in undrained shear strength for two distinct clay units, Upper Marine Clay (UMC) and Lower Marine Clay (LMC), are calibrated for autocorrelation and semi-variogram functions. The Marina South area was reclaimed from the sea using fills placed in three phases from 1970s to 1990s and remains underconsolidated up to date. This study identified variations in the degree of consolidation across the area, which has led to variations in the undrained shear strength in this area. However, the variations in the degree of consolidation were found to have no noticeable influence on the vertical and horizontal scales of fluctuation of either UMC or LMC unit. The vertical scales of fluctuation of UMC and LMC units are 0.57 ± 0.3 m and 0.48 ± 0.17 m , respectively, while the horizontal scales of fluctuations are 148 ± 26 m and 138 ± 28 m , respectively. The present study contributes to the database of the statistical and spatial variability of marine clays and can provide useful guidance for assessing reliability of excavations and foundations in Marina South as well as other areas with similar geological settings.

The Relative Importance of Ocean Advection and Surface Heat Fluxes During the Madden–Julian Oscillation in a Coupled Ocean–Atmosphere Model

AbstractIntraseasonal variability of ocean surface mixed layer temperature (MLT) in the tropics can be linked to the Madden–Julian Oscillation (MJO), the main source of intraseasonal atmospheric variability in the tropics. Here, we conduct a boreal winter mixed layer heat budget using 10‐day forecast composites of a coupled ocean–atmosphere Numerical Weather Prediction model of the UK Met Office to reveal that ocean advection plays a major role in modulating intraseasonal anomalies of MLT over the tropical Indian Ocean and the Maritime Continent. Large scale ( 10) intraseasonal anomalies of MLT ( 0.1 C) are driven by net surface heat flux. Ocean advection dominates at smaller horizontal scales ( 1), contributing up to 0.5 C to the intraseasonal MLT anomaly. Prior to the development of the enhanced MJO convection in the western Indian Ocean (phases 8 and 1), ocean advection reinforces the net heat flux warming in this region. However, ocean advection opposes the net heat flux warming in the Maritime Continent prior to the development of suppressed MJO convection in this region. When the MJO convection develops over the central Indian Ocean (phase 3), ocean advection (net surface heat flux) drives the intraseasonal MLT anomalies in the western Indian Ocean (central Indian Ocean and the Maritime Continent). Our results demonstrate the importance of ocean dynamics during the initiation and growth of the MJO, and raise implications for models that do not resolve these processes.

3D stochastic simulation of a deep-water turbidite system: An example from the Los Molles Formation, southern region of the Neuquén Basin, Argentina

A recurring challenge in geological modeling is bridging the gap between different scales. For example, difficulties arise when connecting outcrop data through production to exploration scale models. An object-based stochastic simulation was performed using outcrop data from the Arroyo La Jardinera area in the southern region of the Neuquén Basin, Argentina. This simulation involved four depositional sequences in a vertical succession that includes turbidites and associated deep marine facies. The aims of this study are (a) to determine the best geological model consistent with field and aerial image data; (b) to validate the application of object modeling to determine facies distribution; (c) to evaluate uncertainties from models based on scarce data. The studied interval covers a transgressive (J1) to regressive succession (J21, J22, and J23) of basin plain to slope depositional settings, featuring sandy and gravelly turbidite channels, turbidite lobes and interlobes, lobe fringes, and muddy slope and basin plain. Each depositional sequence model was constructed using specific input parameters for architectural elements, with lithological proportions based on sedimentary logs. The J1 sequence includes basin plain, lobe fringe, and minor lobe deposits; J21 features turbidite lobes, fringes, and subordinate channels; J22 accommodates turbidite channels scoured into muddy slope facies; and J23 encompasses gravelly and sandy turbidite channels carved on muddy slope facies. The geostatistical modeling of outcrop data has allowed building a quantitative sedimentological model useful for understanding subsurface facies heterogeneity in both exploration (vertical) and production (horizontal) scales.

Intensification of submesoscale frontogenesis and forward energy cascade driven by upper-ocean convergent flows

Upper-ocean fronts are an important component of the global climate system, regulating both the oceanic energy cycle and material transports. In the common paradigm, upper-ocean fronts are generated by frontogenesis at the mesoscale (20–300 km), driven predominantly by confluent horizontal flows initiated by a background straining field. However, the mechanisms by which this frontogenesis extends down to and influences the submesoscale (0.2–20 km), which dominates vertical transports in the ocean, are still understudied. Here, we provide direct observational evidence that submesoscale frontogenesis, defined as the rate at which submesoscale buoyancy gradients intensify, is closely linked to convergent flows. Analysis of year-long measurements by a mooring array in the North Atlantic indicates that both the upper-ocean frontogenetic rate and the horizontal convergence exhibit strong seasonality and scale dependence, with larger magnitudes in winter and at smaller horizontal scales (down to at least 2 km). The frontogenetic rate is found to correlate more strongly with horizontal convergence as the scale decreases, suggesting that convergent flows are the main driver of submesoscale frontogenesis. Crucially, a rapid forward cascade of kinetic energy and enhanced vertical velocities preferentially occur during periods of submesoscale frontogenesis. Our findings highlight a mechanism underpinning the key role of submesoscale fronts in the oceanic kinetic energy cascade and as a focus of vertical transports, and call for a parameterization of such effects in climate-scale ocean models.

Regional differences in cloud characteristics at different depth, intensity and horizontal scale over South Asia during Indian summer monsoon using CloudSat and reanalysis data

Regional differences in cloud characteristics at different depth, intensity and horizontal scale over South Asia during Indian summer monsoon using CloudSat and reanalysis data

Emergent ecology in a microscale model of the surface ocean.

Microbial processes operate at the microscale, which is not resolved by existing ecosystem models. Here, we present a novel model that simulates a 1 mL three-dimensional cube using a hybrid Lagrangian-Eulerian approach, at ecologically relevant timescales. The model simulates individual microbes, including three phytoplankton size classes with healthy, senescent, and dead lifecycle stages; copiotrophic and oligotrophic heterotrophic bacteria; and dissolved organic matter at 50 µm resolution. Diffusion, shear, sedimentation, chemotaxis, and attachment processes are explicitly resolved. The emerging quantitative representation of the ecosystem shows that (1) copiotrophs grow mostly attached to eukaryotic phytoplankters and get almost all of their carbon from them vs. oligotrophs that grow on exudates and lysates of cyanobacteria; (2) contrasting diel patterns in substrate appearance in the phycosphere vs. ambient water and growth of particle-associated copiotrophs vs. free-living oligotrophs; (3) attached bacteria reduce carbon flux from the phycosphere, lowering chemotactic efficiency toward eukaryotes below that toward cyanobacteria; (4) shear reduces chemotactic efficiency and fitness of the copiotroph; and (5) the main benefit of chemotaxis is to locate attachment partners. These patterns are consistent with available observations. Our study provides insights into the microscale ecology of marine bacteria, and the open-source code is a tool for further research in this area.IMPORTANCEA large amount of global CO2 fixation is performed by marine phytoplankton, and a substantial fraction of that is released as dissolved organic carbon and further processed by heterotrophic bacteria. The interaction between phytoplankton and bacteria, i.e., the carbon flux between them, is therefore an important process in the global carbon and climate system. Some bacteria have developed specialized behavioral traits, like swimming and attachment, to increase their carbon acquisition. These interactions occur at the micrometer scale, for example, the immediate vicinity of phytoplankters (the phycosphere), but existing biogeochemical models typically only simulate down to the 1 meter vertical or ~100 kilometer horizontal scale. We present a new microscale model and use it to predict fluxes and other features in the surface ocean. The model makes important predictions about the fluxes between various types of phytoplankton and bacteria and the role of behavioral traits, and it provides a basis and tool for further research in this area.

Terminal Doppler Weather Radar Retrievals in Complex Terrain during a Summer High Ozone Period

Abstract Out of the 45 radars composing the Terminal Doppler Weather Radar (TDWR) network, 21 are located in areas of complex terrain. Their mission to observe low-level wind shear at major airports prone to strong shear-induced accidents puts them in an ideal position to fill critical boundary layer observation gaps within the NEXRAD network in these regions. Retrievals such as velocity azimuth display and velocity volume processing (VVP) are used to create time-height profiles of the boundary layer from radar conical scans, but assume that a wide area around the radar is horizontally homogeneous. This assumption is rarely met in regions of complex terrain. This paper introduces a VVP retrieval with limited radius to make these profiling techniques informative for flows affected by topography. These retrievals can be applied to any operational radar to help examine critical boundary layer processes. VVP retrievals were derived from the TDWR for Salt Lake City International Airport, TSLC, during a summertime high ozone period. These observations highlighted thermally driven circulations and variations in boundary layer depth at high vertical and temporal resolution and provided insight on their influence on air quality. Significance Statement Residents in many urban areas of the United States are exposed to elevated ozone concentrations during the summer months. In complex terrain, thermally driven circulations and terrain-forced flows affect chemical processes by modulating mixing and transport. A novel technique to monitor local boundary layer conditions on small horizontal length scales was applied to data from the Terminal Doppler Weather Radar located near Salt Lake City International Airport during a multiday high ozone event, and effects of these flows on ozone concentrations are illustrated. This technique can be applied to other operational weather radars to create long-term and real-time records of near-surface processes at high vertical and temporal resolution.

Asymmetric vertical transport in weakly forced shallow flows

In this paper, we report on an investigation of the vertical transport of tracer particles released within a shallow, continuously-forced flow by means of numerical simulations. The investigation is motivated by the shallow flows encountered in many environmental situations and inspired by the laboratory experiments conducted in electromagnetically forced shallow fluid layers. The flow is confined to a thin fluid layer by stress-free top and no-slip bottom walls. The dynamics and the transport properties of the shallow flow are investigated under various flow conditions characterized by a Reynolds number related to the forcing, ReF, and the aspect ratio of vertical and horizontal length scales δ. The forcing generates an array of vortices that becomes unsteady when ReFδ2≳10. These vortices are accompanied by upwellings in their cores which are surrounded by narrower, stronger downwellings. Hence, upwellings occur where the horizontal flow is vorticity-dominated, while downwellings where it is strain-dominated. The magnitude of the asymmetry in strength and size of the vertical flows and their correlation with horizontal structures depends on the flow conditions and significantly influences the vertical spreading of particles within the fluid volume. Under conditions leading to a large asymmetry, particles within updrafts are transported slowly upwards, while particles within downdrafts rapidly move downwards. In addition, particles are trapped for longer within the updrafts than downdrafts because of their correlation with vorticity-dominated regions. However, when the flow becomes fully three-dimensional and highly unsteady for large ReFδ2 values, this transport asymmetry subsides because the updrafts and downdrafts exhibit similar strength and size in such flow conditions. Consequently, similar amounts of particles are transported upwards and downwards at similar rates.

Shallow Convective Heating in Weak Temperature Gradient Balance Explains Mesoscale Vertical Motions in the Trades

AbstractEarth's climate sensitivity depends on how shallow clouds in the trades respond to changes in the large‐scale tropical circulation with warming. In canonical theory for this cloud‐circulation coupling, it is assumed that the clouds are controlled by the field of vertical motion on horizontal scales larger than the convection's depth ( 1 km). This assumption has been challenged both by recent in situ observations, and idealized large‐eddy simulations (LESs). Here, we therefore bring together the recent observations, new analysis from satellite data, and a 40‐day, large‐domain ( km2) LES of the North Atlantic from the 2020 EUREC4A field campaign, to study the interaction between shallow convection and vertical motions on scales between 10 and 1,000 km (mesoscales), in settings that are as realistic as possible. Across all data sets, the shallow mesoscale vertical motions are consistently represented, ubiquitous, frequently organized into circulations, and formed without imprinting themselves on the mesoscale buoyancy field. Therefore, we use the weak‐temperature gradient approximation to show that between at least 12.5–400 km scales, the vertical motion balances heating fluctuations in groups of precipitating shallow cumuli. That is, across the mesoscales, shallow convection controls the vertical motion in the trades, and does not simply adjust to it. In turn, the mesoscale convective heating patterns appear to consistently grow through moisture‐convection feedback. Therefore, to represent and understand the cloud‐circulation coupling of trade cumuli, the full range of scales between the synoptics and the hectometer must be included in our conceptual and numerical models.

TC-SRNet: Reconstruction and prediction of typhoon high-resolution turbulent fields based on meteorological numerical forecast scale wind fields and deep learning method

Meteorological numerical forecast models can provide a more accurate typhoon wind fields compared to engineering typhoon models due to their incorporate atmospheric multiphysical processes. However, the latest advancements in supercomputing power indicate that the current finest level of real-time weather forecasting typically operates on grid scales ranging from 1 to 4 km, while the convergence of typhoon intensity and turbulent field characteristics occurs at scales as fine as 62–185 m. Therefore, the primary scientific inquiry lies in determining how to achieve high-precision turbulent wind fields while considering the realistic atmospheric multiphysical processes, that means establish a “bridge” of typhoon wind field between kilometer-level and hundred-meter scales. This study investigates the super-resolution reconstruction of wind fields across different horizontal grid scales, utilizing a benchmark wind field at a 62 m horizontal grid scale (ground truth), which is based on a hybrid down-sampling skip connection (DSC)/multi-scale (MS) model. The research findings demonstrate that compared to traditional interpolation methods, the DSC/MS method significantly improves reconstruction accuracy, albeit with some residual high-frequency energy dissipation issues. Additionally, the DSC/MS method currently exhibits better reconstruction performance for 62 m scale wind fields based on kilometer-scale and smaller horizontal grid scales (1 km, 555 m, 185 m), with improved reconstruction as grid scale decreases. However, significant errors are observed in reconstructing fine turbulent fields at 62 m scale based on wind fields at 1.67 km horizontal grid scale. The findings presented in the present study can provide real and high-precision turbulent wind fields for structural wind engineering and wind energy assessment studies, thereby holding significant scientific and engineering application value.

Intraseasonal Variations and Extreme Occurrence in the Local Sea Level Along the Western Coast of India Remotely Controlled by a Basin‐Scale Climate Variability

AbstractThe equatorial Kelvin waves, remotely excited by basin‐scale climate modes, and subsequent coastal trapped waves significantly influence the intraseasonal variations, their low‐frequency modulations, and the frequency of extreme sea level events along the western coast of India. This study demonstrates that the frequency of extreme events are linked to the phase of the Indian Ocean Dipole mode. The temporal changes in the occurrence frequency of extremes are simulated in an eddy‐resolving ocean model consistently with observations. However, a non‐eddying model significantly underestimate the occurrence frequency of extreme sea level events, suggesting the importance of coastal trapped wave propagations regulated by the horizontal scale with the Rossby radius of deformation. This result implies that many state‐of‐the‐art climate models with a one‐degree ocean horizontal resolution may underestimate future coastal sea level variability and the frequency of extreme events under global warming and potential modulations of major internal climate modes.

Forecasting the flame geometry and ground received radiative heat fluxes of two parallel adjacent fires of hydrocarbon fuel with crosswinds

Radiative heat transfer in fires is a critical parameter and a key aspect of gas storage and fire prevention design. In this study, the flame geometric scale characteristics and ground-received radiative heat fluxes from two parallel adjacent hydrocarbon fuel fires with crosswinds were examined. The separation distance between the two parallel flames, crosswind speed, and heat release rates were considered. The experimental results indicated that the flame tilt angle of the two parallel flames increased with increasing crosswinds. The horizontal flame length scale of the two adjacent parallel flames first increased with the crosswind until a critical point was reached, followed by a fluctuation with a further increase in the wind speed. To further quantify this flame phenomenon, a physical model of the flame interaction between two parallel fires under the effects of crosswinds was proposed. The model analyzed major factors affecting the geometrical parameters of the flame, including the inertial force caused by the crosswind, thermal buoyancy from flame combustion, and the interaction and separation distance between the two fires. Additionally, correlations between the flame tilt angle and the horizontal flame length scale of the two adjacent flames were proposed. It was also demonstrated that the ground-received downstream radiative heat fluxes were the dominant parameters determining flame spread. Based on the assumption of the flame geometry of two adjacent parallel fires, the viewing factor was revised, and the relationship between the position of the radiant point and the horizontal length of the flame was considered in the flame model. Furthermore, based on the updated viewing factor of two parallel adjacent flames, a prediction model of ground-received radiative heat fluxes was proposed, which successfully estimated the variation of ground-received downstream radiative heat flux profiles along the centerline of the two parallel flames under crosswind conditions. This estimation is crucial for future fire research, particularly cross-wind-related experiments.

Data assimilation by combining ABAQUS with ensemble Kalman filter and its application to geotechnical engineering

Geological parameters of soil exhibit spatial variability. Inverse analysis allows the acquisition of accurate spatial distributions of key geological parameters, which is crucial for structural safety assessment. In this study, an ensemble Kalman filter (EnKF) is employed in the context of data assimilation. Random fields are used as the initial input ensembles for the algorithm. The present study effectively integrates the ensemble Kalman filter with the numerical simulation software ABAQUS, enabling the inversion of parameter fields under various operating conditions. An in-house Python code script is developed to control ABAQUS for finite element computations and to obtain observations at target points. During the stepwise computation process, the algorithm can utilize newly acquired observations to accelerate the convergence of the parameter field to the true field. The effectiveness of the algorithm is validated, and the method is applied to a case study of double-tunnel excavation and a stepwise excavation analysis of a three-layered slope. The impact of the number of ensemble members and the ratio of the horizontal correlation scale to the vertical correlation scale of random fields on the effectiveness of updating the parameter field have also been investigated.

Studying the Impacts of Meteorological Factors on Distribution of Cloud Horizontal Scales Based on Active Satellite

AbstractAs a significant macrophysical property, cloud horizontal scales play a role in cloud radiation, precipitation and vertical cloud overlap. Until now, however, the mechanisms behind the variations in cloud scale distribution have received far less attention. This study utilizes active satellite data from 2007 to 2016 to investigate the spatiotemporal distribution of cloud horizontal scales, and explains the variations through two meteorological factors: wind shear and atmospheric stability. Cloud scales exhibit a distinct power‐law behavior when scale break is not considered, and the power‐law exponent β is a characteristic measure of cloud scale distribution. A smaller power‐law exponent β indicates a higher frequency of large clouds. During boreal summer season, the amount of large clouds is extremely large south of the 40°S but rather small between 10°S and 20°S. As wind shear decreases or atmospheric stability increases, more large clouds occur globally. The underlying mechanisms might be associated with cloud entrainment which can be promoted by wind shear but inhibited by atmospheric stability. However, our analysis of the impacts of these two factors on cloud scale distribution across different regions and heights reveals that both wind shear and atmospheric stability play dual roles on the values of the exponent β. The potential physical mechanisms, including the effects of precipitation, are further discussed. It is observed that precipitation also exerts a dual impact on the values of the exponent β. These findings underscore the significance of considering the impacts of meteorological factors on cloud scale distribution in numerical weather prediction models.

2D Magnetotelluric Inversion Using Linear Finite Element Methods and a Discretize‐Last Strategy With First and Second–Order Anisotropic Regularization

AbstractWe present a new inversion scheme for 2D magnetotelluric data. In contrast to established approaches, it is based on a mesh‐free formulation of the Quasi‐Newton Broyden–Fletcher–Goldfarb–Shanno (BFGS) iteration which uses the cost function gradient to implicitly construct approximations of the Hessian inverse to update the unknown conductivity. We introduce conventional first–order regularization as well as second–order regularization where inversions based on the latter are more appropriate for sparse data and can be read as maximum likelihood estimation of the unknown conductivity. We apply first–order finite element method (FEM) discretizations of the inversion scheme, forward and adjoint problems, where the latter is required for the construction of the cost function gradients. We allow for unstructured first–order triangular meshes supporting an enhanced ground level resolution including topographical features and coarsening at the far field leading to significant reduction in computational costs from using structured mesh. Formulating the inversion iteration in continuous form prior to discretization eliminates bias due to local refinements in the mesh and gives way for computationally efficient sparse matrix techniques in the implementation. A keystone in the new scheme is the multi‐grid approximation of the Hessian of the regularizations to construct efficient preconditioning for the inversion iteration. The method is applied to the Commeni4 benchmark and two field data sets. Tests show that for both first and second–order regularization an anisotropic approach is important to address the vast differences in horizontal and vertical spatial scale which in conventional approaches is implicitly introduced through the elongated shape of grid cells.

Thermal Imprints of Mesoscale Eddies in the Global Ocean

Abstract Mesoscale eddies have been widely documented for their significant role in regulating oceanic heat absorption and redistribution. However, our understanding of their thermal impacts on a global scale has been hampered by the scarcity of eddy-targeted observations. Here, we perform a comprehensive global analysis of over 2 million historical hydrographic profile measurements collocated with satellite-based eddy observations between 1993 and 2019, revealing rich geographical variability in the intensity, vertical extent, and asymmetry of the temperature anomalies induced by eddies. In tropical and subtropical oceans, temperature anomalies within eddies are dominated by eddy pumping and heavily influenced by near-surface vertical stratification, resulting in a relatively shallow extent of eddy effects (around 500 m) with subsurface maximum temperature anomalies occurring near 100 m. In midlatitude main current systems with sharp horizontal temperature gradients, the impact of eddy trapping becomes evident, leading to temperature anomalies extending to depths of 1000 m, with vertical peak values exceeding 4°C between 300 and 700 m, equivalent to perturbations in the local mean-state temperature of nearly 30%. This process also results in substantial temperature anomalies on isopycnal surfaces, indicating notable cross-frontal transport of heat and water mass with varying properties. The estimated meridional heat transport by eddy movement is on the order of O(1) MW, generally one order of magnitude smaller than previous estimates of the time-varying meridional heat transport (). However, this does not imply that they are unimportant, as this long-range cross-frontal heat transport may have significant consequences on regional temperature extremes and biogeochemical environments. Significance Statement Mesoscale eddies with a horizontal scale of O(100) km play a crucial role in modulating oceanic heat absorption and redistribution. However, their activities vary significantly across the global ocean, and our understanding of their thermal impacts remains incomplete. In this study, we conduct a global analysis of the influence of eddies on ocean temperature using over 2 million historical in situ temperature and salinity profile measurements combined with satellite-based eddy observations. Our analysis reveals substantial regional variability in the intensity, vertical extent, and asymmetry of temperature anomalies within eddies of different polarities and discusses the underlying mechanisms. Additionally, we estimate the meridional heat transport caused by eddy movement within each 2° × 2° grid, providing insights into the efficient pathways for eddy heat transport in western boundary currents and their extensions. These results enhance our understanding of the global-scale thermal impact of eddies and provide valuable references for assessing their biogeochemical and ecological consequences.

Exploring the paradox of densification and greening in China’ s old cities

Urban densification is widely regarded as a key strategy for curbing urban sprawl and optimizing resource efficiency. However, it still threatens urban greenspaces by altering the original land use. The imperative to preserve and restore urban greenspaces has gained increased attention, aligning with the global spotlight on urban resilience. This prompts the crucial question: How will urban densification impact urban greening? Focusing on the old city areas of 159 cities with over one million population in China, we depicted the dynamics of urban greenness using remote sensing data and explored greening trends under urban densification on both horizontal and vertical scales by generalized additive model (GAM). The findings are as follows: (1) As urban horizontal density increased from 68.4 % to 93.1 %, a significant U-shaped trend in urban greenness emerged within the old city areas over the past three decades. Notably, 80 % of these cities experienced turning points before 2010. (2) Almost half of the cities have recovered the urban greenness to 30 years ago, with a growth of 6.58 % on average. While urban densification led to a loss of greenness (-0.0197±0.0182), urban greenspaces countered this with a gain of 0.0049±0.0075, and the original built-up area contributed a gain of 0.0027±0.0284. (3) We decomposed urban densification into horizontal and vertical growth. The horizontal growth coincides with the greenness loss initially, but the rebound occurs when the horizontal density approaches 83 %. Vertical growth, on the other hand, is negatively correlated with urban greenness. Our study depicts the turning point of urban greening in old city areas unveiling the ecological effect of urban densification, which provides a reference for the sustainable development of future urbanization.

Evolving Preston’s Equation in Chemical Mechanical Planarization

The evolution of semiconductor devices necessitates greater control parameters for enhancing CMP process controllability. Historically, CMP engineers have sought to improve polishing process performance by real-time control of time, pressure, and velocity using Preston’s equation. However, Preston’s equation has traditionally addressed blanket-wafer or non-patterned wafer’s vertical or horizontal scale controllability, such as wafer center to edge or the in-wafer non-uniformity expressed by percentage. However, limited control variables cannot determine patterning profile changes.Upon closer examination of the basic Preston’s equation, other factors were considered constant or environmental parameters, excluding pressure and velocity. Current and future scaled-down devices demand additional control parameters to achieve nanometer-scale vertical controllability with patterned wafers. This presentation introduces an extended Preston’s equation by incorporating more control parameters, including temperature and slurry concentration. The study reveals that lowering and controlling the polishing temperature induces slurry selectivity changes by modulating the activation energy between the slurry and wafer. This temperature control also drives pad material changes that impact selectivity. Furthermore, the study evaluates in-situ slurry composition control to assess its real-time impact on wafer performance. When all five active parameters are combined into the extended Preston’s equation, it is demonstrated that real-time nanometer vertical scaling is achievable. The results of this study provide insights into the future design direction of CMP equipment, which will be communicated in this talk along with the concept of future CMP equipment.

Analysis of a Halocline Mesoscale Eddy in the Northwind Basin, Arctic Ocean

Eddies have been observed at all depths and in all regions of the Arctic Ocean. However, given the complex geographic conditions and dynamic environments of this ocean, the synchronized observations of temperature, salinity, and currents, and the detailed analysis of individual eddies are still lacking in the Northwind Basin. Our study aims to address these research gaps. We observed an eddy from a mooring in the Northwind Basin in late October 2017. It is a large anticyclonic cold eddy within the Arctic halocline, with a maximum azimuthal velocity reaching 52.63 cm/s and a horizontal scale (∼56 km) that significantly exceeds the first local baroclinic Rossby radius of deformation, i.e., it is in mesoscale. Its azimuthal velocity and scale are larger compared with those of nearby eddies, suggesting a relatively young state. This eddy possibly originated from the northern Chukchi Sea shelf, converging near Hanna Shoal with the Chukchi Slope Current before being advected northward into the Northwind Basin. Our study outlines detailed steps for extracting and analyzing eddies from mooring data and contributes to improving the understanding of the characteristics of Arctic Ocean eddies, providing a typical case for the investigation of eddies in the Northwind Basin.