Horizontal Variations Research Articles

Hydraulic Resistance Device for Force, Power, and Force–Velocity–Power Profile Assessment During Resisted Sprints with Different Overloads

This study aimed to evaluate the ability of a hydraulic resistance device (HRD) to assess the force and power output and force–velocity–power profile of short sprints, while examining the effects of hydraulic overload on these outcomes. Twenty-eight amateur athletes performed 20 m sprints under minimal (MiL), moderate (MoL), and high (HiL) overloads. Sprint velocity was measured with the HRD, while resistance force (Fr) was assessed from the pressure via the HRD and from the reaction force via the force plate (FP). Using velocity and Fr during the sprints, maximal velocity (vmax), average horizontal force (Favg), average power (Pavg), and FvP profile variables (F0, v0, and Pmax) were calculated. A two-way ANOVA analysed the effects of overload and calculation method. In addition, a correlation between the HRD and FP measurements was evaluated. For all variables, very high to excellent correlation between the HRD and FP was observed (r ≥ 0.96). However, the Favg, Pavg, F0, and Pmax calculated by the HRD were lower than the FP across all overloads (η2 ≥ 0.51; p < 0.001). Regardless of the method used, Favg, Pavg, and F0 were highest at HiL (η2 ≥ 0.38; p < 0.001), and v0 was highest at MiL (η2 = 0.35; p < 0.001), whereas overload had no significant effect on Pmax (η2 = 0.01; p = 0.770). The HRD is a feasible means for monitoring force and power output during hydraulic resisted sprints but should not be directly compared to other resistance devices. HiL produced the highest Favg, Pavg, and F0 and may be optimal for increasing power output and improving acceleration performance.

On the Horizontal Divergence Asymmetry in the Gulf of Mexico

Due to the geostrophic balance, horizontal divergence-free is often assumed when analyzing large-scale oceanic flows. However, the geostrophic balance is a leading-order approximation. We investigate the statistical feature of weak horizontal compressibility in the Gulf of Mexico by analyzing drifter data (the Grand LAgrangian Deployment (GLAD) experiment and the LAgrangian Submesoscale ExpeRiment (LASER)) based on the asymptotic probability density function of the angle between velocity and acceleration difference vectors in a strain-dominant model. The results reveal a notable divergence at scales between 10 km and 300 km, which is stronger in winter (LASER) than in summer (GLAD). We conjecture that the divergence is induced by wind stress with its curl parallel to the Earth’s rotation.

Observations of Localized Horizontal Geomagnetic Field Variations Associated With a Magnetospheric Fast Flow Burst During a Magnetotail Reconnection Event Detected by the THEMIS Spacecraft

AbstractOn 20 December 2015, three Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft detected a nightside magnetotail reconnection event in the early main phase of a major geomagnetic storm. The spacecraft (P5, P4, and P3) had their footprints located over North America near the Gillam ground magnetometer station in Canada. Multipoint observations, both in space and from the ground, allow for an examination of the spatiotemporal characteristics of the disturbance on the ground and the associated physical drivers in the magnetosphere and ionosphere. This study shows that the horizontal geomagnetic field d/dt localized (on the scale of 100–300 km) feature observed at Gillam ground magnetometer site was caused by an isolated substorm onset near that station driven by a nightside magnetotail reconnection event detected by three THEMIS spacecraft that were located near the central plasma sheet. A close inspection of equivalent ionospheric current and current amplitude maps derived from ground magnetometer measurements using the spherical elementary current system technique indicates that the location of the localization lies roughly between the upward and downward field aligned current system, which is consistent with other earlier studies. This event represents the first reported observation of ground d/dt localization that is directly linked to nightside magnetotail fast flow bursts and reconnection event during the onset phase of a major Geomagnetic disturbance (GMD).

Vertical and horizontal variabilities of ammonia in an agricultural area of Southeast China.

Ammonia (NH3) plays a crucial role in the global nitrogen cycle, the increased NH3 emissions from agricultural activities impacting air, soil, water quality, and human health. Accurately estimating both the vertical and horizontal transport distances of NH3 are important for effective pollution control. Therefore, we used a helium-filled balloon mounted sampler to analyze the vertical profiles of NH3 emissions and their seasonal variations in an agricultural area of southeast China. The annual mean concentration of NH3 in this area was 6.49±0.39μgm⁻3. Vertical measurements revealed a gradual and steady decrease with increasing height, though no significant variation detected between different heights. Seasonal variations showed that the highest concentration occurred in summer (9.98±0.11μgm⁻3) and the lowest in winter (4.65±0.02μgm⁻3). Concentrations in summer significantly higher than those in the other three seasons. NH3 concentrations during the fertilizer application period were much higher than those in the non-fertilizer application time. We also monitored the horizontal transport distance of NH3 after fertilization. It is indicated that NH3 concentrations emitted from agricultural activities decreased exponentially with horizontal transport distance and could only be transported over short distances, up to 250m. Therefore, local emissions are the dominant source of atmospheric NH3. Abetments such as enhanced-efficiency fertilizer could reduce agriculture NH3 emission to promote air quality.

Airborne observations of fast-evolving ocean submesoscale turbulence

Ocean images collected by astronauts onboard the Apollo spacecraft more than 50 years ago revealed a large number of ocean eddies, with a size between 1 and 20 km. Since then, satellite infrared, ocean color, sun glitter and synthetic aperture radar images, with high spatial resolution, have confirmed the ubiquitous presence of these small eddies in all oceans. However, observing the dynamical characteristics and evolution of these eddies has remained challenging. An experiment was recently carried out in the California Current system using the new airborne Doppler Scatterometer (National Aeronautics and Space Administration-Jet Propulsion Laboratory DopplerScatt) instrument that observes surface velocities. Here, with DopplerScatt, we mapped a 30 × 100 km domain over multiple days to unveil numerous 1–20 km ocean eddies, called submesoscale eddies, that evolve over a period of a few hours. The strong interactions between eddies generate horizontal velocity divergence, implying vertical velocities reaching 250 m day−1 at 40 m depth. The velocity field also produces horizontal dispersion of particles over a distance of 50 km within 12 h, which rapidly fills the turbulent eddy field. These observations suggest that submesoscale ocean turbulence may profoundly affect the vertical transport of heat, carbon, and important climatic gases between the atmosphere and the ocean interior, as well as the horizontal dispersion of tracers and particles. As such, submesoscale ocean eddies are a critical element of Earth’s climate system.

Geometric approximations for global atmospheres on moderately oblate planets

AbstractCertain geometric approximations, such as the widely used traditional shallow‐atmosphere, spherical‐geoid (TSA‐SG) and deep‐atmosphere, spherical‐geoid (DA‐SG) approximations, boil down to the specification of a spatial metric tensor. In order to eliminate the leading‐order errors due to the SG and TSA approximations, a sequence of four geometric approximations of decreasing accuracy at high altitudes is obtained. Their Lagrangians possess a simple, closed‐form analytical expression. The approximations capture to leading order the oblateness of the planet, the widening of atmospheric columns with height, the horizontal and vertical variations of gravity, and the non‐traditional part of the Coriolis force. Furthermore, for the last two approximations, the horizontal metric is conformal (proportional) to the spherical metric, which may simplify analytical and numerical formulations of the equations of motion.

Airborne Measurements of Mesoscale Divergence at High Latitudes during HALO–(AC)3

Abstract Boundary layer cloud transformations at high latitudes play a key role for the Arctic climate and are partially controlled by large-scale dynamics such as subsidence. While measuring large-scale and mesoscale divergence on spatial scales on the order of 100 km has proven notoriously difficult, recent airborne campaigns in the subtropics have successfully applied measurement techniques using multiple dropsonde releases in circular flight patterns. In this paper, it is shown that this method can also be effectively applied at high latitudes, in spite of the considerable differences in atmospheric dynamics compared to the subtropics. To show the applicability, data collected during the airborne High Altitude and Long Range Research Aircraft–Transregional Collaborative Research Center TRR 172-Arctic Amplification: Climate Relevant Atmospheric and Surface Processes and Feedback Mechanisms [HALO–(AC)3] field campaign near Svalbard in spring 2022 were analyzed, where several flight patterns involving multiple dropsonde launches were realized by two aircraft. This study presents a first overview of the results. We find that the method indeed yields reliable estimates of mesoscale gradients in the Arctic, producing robust vertical profiles of horizontal divergence and, consequently, subsidence. Sensitivity to aspects of the method is investigated, including dependence on sampling area and the divergence calculation. Significance Statement The aim of this work is to report encouraging results with a recently proposed aircraft-based method for measuring mesoscale vertical motions at high latitudes. Dropsonde data from the recent High Altitude and Long Range Research Aircraft–Transregional Collaborative Research Center TRR 172-Arctic Amplification: Climate Relevant Atmospheric and Surface Processes and Feedback Mechanisms [HALO–(AC)3] campaign are used for this purpose. The method has so far mainly been applied at subtropical to midlatitudes, but not in the Arctic, where the weather and climate conditions are very different. Gaining insight is significant because vertical winds play a key role in the Arctic climate system, including airmass transformations and the behavior of clouds and precipitation. The results motivate the use of the measured vertical winds in follow-up studies with process models.

Unsupervised Ground Roll Attenuation via Implicit Neural Representations

Coherent noise attenuation presents a significant challenge compared to incoherent noise, particularly concerning ground roll in land seismic data. Traditional methods encounter limitations with the substantial overlap of ground roll and reflections, resulting in a compromise between signal distortion and residual noise. Recent deep learning strategies, while promising, predominantly rely on supervised learning, necessitating extensive paired training#xD;data, which is frequently scarce in real-world scenarios. Unsupervised approaches often struggle with convergence issues or excessive parameter tuning. We introduce an unsupervised deep learning framework for separating reflections from ground roll to address these hurdles. Leveraging the inherent low-frequency bias of implicit neural representations (INR), our method prioritizes extracting self-similarity features during training. For seismic data, the network learns self-similarity flattened events before those with deep dips and other incoherent noise. To enhance the self-similarity of reflections, we first apply normal moveout (NMO) correction to flatten reflections and then use the network to extract these flattened reflections from the NMO-corrected data. Moreover, to ensure convergence, we integrate a horizontal derivative regularization term into the loss function, penalizing horizontal variations. This regularization prevents the extraction of unflattened events through extended training, ensuring convergence with high fidelity of flattened reflections. It additionally streamlines parameter tuning, yielding stable outputs and obviating the need for early stopping. We validate our method using synthetic and real land data examples, comparing it with traditional f-k filters with real data and demonstrating its superiority in noise attenuation and signal preservation.

Analysis of Front-End Design in New Energy Vehicles Based on Theory of Visual Perception Dynamics

This study aims to explore how the distribution of visual forces in the front-end design of new energy vehicles influences the overall image of the vehicle and market preferences, providing theoretical references for designers. The study is grounded in the theory of visual perception dynamics, combined with the semantic differential method, and involves a detailed analysis of the front-end designs of four popular new energy SUVs. It begins by selecting new energy vehicle samples based on user surveys, then establishes a semantic vocabulary, and gathers public impressions of the front-end designs of the four models. These designs are then subjected to an in-depth analysis using the theory of visual perception dynamics to examine the distribution of visual forces. The results indicate that different distributions of visual forces and design strategies can effectively convey various visual impressions of the vehicle, thereby meeting the aesthetic needs of different consumer groups. Dynamic visual effects can be created by combining opposing and ascending forces; power and dominance are conveyed through repeated opposition and the convergence of visual elements; elegance and dignity emerge from a balanced distribution of forces; and stability is reinforced by emphasizing horizontal divergence and shifting the visual center downward. This study provides new perspectives and methods for front-end design in new energy vehicles, with the hope of positively influencing future design practices.

Relationship between ball release point variability and pitching performance in major league baseball.

This study examined the relationship between ball release points and pitching performance among professional baseball pitchers, with a focus on variability. We used open-source data to compare ball release point variability between Major League Baseball (MLB) and Minor League Baseball (MiLB) players. The relationship between pitching performance and variability was analyzed using multiple regression analysis. MLB players exhibited smaller ball release point variability compared to MiLB players. The analysis showed that pitching performance was strongly related to ball release point variability, especially in the horizontal direction on the coronal plane. Horizontal ball release point variability was most strongly related to strikeout ability among pitching performances. These results suggest that reducing horizontal ball release point variability may improve pitching performance, particularly by increasing strikeouts and reducing home runs allowed. This study provides a data-driven approach to understanding the mechanics of pitching and can be applied to the development of advanced training methods and technical solutions aimed at improving pitching performance in baseball players.

An aftermath analysis of caving characteristics and movement of overlying strata in fully mechanized longwall gob

The large-scale collapse of overlying strata in the gob directly affect the safe production of coal mines; they are also the major causes of geological disasters, such as ground cracks, surface subsidence, and ground collapse. In this paper, the movement and caved characteristics of overlying strata during coal seam excavation are studied by conducting a physical model experiment. Results show that overlying strata have different movement and caved laws during the initial, intermediate, and later mining stages. During the initial mining stage, overlying strata do not collapse, and the subsidence is extremely small. During the intermediate mining stage, overlying strata cave along the vertical direction, and caved height gradually increases. Large numbers of cavities, abscission layers, and fractures exist between caved strata. The fractured area gradually increases upward, and the subsidence increases considerably. During the later mining stage, overlying strata cave along the horizontal direction. The abscission layers between the caved strata of the central are compacted. The compacted area is surrounded by a fractured area. The compacted and fractured areas increase along the horizontal direction. The subsidence curves exhibit a horizontal variation. Overlying strata evolve from the self-equilibrium stage to the vertical collapse stage, and finally, the horizontal collapse stage. The fractured area changes from a no fractured area to a fractured area, increases vertically, and finally, increases horizontally. The subsidence curve changes from extremely small to large, and finally, changes horizontally.

Studying the kinetic energy budget and moisture transport during a severe case of cyclogenesis

This work aimed to investigate the kinetic energy budget and moisture transport of a case of cyclogenesis that causes intense rains over north and middle parts of Saudi Arabia on November 23–25, 2022. The study of kinetic energy (KE) and its budget concludes that the majority of the KE was concentrated at 400 hPa and above, coinciding with the powerful activity of the subtropical jet stream during the period of cyclogenesis. The KE generation through cross-contour flow serves as a major energy source. During the cyclogenesis process, KE dissipation from grid to subgrid scales is a major energy sink, while the horizontal flux divergence of KE acts as a source of KE. The study of moisture transport through the attributes of moisture-flux components and the dispersion of perceptible water during the cyclogenesis reveals that within the lower tropospheric layer, the rotating component of moisture flux brings moisture from two primary regions: One zone spans the Arabian Sea and includes the south Red Sea, north of Ethiopia, and central Sudan; the other region covers the Mediterranean Sea and the North Atlantic. The primary moisture source in the middle layer is located over central Africa, with origins traced back to the Atlantic Ocean, Arabian Sea, and Indian Ocean.

Novel method to estimate horizontal variability of shear wave velocity through multichannel analysis of surface waves

Scale of fluctuations (SOFs) of spatially variable soil properties have been regarded as one of the important parameters for performing reliability-based design in geotechnical engineering. However, the information required to estimate the SOFs in practice is limited, especially in the horizontal direction. In this study, the potential use of Multichannel Analysis of Surface Waves (MASW) to estimate the SOFs of shear wave velocity (VS) in horizontal direction is investigated through a series of numerical investigations. 2D random field models with a vertically increasing trend of VS were first simulated with different levels of variability controlled by the coefficient of variation (COV) and SOF. Afterwards, a large number of numerical MASW tests were performed using a 2D finite difference method, where the survey lines were progressively shifted. Results show that the COV of VS can be determined from the scatter of the dispersion curves, whereas the horizontal SOF of VS can be appropriately estimated from the phase velocity profile presented in the wavelength form. Additionally, in-situ MASW tests were conducted to estimate the horizontal SOF, and the obtained results align with those estimated by different methods. It is highlighted that the accuracy of the estimation depends on survey length. The interpretation using a long array reflects an averaged site condition of the survey area, thus losing the variability information. Favorable predictions are produced when survey length is shorter than 1.0 SOF. However, it should be noted that use of short survey length may limit the depth of investigation.

Topography Dominates the Spatial and Temporal Variability of Soil Bulk Density in Typical Arid Zones

Soil bulk density is a crucial indicator for assessing soil matter storage and soil quality. Due to the complexity of sampling soil bulk density, particularly in deeper layers, it is essential to study the spatial distribution patterns of soil bulk density and their influencing factors. To address the gap in large-scale studies of vertical (from surface to deeper layers) and horizontal (across a broad area) variations in soil bulk density in arid regions, this study focuses on Changji Prefecture, located in the central northern slope of the Tianshan Mountains and characterized by typical vertical zonation. By integrating classical statistics, geostatistics, and geographic information systems (GISs), this study investigates the spatial distribution patterns and driving factors of soil bulk density. The results indicate that soil bulk density in Changji Prefecture increases with soil depth, with significantly lower values in the surface layer than in deeper layers. Spatially, despite minimal variation in latitude, there is considerable elevation difference within the study area, with the lowest elevations in the central region. Soil bulk density exhibits a spatial distribution pattern of higher values in the northeast (desert areas) and lower values in the southwest (forest areas). The nugget effect in the surface layer (0–20 cm) is substantial at 44.9%, while the deeper layers (20–100 cm) show nugget effects below 25%, suggesting that the influence of both natural and anthropogenic factors on deep soil bulk density is limited and mainly affects the surface layer. Stepwise regression analysis indicates that among topographic factors, slope and elevation are the primary controls of spatial variability in soil bulk density across layers. This research demonstrates that, in arid regions, soil bulk density is influenced primarily by natural factors, with limited impact from human activities. These findings provide valuable data support and theoretical guidance for soil management, agricultural planning, and sustainable ecosystem development in arid regions.

Investigation of the aerodynamic performance of the dragonfly-inspired tandem wings considering the coupling between the stroke plane and phase difference

The dragonfly's tandem wings can make full use of the interference of various spatial vortices to obtain efficient flight capability. The complex coupling among multiple motion parameters will have an important influence on the interference between the forewing (FW) and hindwing (HW). In this paper, the aerodynamic performance of the dragonfly-inspired tandem wings is analyzed using the Computational Fluid Dynamics (CFD) method considering the coupling effect of the stroke plane and phase difference. The variation of the force coefficient, vortex structure and aerodynamic efficiency of the tandem wings in forward flight are analyzed, respectively. The results show that the stroke plane angle affects the distribution of the leading edge vortex (LEV) and trailing edge vortex (TEV), which primarily controls the trend of horizontal force variation. The phase difference of tandem wings will change the fluctuation of the horizontal force coefficient curve by affecting the meeting time of the forewing and hindwing. However, with the increase of stroke plane angle, the fluctuation of aerodynamic coefficient caused by phase difference will decrease. The propulsion efficiency(η) and power loading(PL) can be improved through increasing the stroke plane angle and selecting a reasonable phase difference. The conclusion can provide theoretical guidance for the design of the dragonfly-inspired tandem flapping wing aircraft (DTFWA) and the choice of motion parameters.

Multivariate Environmental Factors and Seasonal Spatial Dynamics Affecting the Phytoplankton Community in Yazhou Bay, South China Sea

This study investigated phytoplankton and water environmental factors in Yazhou Bay, South China Sea, during the winter, spring, and summer of 2023. It examined phytoplankton community structure, subgroup heterogeneity, and key environmental drivers. Phytoplankton abundance ranged from 0.08 to 14.30 × 10⁴ cells·L−1, with high concentrations in estuary and nearshore zones. In summer, currents carry phytoplankton offshore, with stratification leading to high sedimentation in southern offshore waters. RDA results indicated that in winter and spring, inorganic nitrogen mainly influences phytoplankton distribution, while silicate is the primary factor in summer. Although seasonal differences in total phytoplankton abundance are minimal, significant horizontal and vertical distribution variations exist. Diverse preferences of different phytoplankton species for temperature, salinity, nitrogen, and phosphorus result in high species diversity. The Shannon–Wiener diversity index (H′) averages 3.96 ± 0.09, and the Pielou evenness index (J) averages 0.82 ± 0.01. Dominant species include Pseudo-nitzschia pungens, Skeletonema costatum, and Rhizosolenia sinica. Influenced by external oceanic water masses, estuary input, and islands, phytoplankton subgroups show regional and seasonal variations. Despite recorded harmful algal blooms (HABs) in adjacent waters, Yazhou Bay’s high biodiversity and low cell density suggest a low HAB risk, though future risks due to climate change and human activities remain.

Direct Observations of Coastally Generated Near-Inertial Waves During a Wind Event.

Wind over the ocean generates near-inertial velocities. In the open ocean, horizontal variability in the inertial frequency and mesoscale vorticity generate internal waves that transport energy laterally and drive diapcynal mixing in remote locations. In the coastal ocean, horizontal variability is produced by the coastline. This study analyzes observations along a straight coastline in Lake Superior, which acts as a "natural laboratory" for the coastal ocean. Depth-profiles of velocity, temperature, and turbulent miscrostructure were collected during a 96hr repeat survey from 3 to 20km offshore in Aug 2018. Wind work was 2mW and generated 0.2m near-inertial velocities that were inhibited within two internal Rossby radii (6km) of the coast. The velocities are interpreted as a superposition of a "forced flow", which is horizontally uniform, and a "wave flow", associated with offshore propagating near-inertial waves. A 1D momentum equation skillfully predicts the horizontally averaged near-inertial velocities and the TKE shear production, which matches the 1mW observed TKE dissipation rate. The offshore propagating wave has an energy flux of 10W (m-coastline)-1 and a downward energy flux of 1mW . These results suggest that most near-inertial wind work is lost directly to TKE shear production, but some energy is transferred to offshore propagating waves that may help catalyze shear instability away from the coast.

Mercury Spectrophotometric Modeling Using MESSENGER Data

Mercury is covered by a regolith that affects how light is scattered from the planet’s surface. To deduce the physical properties of Mercury’s regolith, we use spectrophotometry from the Mercury Dual Imaging System instrument of NASA’s MErcury Surface, Space ENvironment, GEochemistry and Ranging mission. The data come in eight colors in wavelengths of 433.2–996.2 nm, with phase angles of 20°–125°. A theoretical particulate-medium model is used to interpret the observed reflectance. The model includes a shadowing correction that depends on three geometry parameters of the regolith, allowing for the retrieval of the physical regolith structure from the spectrophotometry. The most important parameter is the packing density v, while the other two parameters describe the regolith’s roughness as a fractional Brownian motion surface: the Hurst exponent H in the horizontal and the amplitude σ in the vertical direction. The numerical implementation of the model includes a set of discrete parameter values, which we extend by using trilinear interpolation: 0.15–0.55 for v, 0.20–0.80 for H, and 0.00–0.10 for σ. We optimize the model parameters in the least-squares sense using the Nelder–Mead simplex method followed by Markov Chain Monte Carlo (MCMC) sampling. Our results indicate that Mercury’s regolith is densely packed (v = 0.547 ± 0.004) with moderate horizontal variations (H = 0.606 ± 0.009) and large height variations (σ = 0.0998 ± 0.0003). The MCMC solution allows us to predict the spectrophotometry for differing viewing geometries. Future work includes improving the implementation of the model by increasing the packing density values.

Study of vowel formant data using Gabmap: A pilot analysis of a Lithuanian dialect

Abstract The article reviews the possibilities of applying the web application Gabmap developed by researchers at the University of Groningen to the analysis of vowel formant data based on the results of the study of one Lithuanian dialect. The Western Aukštaitian dialect of Kaunas is traditionally considered the basis of Standard Lithuanian. The study was based on the data of 18 male speakers from six dialectal localities representing distinctive areas. The normalized mean values of the first two vowel formants (F1, F2) were analyzed in certain word positions illustrating distinguishing features, which were processed using Gabmap tools designed for analyzing numeric sequences. Gabmap tools most beneficial for the researchers of experimental phonetics along with the aspects of their application to research were emphasized in the study; it also underlined those tools the use of which requires additional application of other conventional methods of experimental sound analysis, such as sound spectrum analysis, planimetric models, etc. In the study of the Western Aukštaitian of Kaunas, the Gabmap analysis confirmed significant horizontal variation within the dialect area and foregrounded the most tightly related sites sharing the greatest number of common features in their vocalism.

Avian diversity across guilds in North America versus vegetation structure as measured by the Global Ecosystem Dynamics Investigation (GEDI)

Avian diversity, a key indicator of ecosystem health, is closely related to canopy structure. Most avian diversity models are based on either optical remote sensing or airborne lidar data, but the latter is limited to small study areas. The launch of the Global Ecosystem Dynamics Investigation (GEDI) instrument in 2018 has opened new avenues for exploring the influence of vegetation structure on avian diversity. To examine how direct measurements of canopy structural characteristics explain bird diversity across North America, we analyzed 18 GEDI metrics from 2019 to 2022, along with corresponding Breeding Bird Survey (BBS) counts and AVONET morphological data, analyzing effects across broad regions and at varying spatial extents. We grouped 440 bird species into 20 ecological guilds under six guild categories and employed random forest algorithms to model avian diversity across eight spatial extents (1, 2, 3, 4, 5, 10, 20, and 39.2 km). The models predicted six diversity indices, including species richness (sRich), functional richness (fRich), evenness (fEve), dispersion (fDis), divergence (fDiv), and redundancy (fRed) across eight spatial extents. The best-predicted guilds varied for each diversity index. The most accurate models were sRich (pseudo-R2 = 0.71, RMSE = 4.28) and fRed (pseudo-R2 = 0.60, RMSE = 0.13) for forest specialists guilds; fRich (pseudo-R2 = 0.55, RMSE = 0.18) for urban guilds; fEve (pseudo-R2 = 0.28, RMSE = 0.08) for insectivore guilds; and fDiv (pseudo-R2 = 0.38, RMSE = 0.12) and fDis (pseudo-R2 = 0.53, RMSE = 0.87) for short distance migrants guilds. Our results highlight the critical role of canopy structure, including its horizontal and vertical distribution and variation, in predicting avian diversity, as measured by the mean number of detected modes (num_detectedmodes), the standard deviation of foliage height diversity (FHD), num_detectedmodes, canopy cover, and plant area index (PAI) across the spatial extents centered on BBS routes. Therefore, we recommend incorporating the GEDI metrics into avian diversity modeling and mapping across North America, thereby potentially enhancing bird habitat management and conservation efforts.