Wind Field Research Articles

High-accuracy vertical wind profiling up to 12km using a 1064 nm coherent Doppler Lidar with 10 mJ pulsed laser.

We present a high-performance coherent Doppler wind Lidar (CDWL) system designed for long-range vertical and horizontal wind field detection. The system utilizes a self-developed single-frequency pulsed Nd:YAG laser operating at 1064 nm, delivering a pulse energy of 10 mJ. Coupled with a 180 mm diameter telescope, this CDWL achieves a horizontal line-of-sight (LOS) detection range of 25 km and vertical wind velocity profiling up to 12 km within 1-minute integration time. Notably, it enables continuous wind field retrieval within 10 km altitude through the Doppler beam-swinging (DBS) scanning technique, addressing the challenge of vertical detection limitations in existing systems. Validation against ERA5 reanalysis data demonstrates high consistency, with coefficients of determination (r2) of 0.8709 and 0.9623 for U and V wind components, respectively. This work advances coherent Lidar technology by combining high-energy solid-state lasers with optimized amplification techniques, offering a robust tool for meteorological applications such as wind shear monitoring and atmospheric dynamics research.

FINITE ELEMENT ANALYSIS OF A FLEXIBLE DUAL-SPEED SALIENT POLE SYNCHRONOUS MACHINE

This paper deals with the performance analysis of a DC-excited dual-speed synchronous machine (DSSM) with salient poles equipped with a damper winding. The proposed DSSM can operate at two speeds when connected to the mains. The number of pole pairs can be adjusted while running by the special design of the stator and rotor windings, which can commute between p = 1 and p = 2 pole pairs (by adjusting simultaneously the stator and rotor coil connections). The presence of the damper winding is helpful for the machine to self-start when directly connected to the grid as a motor and to pass smoothly from one speed to the other. The 2D finite element computations used to estimate the machine transient regimes and to determine its specific characteristics were carried out using the professional software package Flux® dedicated to electromagnetic field analysis. The proposed machine was analyzed both as a motor and as a generator.

A new global high-resolution wave model for the tropical ocean using WAVEWATCH III version 7.14

Abstract. Climate change is driving sea-level rise and potentially intensifying extreme events in the tropical belt, thereby increasing coastal hazards. On tropical islands, extreme sea levels and subsequent marine flooding can be triggered by cyclones but also distant-source swells. Knowledge of sea states in the tropical ocean is thus of key importance, and their study is usually based on spectral wave models. However, existing global wave models typically employ regular grids with a coarse resolution, which fail to accurately represent volcanic archipelagos, a problem usually circumvented by the use of obstruction grids but typically resulting in large negative biases. To overcome this problem, this study presents a new global wave model with a focus on distant-source swells, which have received less attention than waves generated by cyclones. To accurately simulate sea states in tropical areas, we implemented the spectral wave model WAVEWATCH III© (WW3) over a global unstructured grid with a spatial resolution ranging from 50 km to 100 m. The model is forced by ERA5 wind fields, corrected for negative biases through a quantile–quantile approach based on satellite radiometer data. The wind input source terms adjusted accordingly and the explicit representation of tropical islands result in improved predictive skills in the tropical ocean. Moreover, this new simulation allows for the first time direct comparisons with the in situ data collected on volcanic islands at water depths ranging from 10 to 30 m, which corresponds to a few hundred meters from the shore.

Application of Three-Dimensional Wind Fields and Dual-Polarization Signals of an X-band Phased Array Weather Radar in Diagnosing Vertical Motion and Cloud Electrification in Convective Storms

Application of Three-Dimensional Wind Fields and Dual-Polarization Signals of an X-band Phased Array Weather Radar in Diagnosing Vertical Motion and Cloud Electrification in Convective Storms

Tracking long-distance power transmission line under uncertain wind fields by QUAV using nonlinear model predictive control

Tracking long-distance power transmission line under uncertain wind fields by QUAV using nonlinear model predictive control

Numerical simulation of spatial wind fields in Xumishan Grottoes over complex terrain

Windy weather frequently occurs in Northwest China, and wind erosion is a typical issue for stone carvings in the caves. In the present study, computational fluid dynamics (CFD) simulations relying on steady 3D Reynolds-averaged Navier-Stokes (RANS) equations were used to simulate the spatial wind field over complex terrain with field measurement validation. This study has the following two aims: (1) to evaluate the accuracy of wind fields simulations with the Interpolated Multiscale Profile (IMP) method over complex terrain; and (2) to provide spatial wind field data of Xumishan Grotto Zone under neutrally stratified atmospheric boundary layer (ABL) over complex terrain. Unmanned aerial vehicle (UAV) oblique photogrammetry and multirotor UAV technology provide application scenarios for the establishment of a high-precision digital model and the determination of accurate inlet boundary conditions. By compiling user-defined functions (UDF) and using the block interpolation method, this method addresses the overestimation of the inlet wind velocity caused by the large elevation difference of the inlet over complex terrain. The results show that the 3D steady RANS simulation based on the IMP method can reasonably and accurately simulate spatial wind fields over complex terrain. This study also provides spatial wind fields data for addressing stone carving erosion caused by strong winds in semi-open Grottoes.

Numerical modelling and backstepping-based control of barge platform-supported offshore wind turbines under wind and wave loads

ABSTRACT Offshore Wind Turbines (OWTs) have gained widespread importance due to increased dependence on renewable energy. The response of turbine may be significantly high in region transitions where the loads are stochastic in nature and therefore they need to be effective after transition of such states. This work proposes a novel controller concept and its application in the barge-type OWTs to achieve the maximum as well as regulated electrical power under irregular wind and waves. The objectives are arrived through geometrical theory-based backstepping control algorithm wherein the structural system non-linearity is retained via Lyapunov functions appropriately to account for the system fluctuating dynamics. The OWTs simulated for three wind speeds (10, 15 and 21 m/s) with a turbulence intensity of 0.1 are selected for the Indian scenario. A sea states being stochastic, the responses are obtained using average of Monte Carlo simulations to rule out the uncertainty by ensemble statistics. The results show that the proposed backstepping controller is able to harvest optimised power effectively in all load case scenarios and performs better than reference Baseline controller. The achieved electrical power through the proposed method is 14 % higher than conventional one for 10 m/s below rated wind field scenario and similar fashion continued in above rated side for response improvement of 35 % in 15 m/s and 23 % in 21 m/s than conventional one. The statistical measuring tools – maxima and mean – are close and hovering to the reference value when wind speeds are close to below rated and above rated wind speeds, whereas the barge motions and tower properties are less using the proposed controller. All the load case scenarios, the ensemble standard deviation is far lower than the conventional one reflects the lesser fluctuations in the output power.

Evaluation of the Sensitivity of PBL and SGS Treatments in Different Flow Fields Using the WRF-LES at Perdigão

This study investigates the effectiveness of the large eddy simulation version of the Weather Research and Forecasting model (WRF-LES) in reproducing the atmospheric conditions observed during a Perdigão field experiment. When comparing the results of the WRF-LES with observations, using LES settings can accurately represent both large-scale events and the specific characteristics of atmospheric circulation at a small scale. Six sensitivity experiments are performed to evaluate the impact of different planetary boundary layer (PBL) schemes, including the MYNN, YSU, and Shin and Hong (SH) PBL models, as well as large eddy simulation (LES) with Smagorinsky (SMAG), a 1.5-order turbulence kinetic energy closure (TKE) model, and nonlinear backscatter and anisotropy (NBA) subgrid-scale (SGS) stress models. Two case studies are selected to be representative of flow conditions. In the northeastern flow, the MYNN NBA simulation yields the best result at a height of 100 m with an underestimation of 3.4%, despite SH generally producing better results than PBL schemes. In the southwestern flow, the MYNN TKE simulation at station Mast 29 is the best result, with an underestimation of 1.2%. The choice of SGS models over complex terrain affects wind field features in the boundary layer more than above the boundary layer. The NBA model generally produces better results in complex terrain when compared to other SGS models. In general, the WRF-LES can model the observed flow with high-resolution topographic maps in complex terrain with different SGS models for both flow regimes.

Bivariate DeepKriging for Large-Scale Spatial Interpolation of Wind Fields

High spatial resolution wind data play a crucial role in various fields such as climate, oceanography, and meteorology. However, spatial interpolation or downscaling of bivariate wind fields, characterized by velocity in two dimensions, poses a challenge due to their non-Gaussian nature, high spatial variability, and heterogeneity. While cokriging is commonly employed in spatial statistics for predicting bivariate spatial fields, it is suboptimal for non-Gaussian processes and computationally prohibitive for large datasets. In this article, we introduce bivariate DeepKriging, a novel method using a spatially dependent deep neural network (DNN) with an embedding layer constructed by spatial radial basis functions for predicting bivariate spatial data. Additionally, we devise a distribution-free uncertainty quantification technique based on bootstrap and ensemble DNN. We establish the theoretical basis for bivariate DeepKriging by linking it with the Linear Model of Coregionalization (LMC). Our proposed approach surpasses traditional cokriging predictors, including those using commonly used covariance functions like the linear model of co-regionalization and parsimonious bivariate Matérn covariance. We demonstrate the computational efficiency and scalability of the proposed DNN model, achieving computation speeds approximately 20 times faster than conventional techniques. Furthermore, we apply the bivariate DeepKriging method to wind data across the Middle East region at 506,771 locations, showcasing superior prediction performance over cokriging predictors while significantly reducing computation time.

Long-Term (1979–2024) Variation Trend in Wave Power in the South China Sea

Wave power (WP) is a strategic oceanic resource. Previous studies have extensively researched the long-term variations in WP in the South China Sea (SCS) for energy planning and utilization. This study extends the analysis of long-term trends to the last year based on ERA5 (European Centre for Medium-Range Weather Forecasts Reanalysis v5) reanalysis data from 1979 to 2024. Our results mainly indicate that the trends in WP after 2011 are significantly different from those before 2011. Before 2011, the WP in the SCS primarily showed an increasing trend, but, after 2011, it shifted to a decreasing trend. This trend has seasonal differences, manifested as being consistent with the annual trend in winter and spring while being inconsistent with the annual trend in summer and autumn. It indicates that the opposite trend in WP before and after 2011 was mainly the result of WP variations in winter and spring. To illustrate the driving factor for the WP’s variations, the contemporary long-term trend of the wind fields is systematically analyzed. Analysis results reveal that, regardless of seasonal differences or spatial distribution, the two trends are consistent in most situations, indicating that wind fields are the dominant factor for the long-term variations in WP. Meanwhile, the effects of the wind fields on the WP variations can also be modulated by environmental factors such as oceanic swell propagation and local topography. This study contributes to the knowledge of the latest trends and driving factors regarding the WP in the SCS.

Impact of Multipole Fields on the Performance and Dynamics of Quadrupole Linear Ion Traps.

Additional multipole fields are unavoidable in real quadrupole linear ion traps (QLITs) and play a crucial role in influencing their performance. In this study, the impact of these multipole fields on ion ejection and dynamics in QLITs is exhaustively analyzed using a vectorized Runge-Kutta method and a comprehensive theoretical model of ion vibration involving all the common multipole fields. The comparison of nonlinear resonance under different added multipole fields reveals obvious ion ejection from hexapole and octopole resonances as well as multiple resonance points in most multipole fields. Ion ejection with dipole excitation under these fields demonstrates distinct variations at different excitation working values, influenced by the inherent power distribution of ion motion in a linear quadrupole and the energy dispersion caused by the added multipole fields at varying stability parameters. Furthermore, theoretical and numerical analyses of ion dynamics mutually validate each other, offering the first comprehensive demonstration of ion excitation responses under various multipole fields across a wide stability range. The results show that for positive even-order multipole fields, forward scans lead to lower and more stable maximum amplitude responses compared to reverse scans, while the opposite is true for negative fields. In hexapole fields, the forward scan responses are lower than the reverse scan responses, and both increase sharply near nonlinear resonance points, regardless of field polarity. This work provides a thorough theoretical foundation for optimizing multipole field applications in QLITs.

Atmospheric mixed Rossby–gravity waves over the tropical Pacific during the austral summer

Abstract. Atmospheric mixed Rossby–gravity wave (MRGW) activity during the austral summer months (December–January–February) is examined by means of observational analyses for the 1991–2020 period. The main objective of the study is to explore the relationship between tropical circulations at upper- and lower-tropospheric levels and tropical convective activity. Using an empirical orthogonal function (EOF) analysis of the high-frequency meridional component anomalies of the wind at 200 hPa, for zonal wavenumbers 4–6, episodes of intense MRGW activity are detected. Composite analyses based on an EOF analysis show a quadrature phase over the central eastern equatorial Pacific between the MRGW structure in the upper and lower troposphere. Lagged correlations between the first two EOFs' principal components, as well as the wind field and outgoing longwave radiation (OLR), show that MRGWs are laterally forced at upper-tropospheric levels over the westerly duct region and later propagate westward and downward. Once the MRGW reaches the lower-tropospheric levels, it induces zones of moisture convergence that modulate convective activity. Tropical convection develops in the MRGW moisture convergence region at 700 hPa and the divergent region of the wave at 200 hPa. Since the MRGW phase tilts eastward with height, moisture convergence at lower-tropospheric levels tends to coincide with divergence at upper levels favoring intense convective activity which results in the antisymmetric outgoing longwave radiation anomalies observed off the Equator near the MRGW. Therefore, the occurrence of MRGWs over the eastern Pacific is a form of tropical–extratropical interaction that generates tropical convection anomalies by means of induced lower-tropospheric moisture convergence and divergence anomalies.

Radial Evolution of a Density Structure within a Solar Wind Magnetic Sector Boundary

Abstract This study focuses on a radial alignment between Parker Solar Probe (PSP) and Solar Orbiter (SolO) on 2021 April 29 (during a solar minimum), when the two spacecraft were, respectively, located at ∼0.075 and ∼0.9 au from the Sun. A previous study of this alignment allowed the identification of the same density enhancement (with a timescale of ∼1.5 hr) and substructures (timescales of ∼20–30 minutes), passing first by PSP and then by SolO after a ∼138 hr propagation time in the inner heliosphere. We show here that this structure belongs to the large-scale heliospheric magnetic sector boundary. In this region, the density is dominated by radial gradients, whereas the magnetic field reversal is consistent with longitudinal gradients in the Carrington reference frame. We estimate the density structure radial size to remain of the order L R ∼ 106 km, while its longitudinal and latitudinal sizes are estimated to expand from L φ,θ ∼ 104–105 km in the high solar corona to L φ,θ ∼ 105–106 km at PSP and L φ,θ ∼ 106–107 km at SolO. This implies a strong evolution of the structure’s aspect ratio during the propagation, due to the plasma’s nearly spherical expansion. The structure’s shape is therefore inferred to evolve from elongated in the radial direction at ∼2–3 solar radii (high corona) to sizes of nearly the same order in all directions at PSP and then becoming elongated in the directions transverse to the radial at SolO. Measurements are not concordant with local reconnection of open solar wind field lines, so we propose that the structure has been generated through interchange reconnection near the tip of a coronal streamer.

Characteristics of Tropical Cyclone Outer Size and Structure Associated With Extratropical Transition

AbstractThere is a lack of consensus on how tropical cyclone outer winds may change, if at all, due to extratropical transition. Hence, this study examines changes in North Atlantic tropical cyclone outer size and structure using a large, multidecadal sample of cases from reanalysis data. These results suggest that tropical cyclone outer size and structure typically remain unchanged until after extratropical transition end. In those minority of cases with strong expansion during extratropical transition, increases in tropical cyclone outer winds begin first in the lower troposphere during extratropical transition and build upwards over time. This broadening of the azimuthal‐mean outer winds is also associated with an increasingly asymmetric outer wind field with the strongest winds concentrated downstream of the tropical cyclone. These storms that expand most strongly during transition are typically smaller at transition start and eventually become embedded in more strongly baroclinic environments by extratropical transition end.

Energy-Efficient Trajectory Planning and Feasibility Assessment Framework for Drone Package Delivery

This paper presents a comprehensive framework for energy-efficient trajectory planning and feasibility assessment in drone package delivery operations across urban areas. The framework is designed to assist unmanned aerial systems operators within the Unmanned Aircraft System Traffic Management architecture by generating feasible operational plans for a given set of package delivery missions. The framework addresses the multifaceted computational challenges of this problem using a two-layer approach. The upper layer consists of a Markov-decision-process-based trajectory planner that generates energy-efficient trajectories by considering factors such as the aircraft model, the length and smoothness of the trajectories, and the interaction of the aircraft with the wind field. The lower layer then assesses the feasibility of these energy-efficient trajectories through a battery state of charge prediction-based uncertainty quantification scheme. We demonstrate the efficacy of the proposed framework in a realistic drone package delivery scenario set in an urban environment in Boston City. In addition, an actual flight experiment was conducted to validate the framework’s performance. The results highlight the framework’s capability to generate energy-efficient trajectories and assess the feasibility of each mission. Source code: github.com/Abenezergirma/ETP-FA-Package-Delivery.

Decadal Linkage of Sea Level Anomalies Between the South China Sea and Western Tropical Pacific

AbstractThe decadal variability of sea level anomalies (SLA) in the South China Sea (SCS) is coherent with those in the Western Tropical Pacific (WTP), and both correlate with the Pacific Decadal Oscillation (PDO) with changing correlation across different decades, characterized by an enhanced relationship after 1993. This study analyzed the underlying factors in the relationship between SLA in the SCS and PDO based on observations and simple ocean model experiments. The results reveal that the key factor is the anomalous atmospheric anticyclonic circulation over the tropical western North Pacific (WNPAAC), which can induce positive decadal SLA responses. The WNPAAC index, defined as the regional mean Wind Stress Curl in the Tropical Western North Pacific (TWNP, 3°–18°N, 130°E–160°W), exhibits a negative correlation (r = −0.68 for 1940–2022, exceeding the 95% confidence level) with the decadal steric sea level first mode principal component of empirical orthogonal function. The index can thus characterize the decadal SLA variations in the SCS and the WTP well. Sensitivity experiments using a 1.5‐layer nonlinear Reduced‐Gravity Ocean model demonstrate that the TWNP wind field accounts for most of the decadal SLA variations in the SCS, with an explained variance percentage (skill) of 60.95%. This study suggests that the TWNP wind field, influenced by tropical central Pacific sea surface temperature anomalies through the Matsuno‐Gill response after 1965, dominates decadal SLA variability in the SCS. This wind field functions as a subsystem within the PDO dynamics, showing relative independence from the PDO.

Effects of slope ratios on wind field over two-dimensional continuous smooth ridges using large eddy simulations

Effects of slope ratios on wind field over two-dimensional continuous smooth ridges using large eddy simulations

A Statistical–Dynamical Downscaling Technique for Wind Resource Mapping: A Regional Atmospheric-Circulation-Type Approach with Numerical Weather Prediction Modeling

Many Caribbean low-latitude small island states lack wind maps tailored to capture their wind features at high resolutions. However, high-resolution mesoscale modeling is computationally expensive. This study proposes a statistical–dynamical downscaling (SDD) method that integrates an atmospheric-circulation-type (CT) approach with a high-resolution numerical weather prediction (NWP) model to map the wind resources of a case study, Trinidad and Tobago. The SDD method uses a novel wind class generation technique derived directly from reanalysis wind field patterns. For the Caribbean, 82 wind classes were defined from an atmospheric circulation catalog of seven types derived from 850 hPa daily wind fields from the NCEP-DOE reanalysis over 32 years. Each wind class was downscaled using the Weather Research and Forecasting (WRF) model and weighted by frequency to produce 1 km × 1 km climatological wind maps. The 10 m wind maps, validated using measured wind data at Piarco and Crown Point, exhibit a small positive average bias (+0.5 m/s in wind speed and +11 W m−2 in wind power density (WPD)) and capture the shape of the wind speed distributions and a significant proportion of the interannual variability. The 80 m wind map indicates from good to moderate wind resources, suitable for determining priority areas for a detailed wind measurement program in Trinidad and Tobago. The proposed SDD methodology is applicable to other regions worldwide beyond low-latitude tropical islands.

Pipeline leakage characteristics under water–oil mixed migration model

With the increase in long distance oil pipeline mileage, leakage caused by pipeline corrosion has become an important safety problem. In order to study the characteristics of pipeline leakage, a lake district was selected as the research object, two-dimensional shallow water equation was used as the basic control equation, and the hydrodynamic model of the lake district was established using the hydrodynamic module of MIKE21 software. Based on oil particle method and coupled particle tracking module, the mixed migration model of water–oil dual system was established. The diffusion process and law of pipeline leakage in water body are studied, and the influence law of wind field, water level, and leakage aperture change on leakage diffusion is compared and analyzed. The study shows that the wind field has the most significant effect on the oil film diffusion trajectory and diffusion velocity. The increase in water level will reduce the diffusion rate of oil particles, and the increase in leakage aperture will significantly increase the oil film concentration, but it has little effect on the diffusion trajectory.

Study of Geomagnetic Storms During Ascending Phase of Solar Cycle 25 and it's Bio- inspired Prediction

The geomagnetic storms have been classified based on the Dst index. The investigation of the ascending phase of Solar Cycle 25 has revealed that 69 moderate storms, 3 intense storms, and one severe storm had occurred from 2019 to 2023 till June. In the present work, we have correlated the coronal mass ejection (CMEs) and geomagnetic storms with a phase of solar cycle 25. In this research work it has also been tried to forecast the disturbed storm time index with artificial neural network (ANN) and bio inspired algorithm called as particle swarm optimization (PSO) along it with genetic algorithm (GA). The parameters such as solar wind density, plasma speed, and magnetic field of solar wind have been applied to analyze geomagnetic storms. In this research work It has also been correlated the rate of occurrence of geomagnetic storms with solar activity. Along with this correlative result, we have also found that the bio-inspired hybridized computational techniques as ANN+ PSO and ANN+PSO+GA have shown very much accurate results for various duration of Dst index.