Current Issue : July-September Volume : 2026 Issue Number : 3 Articles : 5 Articles
Deep learning has become an important tool for wind power forecasting because it can help improve wind energy utilization and support reliable grid-connected operation. For wind farms, accurate turbine-level forecasting depends on spatial interactions among turbines and temporal evolution of historical operating data. In this study, a spatiotemporal forecasting framework is developed by combining a Graph Attention Network with a Temporal Convolutional Network. The graph attention module describes the neighborhood relations among turbines and learns their influence strengths adaptively, while the temporal convolution module extracts temporal patterns from multivariate SCADA sequences for multi-step prediction. On this basis, the learned attention weights are further used to define a node influence metric. This makes it possible to identify a small set of key turbines and use only their historical data to predict the future power output of the whole wind farm. The proposed framework is evaluated using one year of SCADA data from 134 turbines. A sliding-window dataset is constructed, and the model is tested on the training, validation, and test sets. The results show that the method can capture the spatio-temporal dependencies within the wind farm and still provide effective farm-wide forecasting when only limited observation nodes are available. The value of this work lies in organizing existing techniques around a practical wind farm forecasting task and in providing an interpretable prediction strategy based on key turbine selection, rather than in proposing a fundamentally new theoretical model....
The vast potential of deep-sea wind resources has driven substantial research focus on floating offshore wind turbines (FOWTs) in recent years. The wet-towing of the FOWT is critically challenged by the harsh conditions and remote locations of deep-sea sites. This paper proposes an innovative concept of FOWT based on the in-service FOWT “Sanxia Yinling”, establishing a numerical model of wet-towing for the FOWT in AQWA. The experiments of free-decay and wet-towing resistance in still water at the towing tank are carried out to validate reliability of the numerical model-integrated viscous damping and resistance coefficient of wind and current. Then, the method is applied to evaluate the effects of sea states and wet-towing speeds for the dynamic responses of the towing system. The results show that the natural periods of the FOWT in heave, roll and pitch DOFs all exceed 25 s, which is sufficiently longer than the typical wave spectral peak. In addition, the numerical model is verified against experimental data, showing close agreement. For the established towing configuration, safe operation requires sea states to be maintained at or below level 4 (significant wave height ≤ 2.5 m) and the towing speed at or below four knots. It is also found that a slack-taut cycle in towing lines at low speeds, which is attributed to wave excitation....
Low frequency electromagnetic waves emitted by sprite‐producing lightning are normally measured using vertical electric fields or horizontal magnetic fields. Here we report for the first time the simultaneous measurement of electromagnetic waves from sprite‐producing lightning in all six electromagnetic field components Ex, Ey, Ez, Hx, Hy, and Hz. A rigorous assessment of the horizontal electric field measurements with dipole antennas in two independent calibration experiments shows that a timing uncertainty of ∼1−2 ns can be achieved, well above the current fundamental limit of the timing accuracy ∼1–5 ps. The coupling between the electric and magnetic fields is quantified using a transfer matrix, allowing the magnetic field to be reconstructed accurately from electric field measurements. The cross product of electric and magnetic fields is used to calculate peak energy fluxes and arrival azimuths from sprite‐producing lightning. It is found that peak energy fluxes vary between ∼10–1,000 μW/m2 and that the differences between the measured and expected arrival azimuths are practically normally distributed with a mean and standard deviation of −8.0° ± 2.2°. It is concluded that horizontal electric field measurements are well suited to characterize electromagnetic waves with added benefits, including the ease of deployment in harsh environments, costeffectiveness and scalability, for example for polarisation measurements in large low frequency arrays. The significance of this study is that it can be used as a pathfinder mission to identify critical technical requirements for the array deployment during the Africa2Moon lander mission....
Forest wind damage models are typically based on the assumption that windstorm damage results from the interaction between horizontal wind forces and forest stand properties. In complex terrain, mountain waves caused by stably stratified air flowing over mountains can generate standing waves and severe downslope windstorms on the leeward side. Using the windstorm of 19 November 2021 in a mountain valley in southeastern Norway as a case study, we tested two hypotheses: 1. Forest stand properties do not significantly contribute to explaining forest damage during a mountain wave event. 2. Meteorological variables related to atmospheric stratification, turbulence, and non-horizontal airflow significantly contribute to explaining forest damage during a mountain wave event. To test these hypotheses, we combined forest damage observations with a high-resolution numerical weather prediction model and Random Forest modeling. We used SHapley Additive exPlanations (SHAP) values to quantify the contributions of individual model features. Incorporating forest stand variables did not significantly improve predictive performance, whereas potential temperature gradient, vertical airflow velocity, and wind gust speed, capturing turbulence, did. SHAP analysis showed that although wind gust speed helped explain damage, its influence was secondary to that of potential temperature gradient, which had the strongest explanatory power. The model demonstrated good discriminative power between damage and no damage in the test set. Our findings underscore the limitations of conventional models reliant on horizontal wind speed, highlighting the need for high-resolution numerical weather prediction models that resolve three-dimensional flow in complex terrain, especially during mountain wave events....
1. Ship- induced waves significantly impact freshwater ecosystems, estuaries and tidal rivers by accelerating shoreline erosion and reducing aquatic biodiversity. Morphological protection measures are implemented to mitigate these adverse effects, but their effectiveness in preventing shoreline zone deterioration has not been systematically assessed. 2. This meta- analysis evaluates the performance of various measures in influencing hydraulic forces, abiotic processes and biological responses across primary producers, benthic invertebrates and fish. 3. Our findings reveal that the effectiveness of these measures varies depending on the scale of investigation, ecosystem type and response variable. Offshore breakwaters were highly effective in reducing hydraulic forces in freshwater ecosystems (+756%) but had a limited impact in transitional ecosystems (+34%, not significant). In contrast, breakwaters positively influenced benthic invertebrates in transitional ecosystems (+6945%) but had negligible effects in freshwater ecosystems (+91%, n.s.). 4. Increased shoreline complexity had overall positive effects in mesocosm- based studies (+407%) but yielded limited benefits in freshwater field studies (+67%, n.s.). 5. Moreover, the measures showed diverse responses across trophic levels within freshwater ecosystems. Shoreline complexity significantly benefited benthic invertebrates (+336%), while positive effects on fish were found for breakwaters (+74%) and side channels (+205%). 6. These findings highlight the importance of implementing ecosystem- specific management strategies tailored to the needs of target organisms. A combination of offshore breakwaters and increased shoreline complexity appears promising for mitigating the negative impacts of ship- induced waves on all trophic levels in navigable rivers, lakes and estuaries....
Loading....