Search

A systematic verification and validation (V&V) of our previously proposed momentum source wave generation method is performed. Some settings of previous numerical wave tanks (NWTs) of regular and irregular waves have been optimized. The H2-5 V&V method involving five mesh sizes with mesh refinement ratio being 1.225 is used to verify the NWT of regular waves, in which the wave height and mass conservation are mainly considered based on a Lv3 (Hs = 0.75 m) and a Lv6 (Hs = 5 m) regular wave. Additionally, eight different sea states are chosen to validate the wave height, mass conservation and wave frequency of regular waves. Regarding the NWT of irregular waves, five different sea states with significant wave heights ranging from 0.09 m to 12.5 m are selected to validate the statistical characteristics of irregular waves, including the profile of the wave spectrum, peak frequency and significant wave height. Results show that the verification errors for Lv3 and Lv6 regular wave on the most refined grid are −0.018 and −0.35 for wave height, respectively, and −0.14 and for −0.17 mass conservation, respectively. The uncertainty estimation analysis shows that the numerical error could be partially balanced out by the modelling error to achieve a smaller validation error by adjusting the mesh size elaborately. And the validation errors of the wave height, mass conservation and dominant frequency of regular waves under different sea states are no more than 7%, 8% and 2%, respectively. For a Lv3 (Hs = 0.75 m) and a Lv6 (Hs = 5 m) regular wave, simulations are validated on the wave height in wave development section for safety factors FS ≈ 1 and FS ≈ 0.5–1, respectively. Regarding irregular waves, the validation errors of the significant wave height and peak frequency are both lower than 2%. [ABSTRACT FROM AUTHOR]

Electromagnetic ion cyclotron (EMIC) waves are important for Earth's inner magnetosphere as they can effectively drive relativistic electron losses to the atmosphere and energetic (ring current) ion scattering and isotropization. EMIC waves are generated by transversely anisotropic ion populations around the equatorial source region, and for typical magnetospheric conditions this almost always produces field‐aligned waves. For many specific occasions, however, oblique EMIC waves are observed, and such obliquity has been commonly attributed to the wave off‐equatorial propagation in curved dipole magnetic fields. In this study, we report that very oblique EMIC waves can be directly generated at the equatorial source region. Using THEMIS spacecraft observations at the dawn flank, we show that such oblique wave generation is possible in the presence of a field‐aligned thermal ion population, likely of ionospheric origin, which can reduce Landau damping of oblique EMIC waves and cyclotron generation of field‐aligned waves. This generation mechanism underlines the importance of magnetosphere‐ionosphere coupling processes in controlling wave characteristics in the inner magnetosphere. Key Points: We report observations of very oblique electromagnetic ion cyclotron (EMIC) waves around their equatorial source regionOblique EMIC wave generation is associated with field‐aligned thermal ion streams and hot, transversely anisotropic ionsThe presence of field‐aligned thermal ion streams attributes oblique EMIC wave generation to its possible ionospheric source [ABSTRACT FROM AUTHOR]

Waves generated by a horizontally moving disturbance on the seabed have been studied by developing two numerical models, namely, the Navier–Stokes and the Green–Naghdi equations. Various geometries of the bottom disturbances are considered, and waves generated due to a single motion and multiple oscillatory motions of the bottom disturbances are investigated by the two models. Discussion is provided on how the motion of the disturbance on the seafloor results in the generation of surface waves. The wave-field parameters investigated include the surface elevation, velocity, pressure fields and wave celerity. A parametric study is conducted to assess the effect of the geometry of the disturbance and the kinematic characteristics on the wave generation. It is shown that both linear and nonlinear waves can be generated by a horizontally moving disturbance on the seabed. Long waves, followed by a series of dispersive waves, are produced by the single motion of the bottom disturbance. It is also found that, under appropriate conditions, there would be a balance between nonlinearity and dispersion, such that the generated waves propagate over a flat seafloor with little to no change in their form and shape. [ABSTRACT FROM AUTHOR]

Energetic particle injections are commonly observed in Jupiter's magnetosphere and have important impacts on the radiation belts. We evaluate the roles of electron injections in the dynamics of whistler‐mode waves and relativistic electrons using Juno measurements and wave‐particle interaction modeling. The Juno spacecraft observed injected electron flux bursts at energies up to 300 keV at M shell ∼11 near the magnetic equator during perijove‐31. The electron injections are related to chorus wave bursts at 0.05–0.5 fce frequencies, where fce is the electron gyrofrequency. The electron pitch angle distributions are anisotropic, peaking near 90° pitch angle, and the fluxes are high during injections. We calculate the whistler‐mode wave growth rates using the observed electron distributions and linear theory. The frequency spectrum of the wave growth rate is consistent with that of the observed chorus magnetic intensity, suggesting that the observed electron injections provide free energy to generate whistler‐mode chorus waves. We further use quasilinear theory to model the impacts of chorus waves on 0.1–10 MeV electrons. Our modeling shows that the chorus waves could cause the pitch angle scattering loss of electrons at <1 MeV energies and accelerate relativistic electrons at multiple MeV energies in Jupiter's outer radiation belt. The electron injections also provide an important seed population at several hundred keV energies to support the acceleration to higher energies. Our wave‐particle interaction modeling demonstrates the energy flow from the electron injections to the relativistic electron population through the medium of whistler‐mode waves in Jupiter's outer radiation belt. Key Points: Chorus wave generation due to electron injections is demonstrated by their correlative occurrence and wave instability analysisWhistler‐mode waves scatter electrons into the loss cone and cause diffuse auroral precipitation with intensities of 60–160 erg/cm2/sChorus waves cause local acceleration of MeV electrons in several days, further aided by the seed electron population from injections [ABSTRACT FROM AUTHOR]

Whistler‐mode waves are commonly observed within the lunar environment, while their variations during Interplanetary (IP) shocks are not fully understood yet. In this paper, we analyze two IP shock events observed by Acceleration, Reconnection, Turbulence and Electrodynamics of the Moons Interaction with the Sun (ARTEMIS) satellites while the Moon was exposed to the solar wind. In the first event, ARTEMIS detected whistler‐mode wave intensification, accompanied by sharply increased hot electron flux and anisotropy across the shock ramp. The potential reflection or backscattering of electrons by the lunar crustal magnetic field is found to be favorable for whistler‐mode wave intensification. In the second event, a magnetic field line rotation around the shock region was observed and correlated with whistler‐mode wave intensification. The wave growth rates calculated using linear theory agree well with the observed wave spectra. Our study highlights the significance of magnetic field variations and anisotropic hot electron distributions in generating whistler‐mode waves in the lunar plasma environment following IP shock arrivals. Plain Language Summary: The surface of the Earth's Moon is frequently exposed to the incoming solar wind flow and IP shocks due to its lack of internal magnetic fields that can deflect the solar wind particles. Within the lunar environment, whistler‐mode waves, characterized by electromagnetic fluctuations with frequencies below the electron gyrofrequency, are commonly present. Interplanetary shocks that are often associated with significant disturbances in electron flux and magnetic field can potentially lead to anisotropic distributions of electrons, which are known to provide free energy source for whistler‐mode wave generation. To assess the whistler wave generation under shock conditions, we conduct an in‐depth analysis of two IP shock events. These events provide clear evidence of shock‐induced enhancements in electron pitch angle anisotropy and flux, as well as a potential rotation of magnetic field around the shock region, resulting in the intensification of whistler‐mode waves downstream of the shock. We calculated a timeseries of linear wave growth rate for the entire duration of shock events, which remarkably accounted for the observed whistler‐mode wave spectra both before and after the shock arrival. Our findings are important for understanding the associated physical process of whistler‐mode wave generation in the lunar plasma environment during IP shock events. Key Points: Two Interplanetary shock events in the lunar environment are analyzed to unveil whistler wave generation around shock regionLinear wave growth calculations show that whistler‐mode waves are generated locally due to enhanced electron anisotropy and fluxMagnetic field line connection to lunar surface is found to be important for enhancing whistler wave intensity [ABSTRACT FROM AUTHOR]

Waves generated by a horizontally moving disturbance on the seabed have been studied by developing two numerical models, namely, the Navier–Stokes and the Green–Naghdi equations. Various geometries of the bottom disturbances are considered, and waves generated due to a single motion and multiple oscillatory motions of the bottom disturbances are investigated by the two models. Discussion is provided on how the motion of the disturbance on the seafloor results in the generation of surface waves. The wave-field parameters investigated include the surface elevation, velocity, pressure fields and wave celerity. A parametric study is conducted to assess the effect of the geometry of the disturbance and the kinematic characteristics on the wave generation. It is shown that both linear and nonlinear waves can be generated by a horizontally moving disturbance on the seabed. Long waves, followed by a series of dispersive waves, are produced by the single motion of the bottom disturbance. It is also found that, under appropriate conditions, there would be a balance between nonlinearity and dispersion, such that the generated waves propagate over a flat seafloor with little to no change in their form and shape.

Interchange instability is known to drive fast radial transport of particles in Jupiter's inner magnetosphere. Magnetic flux tubes associated with the interchange instability often coincide with changes in particle distributions and plasma waves, but further investigations are required to understand their detailed characteristics. We analyze representative interchange events observed by Juno, which exhibit intriguing features of particle distributions and plasma waves, including Z‐mode and whistler‐mode waves. These events occurred at an equatorial radial distance of ∼9 Jovian radii on the nightside, with Z‐mode waves observed at mid‐latitude and whistler‐mode waves near the equator. We calculate the linear growth rate of whistler‐mode and Z‐mode waves based on the observed plasma parameters and electron distributions and find that both waves can be locally generated within the interchanged flux tube. Our findings are important for understanding particle transport and generation of plasma waves in the magnetospheres of Jupiter and other planetary systems. Plain Language Summary: The centrifugal interchange instability, which has been observed in rapidly rotating planets, like Saturn and Jupiter, moves cold plasmas inside of the magnetosphere further away, and transports hotter, less dense plasmas toward the inner magnetosphere. These moving flux tubes have been observed at Jupiter together with plasma waves, but their detailed characteristics are not fully understood. In the present study, we use observations from the Juno spacecraft to report multiple representative interchange events and evaluate the properties of energetic particles and plasma waves. Furthermore, we use linear theory to calculate the growth rates of Z‐mode and whistler‐mode waves during these events. Our findings reveal the typical features of plasma waves and particles during interchange events, which provide important insights into particle transport and generation of plasma waves at Jupiter and possibly other magnetized planets in our solar system and beyond. Key Points: Several plasma transport events associated with interchange instability are identified alongside plasma waves using Juno observationsLinear growth rate analyses indicate that waves can be locally generated during interchange events due to anisotropic electron distributionsOur findings provide insights into electron transport and plasma wave dynamics during interchange events in planetary magnetospheres [ABSTRACT FROM AUTHOR]

Tsunamis can be generated by an impulsive displacement of water resulting from the entrance of pyroclastic density currents (PDCs). The maximum wave amplitude is of primary interest regarding tsunami modeling and applications to hazard assessment. This study explores tsunami generation by fluidized granular flows and analyzes published relationships predicting maximum wave amplitudes from PDC characteristics. A fluidized column of glass beads is released from a reservoir, flows down an inclined plane and enters a water‐filled flume, generating waves. Fluidized flows of greater mass enter the flume with greater velocities; however, all the analyzed flows impact the water with a supercritical impact Froude number. Flows of greater mass generate a single, high‐amplitude wave, followed by a longer‐period trough. The solitary‐like leading wave propagates along the flume with a nearly constant amplitude. In contrast, the leading wave is followed by a low‐amplitude trough and a second low‐amplitude crest when generated by lower mass flows. Dispersive effects are stronger for waves produced by flows of lower masses, causing the decrease of the amplitudes with distance from the shore. Increased breaking and dissipation cause decreased amplitudes of the waves generated in shallow water depths. The predictive equations, determined based on the impact Froude number and the water depth in the constant‐depth section of the flume, provide relatively good predictions of the maximum wave amplitudes. A new approach is proposed, which calculates the impact Froude number considering the water depth value where the wave generation occurs, providing an improved understanding of the wave generation process. Plain Language Summary: Mixtures of volcanic rocks and gases, called pyroclastic density currents (PDCs), can travel large distances away from the volcano and reach the sea. When these flows enter the sea, they displace water and can generate waves. The maximum height of such waves is important for understanding the tsunami hazard. This research explores tsunami generation by conducting experiments of the entrance of granular flows into the water. The granular material is fluidized to behave like a fluid and mimics PDC behavior. The material flows down an inclined ramp and enters the water, generating a large first wave. While flows of greater mass produce a single large wave, this wave is followed by smaller waves when generated by flows of lower masses. The first wave travels along the flume with a nearly constant height when generated by flows of greater mass, while waves produced by lower masses become smaller with distance from the shore. Equations developed in previous studies performed relatively well in predicting the maximum wave heights generated during these experiments. This research proposes to calculate the wave heights considering the water depth value where the wave is created, improving physical understanding of the process. Key Points: Tsunami generation by pyroclastic density currents was studied through experiments of fluidized granular flows entering the waterFlows of greater mass produce a single leading wave, while this wave is followed by a dispersive wave train when generated by lower massesA redefined Froude number, considering where the wave generation occurs, provides an enhanced understanding of the wave generation process [ABSTRACT FROM AUTHOR]

Theoretical investigations were conducted to study the generation of transient nonlinear water waves by a novel side-hinged paddle wavemaker. A 3D nonlinear solution was derived in a semi-analytical form by applying eigenfunction expansions and FFT. The solution was applied to study the features of nonlinear waves generated by a side-hinged paddle wavemaker. The results show that nonlinear terms in the free-surface boundary conditions and in the kinematic wavemaker boundary condition imply the modification of wave profiles so that wave troughs are flattered and crests are getting steeper and interaction effects between waves in a wave train increase. Moreover, these terms imply the modification of a wave spectrum. A train of originally very narrow-banded waves changes its one-peak spectrum to a multi-peak one. Theoretical results are in a fairly good agreement with experimental data. A reasonable agreement is observed between predicted and measured time series of free-surface elevations and the amplitudes of the corresponding Fourier series. The investigations show that a side-hinged paddle wavemaker is an attractive wave generation system. Simple and reliable boundary condition at the paddle enables verification of advanced 3D nonlinear models and accurate physical modeling of many phenomena where high accuracy of incoming wave properties are important. [ABSTRACT FROM AUTHOR]

A nonlinear numerical wave tank is established using the Harmonic Polynomial Cell (HPC) method, which is incorporated with a mass source. The numerical wave tank consists of the mass source wave generation region and the working region, with sponge layers at both ends for wave absorption. In the mass source region, a generalized HPC method is applied to solve the inhomogeneous elliptic boundary value problems. The Poisson equation's special solution is represented by a bi-quadratic function. In the remaining domains, the HPC method is employed with harmonic polynomials to solve the problems governed by the Laplace equation in each grid cell. The free surface is tackled by the immersed boundary method (IB-HPC), and the kinematic and dynamic conditions of the free surface are described using a semi-Lagrangian approach. A variety of waves propagation are simulated, including Second-order Stokes wave, fifth-order Stokes wave, solitary wave, fifth-order Fenton stream function wave, random wave and the interaction with a straight vertical wall. The numerical solutions are compared with theoretical solutions. The numerical simulation results demonstrate that the present method can generate arbitrary two-dimensional wave fields by specifying an appropriate source function. Additionally, the reflected waves can propagate through the wave generation region, ensuring that the process of wave generation is not affected by the reflections. • A highly accurate and efficient non-reflection nonlinear numerical wave tank has been established by the incorporation of the Harmonic Polynomial Cell (HPC) method with a mass source wave generation method. • The relationship between the internal source function and the expected waveform is investigated. The simulation covered the propagation of various types of waves, including second-order Stokes waves, fifth-order Stokes waves, solitary waves, fifth-order Fenton stream function waves, random waves, and the stationary wave. • The non-reflection characteristics of the HPC-MS method in the region of the wave-making source are investigated by arranging a fully reflective vertical wall. • The numerical tank based on the present HPC-MS method can be employed as a tool for long-time simulation of wave-body interaction, avoiding the effect of second reflection of the propagating wave due to the reflection from the front edge of the body reaching the wave generation boundary again. [ABSTRACT FROM AUTHOR]

The mass source wave-maker is commonly employed for generating water waves in numerical simulations, during which a correct amount of mass is introduced or subtracted from the internal flow region to produce target waves. The method has proven to be effective in producing waves in shallow and intermediate water depths, while its efficiency is declined for short wave generation. The main reason for this efficiency declination is that the internal mass source in deeper water region is not effective to generate short waves with their motions primarily on water surface. In order to overcome this shortcoming, many of the previous numerical treatments have introduced various enhancement factors into the source functions, which are empirically obtained and also violate the law of mass conservation. In this study, we develop a new adaptive internal wave-maker model that can be self-adjusted to suit different wave conditions. The line source starts from the bottom and extends to the computational cell right beneath free surface at each time step. The depth dependent weighting coefficient is introduced to the source function based on the linear wave theory for each wave component. No empirical coefficients are necessary, and the mass conservation is strictly and explicitly enforced. In principle, the method can be applied to all types of linear waves in the entire range of kh. The numerical experiments show that the present method can produce very good results for linear waves with kh up to 16.11, adequate for most of wave conditions in coastal engineering. For generation of fifth-order Stokes waves, the method can be extended straightforwardly for each of five wave components. For irregular waves composed of many linear wave components, different weighting coefficients can be readily calculated for each of them, respectively. As a result, the new model can generate irregular waves with overall better performance of reproducing wave spectrum, whose high-frequency part has been underestimated by previous methods. The numerical experiments also show that the new model can produce better results for focused waves where many linear waves of different frequencies start from the same point with specific phase angles, due to its capability of generating shorter wave components. • An internal wave-maker model has been developed by introducing an adaptive source region that adjusts to the free surface. • This model uses a weighting function proportional to horizontal particle speed of a linear wave to redistribute mass source. • The new model can accurately generate monochromatic waves of a wide range, especially short waves with large kh values. • The model demonstrates superior capability of simulating irregular and focused waves that contain short wave components. [ABSTRACT FROM AUTHOR]

In the context of ocean engineering studies or ocean wave physics research, irregular wave fields are generated in experimental and numerical wave tanks. In these environments, a wave maker generates the waves and the wave field is studied at a target position X t , further in the tank. Therefore, the properties of the wave fields need to be controlled at X t. The state-of-the-art wave generation procedures focus on accurately generating a target wave energy spectrum. However, the wave field is also characterized by its statistical features (crest height distribution, free surface elevation probability density function) that cannot be retrieved from the wave spectrum. To tackle this issue, the present paper introduces a new wave generation procedure that makes use of the natural spatial evolution of the wave statistics to generate at any target location X t a controlled spectrum and a controlled crest distribution. The procedure is tested experimentally and numerically. The results validate the methodology for non-breaking unidirectional wave conditions, for experimental, numerical, and hybrid numerical/experimental configurations. • A new wave generation procedure for wave tank experiments is proposed. • The procedure is designed to control wave statistics at a given target position. • The procedure is successfully applied to experimental and numerical wave tanks. • The methodology is validated for non-breaking unidirectional wave conditions. [ABSTRACT FROM AUTHOR]

A wave flume is primarily intended to reproduce actual sea conditions in order to provide a reliable means of testing for small-scale models. The realization of scaled tests is extremely important for the validation of a project on real scale, since, through the laws of similitude, such tests make it possible to predict the behavior of structures in the ocean as well as their performance during operation. This research aims to develop, test, and validate an active control algorithm for wave absorption in a two-dimensional wave channel--that is, when the waves propagate in only one direction--based on artificial neural networks (ANN). The ANN control algorithm relies on the linear wave theory and the principle of time-reversal of wave propagation; i.e., the phenomenon of wave absorption corresponds to the wave generation when observed in the reverse direction of time. Through this principle, data from wave generation experiments, after proper manipulation, are used to train an ANN capable of generating the control signal used to move the wave-generator device, this time as a wave absorber. [ABSTRACT FROM AUTHOR]

Whistler-mode chorus waves in the magnetosphere play a crucial role in space weather via wave–particle interactions. The past two decades have observed tremendous advances in theory and simulations of chorus generation; however, several details of the generation mechanism are still actively contended. To simulate chorus generation, a new envelope particle-in-cell code is introduced. The model produces a rising tone chorus element in a parabolic geomagnetic field. The initial chorus element “embryo” frequency is shown to initialize near the equator at the frequency of maximum linear growth. A backward resonant current is then observed to propagate upstream of the equator. The trajectory of the backward current follows that of a freely falling electron that has been de-trapped at the equator superimposed with forward motion at the group velocity. The backward current iteratively radiates a rising tone element where the highest frequency components are generated furthest upstream. The work provides new advancements in modeling chorus and corroborates other recent work that has also demonstrated a backward-moving source during the generation of coherent whistler-mode waves.

This paper highlights the issue of the model consistency for wave hindcasts in enclosed basins, such as lakes and lagoons. For these applications, the wind input mechanism is essential and the differences in the model approaches and available settings make it critical and difficult for the users to comprehensively understand each of the model's capabilities and limitations. Therefore, three freely accessible regional scale spectral wave models (SWAN, STWAVE, and CMS-Wave), using the Half and Full plane modes where available, are used for wave hindcast purposes in two locations of the Garda Lake (IT). Results achieved with default settings are compared and discussed. Significant differences are found showing that, unfortunately, specific calibration, which is, however, not possible in many practical cases, is essential for applications in enclosed basins. [ABSTRACT FROM AUTHOR]

In this study, a nonlinear wave simulation code is developed using a higher-order spectral (HOS) method. The HOS method is very efficient because it can determine the solution of the boundary value problem using fast Fourier transform (FFT) without matrix operation. Based on the HOS order, the vertical velocity of the free surface boundary was estimated and applied to the nonlinear free surface boundary condition. Time integration was carried out using the fourth order Runge–Kutta method, which is known to be stable for nonlinear free-surface problems. Numerical stability against the aliasing effect was guaranteed by using the zero-padding method. In addition to simulating the initial wave field distribution, a nonlinear adjusted region for wave generation and a damping region for wave absorption were introduced for wave generation simulation. To validate the developed simulation code, the adjusted simulation was carried out and its results were compared to the eighth order Stokes theory. Long-time simulations were carried out on the irregular wave field distribution, and nonlinear wave propagation characteristics were observed from the results of the simulations. Nonlinear adjusted and damping regions were introduced to implement a numerical wave tank that successfully generated nonlinear regular waves. According to the variation in the mean wave steepness, irregular wave simulations were carried out in the numerical wave tank. The simulation results indicated an increase in the nonlinear interaction between the wave components, which was numerically verified as the mean wave steepness. The results of this study demonstrate that the HOS method is an accurate and efficient method for predicting the nonlinear interaction between waves, which increases with wave steepness.

Solar wind‐magnetosphere coupling is a key link of the space weather chain. There have been increasing reports of solar wind dynamic pressure pulses influencing the whistler‐mode chorus wave growth in the inner magnetosphere, but the response conditions and mechanisms of chorus growth remain under debate. Here we present a statistical study of the immediate impact of solar wind dynamic pressure pulses on inner magnetospheric chorus waves using Van Allen Probes data from 2012 to 2019. A stronger pulse is found to have a greater likelihood to change the chorus amplitude particularly on the dayside. Positive pulses can significantly enhance chorus amplitudes, while negative ones result in a weakening in chorus amplitudes. As supported by direct observations, these pulses alter the linear growth of waves by modifying energetic electron distributions; in contrast, geomagnetic field modeling indicates no significant changes in the geomagnetic field inhomogeneity controlling the nonlinear growth threshold of waves. Plain Language Summary: The geospace environment is highly controlled by the solar wind. In the inner magnetosphere, the whistler‐mode chorus waves, contributing significantly to the radiation belt electron acceleration and the auroral electron precipitation, have been increasingly reported to respond to the solar wind dynamic pressure pulses upstream of the Earth. However, how positive and negative solar wind dynamic pulses affect the inner magnetospheric chorus waves remains under debate. By statistically analyzing and modeling Van Allen Probes data, we show that solar wind dynamic pressure pulses mainly alter the linear growth of waves by modifying energetic electron distributions, with stronger pulses leading to a greater likelihood of causing observable enhancement or weakening in wave amplitudes. The present study contributes to our understanding of the evolution of chorus waves and the chorus‐driven particle dynamics in the inner magnetosphere. Key Points: A stronger solar wind pressure pulse has a greater likelihood to change the magnetospheric chorus amplitude particularly on the daysidePositive (negative) pressure pules can immediately increase (decrease) chorus amplitudes in the inner magnetosphereThese pulses mainly alter the linear growth of chorus waves by modifying the source electron distributions in the inner magnetosphere [ABSTRACT FROM AUTHOR]

In the present paper, the effect of bottom disturbances on wave generation in a viscous liquid in the presence of uniform current is studied. The wave potential and Stokes stream function are used to formulate this problem. Multiple integrals representing the free surface elevation are obtained by mathematical analysis using the Laplace transform in time and the Fourier transform in space. This is divided into various multiple integrals, using the steepest descent method to evaluate them asymptotically for a large time and distance. There are three types of ground disturbances taken into consideration: D 0 (x) = e (− x 2 / 2) , D 0 (x) = e − | x | , and D 0 (x) = δ (x). The effect of uniform current speed (U) and viscosity (ν) on the free surface elevation is illustrated for the three forms of ground disturbances. It is observed that the presence of current often amplifies the energy of the propagating wave and also increases its amplitude. Moreover, as viscosity increases, the amplitude of free surface elevation decreases with respect to time, and further, the period of oscillation of surface elevation becomes smaller for a large time. • The role of transitory ground disturbances on wave generation in the presence of current is analyzed. • Free surface elevation is obtained as infinite integrals using the Fourier and Laplace transforms. • The integrals are evaluated using the steepest descent method. • Three forms of ground disturbances are considered, such as H 0 (x) = e (− x 2 2) , e − | x | , and δ (x). • The wave–current and viscosity of the fluid play a vital role in enhancing the amplitude of free surface elevation. [ABSTRACT FROM AUTHOR]

Storms propagate over the ocean and create moving patches of strong winds that generate swell systems. Here, we describe the dynamics of wave generation under a moving storm by using a simple parametric model of wave development, forced by a temporally and spatially varying moving wind field. This framework reveals how surface winds under moving storms determine the origin and amplitude of swell events. Swell systems are expected to originate from locations different than the moving high‐wind forcing regions. This is confirmed by a physically informed optimization method that back‐triangulates the common source locations of swell using their dispersion slopes, simultaneously measured at five wave‐buoy locations. Hence, the parametric moving fetch model forced with reanalysis winds can predict the displacement between the highest winds and the observed swell source area. The model further shows that the storm's peak wind speed is the key factor determining swell energy since it determines surface wind gradients that lead to the spatial convergence of wave energy into a much smaller area than the wind fetch. Swell generation can then be described to follow a three‐stage process that outlines a focus area where swell energy is enhanced and slightly displaced from the maximum wind locations. This analysis provides an improved understanding of fetches for extra‐tropical swell systems and may help to identify biases in swell forecast models, air‐sea fluxes, and upper‐ocean mixing estimations. Plain Language Summary: Storms generate waves on the ocean surface that can travel across entire ocean basins, the so‐called swell waves. However, it is unclear how the amplitude and period of these surface waves depend on the strength and shape of the storm. One has to consider the movement of the storm in addition to its size, lifetime, and wind speeds. This study shows how all these parameters control the amplitude and period of swell events reaching the coastlines. We find that the storm's movement and its peak wind speed compress the wave energy to a small area, which then appears as a swell source location in the open ocean. This study can help to improve swell forecasts and understand how long‐term changes in mid‐latitude storms would modify the exchange of momentum and heat between the atmosphere and the ocean. Key Points: Wave generation by a moving extra‐tropical storm is described using a Gaussian wind field and a parametric model of wave developmentA new developed machine‐learning algorithm triangulates the space‐time evolving source point of swell systems from buoy measurementsThis model describes the distance between swell source and the storm's maximum wind speed and reveals sensitivities to storm's parameters [ABSTRACT FROM AUTHOR]

In this paper, OpenFOAM wave generation and active wave absorption boundary conditions were used to simulate wave interaction of a specific experimental wave energy converter (WEC) with equilibrium buoys and two power take-off systems that work in parallel, over a broad range of wave conditions. Two solitary and cnoidal wave generation boundary conditions for three different wave heights were implemented at the inlet to generate waves. The validation phase included a comparison of free-surface with numerical results of solitary and cnoidal waves generation at the flume. To investigate the impact of equilibrium buoys, wave flow around the wave energy converter was simulated for two cases. In the first case, WEC was considered as a single box, and in the second, two equilibrium buoys were added to the WEC. By comparison of these two cases, we discovered that although equilibrium buoys decrease the horizontal force on the main box, they cause the production of two efficient vertical forces. One of these forces moves the front equilibrium buoy generating electricity individually from the main box mechanism, and the other vertical force is applied to the back equilibrium buoy accelerating the rotation of the main box. Overall, wave energy absorption is enhanced by using the equilibrium buoys. [ABSTRACT FROM AUTHOR]

An opposing sea was generated in an experimental wave basin. Here, an opposing sea is defined as a sea in which the wave spectrum has two peaks that are separated almost 180° in direction. Such an opposing sea can be observed, for example, when wind waves coexist in the opposite direction with swells. The opposing sea generation is based on an actual sea spectrum hindcast by a third-generation wave model. The experiment was carried out in an actual sea model basin (ASMB) at National Maritime Research Institute. The ASMB is fully surrounded by 382 flap-type wave makers with incident wave absorbing capacity. The estimation of the directional spectrum by the maximum likelihood method (MLM) revealed that the opposing sea was successfully generated in the basin, although an analysis of the corresponding numerical wave field indicated that the MLM inherently estimated the spectrum with wider directional spreading. The reproduction of the opposing sea in this study indicates that any deep-sea wave field with arbitrary directional spectrum can be reproduced in such a wave basin with absorbing wave makers on the periphery. [ABSTRACT FROM AUTHOR]

Magnetosonic (MS) waves are electromagnetic waves that play important roles in the acceleration and scattering of radiation belt electrons. However, previous statistical analyses of the global MS wave distribution were mainly restricted to magnetic field measurements. In this study, we first report a low‐harmonic MS wave event observed only by the electric field instrument in Van Allen Probes. The MS wave frequencies follow the local proton gyrofrequency (fcp), which suggests the characteristics of nearly local generation. We further statistically investigate similar wave events using Van Allen Probes data. The identified MS wave power exhibits peaks between 4fcp and 10fcp, regardless of the L‐shell, but it shows a dependence on magnetic local time. This work is supplemental to previous MS wave frequency spectra and provides new insights to better understand the source region of MS waves in the Earth's magnetosphere. Plain Language Summary: MS waves have been extensively studied, but previous statistical analyses of the global MS wave distribution using Van Allen Probes mostly utilized only magnetic field data, and unintended bias might have been introduced due to the noise floor of the magnetometer. Here, we report an example case study of low‐harmonic MS waves detected only by electric field measurements. Furthermore, we statistically investigate the missed emissions with frequencies at multiples of the proton gyrofrequency (fcp); these observations occurred outside the plasmasphere in the dayside region. High‐sampling‐rate burst mode data are also used to analyze the MS wave frequency spectra and wave power peaks between 4fcp and 10fcp. These results, which complement previous statistics, help us better understand the MS wave frequency spectra and evaluate the wave effects on particle dynamics. Key Points: Van Allen Probes EFW instrument observed low‐harmonic magnetosonic waves with electric field power which could not be captured by MAGThe low‐harmonic magnetosonic waves are important for the electron acceleration at higher energies than the high‐harmonic wavesOur statistics indicates that the wave magnetic field power spectral density peaks within 4–10fcp and is MLT dependent [ABSTRACT FROM AUTHOR]

Magnetosonic (MS) waves and electromagnetic ion cyclotron (EMIC) waves are two important plasma wave modes in the magnetosphere. Previous simulations have shown that both waves could be generated by a ring‐like proton distribution, while direct observational evidence has yet to be reported. Here, we present simultaneous observations of MS and EMIC waves and a detailed case analysis. The linear growth rates estimated for both waves are in good agreement with the observed wave frequency spectra. The measured proton distribution evolution is also compared with the simulation results, providing direct observational evidence for the previous theoretical prediction that anisotropic ring‐like proton distributions could excite MS and EMIC waves simultaneously. Our findings are crucial for understanding the generation mechanisms of and relation between MS and EMIC waves and for evaluating their combined effects on energetic electron and ion dynamics. Plain Language Summary: Magnetosonic (MS) waves and electromagnetic ion cyclotron (EMIC) waves play important roles in energetic particle dynamics in the Earth's magnetosphere. MS waves are typically considered to be excited by ring‐type proton distributions, while EMIC waves are believed to be generated by anisotropic proton distributions. Although previous simulation studies have indicated that both waves could be generated by a ring‐like proton distribution, direct observational evidence of this mechanism is lacking. In this study, we meticulously analyzed an event and employed the observed proton distribution to calculate the linear growth rates, which show excellent agreement with the observed wave spectra. The results confirm that both waves could be generated simultaneously by anisotropic ring‐like proton distributions, supporting a recent theoretical prediction. This case analysis provides crucial information for gaining a better understanding of the relationship between these two wave modes and for quantifying their combined roles in energetic particle dynamics. Key Points: EMIC and MS waves were simultaneously observed during a substorm injection eventAnisotropic ring‐like proton distributions provide free energy for both MS and EMIC waves based on linear growth rate calculationsScattering by MS and EMIC waves may lead to a reduced PSD gradient along v⊥ and anisotropy of proton distributions [ABSTRACT FROM AUTHOR]

The 2D‐parametric model suggested in the companion paper is used to simulate waves under tropical cyclones (TCs). Set of equations describing both wind waves and swell evolution in space and time, is solved using the method of characteristics. Wave‐ray patterns efficiently chart on how wave trains develop and travel through the TC varying wind field, to leave the storm area as swell systems. Depending on TC main characteristics—maximal wind speed (um), radius (Rm), and translation velocity (V), wave‐train rays superpose to exhibit particular coherent spatial patterns of significant wave height, peak wavelength and direction. Group velocity resonance leads to the appearance of waves with abnormally high energy, further outrunning as long swell systems through the TC front sector. Yet, when the TC translation velocity exceeds a threshold value, waves cannot reach group velocity resonance, and travel backwards, to form a wake of swell systems trailing the forward moving TC. Importantly, the model solutions for TC 2D‐wavefields can be parameterized using 2D self‐similar universal functions. Comparisons between self‐similar solutions and measurements, demonstrate a reasonable agreement to warrant scientific and practical applications. Self‐similar solutions provide immediate estimates of azimuthal‐radial distributions of wave parameters under TCs, solely characterized by arbitrary sets of um, Rm, and V conditions. Self‐similar solutions clearly divide TCs between slow TCs, fulfilling conditions Rm/Lcr > 1, and fast TCs corresponding to Rm/Lcr < 1, where Lcr is a critical fetch. Around the region Rm/Lc = 1, group velocity resonance occurs, leading to the largest possible waves generated by a TC.Plain Language Summary: A practical and rapid evaluation of wave conditions under tropical cyclone (TC) is often required for navigation safety and coastal hazards. Building on the fully consistent 2D‐parametric model suggested in the companion paper, a method is presented to map the distribution of wave energy, peak frequency and direction along wave‐rays. Wave‐rays help to visualize how wave trains develop and travel through the TC varying wind field, and how they leave the storm area as swell systems. Depending on the main TC characteristics—maximal wind speed (um), radius (Rm), and translation velocity (V)—the most striking feature of wavefields is generally a strong azimuthal asymmetry, resulting from group velocity resonance between traveling waves and moving TC. This effect can lead to extreme waves, further outrunning as swell forerunners in the TC heading direction. Importantly, it is demonstrated that immediate directional characteristics of TC wavefields can be evaluated using 2D self‐similar universal functions. For scientific and practical applications, these solutions provide fast estimates of waves generated by moving TC with arbitrary sets of um, Rm, and V.Key Points: Superposition of wave‐trains rays provides efficient visualization on how waves develop under tropical cyclone and leave storm area as swellParametric model solutions are described using 2D self‐similar universal functions and tested against the measurementsSelf‐similar solutions demonstrate good agreement with measurements that warrant their scientific and practical applications [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to get the numericalsolutions of the Gardner equation which are widely used in various disciplines.For this purpose, the time integration of the system is achieved by theclassical Crank-Nicolson method owing to its large stability region. Spacediscretization is done by using the trigonometric quintic B-spline functions.Thus the Gardner equation turns into a penta diagonoal matrix equation and theThomas algorithm is applied.

On December 22, 2018, a destructive tsunami related to the phenomena caused by the volcanic eruption of Gunung Anak Krakatau (GAK) was generated following a partial collapse of the volcano that caused serious damage and killed more than 400 people. This recent event challenged the traditional understanding of tsunami hazard, warning and response mechanisms and raised the topic of volcanic tsunami hazard. The complex mechanism of this tsunamigenic volcano collapse still needs further investigation as Anak Krakatau is one of the potentially tsunamigenic volcanoes in the world. This study investigates the possible source mechanisms of this phenomenon and their contribution to explaining the observed sea level disturbances by considering the impacts of this destructive event. We configured a flank collapse scenario with a volume of 0.25 km3 as a combination of submarine and subaerial mass movement as the possible source scenarios to the December 22, 2018 Sunda Strait tsunami. A two-layer model is applied to simulate the tsunami generation by these landslides up to 420 s. The tsunami propagation and inundation are then simulated by NAMI DANCE model in GPU environment. The simulation results suggest that this scenario seems capable of generating such a tsunami observed along the coast of Sunda Strait. However, the contribution of the possible submarine mass movements in the close area between GAK and the surrounding islands either to this event or potential tsunami threat in the region is still questionable. We employed a bathymetric dataset through pre- and post-event analyses, which demonstrate submarine slope failures in the southwestern proximity of GAK. Hence, additional two scenarios of elliptical landslide sources on the slopes of bathymetry change area (could be triggered by seismic motion/volcanic eruption) are considered, searching for the possible effects of the tsunami that might be generated by these submarine landslides. The study may also provide some perspective for potential tsunami generation by combined sources and help to elucidate the extent of volcanic tsunami hazard in the region due to potential future eruptions of Gunung Anak Krakatau. [ABSTRACT FROM AUTHOR]

• Development of a methodology to incorporate wave transmission due to overtopping in spectral wave models. • Validation of a wave generation and transmission module against experimental data. • Simulation of the energy transfer at higher frequencies due to overtopping and its effect on the transmitted spectrum shape. Spectral wave models have experienced constant development and vast improvements over the past decades. They are constantly being extended and refined in order to cover the complex wave transformation processes that take place in the coastal zone. Nevertheless, wave transmission due to overtopping has not been treated similarly yet. In this paper, a methodology to include wave generation due to overtopping in spectral wave models is presented. Incorporation of overtopping aims at better simulating the wave disturbance in the lee side of a system of offshore breakwaters and the induced hydrodynamic processes. So far, the waves generated due to wave overtopping were being neglected. The methodology consists of executing sequential simulations at small time step intervals and whenever wave overtopping occurs in a breakwater, waves are generated and transmitted in the lee side of the structure. This is achieved by modifying the boundary condition at the lee of a coastal structure to account for wave generation due to overtopping. Additionally, the transmitted spectrum source function was modified, to capture the observed transfer of energy in the higher frequencies of the spectrum due to the aforementioned overtopping process. The above methodology was implemented in the open source wave model TOMAWAC and verification with experimental measurements was carried out yielding satisfactory results. Inclusion of wave transmission due to overtopping in spectral wave models is considered to be a valuable asset, especially for the simulation of inshore hydrodynamic processes. [ABSTRACT FROM AUTHOR]

Electromagnetic ion cyclotron (EMIC) waves play an important role in the energy transfer among particles of different energies and species in the magnetosphere, whose drivers have been commonly recognized as solar wind compressions and storm/substorm proton injections. However, how the solar wind decompressions related to frequently occurring discontinuities compete with the proton injections in the evolution of EMIC waves has been rarely investigated. Here we present a complete end‐to‐end observation by Wind, THEMIS, and Van Allen Probes missions during the main phase of the 23 February 2014 storm of a succession of solar wind rotational discontinuities decompressing the magnetosphere within 200 s, adiabatically decelerating the freshly injected >10 keV protons, and thus suppressing the EMIC waves in the inner magnetosphere. Our results highlight the importance of solar wind conditions for the evolution of inner magnetospheric EMIC waves from a new perspective. Plain Language Summary: Magnetospheric electromagnetic ion cyclotron (EMIC) waves are ultralow‐frequency (0.1–5.0 Hz) pulsations observable both on the ground and in space. They contribute significantly to the magnetospheric particle dynamics and the magnetosphere‐ionosphere coupling. Previous studies have recognized two main drivers for EMIC waves: solar wind compressions and magnetospheric storm/substorm proton injections. However, both compressive and decompressive discontinuities, with dynamic pressure jumps on a timescale of seconds to minutes, can occur in the solar wind upstream of Earth, and under the condition of the fresh proton injections, to what extent the solar wind decompressive discontinuities can affect the EMIC waves in the inner magnetosphere remains to be determined. On the basis of observations by three space missions in the solar wind and magnetosphere during the main phase of a moderate storm, we show that the solar wind decompressive discontinuities can cause a relaxation of the magnetosphere, deceleration of the freshly injected protons, and thus quenching of the EMIC waves in the inner magnetosphere. These results illustrate the importance of solar wind conditions for the evolution of inner magnetospheric EMIC waves from a new perspective. Key Points: In the temperature anisotropic solar wind, a group of rotational discontinuities caused a substantial decrease in the dynamic pressureAlong with the magnetospheric relaxation within 200 s, the storm‐injected protons experienced betatron and Fermi decelerationsThe adiabatical reduction of hot proton fluxes suppressed the EMIC wave instabilities in the inner magnetosphere [ABSTRACT FROM AUTHOR]

Tsunamis induced by the landslide will divide into a traveling wave component propagating along the coastline and an offshore wave component propagating perpendicular to the coastline. The offshore tsunami wave has the non-negligible energy and destruction in enclosed basins as fjords, reservoirs, and lakes, which are worth studying. The initial submergence condition, the falling height and sliding angle of slider, are important reference indexes of damage degree of landslide and may also matter at that of the landslide-induced tsunami. Depending on the fully coupled model, the effects of them on the production and propagation of the tsunami were considered in the study. Since the slider used was semi-elliptic, the effect of the ratio of the long axis to the short axis was also analyzed. According to the computational fluid dynamics theory, a numerical wave tank was developed by the immersed boundary (IB) method; besides, the general moving-object module of slide mass was also embedded to the numerical tanker. The results indicate that the effects of the squeezing and pushing of the slider on water produce a naturally attenuated wave at the front of the wave train, and the attenuation becomes more serious with the increase in the initial submersion range of the slider. The effects of the vertical movement of the slider cause the increase in the amplitude of the back of the wave train. As the falling height increases, the large wave height increases when the slider is initially submerged and decreases when it is not initially submerged, except for the accidental elevation of that at smaller falling heights. The results also indicate that the hazard of the subaerial landslide-induced tsunami is greater under a small or large falling angle, and that of the partial subaerial and submarine landslide-induced tsunami is greater under a small falling angle. With the increase in the ratio of the long axis to the short axis, the total induced wave energy decreases and the shape of the wave train proportionally reduces, while the wave propagation mode does not change. [ABSTRACT FROM AUTHOR]

Wave maker is one of the most important experimental equipment in marine engineering. To meet the demands of simulation of higher wave amplitude and compare the effect of piston and flap type wave generation, a new wave generation device was proposed and a new piston and flap type wave maker with a rotary-valve-control vibrator was developed. A mathematical model of the new wave maker was established and analysed by Simulink, and a series of experiments were conducted on the wave maker to analyze wave generation characteristics. The results show that the wave maker can adjust the distance of wave paddle and generate different regular waves. The bigger the axial opening size of the valve port, the larger the wave paddle amplitude and the wave amplitude; the higher the pressure, the higher the wave paddle amplitude and the wave amplitude. High frequency wave making is more efficient than the lower one, and piston type wave making is more efficient than those wave makers that generate waves by flap type. [ABSTRACT FROM AUTHOR]

In the magnetosheath, intense whistler mode waves, called "Lion roars," are often detected in troughs of magnetic field intensity in mirror mode structures. Using data obtained by the four Magnetospheric Multiscale (MMS) spacecraft, we show that reversals of gradient of magnetic field intensity along the magnetic field correspond to reversals of the field‐aligned component of Poynting flux of whistler mode waves in the troughs. Such a characteristic is consistent with the idea that the whistler mode waves are effectively generated near the local minima of magnetic field intensity because of the smallest cyclotron resonance velocity and propagate toward regions of larger magnetic field intensity along the magnetic field lines on both sides. We use the reversal of the Poynting flux as an indicator of wave source regions. In these regions, we find that pancake or an outer edge of butterfly electron distributions above ~100 eV are good candidates for wave generation. Unclear correlations of phase difference and amplitude variations of whistler mode waves in cases of ~40 km spacecraft separation indicate that a simple plane wave approximation with a constant amplitude is not valid at this spatial scale that is much smaller than the ion gyroradius. The whistler mode waves consist of small coherent wave packets from multiple sources with spatial scales smaller than tens of electron gyroradii transverse to the background magnetic field in a mirror mode structure. Key Points: Whistler mode waves are generated near local minima of magnetic field intensity and propagate along field lines on both sidesPancake or an outer edge of butterfly electron distributions above ~100 eV are good candidates for wave generationThe waves consist of many small coherent wave packets of tens of electron gyroradii perpendicular to magnetic fields [ABSTRACT FROM AUTHOR]

Laboratory experiments were conducted to explore the wave trains generated by vertical bed movements. The investigation consisted of 32 cases, involving four different water depths with unimodal and bimodal bed movements. Water surface displacement was measured using gauges positioned along a 30m long tank. A PIV system was set up to provide detailed measurement of the fluid velocity field in the vicinity of the bed movement. Generally, a unimodal movement generated a solitary-like wave, followed by a trailing sequence of waves. A bimodal bed movement induced a more complex flow field, with both the first and second extrema being significant. New analytical solutions have been derived, enabling the calculation of velocity fields. The nature of the wave generation and propagation were characterised using the disturbance-amplitude scale (α) and disturbance-size scale (δ). The applicability of linear theory was investigated, by validating the linear solutions of the generated waves against the experimental observations. For α ≤ 0.25, the analytical solutions were in good agreement with observations of the free surface shape, flow field and wave elevation history. For α ≥ 0.5, non-linearity became more pronounced, and the analytical solutions were only capable of reasonably estimating the amplitude of the first extremum in the vicinity of the moving bed. The initial crest maintained its amplitude and shape more effectively in crest-leading waves, whereas the leading trough decayed significantly in trough-leading waves. Non-linear phenomena were observed, such as wave breaking, air entrapment and twisted free surface. Bimodal bed movements with α ≥ 0.5 generated large, steep crests immediately following the initial trough in trough-leading waves. [ABSTRACT FROM AUTHOR]

Waves in coastal areas and fjords can present inhomogeneities that affect the responses of very large floating structures. However, spatial inhomogeneities of waves are usually not included in model testing. In this paper, the feasibility of generating inhomogeneous wave conditions in an Ocean basin is investigated. For that purpose, a fast linear numerical model of a basin of constant depth is applied, and an optimization method is presented, that allows to find the control signal for the multiflap wavemaker. Comparisons with experiments in SINTEF's Ocean basin demonstrate the validity of the method for generating simple monochromatic synthetic waves, as well as short-crested irregular waves representing realistic conditions in Sulafjorden. • A new method to generate inhomogeneous waves for model tests is proposed. • The method was tested with short-crested inhomogeneous fjord waves in an Ocean basin. • The wavemaker control signal is found by optimization using a linear numerical model. [ABSTRACT FROM AUTHOR]

Plasmaspheric hiss is an important whistler‐mode emission shaping the Van Allen radiation belt environment. How the plasmaspheric hiss waves are generated, propagate, and dissipate remains under intense debate. With the five spacecraft of Van Allen Probes, Exploration of energization and Radiation in Geospace (Arase), and Geostationary Operational Environmental Satellites missions at widely spaced locations, we present here the first comprehensive observations of hiss waves growing from the substorm‐injected electron instability, spreading within the plasmasphere, and dissipating over a large spatial scale. During substorms, hot electrons were injected energy‐dispersively into the plasmasphere near the dawnside and, probably through a combination of linear and nonlinear cyclotron resonances, generated whistler‐mode waves with globally drifting frequencies. These waves were able to propagate from the dawnside to the noonside, with the frequency‐drifting feature retained. Approximately 5 hr of magnetic local time away from the source region in the dayside sector, the wave power was dissipated to e−4 of its original level. Plain Language Summary: A noisy band of electromagnetic waves with frequencies ranging from tens of hertz to several kilohertz in the Earth's plasmasphere is termed plasmaspheric hiss. These waves are recognized to shape the Van Allen radiation belt environment and then affect the spacecraft survivability and lifetime. How the plasmaspheric hiss waves are generated, propagate, and dissipate has been a fundamental unanswered question since their discovery. With three space missions scattered in the inner magnetosphere, we present here the first comprehensive observations of hiss waves growing from the substorm‐injected electron instability, spreading within the plasmasphere, and dissipating over a large spatial scale. These findings have significant implications for the modeling of the plasmaspheric hiss waves and the Van Allen radiation belt dynamics. Key Points: Near the dawnside, energy‐dispersively injected electrons generated plasmaspheric hiss with globally drifting frequenciesThe frequency drift feature allowed tracing the plasmaspheric hiss propagation from the dawnside to the noonsideThe dayside plasmaspheric hiss dissipated away roughly within a magnetic local time span of 5 hr [ABSTRACT FROM AUTHOR]