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1. Gravitational wave memory and the wave equation

   https://doi.org/10.1088/1361-6382/ac7203  

   Garfinkle, David (June 2022, Classical and Quantum Gravity)

   Abstract Gravitational wave memory and its electromagnetic analog are shown to be straightforward consequences of the wave equation. From Maxwell’s equations one can derive a wave equation for the electric field, while from the Bianchi identity one can derive a wave equation for the Riemann tensor in linearized gravity. Memory in both cases is derived from the structure of the source of those wave equations. 

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2. Impacts of Limited Model Resolution on the Representation of Mountain Wave and Secondary Wave Dynamics in Local and Global Models: 2. Mountain Wave and Secondary Wave Evolutions in the Thermosphere

   https://doi.org/10.1029/2021JD036035  

   Fritts, David C.; Lund, Adam C.; Lund, Thomas S.; Yudin, Valery (May 2022, Journal of Geophysical Research: Atmospheres)
3. Spectral Indices and Evidence of Wave–Wave Modulation in Observations of the Interplanetary Magnetic Field

   https://doi.org/10.3847/1538-4357/ad5314  

   Loto’aniu, Paul_T_M; Krista, Larisza (July 2024, The Astrophysical Journal)

   Abstract We present wave and turbulence observations from the DSCOVR spacecraft during the 2017 September solar flare and coronal mass ejection (CME) events. On September 4–12, the spectral index within the magnetic field power spectral density inertial range was consistent with Kolmogorov −5/3. This is despite the 9 days being composed of a complex mix of different features, including solar flares, solar energetic particle events, and CMEs. When analyzing shorter time periods, the spectral index varies. For two days where there were consecutive CMEs, the index follows Kraichnan–Iroshinikov −3/2, while on two quiet days, it was a mixture of −1, −3/2, and −2. The inertial range spectral index taken over the entire 9 days hides or averages out spectral features that occur over shorter time periods. We use a more realistic estimate of the amount of Doppler shifting into the spacecraft frame to show that the break frequencies on most days were located close to the H+ cyclotron frequency. We present evidence of wave–wave modulation and suggest that lower-frequency waves in the solar wind can modulate the growth rates/propagation of ion cyclotron waves, providing a method to transfer energy in the solar wind to smaller scales. Furthermore, we suggest that the indices in the inertial range can be explained by combining containment due to wave generation/propagation and stochastic Brownian motion in the solar wind. When these two phenomena are equal, they combine to create a −3/2 index. 

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4. Wave Packets and Life Cycles of Troughs in the Framework of Local Finite-Amplitude Wave Activity

   https://doi.org/10.1175/JAS-D-24-0197.1  

   Zhang, Rui; Chang, Edmund_K M; Nakamura, Noboru (April 2025, Journal of the Atmospheric Sciences)

   Abstract Synoptic eddies embedded in a westerly flow undergo downstream developments due to their dispersive nature. This paper examines the finite-amplitude aspects of downstream development with the budget of local wave activity (LWA), including explicit contributions from diabatic heating. LWA captures well individual troughs/ridges and the wave packet, and its column budget affords simplified interpretations. In the LWA framework, (linear) downstream development demonstrated in previous analyses is represented by the LWA advection by the zonal reference flow plus LWA flux induced by the radiation of Rossby waves. In addition, convergence of nonlinear advective LWA flux, baroclinic sources at the lower boundary, meridional redistribution by eddy momentum flux, and diabatic sources and sinks complete the column budget of LWA. When applied to the life cycles of troughs within coherent wave packets in the Southern Hemisphere, the LWA budget reveals that individual troughs grow mainly through downstream development, convergence of nonlinear advective flux by eddies, and diabatic heating. Downstream development and divergence of nonlinear flux also dominate trough decay. Contributions from nonlinear advective eddy flux are large in the presence of a strong ridge either immediately upstream or downstream of the trough. Furthermore, anticyclonic components of advective LWA fluxes associated with the upstream or downstream ridge transfer LWA into or out of the trough. Diabatic contributions are significant when the heating exhibits a tilted vertical structure that gives rise to enhanced vertical gradient in heating. 

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5. Transcriptomics and metatranscriptomics in zooplankton: wave of the future?

   https://doi.org/10.1093/plankt/fbaa058  

   Lenz, Petra H; Lieberman, Brandon; Cieslak, Matthew C; Roncalli, Vittoria; Hartline, Daniel K (December 2020, Journal of Plankton Research)

   Irigoien, Xabier (Ed.)

   Abstract Molecular tools have changed the understanding of zooplankton biodiversity, speciation, adaptation, population genetics and global patterns of connectivity. However, the molecular resources needed to capitalize on these advances continue to be limited in comparison with those available for other eukaryotic plankton. This deficiency could be addressed through an Ocean Zooplankton Open ‘Omics Project (Ocean ZOOP) that would generate de novo assembled transcriptomes for hundreds of metazoan plankton species. A collection of comparable reference transcriptomes would generate a new framework for ecological and physiological studies. Defining species niches, identifying optimal habitats, assessing adaptive capacity and predicting changes in phenology are just a few examples of how such a resource could transform studies on zooplankton ecology. 

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