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In this thesis, we theoretically predict the normal characteristics of Very Low Frequency (3~30 kHz) radio wave propagation through Earth-ionosphere waveguide corresponding to normal behavior of the D-region ionosphere. We took the VLF…

Earth and Planetary Astrophysics · Physics 2015-03-20 Sujay Pal

We have investigated a dependence of the relative density of phase slips in the GPS navigation system on the disturbance level of the Earth's magnetosphere. The study is based on using Internet-available selected data from the global GPS…

Geophysics · Physics 2007-05-23 E. L. Afraimovich , O. S. Lesyuta , I. I. Ushakov

The interstellar turbulence is magnetized and thus anisotropic. The anisotropy of turbulent magnetic fields and velocities is imprinted in the related observables, rotation measures (RMs), and velocity centroids (VCs). This anisotropy…

Astrophysics of Galaxies · Physics 2021-04-07 Siyao Xu , Yue Hu

We measure the power and spectral index anisotropy of high speed solar wind turbulence from scales larger than the outer scale down to the ion gyroscale, thus covering the entire inertial range. We show that the power and spectral indices…

Space Physics · Physics 2015-05-18 R. T. Wicks , T. S. Horbury , C. H. K. Chen , A. A. Schekochihin

We have performed a simulation study of Langmuir turbulence in the Earth's ionosphere by means of a Zakharov model with parameters relevant for the F layer. The model includes dissipative terms to model collisions and Landau damping of the…

Space Physics · Physics 2015-05-13 Bengt Eliasson , Bo Thidé

Velocity oscillations in sunspot umbrae have been measured simultaneously in two spectral lines: the photospheric Silicon I 10827 A line and the chromospheric Helium I 10830 A multiplet. From the full Stokes inversion of temporal series of…

Astrophysics · Physics 2009-11-13 Rebecca Centeno , Manuel Collados , Javier Trujillo Bueno

We report measurements of conditional Eulerian and Lagrangian structure functions in order to assess the effects of non-universal properties of the large scales on the small scales in turbulence. We study a 1m $\times$ 1m $\times$ 1.5m flow…

Fluid Dynamics · Physics 2015-05-13 Daniel B. Blum , Surendra Kunwar , James Johnson , Greg A. Voth

We discuss observations of the linearly polarized component of the diffuse galactic radio background. These observations, with an angular resolution of 4', were made with the Westerbork Synthesis Radio Telescope (WSRT) in 5 frequency bands…

Astrophysics · Physics 2007-05-23 M. Haverkorn , P. Katgert , A. G. de Bruyn

The phase space structure of certain quantum states reveals structure on a scale that is small compared to the Planck area. Using an analog between the wavefunction of a single photon and the electric field of a classical ultrashort optical…

Optics · Physics 2015-05-14 Dane R. Austin , Tobias Witting , Ian A. Walmsley

Rotation Measure synthesis (RM synthesis) of the Westerbork Synthesis Radio Telescope (WSRT) observations at 2 m wavelength of the FAN region at l=137deg, b=+7deg shows the morphology of structures in the ionized interstellar medium. We…

Astrophysics of Galaxies · Physics 2015-06-11 Marco Iacobelli , Marijke Haverkorn , Peter Katgert

Probing magnetic fields in the interstellar medium (ISM) is notoriously challenging. Motivated by the modern theories of magnetohydrodynamic (MHD) turbulence and turbulence anisotropy, we introduce the Structure-Function Analysis (SFA) as a…

Astrophysics of Galaxies · Physics 2021-04-21 Yue Hu , Siyao Xu , A. Lazarian

We report on a measurement of the angular power spectrum of the anisotropy in the Cosmic Microwave Background. The anisotropy is measured in 23 different multipole bands from l=54 (~3 deg) to l=404 (~0.45 deg) and in 6 frequency bands from…

Astrophysics · Physics 2009-10-28 C. B. Netterfield , M. J. Devlin , N. Jarosik , L. Page , E. J. Wollack

In the study on nonlinear wave-wave processes in an ionosphere and a magnetosphere usually the main attention is paid to investigation of plasma turbulence at well developed stage, when the wide spectrum of plasma wave is present. On the…

Plasma Physics · Physics 2009-11-13 A. S. Volokitin , B. Atamaniuk

In order for telescopes to obtain good and precise images they need to see through atmospheric turbulence. To accomplish this and compensate for atmospheric turbulence we use Adaptive Optics technologies. In this thesis we analyze the…

Instrumentation and Methods for Astrophysics · Physics 2023-10-13 Cesar Laguna

A particular form for the quantum indeterminacy of relative spacetime position of events is derived from the limits of measurement possible with Planck wavelength radiation. The indeterminacy predicts fluctuations from a classically defined…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Craig J. Hogan

In this study, global nonlinear electromagnetic gyrokinetic simulations are conducted to investigate turbulence in the Internal transport barrier (ITB) region of the EAST tokamak discharge with weakly reversed magnetic shear. Linear…

Plasma Physics · Physics 2025-11-07 Yuehao Ma , Pengfei Liu , Jian Bao , Zhihong Lin , Huishan Cai

Although the interplanetary magnetic field variability has been extensively investigated in situ by means of data coming from several space missions, the newly launched missions providing high-resolution measures and approaching the Sun,…

In this paper, we study the possibility of detection of short term terrestrial lower ionospheric response to gamma ray bursts (GRBs) using a statistical analysis of perturbations of six very low or low frequency (VLF/LF) radio signals…

Space Physics · Physics 2018-02-01 Aleksandra Nina , Saša Simić , Vladimir A. Srećković , Luka Č. Popović

Magnetic field fluctuations in the vicinity of the Earth's bow shock have been investigated with the aim to characterize the intermittent behaviour of strong plasma turbulence. The observed small-scale intermittency may be the signature of…

comp-gas · Physics 2020-01-29 T. Dudok de Wit , V. V. Krasnosel'skikh

We present a study of the structure of the Galactic interstellar medium through the Delta-variance technique, related to the power spectrum and the fractal properties of infrared/sub-mm maps. Through this method, it is possible to provide…