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Full-Text Articles in Physics
Foundations Of Wave Phenomena, Charles G. Torre
Foundations Of Wave Phenomena, Charles G. Torre
Charles G. Torre
This is an undergraduate text on the mathematical foundations of wave phenomena. Version 8.2.
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 1. The Unstablelayer And Gradient Drift Waves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 1. The Unstablelayer And Gradient Drift Waves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Bela G. Fejer
Electric field and plasma density instrumentation on board a sounding rocket launched from Punta Lobos, Peru, detected intense electrostatic waves indicative of plasma instabilities in the daytime equatorial electrojet. Simultaneous measurements taken by the Jicamarca radar showed strong 3-m type 1 electrojet echoes as well as evidence of kilometer scale horizontally propagating waves. The in situ electric field wave spectra displayed three markedly different height regions within the unstable layer: (1) a two-stream region on the topside between 103 and 111 km where the electron current was considered to be strongest, (2) a gradient drift region between 90 and 106.5 …
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 2. Two-Streamwaves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 2. Two-Streamwaves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Bela G. Fejer
Both primary and secondary two-stream (Farley-Buneman) waves have been detected by in situ electric field and plasma density probes in the strongly driven daytime equatorial electrojet over Peru. Simultaneous Jicamarca radar observations showed strong vertical and oblique 3-m type 1 echoes, also indicative of the two-stream mechanism. The rocket data show the two-stream region on the topside of the unstable layer to be situated between 103 and 111 km where the electron current was the strongest. This region was characterized by broadband plasma oscillations extending past 1 kHz in the rocket frame. Furthermore, above 106.5 km, where the electron density …
Auroral E-Region Plasma Waves Andelevated Electron Temperatures, Bela G. Fejer, J. Providakes, D. T. Farley, W. E. Swartz
Auroral E-Region Plasma Waves Andelevated Electron Temperatures, Bela G. Fejer, J. Providakes, D. T. Farley, W. E. Swartz
Bela G. Fejer
We have observed 3-m auroral E region plasma waves with a high-resolution 50-MHz radar interferometer at Ithaca. During postmidnight periods of very strong magnetic activity at Ottawa (L = 3.5), the backscattered power and Doppler spectra vary rapidly with time and range and may have both mean Doppler shifts and half power widths in excess of 200 Hz (600 m/s). In addition, when the radar and magnetometer data imply that the current is approximately parallel to the radar line of sight, sharp spectral peaks corresponding to phase velocities approaching 1 km/s sometimes appear suddenly. These persist for at most several …
Ion Cyclotron Waves As Apossible Source Of Resonant Auroral Radar Echoes, Bela G. Fejer, R. W. Reed, D. T. Farley, W. E. Swartz, M. C. Kelley
Ion Cyclotron Waves As Apossible Source Of Resonant Auroral Radar Echoes, Bela G. Fejer, R. W. Reed, D. T. Farley, W. E. Swartz, M. C. Kelley
Bela G. Fejer
Auroral backscatter radar observations were made from Ithaca, New York, at 50 MHz during the early morning of April 1, 1976, a period of high magnetic disturbance (Kp ∼ 8). The backscattered power showed large rapid (time scale of a few minutes or less) variations, characteristic of discrete radar aurora, from L = 3.5–4. Doppler spectra of waves propagating in nearly the north-south direction from up to 28 different ranges were obtained simultaneously with good spatial (7.5 km) and temporal (2 s) resolution. Some unusual spectra with very narrow peaks at Doppler shifts between about 70 and 90 Hz were …
Theory Of Plasma Waves In The Auroral E-Region, Bela G. Fejer, J. Providakes, D. T. Farley
Theory Of Plasma Waves In The Auroral E-Region, Bela G. Fejer, J. Providakes, D. T. Farley
Bela G. Fejer
We have extended the linear fluid theory of electrojet plasma waves to the region where ion magnetization effects are important. Our general dispersion relation includes the effect of cross-field and field-aligned drifts, ion inertia, electron density gradients, and recombination. In the absence of density gradients and recombinational damping, the oscillation frequency at marginal instability is changed by the ion magnetization effects from the ion acoustic frequency, ω = kCs, to the modified ion cyclotron frequency ω² = Ωi² + k²Cs². These upper E region waves can be driven by field-aligned and/or cross-field drifts and have the smallest threshold drift velocities …