ROCKET INSTRUMENTATION FOR THE MEASUREMENT OF AC CONDUCTIVITY, WITH A CAPACITIVE PROBE, AND LONG WAVE PROPAGATION IN THE LOWER IONOSPHERE

1962 ◽  
Author(s):  
T. A. Seliga ◽  
R. W. Vogt
Keyword(s):  
Wave Propagation ◽  
Ac Conductivity ◽  
Lower Ionosphere ◽  
Long Wave ◽  
Capacitive Probe

Long Wave Propagation in Idealized Estuary

1973 ◽  
Vol 99 (7) ◽  
pp. 993-1007
Author(s):  
Donald W. Knight
Keyword(s):  
Wave Propagation ◽  
Long Wave

scholarly journals A modeling study of asymmetries in plasma irregularity characteristics near gradient reversals

2016 ◽  
Vol 34 (9) ◽  
pp. 709-723 ◽  
Author(s):  
Leslie J. Lamarche ◽  
Roman A. Makarevich
Keyword(s):  
Growth Rate ◽  
Wave Propagation ◽  
Plasma Density ◽  
Large Scale ◽  
Strong Dependence ◽  
Critical Role ◽  
Lower Ionosphere ◽  
Transitional Region ◽  
Plasma Convection ◽  
High Latitude Ionosphere

Abstract. Asymmetries in plasma density irregularity generation between the leading and trailing edges of the large-scale plasma density structures in the high-latitude ionosphere are investigated. A model is developed that evaluates the gradient-drift instability (GDI) growth rate differences across the gradient reversal that is applicable at all propagation directions and for the broad range of altitudes spanning the entire lower ionosphere. In particular, the model describes asymmetries that would be observed by an oblique scanning radar near density structures in the polar cap such as elongated polar patches. The dependencies on the relative orientations between the directions of the gradient reversal, plasma convection, and wave propagation are examined at different altitudinal regions. At all altitudes, the largest asymmetries are expected for observations along the gradient reversals, e.g., when an elongated structure is oriented along the radar boresight. The convection direction that results in the strongest asymmetries exhibits a strong dependence on the altitude, with the optimal convection being parallel to the gradient reversal in the E region, perpendicular to it in the F region, and at some angle between these extremes in the transitional region. Implications for observations of polar patches by oblique scanning radars within the Super Dual Auroral Radar Network are discussed. It is demonstrated that the wave propagation direction relative to the prevalent convection and gradient directions plays a critical role in controlling both the irregularity growth rate and its asymmetries near gradient reversals.

scholarly journals Upstream Propagating Long-Wave Modes at a Microtidal River Mouth

2020 ◽  
Vol 2 (1) ◽  
pp. 15
Author(s):  
Matteo Postacchini ◽  
Lorenzo Melito ◽  
Alex Sheremet ◽  
Joseph Calantoni ◽  
Giovanna Darvini ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Field Data ◽  
Tide Gauge ◽  
Low Frequency ◽  
River Mouth ◽  
Long Waves ◽  
Tidal Forcing ◽  
Long Wave ◽  
Low Frequency Waves ◽  
Wave Modes

We illustrate recent findings on the upriver propagation of long waves entering the mouth of the Misa River (Senigallia, Italy). Such a microtidal environment has been recently studied to understand river–sea interactions: it has been found that the river forcing dominates over the marine actions in winter, especially during storms. However, upriver wave propagation is not negligible with low-frequency waves propagating upriver for distances of the order of kilometers. With the aim to better understand the behavior of low-frequency waves propagating upriver, the analysis of the present work builds on field data collected by instruments installed close to the mouth and along the final reach of the Misa River: a tide gauge, two hydrometers and an acoustic Doppler sensor. It has been here observed that the tidal forcing (periods of the order of hours/days) is significantly strong at a distance of more than one kilometer from the river mouth, while shorter waves, like seiches (periods of some hours), are less important and are supposed to largely dissipate at the estuary, although their role could be of importance during relatively short events (e.g., floods).

scholarly journals Modeling solar flare induced lower ionosphere changes using VLF/LF transmitter amplitude and phase observations at a midlatitude site

2013 ◽  
Vol 31 (4) ◽  
pp. 765-773 ◽  
Author(s):  
E. D. Schmitter
Keyword(s):  
Solar Flare ◽  
Continuous Monitoring ◽  
Lower Ionosphere ◽  
Signal Propagation ◽  
Electron Density Profile ◽  
Propagation Model ◽  
Inexpensive Method ◽  
Long Wave ◽  
Phase Data ◽  
Solar Flare Effects

Abstract. Remote sensing of the ionosphere bottom using long wave radio signal propagation is a still going strong and inexpensive method for continuous monitoring purposes. We present a propagation model describing the time development of solar flare effects. Based on monitored amplitude and phase data from VLF/LF transmitters gained at a mid-latitude site during the currently increasing solar cycle no. 24 a parameterized electron density profile is calculated as a function of time and fed into propagation calculations using the LWPC (Long Wave Propagation Capability). The model allows to include lower ionosphere recombination and attachment coefficients, as well as to identify the relevant forcing X-ray wavelength band, and is intended to be a small step forward to a better understanding of the solar–lower ionosphere interaction mechanisms within a consistent framework.

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