Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 36 for “"F-region"”.
-
F-region winds over the central polar cap
F-region neutral winds across the polar cap have been studied by utilizing a Fabry-Perot interferometer located at Eureka (89° CGM), Nunavut Territory, over a 2-winter period 1997/98 and 1998/99. The dependence of neutral winds on the interplanetary magnetic field (IMF) was studied with …
-
Investigation of the Physics of Dynamical Processes in the Topside F Region
Made available in DSpace on 2015-05-12T22:38:46Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7212115.PDF: 7982708 bytes, checksum: a340e80dfc4993ecacb8cad7dc8a0d0a (MD5) Previous issue date: 1971
-
Long-pulse incoherent scatter probing of the F-region ionosphere at Arecibo
… scatter radar (ISR) experiments probing the F-region ionosphere at Arecibo utilize three types of transmission envelopes having different range-mixing and error statistical models on their corresponding backscattered pulse returns. The binary-coded envelope with wide bandwidth (0.44 ms duration …
-
F-region Dusk Ion Temperature Spikes at the Equatorward Edge of the High Latitude Convection Region
… Flat, Alaska, short-lived enhancements in the F-region ion temperature, or "Tᵢ spikes", were discovered in the evening while the radar was on the equatorward edge of the high latitude convection region. These enhancements were several hundred Kelvin above the background temperature, would last …
-
An Incoherent Scatter Investigation of the Properties of Internal Gravity Waves in the Ionospheric F-Region
Made available in DSpace on 2014-12-12T20:54:37Z (GMT). No. of bitstreams: 1 7726675.pdf: 5231681 bytes, checksum: e76198194a345278ed10ad338f71a1da (MD5) Previous issue date: 1977
-
Calibration of Jicamarca radar using F-region incoherent scatter for measurements of D-region backscatter RCS
This thesis presents calibrated radar measurements of absolute backscatter cross sections of mesospheric radar echoes observed at the Jicamarca Radio Observatory in Perú. Radar system calibration is accomplished by simulating the propagation of transmitted and backscattered radio waves through the …
-
Equatorial F -Region Plasma Density Estimation With Incoherent Scatter Radar Using a Transverse -Mode Differential -Phase Method
The full correlation method is formulated and applied to the June 2002 data. Compared to the differential-phase method, this method is different in the sense that it utilizes the real and imaginary parts of the cross-correlation of orthogonal antenna outputs at the high altitudes where SNR is low …
-
Inversion techniques for analyzing long pulse incoherent scatter radar data with a focus on F-region ion drift estimation
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-03-28 without embargo terms
-
Estimation of ion drift velocity vector in F region ionosphere based on incoherent scattered pulse data using machine learning technique
… of the plasma at different altitudes in the F region of the ionosphere using machine learning techniques. The computation is based on the radar data acquired with the ALTAIR (Automatic Radar Plotting Aid (ARPA) Long-Range Tracking and Instrumentation Radar) incoherent scatter radar (ISR). The …
-
Incoherent scatter modeling of Jicamarca radar spectra
… and Milla (2011) for a collisional equatorial F-region ionosphere. This single-ion model of Kudeki and Milla captures the essential physics of the equatorial F-region ionosphere where random displacements of the dominant oxygen ions are characterized as a Brownian-motion process, while electron …
-
Incoherent Scatter Radar Observations of Dynamic Ion Composition Changes at High Latitudes during Geomagnetic Storms
<p>Two new methods are developed for estimating F region ion composition from field-aligned incoherent scatter radar (ISR) measurements. These methods address incoherent scatter spectra temperature-mass ambiguities by self-consistently modeling ion temperature profiles as a function of electric …
-
Tools for Comparing ICON EUV Data with Different Ground Based and Space-based Proxies
… contains ionized particles and plasma. In this region at about 150 kilometers above the surface of the earth starts the F region and it extends up to 500 kilometers. The Ionosphere is filled with tenuous gases and is a mixture of neutral and charged particles. These winds do not follow any flow …
-
The mid-latitude ionosphere under quiet geomagnetic conditions: propagation analysis of SuperDARN radar observations from large ionospheric perturbations
… nighttime, and equatorward of both the auroral regions and the plasmapause boundary. An initial analysis suggested that the Temperature Gradient Instability (TGI) was responsible for the growth of such irregularities. We first used our ray-tracing model to distinguish between HF propagation …
-
Total Electron Content During Auroral Conditions
… as a function of altitude for E and lower F regions is used to calculate electron density height profiles for the approximately vertical, polar geomagnetic field lines that may be traced upwards in the field of view of the photometers. Total electron content obtained by summing across field …
-
Solar flare effects observed over Jicamarca during MST-ISR experiments
… of incoherent scatter (IS) returns from F-region ionosphere and IS theory [Kudeki and Milla, 2011; Milla and Kudeki, 2011]. The present study focuses on the effects of six solar flare events observed to cause significant changes in the mesosphere and the thermosphere. The largest event in …
-
Radio Propagation Through Density Irregularities in the Auroral Ionosphere
… is commonly seen in equatorial and high-latitude regions. This study centers around the scintillation and its causative plasma processes that dominantly happen in the high-latitude ionosphere over the auroral regions (or the auroral ionosphere where we see northern and southern lights). The aim of …
-
Radio and Optical Techniques for Locating Equatorial Plasma Irregularities
… density depletions occur in the post-sunset F region ionosphere almost nightly during certain seasons at equatorial latitudes. These depletions contain density irregularities of scales ranging from a few centimeters to thousands of kilometers. Spread-F, the disruption of ionospheric …
-
Characterization and Modeling of Solar Flare Effects in the Ionosphere Observed by HF Instruments
… intensity, and made some inferences about D-region ion-chemistry using a simulation study. Specifically, we found solar flares alter the D-region chemistry by enhancing the electron detachment rate due to a sudden rise in molecular vibrational and rotational energy under the influence of …
-
Dynamics of the geomagnetically disturbed ionosphere as measured by GPS receivers and SuperDARN HF radars
… We present the first observations of a recurrent region of anomalous enhanced TEC at mid-latitudes over North America and attempt to characterize its frequency of occurrence. Next, we examine the relationship of convection electric fields to the formation of a polar cap tongue of ionization (TOI) …
Page 1 of 2