Aurora and the lower ionosphere in relation to satellite observations of particle precipitation
Aurora and lower ionosphere in relation to satellite observations of electron precipitation
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Aurora and lower ionosphere in relation to satellite observations of electron precipitation
Direct observation of electron precipitation with rockets and satellites, showing that results agree with fluxes predicted from optical measurement of auroras
Dynamic motions of Aurora 7 towards equator
Visible and invisible aurora discussing morphology, occurrence, magnetic activity, absorption, geophysical and energy particle
Patches and irregular bands and eastward motions in morning sector of auroras
Equatorward motions of auroras
Diurnal and annual variations in atmospheric electric field intensity during polar aurorae
Correlation of ULF radiation with polar aurorae, and ULF propagation in ionosphere
Electron measurements near weak aurora during rocket flight
In 1996 during the first four orbits of the satellite tour the Galileo Ultraviolet Spectrometer (UVS) (1100-4300 Angstroms) and Extreme Ultraviolet Spectrometer (EUVS) (550-1300 Angstroms) performed near-simultaneous observations of the Jupiter aurora in both the north and south polar regions.
A new generation of high resolution UV imaging spacecraft (Polar, Galileo, HST) are studying the airglow and aurora of the Earth and the Jovian planets. To keep pace with these technological improvements we have developed a laboratory program to provide electron collision cross sections of the major molecular planetary gases (H (sub 2) , H, O, N (sub 2) , CO (sub 2) , SO (sub 2) , O (sub 2) , H (sub 2) O, and CO).
This oral report describes the first images of Saturn's far- ultraviolet polar aurora taken with the Hubble Space Telescope Wide Field and Planetary Camera 2 in October 1994. The images revealed auroral emissions from atomic and molecular hydrogen in both the north and south circumpolar region. Details of this observational data are given and interpreted.
We have determined the spatiotemporal characteristics of the magnetosphere-ionosphere (M-I) coupling using auroral imaging. Observations at fixed positions for an extended period of time are provided by a ground-based all-sky imager measuring the 557.7 nanometer auroral emissions. We report on a single event of nightside aurora (at approximately 22 magnetic local time) preceding a substorm onset. To determine the spatiotemporal characteristics, we perform an innovative analysis of an all-sky imager movie (19 minutes duration, images at 3.31 hertz) that combines a two-dimensional spatial fast Fourier transform with a temporal correlation. We find a scale size-dependent variability where the largest scale sizes are stable on timescales of minutes while the small scale sizes are more variable. When comparing two smaller time intervals of different types of auroral displays, we find a variation in their characteristics. The characteristics averaged over the event are in remarkable agreement with the spatiotemporal characteristics of the nightside field-aligned currents during moderately disturbed times. Thus, two different electrodynamical parameters of the M-I coupling show similar behavior. This gives independent support to the claim of a system behavior that uses repeatable solutions to transfer energy and momentum from the magnetosphere to the ionosphere.
In 1996 during the first four orbits of the satellite tour the Galileo ultraviolet spectrometer (UVS) (1130-4320 A) and extreme ultraviolet spectrometer (EUVS)(540-1280 A) performed near-simultaneous observations of the Jupiter aurora in both the north and south polar regions.
In addition to wave particle scattering in the magnetosphere, atmospheric backscatter of magnetospheric electrons is an important process that contributes to the formation of the precipitated electrons in the region of diffuse aurora. Two magnetically conjugate regions are involved in a complex magnetosphere-ionosphere (MI) particle and energy interplay. Based on synthesizing previous theoretical/modeling studies and experimental evidence, we demonstrate the need for improving the quantification of magnetospheric electrons backscatter processes that can affect inner magnetospheric electrodynamics, transport and loss in a way that is not easily predicted. We discuss how these complex and energy-dependent MI coupled processes can be treated in magnetospheric modeling.
Auroras and airglow emissions during international geophysical year
Continuum emission in airglow and aurorae
Spectroelectrophotometry of hydrogen emission in aurorae