Interplanetary Causes of Great and Superintense Magnetic Storms
We examine possible interplanetary mechanisms for the Creation of the largest magnetic storms at the Earth.
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We examine possible interplanetary mechanisms for the Creation of the largest magnetic storms at the Earth.
Structural changes in outer radiation belt caused by magnetic storms - explorer xii data
Energetic electron precipitation from geomagnetic field during magnetic storm
An improved formulation for empirical modeling of magnetic storm effects in neutral thermospheric composition and temperature is utilized in a study of two disturbed periods. The formulation, which incorporates the prior history of the heat input rather than a single phase delay, is based on a Fourier integral representation of an existing theoretical model. This results in an improved representation of the detailed time variations and a better carry-over of model parameters from one storm to the other and provides a basis for theoretical interpretation.
Change in boundary of outer radiation zone following magnetic storm of september 30, 1961 - explorer vii data on trapped electron intensities
This presentation examines the magnetic field fluctuations within Corotating Interaction Regions (CIRs) detected by Ulysses at mid- and low-latitudes. CIRs are formed by the interaction of high-speed streams flowing from the polar coronal hole with slow-speed streams. Several wave modes are identified, and the effectiveness of these waves causing magnetic storms at Earth will be discussed.
Changes in ion and neutral compositions and in neutral, ion, and electron temperatures during the main phase of a magnetic storm are studied by solving a system of basic ionospheric and atmospheric differential equations. It is shown that a decrease in the atomic-to-molecular concentration ratio in the lower thermosphere may help explain several phenomena observed during a magnetic storm. These phenomena include decreases in the columnar electron content and increases in neutral temperature.
This talk provides a brief summary of the first conference devoted entirely to magnetic storms. Topics cover the relevant phenomena at the Sun/corona, propogation of these structures through interplanetary space, the response of the magnetosphere to interaction with these interplanetary structures, the formation of the storm time ring current (in particular the oxygen content of the ring-current), and storm ionospheric effects and ground based effects.
We discuss possible interplanetary mechanisms for the creation of the great magnetic storms at the Earth. We consider the effects of interplanetary shock events on magneic cloud and sheath plasma, leading to potentially stronger interplanetary magnetic field magnitudes.
This publication is a product of the continuing study of the properties of charged particles and fields in space being conducted by The RAND Corporation under contract No. NAS5-276 for the National Aeronautics and Space Administration. Magnetic storms, revealed by world-wide changes in the intensity of the earth's magnetic field, and emphasized by disturbances in electromagnetic communication channels, form detectable patterns on the surface of the earth and above it. The author draws together data from various times, places, and altitudes and, coupling these with what is known or inferred about the aurora, the ionosphere, and the relationship between them and the earth's radiation belts, creates a picture of what is believed to occur during a magnetic storm.
Results are presented for a statistical analysis of the temporal variations of precipitating O(+) and H(+) ions in the energy range 0.7-12 keV during the magnetic storms on Dec. 16-18, 1971. Emphasis is on the temporal variations of parameters describing the intensity, average energy, and spatial location of the precipitation zones of the two ionic species. It is shown that the intensity of the precipitating O(+) ions correlate well with the geomagnetic indices which measure the strength of magnetospheric substorm activity and the strength of the storm time ring current, indicating that a previously unknown strong coupling mechanism existed between the magnetosphere and the ionosphere during the storm period. Correlations are found between the locations of the O(+) and H(+) precipitation zones and between the average energies of the two ionic species. Precipitation is shown to be an important loss mechanism for ring current ions with energy less than 12 keV during the magnetic storm period studied.
We have developed a model and associated computational procedure for estimating energetic proton exposures during a major solar proton event that occur in combination with a large magnetic storm. Transmission functions for solar protons are computed using geomagnetic vertical cutoff data for quiescent amd disturbed conditions. Predicted exposures in low altitude polar orbit are found to be orders of magnitude greater for severe magnetic storm conditions than are corresponding exposures in the absence of major disturbances. We examine the response scenario for the events of November 1960 as an example.
Middle latitude changes in topside electron density during magnetic storm
Observations of F-layer irregularity development and intensity were obtained between September and October 1981, primarily over subauroral latitudes in the area of the plasmapause. The results reveal the descent of the auroral irregularity region to include subauroral latitudes in the general area of the plasmapause during the main phases of a series of magnetic storms. Irregularities were found primarily at lower latitudes during the subauroral or plasmapause storm. A model for the subauroral irregularities in recovery phases of magnetic storms is proposed in which energy stored in the ring current is slowly released.
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During and a few years after solar maximum, the dominant interplanetary phenomena causing intense magnetic storms are the remnants of fast coronal mass ejections, high-speed solar ejects.
Proton density energy distributions during two magnetic storms on Dec. 16 and 18, 1971, are derived from proton detector data of the S3-A satellite and are analyzed to show the contrast in the ring current developments during the two events. Ground magnetograms are also used in the analysis to show the magnetic field variations during the storms. Satellite orbits 97 through 103 are covered.
Redistribution of high-energy geomagnetically trapped protons during magnetic storm obtained with aid of scintillation detector aboard Relay I satellite