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Showing 1 to 20 of 34 for “"Interplanetary Magnetic Field"”.
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Correlation of the interplanetary magnetic field with auroral form and latitudinal position
Hourly values of the interplanetary magnetic field were compared with photographs of the auroral zone taken by satellite. The photographs were first classified according to the level of auroral activity. It was found that there was a correlation between the north-south component of the magnetic …
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Numerical Analysis and Theory of Oblique Alfvenic Solitons Observed in the Interplanetary Magnetic Field
<p>Recently, there have been reports of small magnetic pulses or bumps in the interplanetary magnetic field observed by various spacecraft. Most of these reports claim that these localized pulses or bumps are solitons. Solitons are weakly nonlinear localized waves that tend to retain their form as …
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Multitaper Methods for Cyclostationary Feature Detection in Time Series Data: Application to ACE Interplanetary Magnetic Field Data
… data. Moreover, it is hypothesized here that interplanetary magnetic field data collected at ACE is almost-cyclostationary and this thesis aims to determine a set of low-frequency periodic components of its autocorrelation function.
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Solar wind-magnetosphere interactions : a statistical analysis of spacecraft measurements
… to understand how the solar wind, and the interplanetary magnetic field (IMF) frozen into it, behaves as it reaches the Earth. Magnetic reconnection, for example, is a phenomenon whose morphology is governed by the IMF orientation and wields a large influence over many of the processes …
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Interstellar helium pickup ion flux variations observed with SOHO/CELIAS
… are charged they become a component of the interplanetary plasma and are transported outward with the solar wind (SW). Measurements of these particles give information about the local interstellar gas in which our sun resides. However, fluxes of pickup ions in the solar wind are observed to …
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A Method to Compute Three Dimensional Magnetospheric Equilibria with Dipole Tilt and its Application in Estimating Magnetic Flux Tube Volume
… includes an arbitrary Earth's dipole tilt and interplanetary magnetic field. We also describe the algorithms of this new friction code that trace magnetic field lines, locate the neutral sheet, and identify the magnetopause In addition, we present a generalized theory for calculating magnetic …
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A stochastic ensemble forecast model for geosynchronous relativistic electron fluxes
… is a function of the solar wind velocity and interplanetary magnetic field, and the Fluxpred model is a multi-layer feed-forward neural network with electron flux and summed Kp as input. Individual model results were combined using a multivariate regression to produce significantly better …
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Reverse Convection Potential Saturation in the Polar Ionosphere
… ionosphere during periods of steady northward interplanetary magnetic field (IMF) are reported. While it has been shown that the polar cap potential in the ionosphere exhibits non-linear saturation behavior when the IMF becomes increasingly southward, it has yet to be shown whether the high …
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Statistical Study of Solar Wind Conditions Prior to Substorm Onsets
… to predict. The northward turning of the interplanetary magnetic field was considered the primary candidate as an external triggering mechanism for substorm onsets. However, that was later shown to be coincidental in nature. This study is motivated by recent multi-spacecraft observations …
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Astrodynamics of the Next Generation Space Weather Prediction Mission
… prediction of the solar wind properties, interplanetary magnetic field direction and various space weather phenomena becomes ever more important as our dependence on Earth orbiting spacecraft increases. Different solar wind drivers can lead both to enhancements and losses of relativistic …
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ΜΕΛΕΤΗ ΔΥΝΑΜΙΚΩΝ ΜΟΝΤΕΛΩΝ ΜΑΓΝΗΤΙΚΩΝ ΠΕΔΙΩΝ ΜΕ ΕΦΑΡΜΟΓΗ ΣΤΗΝ ΜΑΓΝΗΤΟΣΦΑΙΡΑ
… THIS MODEL IS A SUPERPOSITION OF THE FIELD OF A DIPOLE AND A TAIL FIELD. ONE OF THE COMPONENTS OF THE LATER IS A UNIFORM MAGNETIC FIELD OF THE SAME DIRECTION WITH THE MAGNETIC DIPOLE'S MOMENT. THE PICTURE WHICH IS DERIVED FROM THIS MODEL AGREES QUALITATIVELY WITH THIS OF THE …
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A scale-free analysis of magnetic holes in the solar wind
Magnetic holes are isolated intervals of depleted interplanetary magnetic field (IMF) strength on timescales of several seconds to several hours. These intervals have been seen as often as several times per day in the ecliptic and at high heliospheric latitudes from 1 AU to 5.4 AU. We present a …
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Empirical Study of Subauroral Polarization Streams (SAPS) through Decades of Satellite Observations
… westward ion drifts driven by poleward electric fields in the subauroral ionosphere associated with field-aligned currents (FACs) generated by magnetospheric processes. In this dissertation, we have studied SAPS by analyzing the statistics of in-situ measurements of the subauroral ionosphere made …
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Initial mapping of the earth's bow shock, magnetosheath and magnetic tail by Explorer 33
… earth orbit. The Goddard Space Flight Center magnetic field experiment onboard the spacecraft consists of a triaxial fluxgate sensor with a maximum dynamic range of ±64 gammas and a sensitivity of ±0.25 gammas along each axis. Because of the initial apogee-earth-sun angle of 118° west of the …
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Double streaming at 35 AU during the coronal mass ejections of March 1991
… later by a large scale polarity reversal in the interplanetary magnetic field at Voyager 2. This reversal is thought to be a site of magnetic reconnection, where energy in the field is being converted into particle energy. We speculate that the free energy involved in the earlier double streaming …
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A Three-Year Study of the Magnetic Field Fluctuations in the Magnetospheric Cusp
… magnetospheric cusps are regions of significant magnetic field turbulence. There are also magnetic field fluctuations that cannot be called turbulence. Some of the low frequency fluctuations observed in the cusp have been shown to be motion of the cusp structure by the spacecraft (back and forth …
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Case Studies of IMF Driven Auroral Emissions
… at the polar cusp. At the cusp Earth's magnetic fields lines are open and connect .directly to the magnetic field lines of the solar wind. The energy from the solar wind particles precipitating into the ionosphere are dissipated as the aurora. The purpose of this thesis was to present …
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Quantitative modeling of time-dependent phenomena in the magnetospheric magnetic field
A series of improvements to the Rice Field Model (RFM) are described, which both increase the accuracy and extend the capabilities of the model. A new ring current parameterization improves the determination of storm-time fields in the inner magnetosphere. Replacement of the tail current module …
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Ionospheric Convection and Auroral Responses to Solar Wind Driving
… due to solar wind driving. When the interplanetary magnetic field (IMF) is orientated southward, reconnection on the dayside magnetopause opens magnetic flux, which eventually reconnects in the magnetotail. When dayside reconnection is dominant, the polar cap, the area where open …
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Experimental studies of magnetic reconnection in 3D geometries
Magnetic reconnection is an important and prevalent plasma physics phenomenon occurring in astrophysical (solar flares), space (magnetospheric substorms), and laboratory settings (tokamak sawtooth oscillations). It allows for a change in the magnetic field topology in plasmas while also …
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