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Full-Text Articles in Physics
The Occurrence Of Ionospheric Signatures Of Plasmaspheric Plumes Over Different Longitudinal Sectors, E. Yizengaw, J. Dewar, J. Macneil, D. Galvan, Jeff Sanny, David Berube, B. Sandel
The Occurrence Of Ionospheric Signatures Of Plasmaspheric Plumes Over Different Longitudinal Sectors, E. Yizengaw, J. Dewar, J. Macneil, D. Galvan, Jeff Sanny, David Berube, B. Sandel
Physics Faculty Works
Plasmaspheric plumes have ionospheric signatures and are observed as storm-enhanced density (SED) in global positioning system (GPS) total electron content (TEC). These ionospheric signatures have been primarily observed over the American sector and in a few limited examples over the European sector. This study examines the longitudinal occurrence frequency of plasmaspheric plumes. We analyzed all images from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) Extreme Ultraviolet Imager (EUV) databases for the first half of 2001 and identified a total of 31 distinct plume intervals observed during different storm events. Out of the total IMAGE EUV plumes that we identified, 12 …
Global Profiles Of Compressional Ultralow Frequency Wave Power At Geosynchronous Orbit And Their Response To The Solar Wind, Jeff Sanny, D. Judnick, M. B. Moldwin, David Berube, D. G. Sibeck
Global Profiles Of Compressional Ultralow Frequency Wave Power At Geosynchronous Orbit And Their Response To The Solar Wind, Jeff Sanny, D. Judnick, M. B. Moldwin, David Berube, D. G. Sibeck
Physics Faculty Works
We investigate the global local-time profiles of compressional wave power in three ultralow frequency (ULF) bands corresponding to Pc3, Pc4, and Pc5 pulsations using magnetic field data from the geosynchronous GOES satellites. The global power profiles of the three frequency bands are studied for low, moderate, and high levels of geomagnetic activity based on the Dst index. We also consider the seasonal variation of the ULF power profiles, as well as the effects of solar wind and interplanetary magnetic field (IMF) parameters. For high geomagnetic activity, we find that the greatest power is associated with compressional Pc5 pulsations in the …
Quiet Time Variability Of The Geosynchronous Magnetic Field And Its Response To The Solar Wind, Jeff Sanny, J. A. Tapia, D. G. Sibeck, M. B. Moldwin
Quiet Time Variability Of The Geosynchronous Magnetic Field And Its Response To The Solar Wind, Jeff Sanny, J. A. Tapia, D. G. Sibeck, M. B. Moldwin
Physics Faculty Works
We present a survey of the variability of the geosynchronous magnetic field strength on the dayside using observations by the GOES satellites over a period exceeding 4 years. Only intervals of reduced geomagnetic activity, as defined by Dst > −20 nT, were considered in this study. The magnetic field strength data were filtered with a passband of 1.7 mHz to 17 mHz (1–10 minutes), a process that eliminates the diurnal variation of the field strength and the effects of most of the higher frequency (>17 mHz) ultralow-frequency (ULF) waves. The geosynchronous field strength appears to exhibit the greatest variability in …
A Statistical Study Of Transient Event Motion At Geosynchronous Orbit, Jeff Sanny, David Berube, D. G. Sibeck
A Statistical Study Of Transient Event Motion At Geosynchronous Orbit, Jeff Sanny, David Berube, D. G. Sibeck
Physics Faculty Works
The geosynchronous GOES 5 and GOES 6 satellites frequently observe transient events marked by magnetic field strength increases and bipolar magnetic field signatures lasting several minutes. In this study we report a survey of 87 events observed simultaneously by both GOES spacecraft (for a total of 174 individual observations) from August to December 1984. Events detected in the prenoon sector outnumbered those in the postnoon sector by about a 3 to 1 ratio. The distribution of the events versus local time exhibited a significant prenoon peak like the distribution of magnetic impulse events observed in high-latitude ground magnetometers. A cross-correlation …
A Statistical Study Of The Magnetic Signatures Of Ftes Near The Dayside Magnetopause, Jeff Sanny, C. Beck, D. G. Sibeck
A Statistical Study Of The Magnetic Signatures Of Ftes Near The Dayside Magnetopause, Jeff Sanny, C. Beck, D. G. Sibeck
Physics Faculty Works
During magnetopause crossings, the AMPTE CCE satellite frequently observed flux transfer events (FTEs) characterized by fluctuations in the magnetic field strength (B) and bipolar signatures in the field component (BN) normal to the nominal magnetopause. In this study, we survey 110 events observed from October to December 1984 and during January 1986. Nearly all events exhibited increases in B, and although the majority of events exhibited a symmetric bipolar signature in BN, a significant number (31 of 110) had asymmetric bipolar signatures in which the trailing pulse was dominant. Most of the …
A Statistical Study Of Transient Events In The Outer Dayside Magnetosphere, Jeff Sanny, D. G. Sibeck, C. C. Venturini, C. T. Russell
A Statistical Study Of Transient Events In The Outer Dayside Magnetosphere, Jeff Sanny, D. G. Sibeck, C. C. Venturini, C. T. Russell
Physics Faculty Works
The AMPTE CCE satellite frequently observed transient (1 ≤ τ ≤ 8 min) events marked by magnetic field strength increases and bipolar magnetic field signatures (peak-to-peak amplitudes ≥ 4 nT) while in the outer dayside magnetosphere. We report a survey of 59 prominant events observed from August to November 1984. The bipolar signatures and minimum variance analysis reveal that most events move poleward and antisunward, except in the immediate vicinity of local noon. Here the motion of the events appears to be better governed by the spiral/orthospiral interplanetary magnetic field (IMF) orientation than magnetic curvature forces associated with IMF By. …