A study of AMPTE CCE magnetic field data covering the frequency range 0.1–4.0 Hz using all obtained during first complete local time precession satellite orbit major axis (7500 hours observations) has been made to evaluate occurrence transverse, narrowband Pc 1–2 emissions, identified as electromagnetic ion cyclotron (EMIC) waves, in equatorial magnetosphere from L = 3.5 9 at times. We report this work a pair papers which is first. set example events illustrates pattern occurrence: occur...

A statistical study of narrowband transverse 0.1‐ to 4.0‐Hz magnetic pulsations, essentially Pc 1–2 (0.1–5.0 Hz), occurring from L =3.5 =9, |MLAT| < 16°, and all local times, has been made using data the AMPTE CCE satellite. This work is reported in a pair papers which this second. In first paper (Anderson et al., issue) occurrence distributions were reported, here we present normalized frequency, X = F/F H + ( F are wave frequency proton gyrofrequency, respectively); ellipticity, ε,...

Observations obtained by the Freja satellite at altitudes around 1700 km in high‐latitude magnetosphere are used to study ion energization perpendicular geomagnetic field. Investigations of ions, electrons, plasma densities, electric and magnetic wave fields, field‐aligned currents O + heating mechanisms. Three events studied detail, 20 a detailed statistical study. More than 200 classified as belonging one four major types ordered function local time. The most common associated with...

This paper addresses the occurrence of low‐ L (3.5 < 5) electromagnetic ion cyclotron (EMIC) waves during magnetic storms. Using ∼10 years data, a statistical analysis indicates that EMIC in equatorial magnetosphere occur 5 times more often storms than quiet times. wave is important because pitch angle scatter energetic protons and thus represent ring current loss mechanism. Observations magnetosphere, acquired by Dynamic Explorer 1 (DE 1) satellite, are used to show simultaneous enhanced...

We have conducted a statistical study of large‐scale Birkeland currents, hot plasma, and the B y component interplanetary magnetic field. Forty‐eight Viking orbits from July 19, 1986, to September 2, were used in during time period when 3‐ R E geocentric apogee was located near dayside high‐latitude region usually associated with polar cusp. first compared location magnetosheathlike electrons 1 “traditional cusp” current systems noon. It found that system colocated most intense electron...

Magnetic and electric field fluctuations in the Pc 1 frequency range (0.2–5 Hz) have been observed by polar‐orbiting Viking satellite. The fluctuations, interpreted here as electromagnetic ion cyclotron (EMIC) waves, were during 21 of 450 orbits surveyed between 0900 1400 MLT, near 3 R E geocentric altitude, at invariant latitudes from 59° to 77°. structure waves is investigated, using spectral analysis determining distribution wave a function latitude. At 72°, EMIC below equatorial He +...

A unique alignment of the Active Magnetospheric Particle Tracer Explorers (AMPTE) CCE and Viking satellites with respect to EISCAT Magnetometer Cross has provided an opportunity study transient ULF pulsations associated variations in solar wind plasma density observed by IMP 8 satellite. These observations were acquired during a relatively quiet period on April 24, 1986, Polar Region Outer Magnetosphere International Study (PROMIS) period. An isolated 4‐mHz (4‐min period) pulsation was...

Simultaneous, conjugate measurements of magnetic fields and charged particles at low altitude in the high‐latitude prenoon sector magnetosheath were made with DMSP F7, HILAT, Active Magnetospheric Particle Tracer Explorers (AMPTE) CCE satellites on November 1, 1984. These data show that low‐latitude portion traditional “cusp” particle signature is coincident region 1 current system both hemispheres for northward southward interplanetary (IMF). The Birkeland currents are associated dispersion...

Extremely low‐frequency (ELF) magnetic and electric field plasma wave emissions were recorded on 2 October 1993 auroral lines by the Magnetic Field Experiment during Freja orbit 4770. The ELF frequencies below local oxygen gyrofrequency (25 Hz) between helium proton gyrofrequencies (100 to 400 Hz). waves, interpreted as electromagnetic ion cyclotron (EMIC) observed in a region of inverted‐V‐type electron precipitation. EMIC waves correlated over time with lower energy (≈100 eV) electrons,...

Follow-up examination of a 61-year-old woman who recently had papillary transitional cell carcinoma removed from her urinary bladder revealed 5-cm mass in the left adrenal gland. Clinicopathologic studies showed tumor to be heretofore undocumented virilizing oncocytic cortical adenoma. Ultrastructural disclosed that cytoplasm was filled with mitochondria, many which tubulovesicular cristae. The smooth endoplasmic reticulum well developed, as Golgi apparatus. Lysosomes various types,...

Ion conics are often observed in the dayside polar cusp region of magnetosphere by orbiting Viking satellite. These ion distributions may be locally heated perpendicularly to ambient magnetic field temperatures about 100 eV. The closely associated with increased electron fluxes but occur equatorward ions injected from magnetosheath. They also related waves frequencies up Hz. wave electric is directed mainly perpendicular and shows no clear structure near gyrofrequencies or their harmonics....

The Viking spacecraft carries a high‐resolution Magnetic Field Experiment that acquires approximately 53 vector samples per second. It has four automatically switchable ranges from ±1024 to ±65,536 nT (full scale) and resolutions commensurate with 13 bit A/D converter in each range (±0.125 ±8 nT). Data acquired on March 25, 1986 (just month after Viking's launch) at ∼ 13,000 km altitude over the morning sector near 08:30 MLT indicate large‐scale (>0.5° invariant latitude wide) region 1 2...

Electric field and satellite potential (which is a rough measure of plasma density) observations along 42 Viking orbits in the high‐altitude (2 R E ) polar cusp dayside auroral region have been examined. A useful, straightforward way to identify from demonstrated, results being excellent agreement with those based on particle data. Within density usually reaches maximum, it typically very homogeneous, contrast irregular lower cleft regions. The maxima are sometimes anticorrelated magnetic...

A statistical study of Pc 1 waves has been performed using electric field data recorded in the ionosphere by Dynamics Explorer 2 satellite. The was applying an automated wave detection algorithm to over 900 hours at invariant latitudes (INV) greater than 40° from December 6, 1981, February 16, 1983. total 390 were identified a selection technique based on spectral peak frequency range 0.2 6.0 Hz. Most events observed frequencies between 0.4 and 2.0 Hz dawn (0400–0600 MLT) noon (1000–1500...

A unique alignment of the Viking satellite with respect to a network magnetometers in Greenland has provided opportunity study relationship pulsations and plasma characteristics dayside cusp. Observations interplanetary medium were not available during event studied here, but particle data from DMSP hot observations provide strong evidence that IMF had northward component. The presence Pc 1 bursts, 4–5 pulsations, tailward traveling twin vortex pattern ionospheric convection suggests...

On July 24, 1986 narrow band magnetic field fluctuations were observed by VIKING near the apogee altitude of 13,500 km in polar cusp region during a period strong southward interplanetary (IMF). The experiment obtained vector measurements up to nearly proton cyclotron frequency ( f H =28 Hz). Simultaneously, magnetosheath‐like electrons and ions as well an upward‐flowing field‐aligned current observed. most intense flux colocated with 35 nT depression total strength 1860 nT, interpreted...

Pearl pulsations, with an average repetition period of 60 s, were recorded using the magnetic and electric field experiments on polar‐orbiting Viking satellite. The wave event occurred September 30, 1986, during orbit 1212 at 1030 MLT, from L = 3.6 to 4.1, altitude 13,500 km. Electron density observations obtained show that waves generated plasmapause lower amplitudes in plasmasphere. Poynting flux, calculated field, indicated generally propagating downward toward ionosphere, although upward...

Electromagnetic ion cyclotron waves in the Pc1–2 frequency range (0.1–5 Hz) have been observed Earth's equatorial magnetosphere over L =3 to 9 by AMPTE/CCE magnetic fields experiment. We report detailed analysis of data from two orbits together with preliminary occurrence statistics 31 days. One example occurred during disturbed geomagnetic conditions (maximum AE>1000 nT) and exhibited intense Pc1 =5 magnetopause ( ≈7.5). The second moderate quiet (average AE≈300 displayed distinct...

The UV images obtained with the Viking satellite often show bright features which resemble “beads” or “pearls” aligned in east–west direction between noon and 1800 MLT ( Lui et al ., 1989). acquired a series of 25 during 28‐min period on July 29, 1986, showed distinctive periodic this region. Magnetic field hot plasma measurements by confirm that emissions are colocated line projection an upward‐flowing region 1 Birkeland current precipitating energetic (∼200 eV) electrons. These...

This paper discusses results from a statistical study of narrowband auroral electromagnetic ion cyclotron (EMIC) waves recorded by the Freja magnetic field experiment December 1, 1993, to November 30, 1994. The involves data collected at all local times (MLT), invariant latitudes between 40° and 75°, altitudes 1200 1750 km. Wave events have been identified using two‐step process. First, spectra in frequency range 5 256 Hz were surveyed an automated procedure which detects spectral peaks....

On April 11, 1986, at about 0600 UT a long Pc 1 wave event of the hydromagnetic chorus type started on ground, as registered by Finnish pulsation magnetometer network. The main band 0.3 Hz was observed for several hours. Soon after start, this smoothly extended to higher frequencies, forming another separate which finally reached up 0.5 Hz. During Viking satellite its southbound pass over Scandinavia, close MLT sector ground From 0650 until 0657 UT, chain bursts with increasing frequency....

Geomagnetic pulsations from 0.2 to 5.0 Hz (Pc 1) observed on the ground could be used monitor magnetospheric processes generating them if their source regions were known. We report simultaneous observations of Pc 1 bursts at South Pole Station and in space 9 R e geocentric distance near magnetic equator showing that subsolar outer magnetosphere, earthward low latitude boundary layer, is region bursts. The extends 2 hours azimuthally radially. Correlation magnetopause displacements indicates...

Structured Pc 1 pulsations are investigated using simultaneous multipoint ground‐satellite observations recorded on September 10, 1986, during Viking orbit 1103. The were acquired the magnetic field experiment at 13,550 km altitude from L = 5.1 to 5.5 and three Finnish ground stations Rovaniemi, Ivalo, Kilpisjärvi. These all located within 30 min local time 1° in latitude of ionospheric line footprint source line. between 0.5 1.0 Hz observed both space similar frequencies, with frequency...

Ground measurements of bursts Pc 1 pulsations (minutes duration) are a common dayside phenomenon at high latitudes. For the past several years, ground similar‐duration 5 period pulsations, magnetic impulse events (MIE), have attracted great deal interest concerning their role in reconnection. From an analysis years induction antenna data from southern and northern hemisphere sites Antarctic, Greenland, Canada, it is found that about 70% all isolated MIE associated with bursts, half conjugate...