Fluxes of > or =50-keV protons and > or =30-keV electrons at approx. 35 R/sub E/ 2. Morphology and flow patterns in the magnetotail

Journal Article · Sat May 01 04:00:00 EDT 1976 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA081i013p02315· OSTI ID:7346130

Keath, E P; Roelof, E C; Bostrom, C O; Williams, D J

Six main results from statistical analyses of the morphology of 50- to 200-keV protons and 30- to 90-keV electrons in the magnetotail and magnetosheath are presented, using approximately 1 year of data from the NOAA/APL energetic particle experiment (EPE) aboard the Imp 7 satellite at approx.35 R/sub E/ with an orbital inclination of approx.30degree to the ecliptic plane. (1) The 50- to 200-keV proton and 30- to 90-keV electron events in the magnetotail occur primarily in the plasma sheet region. (2) The protons show a dawn-dusk asymmetry in the probability of occurrece of the events, while the electrons show little evidence of an asymmetry. (3) The correlation of the electron and proton events in the magnetotail was highest in the dawn sector. (4) The electron event probabilities show a clear correlation with Kp index in both the dawn and the dusk sectors of the magnetotail, although the correlation of proton events with Kp is found only in the dawn sector. (5) The protons show characteristic flow patterns: in the magnetosheath the flow is consistenly tailward; in the dusk plasma sheet the proton flow is predominantly sunward, while in the dawn magnetotail the flow pattern is not well defined. (6) Very high intensity, highly anisotropic proton events with antisunward flow were measured in the plasma sheet near the dusk magnetopause. During the 1-year interval used in this study a total of 16 events were observed. All occurred in the dusk sector of the magnetotail within a region defined by the lines Z/sub SM/= +- R/sub E/ and Y/sub SM/ =4--22 R/sub E/. In all cases the events were followed by an extended period (approx.8 hours) in which the protons flow sunward (<100 km s/sup -1/) with thermal energy in the range of 6--12 keV. (AIP)

• Research Organization: Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland 20510
• OSTI ID: 7346130
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Journal Issue: 13 Vol. 81:13; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
BARYONS
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXPLORER SATELLITES
FERMIONS
HADRONS
KEV RANGE
KEV RANGE 10-100
KEV RANGE 100-1000
LEPTONS
MAGNETOSHEATH
MAGNETOTAIL
NUCLEONS
PLASMA SHEET
PROTONS
SATELLITES