skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evidence of high densities and ion outflows in the polar cap during the recovery phase

Abstract

During the recovery phase of a large storm on October 14, 1981, instruments on board Dynamics Explorer 1 (DE 1) the Retarding Ion Mass Spectrometer (RIMS), the High Altitude Plasma Instrument (HAPI), and the Plasma Wave Instrument (PWI) detected unusually high plasma densities and ion flows in the polar cap. At the time of detection, DE 1 was located at a radial distance of about 3.5 earth radii, a magnetic local time near midnight, and between 70/sup 0/ and 80/sup 0/ invariant latitude. Total plasma density was found to be about 50 cm/sup -3/, an order of magnitude above median polar cap densities at the altitude of observation. In addition, highly collimated flows of hydrogen and oxygen are found flowing through a background hydrogen plasma. The O/sup +/ component of the plasma discussed is not directly identified but is inferred to be O/sup +/ through the combined analysis of data from three instruments. Results of the combined instrument analysis indicate that the detected plasma was composed of outflowing H/sup +/ with a density of 6-10 cm/sup -3/ with a temperature of about 0.15 eV; isotropic H/sup +/ with a density of about 15-20 cm/sup -3/; and outflowing and strongly convectingmore » O/sup +/ with an average density of about 20 cm/sup -3/ and a temperature of about 0.26 eV. The flux of outflowing H/sup +/ and O/sup +/ are both about 10/sup 7/ cm/sup -2/ s/sup -1/. The data indicate that the O/sup +/ detected by HAPI seems to originate in the dayside ionosphere, while the H/sup +/ detected by RIMS has a source in the nightside polar cap.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Space Science Laboratory, NASA Marshall Space Flight Center, Huntsville, Alabama
OSTI Identifier:
5961345
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Geophys. Res.; (United States); Journal Volume: 91:A3
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; IONOSPHERE; ION DRIFT; PLASMA DENSITY; DAILY VARIATIONS; EXPLORER SATELLITES; HYDROGEN IONS; ION TEMPERATURE; MAGNETIC STORMS; OXYGEN IONS; POLAR REGIONS; CHARGED PARTICLES; EARTH ATMOSPHERE; IONS; PLANETARY IONOSPHERES; SATELLITES; VARIATIONS; 640201* - Atmospheric Physics- Auroral, Ionospheric, & Magetospheric Phenomena

Citation Formats

Gallagher, D.L., Menietti, J.D., Burch, J.L., Persoon, A.M., Waite J.H. Jr., and Chappell, C.R. Evidence of high densities and ion outflows in the polar cap during the recovery phase. United States: N. p., 1986. Web. doi:10.1029/JA091iA03p03321.
Gallagher, D.L., Menietti, J.D., Burch, J.L., Persoon, A.M., Waite J.H. Jr., & Chappell, C.R. Evidence of high densities and ion outflows in the polar cap during the recovery phase. United States. doi:10.1029/JA091iA03p03321.
Gallagher, D.L., Menietti, J.D., Burch, J.L., Persoon, A.M., Waite J.H. Jr., and Chappell, C.R. Sat . "Evidence of high densities and ion outflows in the polar cap during the recovery phase". United States. doi:10.1029/JA091iA03p03321.
@article{osti_5961345,
title = {Evidence of high densities and ion outflows in the polar cap during the recovery phase},
author = {Gallagher, D.L. and Menietti, J.D. and Burch, J.L. and Persoon, A.M. and Waite J.H. Jr. and Chappell, C.R.},
abstractNote = {During the recovery phase of a large storm on October 14, 1981, instruments on board Dynamics Explorer 1 (DE 1) the Retarding Ion Mass Spectrometer (RIMS), the High Altitude Plasma Instrument (HAPI), and the Plasma Wave Instrument (PWI) detected unusually high plasma densities and ion flows in the polar cap. At the time of detection, DE 1 was located at a radial distance of about 3.5 earth radii, a magnetic local time near midnight, and between 70/sup 0/ and 80/sup 0/ invariant latitude. Total plasma density was found to be about 50 cm/sup -3/, an order of magnitude above median polar cap densities at the altitude of observation. In addition, highly collimated flows of hydrogen and oxygen are found flowing through a background hydrogen plasma. The O/sup +/ component of the plasma discussed is not directly identified but is inferred to be O/sup +/ through the combined analysis of data from three instruments. Results of the combined instrument analysis indicate that the detected plasma was composed of outflowing H/sup +/ with a density of 6-10 cm/sup -3/ with a temperature of about 0.15 eV; isotropic H/sup +/ with a density of about 15-20 cm/sup -3/; and outflowing and strongly convecting O/sup +/ with an average density of about 20 cm/sup -3/ and a temperature of about 0.26 eV. The flux of outflowing H/sup +/ and O/sup +/ are both about 10/sup 7/ cm/sup -2/ s/sup -1/. The data indicate that the O/sup +/ detected by HAPI seems to originate in the dayside ionosphere, while the H/sup +/ detected by RIMS has a source in the nightside polar cap.},
doi = {10.1029/JA091iA03p03321},
journal = {J. Geophys. Res.; (United States)},
number = ,
volume = 91:A3,
place = {United States},
year = {Sat Mar 01 00:00:00 EST 1986},
month = {Sat Mar 01 00:00:00 EST 1986}
}
  • Ion flow velocities both parallel and perpendicular to the magnetic field and including the effects of spacecraft charging and spacecraft velocity have been measured during the recovery phase of two large magnetic storms on October 14 and 21 of 1981. These measurements were made both inside and outside the plasmasphere and indicate unreported yet substantial outflows of ions within the dayside plasmasphere (October 14). Combined data from instruments on board the Dynamics Explorer satellite, including the high altitude plasma instrument (HAPI), the energetic ion composition spectrometer (EICS), the retarding ion mass spectrometer (RIMS) and the plasma wave instrument (PWI), indicatemore » that these ions are most likely dominantly O/sup +/ at energies at least as low as 5 eV. The nightside pass (October 21), which occurred during the recovery phase of a similar storm, showed no plasmaspheric outflows. the results indicate that a large contribution to the outflux into the dayside plasmasphere during the recovery period is due to E>5 eV ions.« less
  • We present spectroscopic analysis of the broad absorption line (BAL) outflow in quasar SDSS J1512+1119. In particular, we focus our attention on a kinematic component in which we identify P V and S IV/S IV* absorption troughs. The shape of the unblended phosphorus doublet troughs and the three S IV/S IV* troughs allow us to obtain reliable column density measurements for these two ions. Photoionization modeling using these column densities and those of He I* constrain the abundance of phosphorus to the range of 0.5-4 times the solar value. The total column density, ionization parameter, and metallicity inferred from themore » P V and S IV column densities lead to large optical depth values for the common transition observed in BAL outflows. We show that the true C IV optical depth is {approx}1000 times greater in the core of the absorption profile than the value deduced from its apparent optical depth.« less
  • The characteristics of the polar ion outflows as observed in the topside polar ionosphere by the Dynamics Explorer Retarding Ion Mass Spectrometer are reported in this study. The study is restricted to altitudes between 1,000 and 4,000 km in order to focus on the phenomenon of the classical polar wind. Except insofar as they convect into the polar cap at these altitudes, auroral and cusp/cleft outflows are specifically excluded from this study. Using a method based on the relative wind of ions as seen from the moving spacecraft, averages and variances of the magnetic field-aligned ion flux and velocity, andmore » the species densities, are derived and binned for examination of their altitudinal, seasonal, and magnetic activity dependencies. The data set used encompasses the period from autumn 1981 through 1983, the altitude range from 1,000 to 4,000 km, and invariant latitudes greater than 70{degree}. Observations of H{sup +}, He{sup +}, and O{sup +} with energies down to spacecraft potential are reported. It is found that the polar outflows are not well correlated with common indicators of solar or geomagnetic activity. The average parameters of the outflows exhibit a winter enhancement of He{sup +} flux, a winter decrease in H{sup +} flux, and a summer enhancement of the asymptotic outflow speeds of all species. The solar F{sub 10.7} (and hence EUV) flux is correlated with the acceleration profile of the flows, with slower flow velocities at 2,500 km altitude for active solar conditions. Evidence is found that the H{sup +} flows are, at times, subsonic in the altitude range studied, in contrast to cold polar wind models.« less