Search Results - (Author, Cooperation:J. C. Foster)
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1Latest Papers from Table of Contents or Articles in PressD. N. Baker ; A. N. Jaynes ; V. C. Hoxie ; R. M. Thorne ; J. C. Foster ; X. Li ; J. F. Fennell ; J. R. Wygant ; S. G. Kanekal ; P. J. Erickson ; W. Kurth ; W. Li ; Q. Ma ; Q. Schiller ; L. Blum ; D. M. Malaspina ; A. Gerrard ; L. J. Lanzerotti
Nature Publishing Group (NPG)
Published 2014Staff ViewPublication Date: 2014-11-28Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsPublished by: -
2Latest Papers from Table of Contents or Articles in PressB. M. Walsh ; J. C. Foster ; P. J. Erickson ; D. G. Sibeck
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-03-08Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
3Articles: DFG German National LicensesStaff View
ISSN: 0002-9556Topics: PsychologyNotes: BOOK REVIEWSURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 0002-9556Topics: PsychologyNotes: BOOK REVIEWSURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 0002-9556Topics: PsychologyNotes: BOOK REVIEWSURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 0992-7689Keywords: Ionosphere (wave propagation) ; Meteorology and atmospheric dynamics (waves and tides)Source: Springer Online Journal Archives 1860-2000Topics: GeosciencesPhysicsNotes: Abstract Observations of traveling ionospheric disturbances (TIDs) associated with atmospheric gravity waves (AGWs) generated by the moving solar terminator have been made with the Millstone Hill incoherent scatter radar. Three experiments near 1995 fall equinox measured the AGW/TID velocity and direction of motion. Spectral and cross-correlation analysis of the ionospheric density observations indicates that ST-generated AGWs/TIDs were observed during each experiment, with the more-pronounced effect occurring at sunrise. The strongest oscillations in the ionospheric parameters have periods of 1.5 to 2 hours. The group and phase velocities have been determined and show that the disturbances propagate in the horizontal plane perpendicular to the terminator with the group velocity of 300–400 m s−1 that corresponds to the ST speed at ionospheric heights. The high horizontal group velocity seems to contradict the accepted theory of AGW/TID propagation and indicates a need for additional investigation.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 0992-7689Keywords: Ionosphere (ionosphere-magnetosphere interactions; plasma temperature and density) ; Magnetospheric physics (plasmasphere)Source: Springer Online Journal Archives 1860-2000Topics: GeosciencesPhysicsNotes: Abstract During a nearby passage of the Active satellite above the Millstone Hill radar on 21 March 1990 at local sunset, the satellite and the radar performed simultaneous measurements of upper ionospheric parameters in nearly the same spatial volume. For this purpose the radar carried out a special azimuth-elevation scan to track the satellite. Direct comparisons of radar data and in situ satellite measurements have been carried out quite rarely. In this case, the coincidence of co-ordinated measurements and active ionospheric-magnetospheric processes during an extended storm recovery phase presents a unique occasion resulting in a very valuable data set. The measurements show generally good agreement both during quiet prestorm and storm conditions and the combination of radar and satellite observations gives a more comprehensive picture of the physical processes involved. We find a close relationship between the rapid westward ion drift peak at subauroral latitudes (SAID event) and the occurrence of a stable auroral red (SAR) arc observed after sunset by an all-sky imager and reported in an earlier study of this event. The SAID electric field is caused by the penetration of energetic ions with energies between about 1 keV and 100 keV into the outer plasmasphere to a latitude equatorward of the extent of the plasmasheet electrons. Charge separation results in the observed polarisation field and the SAID. Unusually high molecular ion densities measured by the satellite at altitudes of 700–870 km at subauroral and auroral latitudes point on strong upward-directed ion acceleration processes and an intense neutral gas upwelling. These structures are collocated with a narrow trough in electron density and an electron temperature peak as observed simultaneously by the radar and the satellite probes.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 0992-7689Keywords: Ionosphere (active experiments; ionospheric disturbances) ; Magnetospheric physics (storms and substorms)Source: Springer Online Journal Archives 1860-2000Topics: GeosciencesPhysicsNotes: Abstract Elevation scans across geomagnetic mid latitudes by the incoherent scatter radar at Millstone Hill captured the ionospheric response to the firing of the Space Shuttle Challenger OMS thrusters near the peak of the F layer on July 30, 1985. Details of the excitation of airglow and the formation of an ionospheric hole during this event have been reported in an earlier paper by Mendillo et al.. The depletion (factor ∼2) near the 320 km Shuttle orbital altitude persisted for ∼35 min and then recovered to near normal levels, while at 265 km the density was reduced by a factor of ∼6; this significant reduction in the bottomside F-region density persisted for more than 3 hours. Total electron content in the vicinity of the hole was reduced by more than a factor of 2, and an oscillation of the F-region densities with 40-min period ensued and persisted for several hours. Plasma vertical Doppler velocity varied quasi-periodically with a ∼80-min period, while magnetic field variations observed on the field line through the Shuttle-burn position exhibited a similar ∼80-min periodicity. An interval of magnetic field variations at hydromagnetic frequencies (∼95 s period) accompanied the ionospheric perturbations on this field line. Radar observations revealed a downward phase progression of the 40-min period density enhancements of -1.12° km−1, corresponding to a 320-km vertical wavelength. An auroral-latitude geomagnetic disturbance began near the time of the Spacelab-2 experiment and was associated with the imposition of a strong southward IMF Bz across the magnetosphere. This created an additional complication in the interpretation of the active ionospheric experiment. It cannot be determined uniquely whether the ionospheric oscillations, which followed the Spacelab-2 experiment, were related to the active experiment or were the result of a propagating ionospheric disturbance (TID) launched by the enhanced auroral activity. The most reasonable conclusion is that the ionospheric oscillations were a result of the coincident geomagnetic disturbance. The pronounced depletion of the bottomside ionosphere, however, accentuated the oscillatory behavior during the interval following the Shuttle OMS burn.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1573-9120Source: Springer Online Journal Archives 1860-2000Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsNotes: Abstract Based on Milston Hill incoherent scatter radar data, the behavior of the electron and ion plasma temperatures in the ionosphere F layer and the correlation of these parameters with the $$\vec E{\text{ }} \times {\text{ }}\vec B$$ plasma drift are briefly discussed. Using this analysis, an attempt is made to evaluate a role of the longituainal currents in the thermal processes taking place in the perturbated upper atmosphere, is made.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1573-1995Source: Springer Online Journal Archives 1860-2000Topics: Electrical Engineering, Measurement and Control TechnologyNotes: Abstract Results are presented from an experiment to measure objective and subjective user responses towards three implementations of an automated voice response telephone service, two embodying rich implementations of metaphors in the service messages including appropriate sound effects to enhance realism, a third using a non-metaphorical presentation of standard menu prompts. It was found that task completion rates, navigation of the service and attitudes were all improved with the use of metaphors.Type of Medium: Electronic ResourceURL: