B. Ahn - Academia.edu (original) (raw)

Papers by B. Ahn

Research paper thumbnail of Ionospheric conductivity dependence of the cross-polar cap potential difference and global Joule heating rate

Journal of Atmospheric and Terrestrial Physics, 1989

The Aerospace Corporation functions as an "architect-engineer" for national security projects, sp... more The Aerospace Corporation functions as an "architect-engineer" for national security projects, specializing in advanced military space systems. Providing research support, the corporation's Laboratory Operations conducts experimental and theoretical investigations that focus on the application of scientific and technical advances to such systems. Vital to the success of these investigations is the technical staff's wide-ranging expertise and its ability to stay current with new developments. This expertise is enhanced by a research program aimed at dealing with the many problems associated with rapidly evolving space systems. Contributing their capabilities to the research effort are these individual laboratories: Aerophysics laboratory: Launch vehicle and reentry fluid mechanics, heat transfer and flight dynamics; chemical and electric propulsion, propellant chemistry, chemical dynamics, environmental chemistry, trace detection; spacecraft structural mechanics, contamination, thermal and structural control; high temperature thermomechanics, gas kinetics and radiation; cw and pulsed chemical and excimer laser development, including chemical kinetics, spectroscopy, optical resonators, beam control, atmospheric propagation, laser effects and countermeasures.

Research paper thumbnail of Mapping electrodynamic features of the high-latitude ionosphere from localized observations: Combined incoherent-scatter radar and magnetometer measurements for January 18–19, 1984

Journal of Geophysical Research, 1988

The large-scale electric potential patterns, describing ionospheric convection, are estimated for... more The large-scale electric potential patterns, describing ionospheric convection, are estimated for northern high latitudes during January 18-19, 1984, from combined incoherent-scatter radar and ground magnetometer observations, using the technique of Richmond and Kamide (this issue). The patterns usually have a dominant two-cell ch:•racteristic, although the intensities, orientations and sh:•pes of the cells undergo considerable changes with time. Often evident during substorm expansive phases is a "tongue" of low electric potential extending toward the east along the low-latitude edge of the high potential cell at night. Time-series plots of the maximum and minimum electric potentials show that they can respond rapidly to changes in the interplanetary magnetic field B z component. Total estimated potential drops for this 2-day period range from about 15 kV up to 108 kV. The influence of the different types of data on the resultant estimated electric

Research paper thumbnail of The auroral energy deposition over the polar ionosphere during substorms

Planetary and Space Science, 1989

Research paper thumbnail of Mapping electrodynamic features of the high-latitude ionosphere from localized observations: Combined incoherent-scatter radar and magnetometer measurements for January 18–19, 1984

Journal of Geophysical Research, 1988

On Saturday, 19 February from 19:00–21:00 (7–9:00 pm EST) the AGU website will be unavailable due... more On Saturday, 19 February from 19:00–21:00 (7–9:00 pm EST) the AGU website will be unavailable due to a scheduled maintenance, due to last for a maximum of 2 hours. ... High Altitude Observatory, National Center for Atmospheric Research, Boulder, Colorado.

Research paper thumbnail of Ionospheric conductivity dependence of the cross-polar cap potential difference and global Joule heating rate

Journal of Atmospheric and Terrestrial Physics, 1989

The Aerospace Corporation functions as an "architect-engineer" for national security projects, sp... more The Aerospace Corporation functions as an "architect-engineer" for national security projects, specializing in advanced military space systems. Providing research support, the corporation's Laboratory Operations conducts experimental and theoretical investigations that focus on the application of scientific and technical advances to such systems. Vital to the success of these investigations is the technical staff's wide-ranging expertise and its ability to stay current with new developments. This expertise is enhanced by a research program aimed at dealing with the many problems associated with rapidly evolving space systems. Contributing their capabilities to the research effort are these individual laboratories: Aerophysics laboratory: Launch vehicle and reentry fluid mechanics, heat transfer and flight dynamics; chemical and electric propulsion, propellant chemistry, chemical dynamics, environmental chemistry, trace detection; spacecraft structural mechanics, contamination, thermal and structural control; high temperature thermomechanics, gas kinetics and radiation; cw and pulsed chemical and excimer laser development, including chemical kinetics, spectroscopy, optical resonators, beam control, atmospheric propagation, laser effects and countermeasures.

Research paper thumbnail of Mapping electrodynamic features of the high-latitude ionosphere from localized observations: Combined incoherent-scatter radar and magnetometer measurements for January 18–19, 1984

Journal of Geophysical Research, 1988

The large-scale electric potential patterns, describing ionospheric convection, are estimated for... more The large-scale electric potential patterns, describing ionospheric convection, are estimated for northern high latitudes during January 18-19, 1984, from combined incoherent-scatter radar and ground magnetometer observations, using the technique of Richmond and Kamide (this issue). The patterns usually have a dominant two-cell ch:•racteristic, although the intensities, orientations and sh:•pes of the cells undergo considerable changes with time. Often evident during substorm expansive phases is a "tongue" of low electric potential extending toward the east along the low-latitude edge of the high potential cell at night. Time-series plots of the maximum and minimum electric potentials show that they can respond rapidly to changes in the interplanetary magnetic field B z component. Total estimated potential drops for this 2-day period range from about 15 kV up to 108 kV. The influence of the different types of data on the resultant estimated electric

Research paper thumbnail of The auroral energy deposition over the polar ionosphere during substorms

Planetary and Space Science, 1989

Research paper thumbnail of Mapping electrodynamic features of the high-latitude ionosphere from localized observations: Combined incoherent-scatter radar and magnetometer measurements for January 18–19, 1984

Journal of Geophysical Research, 1988

On Saturday, 19 February from 19:00–21:00 (7–9:00 pm EST) the AGU website will be unavailable due... more On Saturday, 19 February from 19:00–21:00 (7–9:00 pm EST) the AGU website will be unavailable due to a scheduled maintenance, due to last for a maximum of 2 hours. ... High Altitude Observatory, National Center for Atmospheric Research, Boulder, Colorado.