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  Faculty Profile  Faculty ProfileLast Modified Time: 08:21:21 AM Fri, 23 Jan 2009 
Dr. James L Horwitz
 Contact Information
Dr. James L Horwitz
Professor & Chairperson-Physics
 
In Memoriam In Memoriam   
 Professional Preparation
 DegreeMajorInstitutionYear
 Ph.D.Applied PhysicsUniversity of California, San Diego1976
 M.S.PhysicsUniversity of California, San Diego1972
 B.A.PhysicsUniversity of California, San Diego1970
 Research and Expertise
Space Physics
 
Space Physics Research Group
Development and application of the Dynamic Fluid-Kinetic(DyFK) model for simulation investigations of ionospheric plasma transport into the magnetosphere, including effects of soft-electron precipitation, transverse ion heating by waves, and parallel electric fields produced by hot plasma differential anisotropies. Particular focus on the dynamic behavior of the collisional-collisionless transition region of the high-latitude ionosphere-magnetosphere coupling zone. Analysis of observations from satellite-borne plasma and field detectors of low-energy plasma transport in the magnetosphere and F-region/topside ionosphere, particularly the Thermal Ion Dynamics Experiment (TIDE) on NASA's POLAR spacecraft. Current investigations focus on the morphology of O+ density troughs within the polar cap at 5000 km altitude, and near-simultaneous near-conjunction ion transport measurements made by POLAR/TIDE(at 5000 km altitude) and DMSP(near 840 km altitude) ion detectors at high-latitudes, and use of DyFK simulations to model direct spacecraft observations.

Research Interests
 
Space plasma physics, particularly of the terrestrial magnetosphere and ionosphere.

toggle toggle  Publications/Creative Works
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Year Description Type Tags Status
2008Jaafari, F.; Horwitz, J. L.; Zeng, W. Simulation of the formation of O+ density troughs at 6000 km altitude in the polar cap ionosphere-magnetosphere region. J. Geophys. Res. 2008, 113 (A07207). 10.1029/2007JA012690Journal ArticleNon-RefereedAccepted
2008Zeng, W.; Horwitz, J. L. Storm enhanced densities (SED) as possible sources for cleft ion fountain dayside ionospheric outflows. Geophys. Res. Lett. 2008, 35 (L04103). 10.1029/2007GL032511Journal ArticleNon-RefereedAccepted
2008Horwitz, J. L.; Zeng, W. Physics-based formula representations of high-latitude ionospheric outflows: H+ and O+ densities, flow velocities and temperatures vs. soft electron precipitation, wave-driven transverse heating, and solar zenith angle effects. J. Geophys. Res. 2008, 113.Journal ArticleRefereed/JuriedAccepted
2007Zeng, W.; Horwitz, J. L. Formula representation of auroral ionospheric O+ outflows based on systematic simulations with effects of soft electron precipitation and transverse ion heating. Geophys. Res. Lett. 2007, 34 (6). L0610310.1029/2006GL028632Journal ArticleNon-RefereedAccepted
2007Moore, T. E.; Horwitz, J. L. Stellar ablation of planetary atmospheres. Rev. Geophys. 2007, 45. 10.1029/2005RG000194Journal ArticleRefereed/JuriedPublished
 Presentations and Projects
Presentation Abstracts:    2007 - present
  • Horwitz, J. L. and W. Zeng, Compact analytic expressions for high-latitude ionospheric outflows: H+ and O+ densities and flow velocities vs. precipitation, wave-heating, and solar zenith angle effects, to be presented to COSPAR, Montreal, July 13-20, 2008.
  • Horwitz, J. L. and W. Zeng, Storm enhanced density (SED) plumes as possible suppliers of dayside cleft ion fountain, to be presented to COSPAR, Montreal, July 13-20, 2008.
  • Horwitz, J. L., F. Jaafari, W. Zeng, S. Jones, and Y.-J. Su, The interaction of Alfvenic electrons and the auroral ionosphere: First results, presented to COSPAR, Montreal, July 13-20, 2008.
  • Horwitz, J. L. and W. Zeng, Analytic formulas expressing high-latitude ionospheric outflows for possible incorporation into large-scale magnetospheric modeling, presentation and abstract for Western Pacific meeting in Cairns, Australia, July 29-August 1, 2008.
  • Horwitz, J. L., W. Zeng, J. C. Foster, R. J. Strangeway, M. L. Adrian, and T. E. Moore, Do  Plasmasphere Plume-associated Storm-Enhanced Densities (SEDS) Supply  Ionospheric Outflows to the Magnetosphere?, presentation and abstract for Western Pacific meeting in Cairns, Australia, July 29-August 1, 2008.
  • Jaafari, F. B., J. L. Horwitz, S. Jones, and Y.-J. Su,  Simulation of the  interaction of Alfvénic electrons with the auroral ionospheric plasma transport, presentation and abstract for Western Pacific meeting in Cairns, Australia, July 29-August 1, 2008.
  • Horwitz, J. L., W. Zeng, J. C. Foster, R. J. Strangeway, Mark L. Adrian, and T. E. Moore, Plasmasphere Plume-associated Storm-Enhanced Densities (SED) as Suppliers of Ionospheric Outflows to the Magnetosphere, in abstract book, presented to Texas Section of American Physical Society, University of Texas at El Paso, El Paso Texas, October 16-18, 2008.
  • Jaafari, F., J. L. Horwitz, S. Jones, Y.-J. Su, and W. Zeng, The interplay of Alfvén waves and energized electrons with auroral ionospheric plasma, in abstract book, presented to Texas Section of American Physical Society, University of Texas at El Paso, El Paso Texas, October 16-18, 2008.
  • Horwitz, J. L., and W. Zeng, Analytic representations of high-altitude auroral H+ and O+ densities, flow velocities and temperatures in terms of drivers for incorporation into global magnetospheric models, , in abstract book, presented to Texas Section of American Physical Society, University of Texas at El Paso, El Paso Texas, October 16-18, 2008.
  • Horwitz, J. L., W. Zeng, J. C. Foster, R. J. Strangeway, M. L. Adrian, and T. E. Moore, Dynamic Fluid-Kinetic (DyFK) Simulations of Storm-Enhanced Density Supply of Cleft Ion Fountain Outflows, to be presented to American Geophysical Union meeting, San Francisco, CA, December 15-19, 2008.
  • Jaafari, F., J. L. Horwitz, S. Jones, Y.-J. Su, and W. Zeng, Alfvén waves and electron energization and their interaction with auroral ionospheric plasma transport, in abstract book, to be presented to American Geophysical Union meeting, San Francisco, CA, December 15-19, 2008.
  • Zeng, W., and J. L. Horwitz, High-latitude ionospheric outflows characterized through analytic formulas, in abstract book, to be presented to American Geophysical Union meeting, San Francisco, CA, December 15-19, 2008.
  • Strangeway, R J., J.  L. Horwitz, and W. Zeng, Comparison between data-based and simulation-based ion outflow scaling laws, in abstract book, to be presented to American Geophysical Union meeting, San Francisco, CA, December 15-19, 2008
  • Horwitz, J. L., Ionospheric plasma supply to magnetosphere, abstract for invited talk presented to 8th International School for Space Simulations (ISSS-8), Kauai, Hawaii, February 25 - March 3, 2007.
  • Horwitz, J. L., Dynamic Fluid-Kinetic simulations of high-latitude ionospheric outflows and their compact parameterization for use in global magnetospheric modeling, abstract for invited talk presented to High-Altitude Observatory, Boulder, Colorado, April 4, 2007.
  • Jaafari, F., J. L. Horwitz, and W. Zeng, Modeling the O+ trough region in the polar cap ionospheremagnetosphere coupling region, presentation and abstract for Spring Joint Assembly with American Geophysical Union, Acapulco, Mexico, May 21-26, 2007.
  • Horwitz, J. L., and W. Zeng, Further Advances in formula representation of high-altitude O+ ionospheric outflows based on DyFK simulations, presentation and abstract for Spring Joint Assembly with American Geophysical Union, Acapulco, Mexico, May 21-26, 2007.
  • Jaafari, F., J. L. Horwitz, and W. Zeng, Simulations of the O+ trough region in the polar cap ionosphere-magnetosphere coupling region with the UT Arlington DyFK model, presentation and abstract for IUGG/IAGA meeting, Perugia, Italy, July 2-13, 2007.
  • Horwitz, J. L., and W. Zeng, New formula representations of high-latitude O+ ionospheric outflows for use in global magnetospheric modeling, presentation and abstract for IUGG/IAGA meeting, Perugia, Italy, July 2-13, 2007.
  • Jaafari, F., J. L. Horwitz, and W. Zeng, Formation of O+ trough zones in the polar cap ionospheremagnetosphere coupling region: Dynamic Fluid-Kinetic Simulations, in abstract book, presented to Texas Section of American Physical Society, Texas A&M University, College Station, Texas, October 18-20, 2007.
  • Horwitz, J. L., and W. Zeng,  Compact representations of high-latitude ionospheric outflows, in abstract book, presented to Texas Section of American Physical Society, Texas A&M University, College Station,  Texas, October 18-20, 2007.
  • Zeng, W. and J. L.  Horwitz, Simulations of the cleft ion fountain outflows resulting from the passage of storm enhanced density (SED) plasma flux tubes through the dayside cleft auroral processes region, in abstract book, presented to Texas Section of American Physical Society, Texas A&M University, College Station,  Texas, October 18-20, 2007.
  • Horwitz, J. L., Astrophysics and Space Physics at the University of Texas at Arlington, in abstract book, invited  presentation to Changwon International Symposium on Advanced Science and Technology (CISAS), Changwon National University, Changwon, South Korea, November, 2007.
  • Zeng, W., and J. L. Horwitz, Fluid-kinetic simulations of the passage of Storm Enhanced Density (SED) plasma flux tubes through the dayside cleft auroral processes region, presentation and abstract for American Geophysical Union meeting, San Francisco, California, December 10-14, 2007.
  • Jaafari, F., J. L. Horwitz, and W. Zeng, Simulations of the formation of O+ trough zones in the polar cap ionosphere-magnetosphere coupling region, presentation and abstract for American Geophysical Union meeting, San Francisco, California, December 10-14, 2007.
  • Zeng, W., and J. L. Horwitz, Physics-based formula representations of high-latitude ionospheric outflows: H+ and O+ densities and flow velocities vs. precipitation, wave-heating, and solar zenith angle effects, presentation and abstract for American Geophysical Union meeting, San Francisco, California, December 10-14, 2007.

Presentation Abstracts:    1973 - 2006
  • Horwitz, J. L., and J. R. Doupnik, Incoherent scatter measurements of ion and electron temperatures in the auroral zone, EOS Trans., Vol. 54, No. 27, 1973/Supplement.
  • Doupnik, J. R., P. M. Banks, J. L. Horwitz, and J. C. Siren, Measurements of the latitudinal variations of the convection electric field in the auroral zone, EOS Trans., Vol. 56, No. 29, 1974/Supplement.
  • Horwitz, J. L., The latitudinal distribution of transverse electric fields related to E11, large scale auroral features and to ground and interplanetary magnetic field variations. In program for the Proceedings of the Chatanika Radar Advisory Group Meeting, Stanford Research Institute, 1977.
  • Langford, J., and J. L. Horwitz, Inferring trapped plasma distributions along a magnetic field line from equatorial measurements, EOS Trans., Vol. 59, 349, 1978.
  • Comfort, R. H., and J. L. Horwitz, Dayside low-energy proton pitch angle distributions at geosynchronous altitudes, EOS Trans., Vol. 59, 349, 1978.
  • Horwitz, J. L., and C. R. Chappell, Equatorial observations of low-energy plasma in the dayside plasma trough, EOS Trans., Vol. 59, 353, 1978.
  • Horwitz, J. L., C. R. Bower, E. G. Shelley, and D. T. Young, Conical pitch angle distributions of low-energy ion fluxes: evidence for cyclotron acceleration, EOS Trans., Vol. 59, 1144, 1978.
  • Horwitz, J. L. C. R. Baugher, J. Ransom, E. G. Shelley, and D. T. Young, Thermal ion distribution functions observed in the magnetosphere with ISEE-1, EOS Trans., Vol. 59, 348, 1979.
  • Horwitz, J. L., C. R. Baugher, C. R. Chappell, E. G. Shelley, and D. T. Young, Occurrence of pancake distributions in E<100 eV ions observed with ISEE-1. EOS Trans., Vol. 60, 929, 1979.
  • Baugher, C. R., J. L. Horwitz, C. R. Chappell, E. G. Shelley, and D. T. Young, Occurrence of isotropic and field-aligned distributions in low-energy ions near the plasmapause, EOS Trans., Vol. 60, 929, 1979.
  • Horwitz, J. L., G. O. Dennis, C. R. Baugher, C. R. Chappell, E. G. Shelley, and D. T. Young, Analytic representations for thermal ions observed by ISEE-1, EOS Trans., Vol. 61, No. 34, 1980.
  • Horwitz, J. L., C. R. Baugher, C. R. Chappell, E. G. Shelley, and D. T. Young, ISEE-1 observations of plasmasphere refilling, EOS Trans., Vol. 61, No. 34, 1980/Supplement.
  • Horwitz, J. L., C. R. Chappell, D. L. Reasoner, C. R. Baugher, J. L. Green, and P. D. Craven, Low-energy plasma composition results from the ISEE-1 and SCATHA satellites (invited review paper). In program for the Assembly of International Association of Geomagnetism and Aeronomy, Edinburgh, Scotland, 1981.
  • Waite, J. H., Jr., and J. L. Horwitz, He+ in the terrestrial plasmasphere, EOS Trans., Vol. 62, No. 35, 1981/Supplement.
  • Comfort, R. H., J. L. Horwitz, C. R. Baugher, and C. R. Chappell, Identification of M/Z = 2 ions inside the plasmasphere, EOS Trans., Vol. 62, No. 35, 1981/Supplement.
  • Horwitz, J. L., W. K. Cobb, C. R. Baugher, C. R. Chappell, L. A. Frank, T. E. Eastman, E. G. Shelley, and D. T. Young, The relationship of the plasmapause to the equatorward boundary of the auroral oval and to the inner edge of the electron plasma sheet, EOS Trans., Vol. 62, No. 35, 1981/Supplement.
  • Horwitz, J. L., and C. R. Chappell, Detached plasma regions, EOS Trans., Vol. 63, No. 36,  1982/Supplement.
  • Comfort, R. H., C. R. Chappell, J. H. Waite, Jr., J. F. E. Johnson, J. L. Horwitz, S. D. Shawhan, and R. L. Huff, DE-1 plasma densities from particle and wave measurements, EOS Trans., Vol. 63, No. 36, 1982/Supplement.
  • Horwitz, J. L., R. H. Comfort, S. Lee, C. R. Chappell, J. H. Waite, Jr., J. L. Green, and J. F. E.  Johnson, Plasmaspheric ion composition, EOS Trans., Vol. 63, No. 36, 1982/Supplement.
  • Roberts, W. T., J. L. Horwitz, C. R. Chappell, J. H. Waite, Jr., J. L. Green, and J. F. E. Johnson, Torus of thermal heavy ions in the vicinity of the plasmapause, EOS Trans., Vol. 63, No. 36, 1982/Supplement.
  • Horwitz, J. L., and D. T. Young, Composition and dynamics of < 1 keV plasmas in the Earth's magnetosphere, EOS Trans., Vol. 63, No. 36, 1982/Supplement.
  • Comfort, R. H., J. L. Horwitz, C. R. Chappell, and J. H. Waite, Jr., Thermal equilibrium among plasmaspheric ions as observed by DE/RIMS, EOS Trans., Vol. 64, No. 37, 1983/Supplement.
  • Nagai, T., J. L. Horwitz, R. R. Anderson, and C. R. Chappell, Plasmapause structure from ISEE-1 low-energy ion and plasma wave observations, EOS Trans., Vol. 64, No. 37, 1983/Supplement.
  • Horwitz, J. L., J. Turnley, M. O. Chandler, C. R. Chappell, T. Nagai, J. D. Craven, L. A. Frank, S. D. Shawhan, J. L. Burch, J. D. Winningham, and D. W. Slater, Comparison of observed plasma boundaries in the inner magnetosphere, EOS Trans., Vol. 64, No. 37, 1983/Supplement.
  • Horwitz, J. L., The plasmapause: Classical and new concepts on its identification, formation, dynamics, and relationship to other magnetospheric structure. In program for the Huntsville Workshop: Fundamental Magnetospheric Processes in the Plasmapause Region, Huntsville, AL, 1983.
  • Craven, J. D., L. A. Frank, and J. L. Horwitz, Association of the plasmapause position in the evening sector with prior auroral activity. In program for the Huntsville Workshop: Fundamental Magnetospheric Processes in the Plasmapause Region, Huntsville, AL, 1983.
  • Horwitz, J. L., R. H. Comfort, M. O. Chandler, and C. R. Chappell, Evolution of plasmasphere structure during refilling periods. In program for the Huntsville Workshop: Fundamental Magnetospheric Processes in the Plasmapause Region, Huntsville, AL, 1983.
  • Roberts, W. T., Jr., J. L. Horwitz, J. H. Waite, Jr., J. D. Winningham, R. H. Comfort, J. L. Green, and C. R. Chappell, Observations of heavy ion enhancements in the outer plasmasphere. In program for the Huntsville Workshop: Fundamental Magnetospheric Processes in the Plasmapause Region, Huntsville, AL, 1983.
  • Biddle, A. P., J. L. Horwitz, C. R. Chappell, and J. D. Winningham, Response of the plasmasphere to magnetospheric storms. In program for the Huntsville Workshop: Fundamental Magnetospheric Processes in the Plasmapause Region, Huntsville, AL, 1983.
  • Horwitz, J. L., M. Pendergrass, R. H. Comfort, and C. R. Chappell, Plasmapause and plasmasphere structure from DE-1 observations, EOS Trans., Vol. 64, No. 37, 1983/Supplement.
  • Horwitz, J. L., R. H. Comfort, and C. R. Chappell, Satellite observations of the formation of the outer plasmasphere, EOS Trans., Vol. 64, No. 37, 1983/Supplement.
  • Horwitz, J. L., A simple formula relating the dusk sector radial electric field to electron energy dispersion at the inner edge of the plasma sheet, EOS Trans., Vol. 65, No. 38, 1984/Supplement.
  • Lockwood, M., J. H. Waite, Jr., T. E. Moore, M. O. Chandler, J. L. Horwitz, M. Loranc, and R. A. Heelis, Mass and energy dispersions of ionospheric ions injected in the magnetosphere near the cusp, EOS Trans., Vol. 65, No. 38, 1984/Supplement.
  • Horwitz, J. L., L. H. Brace, R. H. Comfort, and C. R. Chappell, Near-conjugate measurements of plasmasphere and ionosphere structure, EOS Trans., Vol. 65, No. 38, 1984/Supplement.
  • Forest, G., J. L. Horwitz, and M. Lockwood, Ion trajectories in the polar magnetosphere and DE-1 observations, EOS Trans., Vol. 65, No. 38, 1984/Supplement.
  • Horwitz, J. L., M. Lockwood, J. H. Waite, Jr., T. E. Moore, and M. O. Chandler, Transport of O+ through the polar magnetosphere: Modeling and DE-1 observations. In program for the International School for Space Simulations – 2, Kuaii, Hawaii, 1985.
  • Waite, J. H., Jr., M. Lockwood, T. E. Moore, M. O. Chandler, J. L. Horwitz, and C. R. Chappell, Solar wind control of the geomagnetic mass spectrometer. In program for the Solar Wind-Magnetosphere Coupling Workshop, 1985.
  • Horwitz, J. L., The tail lobe ion spectrometer. In program for the Chapman Conference: Magnetotail Physics, JHU/APL, Laurel, MD, 1985.
  • Green, J. L., and J. L. Horwitz, Destiny of earthward-streaming plasma in plasma sheet boundary layer. In program for the Chapman Conference: Magnetotail Physics. JHU/APL, Laurel, MD, 1985.
  • Horwitz, J. L., The new thermal ion composition measurements of the plasmasphere and plasmapause region: Important questions for modelers, EOS Trans., Vol. 66, No. 39, 1985/Supplement.
  • Horwitz, J. L., J. H. Waite, Jr., and T. E. Moore, Creation of 'supersonic' ion outflows in the polar magnetosphere via the geomagnetic spectrometer, EOS Trans., Vol. 66, No. 39, 1985/Supplement.
  • Horwitz, J. L., The ion bowl distribution: A fundamental consequence of transport from a restricted source, EOS Trans., Vol. 66, No. 39, 1985/Supplement.
  • Swinney, K. R., and J. L. Horwitz, Three-Dimensional ion trajectories in the magnetosphere, EOS Trans., Vol. 66, No. 39, 1985/Supplement.
  • Reyes, T. R., and J. L. Horwitz, Three-Dimensional model for the electric potential distribution at high latitudes: A first approach, EOS Trans., Vol. 66, No. 39,1985/Supplement.
  • Horwitz, J. L., Tail lobe ion distributions supplied by the cleft ion fountain. In program for the Yosemite Chapman Conference: Ionospheric Plasma in the Magnetosphere Yosemite, CA, 1986.
  • Horwitz, J. L., Parametric model study of 'parabolic' and 'hopping' flows from the cleft ion fountain. In program for the Yosemite Chapman Conference: Ionospheric Plasma in the Magnetosphere, Yosemite, CA, 1986.
  • Horwitz, J. L., R. H. Comfort, L. H. Brace, and C. R. Chappell, Dual spacecraft measurements of plasmasphere-ionosphere coupling. In program for the Yosemite Chapman Conference: Ionospheric Plasma in the Magnetosphere, Yosemite, CA, 1986.
  • Swinney, K. R., and J. L. Horwitz, Transport of ionospheric ions in the magnetosphere: Three-dimensional trajectories. In program for the Yosemite Chapman Conference: Ionospheric Plasma in the Magnetosphere, Yosemite, CA, 1986.
  • Craven, P. D., J. L. Green, J. D. Craven, C. R. Chappell, L. A. Frank, and J. L. Horwitz, An auroral source of suprathermal ions. In program for the Yosemite Chapman Conference: Ionospheric Plasma in the Magnetosphere, Yosemite, CA, 1986.
  • Horwitz, J. L., R. H. Comfort, and C. R. Chappell, Plasmasphere and plasmapause characteristics as measured by DE-1. In program for the XXVI COSPAR Meeting, p. 103, Toulouse, France, 1986.
  • Candidi, M., J. L. Horwitz, and S. Orsini, The tail ion spectrometer effect: Theory and observations. In program for the XXVI COSPAR Meeting, p. 106, Toulouse, France, 1986.
  • Brace, L. H., W. Hoegy, and J. L. Horwitz, The relationship of the plasmapause and ionospheric signatures. In program for the XXVI COSPAR Meeting, p. 106, Toulouse, France, 1986.
  • Lockwood, M., J. H. Waite, Jr., T. E. Moore, C. R. Chappell, and J. L. Horwitz, Low-energy ionospheric ion flows into the magnetosphere. In program for the XXVI COSPAR Meeting, p. 103, Toulouse, France, 1986.
  • Horwitz, J. L., Parabolic heavy ion flow in the polar magnetosphere, EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Chandler, M. O., J. L. Horwitz, R. H. Comfort, and J. T. Ponthieu, Theoretical investigations of O+ and O++enhancements in the outer plasmasphere, EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Giles, B. L., C. R. Chappell, J. H. Waite, Jr., T. E. Moore, and J. L. Horwitz, The auroral ion fountain: MLT, L-shell and magnetic activity dependencies, EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Swinney, K., and J. L. Horwitz, Parametric studies of three-dimensional ion trajectories in the magnetosphere, EOS Trans., Vol. 67, p. No. 40, 1986/Supplement.
  • Orsini, S., M. Candidi, and J. L. Horwitz, Observations and a model for the tail lobe ion spectrometer, EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Horwitz, J. L., Simulation and measurements of low-energy ionospheric plasmas in the magnetosphere. In program for the International Symposium on Space Physics, Beijing China, 1986.
  • Horwitz, J. L., The kinetic approach in global plasma transport modeling, advantages and difficulties.  In program for the Huntsville Workshop: Magnetosphere/Ionosphere Models, Guntersville, AL, 1986.
  • Giles, B. L., C. R. Chappell, J. H. Waite, Jr., T. E. Moore, and J. L. Horwitz, Dynamical evolution of low-energy ions in the terrestrial magnetosphere. In program for the Huntsville Workshop: Magnetosphere/Ionosphere Models, Guntersville, AL, 1986.
  • Chandler, M. O., J. U. Kozyra, J. L. Horwitz, R. H. Comfort, W. K. Peterson, and L. H. Brace, Modeling of the thermal plasma in the outer plasmasphere: A magnetospheric heat source. In program for the Huntsville Workshop: Magnetosphere/Ionosphere Models Workshop, Guntersville, AL, 1986.
  • Brace, L. H., and J. L. Horwitz, Plasmasphere and ionosphere signatures from Dynamics Explorer. EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Horwitz, J. L., W. B. Hanson, R. A. Heelis, M. O. Chandler, R. H. Comfort, and L. H. Brace, Plasmasphere-ionosphere coupling from dynamics explorer: inclusion of topside ionosphere ion composition, EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Swinney, K., and J. L. Horwitz, DE-inspired kinetic modeling of the transport of ionospheric ions into the magnetosphere, EOS Trans., Vol. 67, No. 40, 1986/Supplement.
  • Horwitz, J. L., N. Singh, K. R. Swinney, C. R. Chappell, D. Delcourt, B. L. Giles, T. E. Moore, and J. R. Waite, Jr., Acceleration and transport of ionospheric ions in magnetosphere-ionosphere coupling processes. In program for the International Symposium: Quantitative Modeling of Magnetosphere-Ionosphere Coupling Processes, Kyoto, Japan, 1987.
  • Candidi, M., S. Orsini, and J. L. Horwitz, The tail lobe spectrometer: theory and observations. In program for the International Symposium: Quantitative Modeling of Magnetosphere-Ionosphere Coupling Processes, Kyoto, Japan, 1987.
  • Saflekos, N., J. L. Burch, M. Sugiura, D. A. Gurnett, and J. L. Horwitz, Observation of reconnected flux tubes within the mid-altitude cusp, EOS Trans., Vol. 68, No. 41, 1987/Supplement.
  • Moore, T. E., D. L. Gallagher, J. L. Horwitz, and R. H. Comfort, MHD wave braking in the outer plasmasphere, EOS Trans., Vol. 68, No. 41, 1987/Supplement.
  • Horwitz, J. L., G. Wilson, and K. Swinney, Kinetic modeling of the transport of ionospheric ions into the magnetosphere. In program for the Cambridge Workshop: Polar cap dynamics and high latitude ionospheric turbulence, Boston, MA, 1988.
  • Giles, B. L., C. R. Chappell, J. H. Waite, Jr., T. E. Moore, and J. L. Horwitz, Low-energy ion outflow events revisited, EOS Trans., Vol. 69, No. 42, 1988/Supplement.
  • Giles, B. L., C. R. Chappell, T. E. Moore, J. L. Horwitz, and J. H. Waite, Jr., Variability of low-energy ion outflow events, EOS Trans., Vol. 70, No. 43, 1989/Supplement.
  • Pollock, C. J., C. R. Chappell, J. L. Horwitz, and J. D. Winningham, Occurrence and effects of field-aligned electrostatic potential drops above the ionospheric polar caps. In program for the Huntsville workshop: Magnetosphere/Ionosphere Plasma Models, Huntsville, AL, of 1989.
  • Ho, C. W., J. L. Horwitz, and G. R. Wilson, A time-dependent kinetic model of polar plasma outflow: Initial results. In program for the Huntsville workshop: Magnetosphere/Ionosphere Plasma Models, Huntsville, AL, 1989.
  • Ho, C. W., J. L. Horwitz, and G. R. Wilson, A new time-dependent one-dimensional kinetic polar plasma outflow model, EOS Trans., Vol. 70, No. 43, 1989/Supplement.
  • Lin, J., J. L. Horwitz, and G. R. Wilson, An early-stage refilling model based on a "kinetic" approach with trapping due to turbulent ion heating, EOS Trans., Vol. 70, No. 43, 1989/Supplement.
  • Horwitz, J. L., R. H. Comfort, P. G. Richards, M. O. Chandler, C. R. Chappell, P. Anderson, W. B. Hanson, and L. H. Brace, Plasmasphere-ionosphere coupling II: Ion composition measurements at plasmaspheric and ionospheric altitudes and comparison with modeling results, EOS Trans., Vol. 70, No. 43, 1989/Supplement.
  • Lin, J., J. L. Horwitz, and K. -S. Hwang, An early-stage refilling of the plasmasphere: Effect of turbulent heating and pitch-angle scattering. In program for the Huntsville Workshop: Magnetosphere/Ionosphere Plasma Models, Huntsville, AL, 1989.
  • Singh, N., C. W. Ho, J. L. Horwitz, and G. R. Wilson, Evolution of density perturbations in kinetic and hydrodynamic models of polar plasma outflow, EOS Trans., 71, No. 43, 1990/Supplement.
  • Ho, C. W., J. L. Horwitz, G. R. Wilson, N. Singh, and T. E. Moore, Magnetospheric electron effects on polar plasma outflow, EOS Trans., Vol. 71, No. 43, 1990/Supplement.
  • Brown, D. G., J. L. Horwitz, G. R. Wilson, and D. L. Gallagher, Effects of currents on polar plasma outflow: A time-dependent semi-kinetic description, EOS, Vol. 71, No. 43, 1990/Supplement.
  • Horwitz, J. L., C. J. Pollock, Toward a 'quasi-empirical' scenario for plasmasphere refilling from recent thermal ion measurements. In program for the Plasmasphere Refilling Workshop, Huntsville, AL, 1990.
  • Lin, J., J. L. Horwitz, and G. R. Wilson, A model for early-stage plasmasphere refilling based on a kinetic approach with wave-particle interactions. In program for the Plasmasphere Refilling Workshop, Huntsville, AL, 1990.
  • Horwitz, J. L., C. J. Pollock, T. E. Moore, W. K. Peterson, J. L. Burch, J. D. Winningham, P. D. Craven, L. A. Frank, and A. Persoon, Outflowing O+ beams in the polar cap regions, EOS Trans., Vol. 71, No. 43, 1990/Supplement.
  • Comfort, R. H., J. L. Horwitz, P. D. Craven, and C. R. Chappell, Characteristic refilling rates in the plasma trough from observations by DE-1/RIMS, EOS Trans., Vol. 72, No. 17, 1991/Supplement.
  • Wilson, G. R., J. L. Horwitz, and J. Lin, The effects of Coulomb self-collisions on the refilling of a plasmaspheric flux tube: A kinetic perspective, EOS Trans., Vol. 72, No. 17, 1991/Supplement.
  • Brown, D. G., G. R. Wilson, J. L. Horwitz, and D. L. Gallagher, A 'self-consistent' kinetic model of plasma heating and transport on auroral field lines, EOS Trans., Vol. 72, No. 17, 1991/Supplement.
  • Singh, N., G. R. Wilson, and J. L. Horwitz, Comparison Between Hydrodynamic and Semi-Kinetic Models for Plasmasphere Refilling, EOS Trans., Vol. 72, No. 44, 1991/Supplement.
  • Brown, D. G., J. L. Horwitz, G. R. Wilson, and D. L. Gallagher, 'Self-consistent' ion conic production on auroral field lines: A time-dependent semi-kinetic model. In program for the fourth International School for Space Simulation (ISSS-4), Kyoto, Japan, 1991.
  • Ho, C. W., J. L. Horwitz, N. Singh, and G. R. Wilson, Comparison of time-dependent semikinetic and hydrodynamic polar wind models: Initial polar wind expansion, density cavities and density enhancements. In program for the workshop on Controversial Issues and New Frontier Research in Geoplasmas, Cambridge, MA, 1992.
  • Lin, J., J. L. Horwitz, G. R. Wilson, and D. G. Brown, Early stage plasmasphere refilling: Effect of spatial and temporal variations in ion and electron heating and ionospheric inflow. In program for the workshop on Controversial issues and new frontier research in geoplasmas, Cambridge, MA, 1992.
  • Wilson, G. R., J. L. Horwitz, and J. Lin, Semikinetic modeling of plasma flow on outer plasmaspheric field lines. In program for the XXIX COSPAR Meeting, Washington, DC, 1992.
  • Wilson, G. R., J. L. Horwitz, C. W. Ho, D. G. Brown, R. W. Schunk, and A. R. Barakat, Recent theoretical progress in the study of the outflow of core plasma from the high latitude ionosphere. In program for the Huntsville workshop: Magnetosphere-ionosphere plasma models: Sources transport, energization, and loss of magnetospheric plasmas, Guntersville, AL, 1992.
  • Ho, C. Wing, J. L. Horwitz, N. Singh and G. R. Wilson, Comparison of semikinetic and hydrodynamic models in the study of time-dependent phenomena in the polar wind. In program for the Huntsville Workshop: Magnetosphere-ionosphere plasma models: Sources, transport, energization, and loss of magnetospheric plasmas, Guntersville, AL, 1992.
  • Lin, J., J. L. Horwitz, D. G. Brown, and G. R. Wilson, Hemispheric decoupling in plasmasphere refilling by equatorial ion and electron heating. In program for the Huntsville workshop: Magnetosphere-ionosphere plasma models: Sources, transport, energization, and loss of magnetospheric plasmas, Guntersville, AL, 1992.
  • Brown, D. G., G. R. Wilson, and J. L. Horwitz, Synergism of magnetospheric particle anisotropies and wave heating in auroral ion beam formation and the "pressure cooker": A dynamic semikinetic model. In program for the Huntsville workshop: Magnetosphere-ionosphere plasma models: Sources, transport, energization, and loss of magnetospheric plasmas, Guntersville, AL, 1992.
  • Frey, M. A., C. E. Rasmussen, J. L. Horwitz, and R. W. Spiro, Detached regions on plasmaspheric streamer. In program for the Huntsville workshop: Magnetosphere-ionosphere plasma models: Sources, transport, energization, and loss of magnetospheric plasmas, Guntersville, AL, 1992.
  • Horwitz, J. L., J. Lin, D. G. Brown, and G. R. Wilson, Core plasma evolution at L=4-7: hemispheric "decoupling" by equatorial ion and electron heating, EOS Trans., Vol. 73, No. 43, 1992/Supplement.
  • Ho, C. W., J. L. Horwitz, M. Loranc, and M. O. Chandler, Statistical survey of 0+ bulk parameters in the midaltitude polar cap magnetosphere, EOS Trans., Vol. 73, No. 43, 1992/Supplement.
  • Lin, J., J. L. Horwitz, R. C. Olsen, and B. L. Giles, Properties of the latitudinal transition from field-aligned to trapped core ions in the equatorial inner magnetosphere, EOS Trans., Vol. 73, No. 43, 1992/Supplement.
  • Neergaard, L., J. L. Horwitz, R. H. Comfort, P. C. Anderson, and M. O. Chandler, Plasmasphere-ionosphere coupling: ion heat fluxes and correlations among ion temperatures, composition and field-aligned flows from DE-1/2, EOS Trans., Vol. 73, No.43, 1992/Supplement.
  • Brown, D. G., G. R. Wilson, and J. L. Horwitz, Mesoscale auroral plasma transport (MAPT): Effects of magnetospheric populations and wave heating in a time-dependent semikinetic model, EOS Trans., Vol. 73, No. 43, 1992/Supplement.
  • Horwitz, J. L., G. R. Wilson, D. G. Brown, C. W. Ho, and J. Lin, Generalized semikinetic (GSK) models for space plasma transport, EOS Trans., Vol. 74, No. 16, 1993/Supplement.
  • Lin, J., J. L. Horwitz, R. C. Olsen, C. J. Pollock, and D. L. Gallagher, Streaming/trapped ion interface in the equatorial inner magnetosphere, EOS Trans., 74, No. 16, 1993/Supplement.
  • Brown, D. G., J. L. Horwitz, and G. R. Wilson, Generalized semikinetic (GSK) model of an auroral "pressure cooker", EOS Trans., Vol. 74, No. 16, 1993/Supplement.
  • Ho, C. W., J. L. Horwitz, M. Loranc, and T. E. Moore, Characterization of core O+ density, flow velocity and temperature in the 3-5 Re polar cap, EOS Trans., Vol. 74, No. 43, 1993/Supplement.
  • Brown, D. G., J. L. Horwitz, and G. R. Wilson, Modeling of auroral plasma transport, EOS Trans., Vol. 74, No. 43, 1993/Supplement.
  • Rasmussen, C. E., M. A. Frey, D. L Carpenter, J. L. Horwitz, M. Smiddy, and R. W. Spiro, Plasmasphere evolution during a magnetic storm: Global simulation and CRRES observations, EOS Trans., Vol. 74, No. 43, 1993/Supplement.
  • Ho, C. W., J. L. Horwitz, H. D. Scarbro, G. R. Wilson, and T. E. Moore, Centrifugal acceleration of the polar wind, EOS Trans. Vol. 74, No. 43, 1993/Supplement.
  • Horwitz, J. L., G. R. Wilson, D. G. Brown, C. W. Ho, and J. Lin, Generalized semikinetic (GSK) transport modeling: Science highlights, EOS Trans., Vol. 74, No. 43, 1993/Supplement.
  • Lee, J., J. L. Horwitz, J. Lin, D. G. Brown, and G. R. Wilson, Generalized semikinetic (GSK) simulation of the effects of preexisting hot plasma on plasmasphere refilling processes, EOS, Vol. 75, No. 16, 1994/Supplement.
  • Horwitz, J. L., G. R. Wilson, D. G. Brown, C. W. Ho, and P. G. Richards, Generalized semikinetic (GSK) simulation of the response of the ionosphere-magnetosphere transition region to auroral electron precipitation, EOS Trans., Vol. 75, No. 16, 1994/Supplement.
  • Brown, D. G., P. G. Richards, G. R. Wilson, J. L. Horwitz, and C. Ho, Effects of precipitating auroral electrons on ionospheric plasma transport: A dynamic semikinetic model. In program for the Huntsville workshop: Coupling of micro- and mesoscale processes in space plasma transport, Guntersville, AL, 1994.
  • Ho, C. W., J. L. Horwitz, G. Wilson, and D. G. Brown, Field-aligned transport of ionospheric O+ ions from 200 km to 1 RE due to ExB convection heating and centrifugal acceleration: A generalized semikinetic (GSK) treatment. In program for the Huntsville workshop: Coupling of micro- and mesoscale processes in space plasma transport. Guntersville, AL, 1994.
  • Reyes, T., and J. L. Horwitz, The acceleration of ionospheric ions through three-dimensional auroral electric field structures. In program for the Huntsville workshop: Coupling of micro- and mesoscale processes in space plasma transport. Guntersville, AL, 1994.
  • Frey, M., C. Rasmussen, R. Anderson, D. Carpenter, J. L. Horwitz, N. Maynard, M. Smiddy, R. Spiro, J. Wygant, and R. Zwikl, A study of the evolution of plasmaspheric structures during a magnetic storm.  In program for the Huntsville workshop: Coupling of micro-and mesoscale processes in space plasma transport, Guntersville, AL, 1994.
  • Lee, J., J. L. Horwitz, G. Wilson, J. Lin, and D. G. Brown, On the interaction of cold ionospheric plasma inflows with the pre-existing equatorial warm plasmas on inner magnetospheric flux tubes: Warm plasma thermalization and effects of varying ionospheric inflow speeds. In program for the Huntsville workshop: Coupling of micro-and mesoscale processes in space plasma transport, Guntersville, AL, 1994.
  • Fraser, B. J., J. L. Horwitz, and J. A. Slavin, Heavy ion mass loading of geomagnetic field lines near the plasmapause: ULF wave implications, EOS Trans., Vol. 75, No. 44, 1994/Supplement.
  • Wilson, G. R., D. G. Brown, P. G. Richards, and J. L. Horwitz, Effects of auroral electron precipitation on ionospheric ion outflow: A dynamic semikinetic model, EOS Trans., Vol. 75, No. 44, 1994/Supplement.
  • Ho, C. W., J. L. Horwitz, and G. R. Wilson, Effects on high-latitude ionospheric ion upflows due to ExB frictional heating and centrifugal acceleration, EOS Trans., Vol. 75, No. 44, 1994/Supplement.
  • Lee, J., J. L. Horwitz, G. R. Wilson, J. Lin, and D. G. Brown, GSK Simulation of warm ion thermalization on inner magnetospheric flux tubes. In program for the Cambridge Symposium/Work-shop, Bermuda, 1995.  
  • Ober, Daniel, J. L. Horwitz, and D. L. Gallagher, Convection effects on global plasmasphere evolution. In program for the Cambridge Symposium, Bermuda, 1995.
  • Su, Y. -J., L. H. Lyu, and J. L. Horwitz, The evolution of nonlinear compressed Alfven wavetrains.    In program for the Cambridge Symposium, Bermuda, 1995.
  • Horwitz, J. L., Multiscale processes in ionospheric outflows. In program for the Cambridge Symposium, Bermuda, February of 1995.
  • Horwitz, J. L., C. Liu, and P. G. Richards, Effects of convection ion heating and soft electron precipitation on high-latitude F-region upflows, Trans. Am Geophys.Un., Vol. 75, 265, 1995a.
  • Liu, C., and J. L. Horwitz, Formation of low-energy trapped and field-aligned ion populations during substorm dipolarization events, Trans. Am. Geophys. Un., Vol. 75, 262, 1995b.
  • Horwitz, J. L., C. Liu, and P. G. Richards, Effects of frictional ion heating and soft-electron precipitation on high-latitude F-region upflows, EOS Trans., Vol. 75, No. 45, 1995/Supplement.
  • Ober, D., J. L. Horwitz, and D. L. Gallagher, Effects of sub auroral ion drifts (SAIDs) on global plasmasphere evolution, Trans. Am. Geophys. Un., Vol. 75, 243, 1995a.
  • Ober, D. M., J. L. Horwitz, and D. L. Gallagher, Convection effects on global plasmasphere evolution during a SAID event, EOS Trans., Vol. 75, No. 45, 1995/Supplement.
  • Liu, C., and J. L. Horwitz, Formation of low-energy trapped and field-aligned ion distributions in substorm dipolarization events, EOS Trans., Vol. 75, No. 45, 1995/Supplement.
  • Su, Y. -J., J. L. Horwitz, C. W. Ho, P. G. Richards, and G. R. Wilson, A coupled fluid-semikinetic treatment for ionospheric plasma outflow: first results, EOS Trans., Vol. 76, No.46, 1995/Supplement.
  • Horwitz, J. L., G. Khazanov, P. G. Richards, and G. R. Wilson, Effects on ion outflows of ionization and heating caused by precipitating soft auroral electrons, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Horwitz J. L., and C. Liu, Simulation of depolarization-driven ionospheric outflows, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Caton, R., J. L. Horwitz, C. Liu, and P. G. Richards, Modeling F-region ion upflows observed by EISCAT, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Wilson, G. R, and J. L. Horwitz, A primer for generalized semikinetic (GSK) modeling, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Ho, C. W., J. L. Horwitz, and G. R. Wilson, Dynamic field-aligned transport of H+ and O+ ions in the collisional/collisionless ionospheric transition region over the polar cap, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Ober, D. M., J. L. Horwitz and D. L. Gallagher, Formation of density structures from the outer plasmasphere by storm-enhanced convection and sub-auroral ion drifts, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Lee, J., J. L. Horwitz, and G. R. Wilson, GSK simulation of warm ion thermalization by coulomb collisions with cool plasmas on outer plasmaspheric flux tubes, EOS Trans. Vol. 76, No. 46, 1995/Supplement.
  • Caton, R., J. L. Horwitz, C. Liu, and P. G. Richards, Modeling F-region ion upflows observed by EISCAT, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Lee, J., J. L. Horwitz, and G. R. Wilson, GSK simulation of warm ion thermalization by coulomb collisions with cool plasmas on outer plasmaspheric flux tubes, EOS Trans., Vol. 76, No. 46, 1995/Supplement.
  • Caton, R., J. L. Horwitz, B. J., Fraser J. L. Horwitz, and J. A. Slavin, The evolution of plasmapause refilling and heavy ion mass loading: DE-1 observations. In program for the International Union of Geodesy and Geophysics XXI General Assembly, 1995.
  • Horwitz, J. L., G. R. Wilson, D. G. Brown, Y. -J. Su, P. G. Richards, and G. V. Khazanov, Kinetic features of high latitude plasma outflows, EOS Trans., Vol. 77, No. 17, April 23, 1996/Supplement.
  • Su, Y. -J., J. L. Horwitz, G. R. Wilson, D. G. Brown, and G. Khazanov, The effect of photoelectrons on plasma outflow at high latitude, EOS Trans., Vol. 77, No. 17, April 23, 1996/Supplement.
  • Seo, Y. H., N. Sandridge, R. G. Caton, and J. L. Horwitz, Statistical relationships between high-latitude ionospheric F-region upflows and their drivers: DE-2, EOS Trans., Vol. 77, No. 17, April 23, 1996/Supplement.
  • Krivorutsky, E. N., J. L. Horwitz, G. V. Khazanov, T. E. Moore, and M. W. Liemohn, Lower hybrid oscillations in multicomponent space plasmas subjected to low-frequency waves, EOS Trans., Vol. 77, No. 17, April 23, 1996/Supplement.
  • Ober, D. M., J. L. Horwitz, and D. L. Gallagher, Dusk-evening plasmasphere density troughs observed in association with subauroral ion drifts (SAID), EOS Trans., Vol. 77, No. 17, April 23, 1996/Supplement.
  • Krivorutsky, E. N., J. L. Horwitz, G. V. Khazanov, T. E. Moore, and M. W. Liemohn, Lower hybrid oscillations in multicomponent space plasmas subjected to low-frequency waves, EOS Trans., Vol. 77, No. 17, April 23, 1996/Supplement.
  • Horwitz, J. L., The dynamics of core plasmas in the inner magnetosphere: What we (think) we know and what we might learn in the next five years (Tutorial). In program for the Geospace Environment ModelingWorkshop, Sowmass, CO, 1996.
  • Su, Y. -J., and J. L. Horwitz, Plasmasphere refilling questions. In program for the Geospace Environment ModelingWorkshop, Snowmass, CO, 1996.
  • Su, Y. -J., and J. L. Horwitz, High and low altitude observations of the POLAR cusp by the TIDE/PSI. In program for the Geospace Environment ModelingWorkshop, Snowmass, CO, 1996.
  • Brown, D. G., and J. L. Horwitz, Computer simulation of multiple scale processes in space plasmas: 1993-95. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Brown, D. G., J. L. Horwitz, G. V. Khazanov, P. G. Richards, and G. R. Wilson, Effects on outflows of ionospheric plasma upflows/abrupt ionization and heating caused by precipitation of soft auroral electrons. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Caton, R. G., J. L. Horwitz, C. Liu, and P. G. Richards, Modeling F-region ion upflows observed by EISCAT. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Ober D. M., and J. L. Horwitz, Global plasmasphere evolution subjected to enhanced large-scale convection and sub-auroral ion drift (SAID) events. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Wilson, G. R. and J. L. Horwitz, A primer for generalized semikinetic (GSK) modeling. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, August 1996.
  • Horwitz, J. L., and C. Liu, Simulation of dipolarization-driven ionospheric outflows. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Su, Y. -J., J. L. Horwitz, C. W. Ho, P. G. Richards, and G. R. Wilson, A coupled fluid-semikinetic treatment for ionospheric plasma outflow: first results. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Ho, C. W., J. L. Horwitz, and G. R. Wilson, Dynamic field-aligned transport of H+ and O+ ions in the high-latitude collisional/collisionless ionospheric transition region. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Lee, J., J. L. Horwitz, and G. R. Wilson, GSK simulation of warm ion thermalization by coulomb collisions with cool plasmas on outer plasmaspheric flux tubes. In program for the XXV General Assembly of the International Union of Radio Science, Lille, France, 1996.
  • Estep, G. M., Y. -J. Su, J. L. Horwitz, P. G. Richards, G. R. Wilson, and D. G. Brown, Toward a time-dependent coupled fluid-semikinetic model for ionosphere-magnetosphere plasma transport: Initial results. In program for the Huntsville ISTP Workshop, Guntersville, AL, 1996.
  • Seo, Y. -H., J. L. Horwitz, and R. G. Caton, Statistical properties of high-latitude ionospheric F-region upflows: DE-2 observations. In program for the Huntsville ISTP Workshop, Guntersville, AL, 1996.
  • Ober, D. M., J. L. Horwitz, and D. L. Gallagher, Convection of core plasma into the outer magnetosphere/boundary layer region: Initial results. In program for the Huntsville ISTP Workshop, Guntersville, AL, 1996.
  • Moore, T. E., M. O. Chandler, P. D. Craven, B. L. Giles, M. Hirahara, J. L. Horwitz, and C. J. Pollock, Plasma transport in the magnetospheric cleft. In program for the Huntsville ISTP Workshop, Guntersville, AL, 1996.
  • Hirahara, M., J. L. Horwitz, G. A. Germany, T. E. Moore, J. M. Spann, M. O. Chandler, and B. L. Giles, Properties of up-flowing ionospheric ion conics and magnetosheath observations from the TIDE and UVI instruments on POLAR. In program for the Huntsville ISTP Workshop, Guntersville, AL, 1996.
  • Horwitz, J. L., Contemporary issues in ionspheric outflows. In program for the International Space Science Institute Meeting, Bern, Switzerland, 1996.
  • Nagai, T., Y. Saito, T. Yamamoto, T., Mukai, A. Nishida, S. Kokubun, M., Hirahara, G. Germany,    J. L. Horwitz, J. Spann, and M. Brittnacher, GEOTAIL-POLAR simultaneous observations of substorm onsets, EOS Trans., Vol. 77, No. 46, November 12, 1996/Supplement.
  • Seo, Y. -H. and J. L. Horwitz, Relationship of auroral F-region and topside ionization structure to soft auroral electron precipitation, EOS Trans., Vol. 77, No. 46, November 12, 1996/Supplement.
  • Ober, D. M., J. L. Horwitz, and D. L. Gallagher, Convection of core plasma into the outer magnetosphere/boundary layer region: Initial results, EOS Trans., Vol. 77, No. 46, November 12, 1996/Supplement.
  • Estep, G. M., Y. -J Su, J. L. Horwitz, P. G. Richards, G. R. Wilson, and D. G. Brown, A time-dependent coupled fluid-semikinetic model for ionosphere magnetosphere plasma transport: Initial results, EOS Trans., Vol. 77, No. 46, November 12, 1996/Supplement.
  • Horwitz, J. L., G. Kunin, M. Hirahara, G. A. Germany, D. G. Brown, J. A. Spann, T. Nagai, and R. Lepping, Auroral and magnetospheric activity during intervals of steady southward interplanetary magnetic field from ISTP POLAR and WIND observations, EOS Trans., Vol. 77, No. 46, November 12, 1996/Supplement.
  • Horwitz, J. L., Contemporary issues in ionspheric outflows. In program for the International Space Science Institute Meeting, Bern, Switzerland, 1997.
  • Horwitz, J. L., G. R. Wilson, D. G. Brown, Y. -J. Su, P. G. Richards, and G. V. Khazanov, Kinetic features of high-latitude plasma kinetic features of high-latitude plasma outflows, EOS Trans., Vol. 78, No. 17, April 29, 1997/Supplement.
  • Su, Y. -J., J. L. Horwitz, M. Hirahara, T. E. Moore, M. O. Chandler, B. L. Giles, P. D. Craven, C. J. Pollock, and J. Scudder, Survey of the polar wind from 5000 km to 8 RE altitude with POLAR, EOS Trans., Vol. 78, No. 17, April 29, 1997/Supplement.
  • Seo, Y. H. and J. L. Horwitz, High-latitude F-region and topside ionization structure observed by DE-2, EOS Trans., Vol. 78, No. 17 April 29, 1997/Supplement.
  • Ober, D. M. and J. L. Horwitz, Modeling the circulation of the outer plasmasphere into the outer magnetosphere/boundary layer region, EOS Trans., Vol. 78, No.17, April 29, 1997/Supplement.
  • Horwitz, J. L., Flow of ionospheric core plasmas in top the magnetosphere: Recent simulation and observations from the thermal ion dynamics experiment/plasma source instrument on-board the POLAR spacecraft. In program for the International Symposium: Solar-Terrestrial Coupling Processes, Paros, Greece, 1997.
  • Su, Y. -J., J. L. Horwitz, T. E. Moore, M. O. Chandler, P. D. Craven, B. L. Giles, and C. J. Pollock, Polar wind survey with TIDE/PSI suite aboard POLAR, EOS Trans., Vol. 78, No. 46, November 18, 1997/Supplement.
  • Adrian, M. L., Y. - J. Su, J. L. Horwitz, P. G. Richards, C. J. Pollock, T. E. Moore, P. M. Kintner, J. Bonnell, D. A. Lorentzen, C. S. Deehr, I. Minow, R. W. Smith, H. C. Stenbaek-Nielsen, F. Sigernes, J. Moen, M. Oieroset, B. Lybekk, and J. Holte, SCIFER/TECHS observations of an electron density structural equatorward of the high-altitude prenoon ionospheric cleft, EOS Trans., Vol. 78, No. 46, November 18, 1997/Supplement.
  • Su, Y. -J., J. L. Horwitz, T. E. Moore, B. L. Giles, M. O. Chandler, C. R. Chappell, and P. D. Craven, Polar wind in the context of the auroral plasma fountain from 2 to 8 RE , EOS Trans., Vol. 78, No. 46, November 18, 1997/Supplement.
  • Horwitz, J. L. and D. L. Gallagher, Convection of core plasma into the outer magnetosphere/boundary layer region: initial results, EOS Trans., Vol. 78, No. 46, November 18, 1997/Supplement.
  • Estep, G. M., Y. -J Su, J. L. Horwitz, P. G. Richards, G. R. Wilson, and D. G. Brown, A time-dependent coupled fluid-semikinetic model for ionosphere magnetosphere plasma transport: Initial Results. EOS Trans., Vol. 78, No. 46, November 18, 1997/Supplement.
  • Horwitz, J. L., G. Kunin, M. Hirahara, G. A. Germany, D. G. Brown, J. A. Spann, T. Nagai, and R. Lepping, Auroral and magnetospheric activity during intervals of steady southward interplanetary magnetic field from ISTP POLAR and WIND observations, EOS Trans., Vol. 78, No. 46, November 18, 1997/Supplement.
  • Moore, T. E., C. J. Pollock, B. L. Giles, M. O. Chandler, C. R. Chappell, P. D. Craven, Y. -J. Su, R. H. Comfort, H. A. Elliott, J. L. Horwitz, and D. C. Delcourt, POLAR/ TIDE results on polar ion outflow". In program for the ISTP and GEM Workshop, Toward Solar Max 2000: The present achievements and future opportunities of ISTP and GEM, Yosemite National Park, 1998.
  • Pollock, C. J., T. E. Moore, B. L. Giles, M. O. Chandler, C. R. Chandler, C. R. Chappell, P. D. Craven, Y. -J. Su, R. H. Comfort, H. A. Elliott, J. L. Horwitz, N. Singh, and D. Thompson, TIDE and PSI on Polar: detailed polar ion outflow observations and the nature of the spacecraft sheath. In program for the ISTP and GEM Workshop, Toward Solar Max 2000: The present achievements and future opportunities of ISTP and GEM, Yosemite National Park, 1998.
  • Su, Y. -J., J. L. Horwitz, X. Y. Wu, T. E. Moore, M. O. Chandler, P. D. Craven, B. L. Giles, S. -W. Chang, and J. D. Scudder, POLAR wind and low-energy electron variations at POLAR apogee, EOS Trans., Vol. 79, No. 17, April 28, 1998/Supplement.
  • Horwitz, J. L., Y. –J. Su, T. E. Moore, B. Giles, M. O. Chandler, P. D. Craven, S. W. Chang, J. D. Scudder, Low energy electron effects of the POLAR wind by the spacecraft, EOS Trans., Vol. 79, No. 17, April 28, 1998/Supplement.
  • Seo, Y. H., J. L. Horwitz, and X. -Y. Wu, Statistical survey of f-region and topside ion upflows at high latitudes, EOS Trans., Vol. 79, No. 17, April 28, 1998/Supplement.
  • Estep, G. M., Y. -J. Su, J. L. Horwitz, P. G. Richards, G. R. Wilson, and D. G. Brown, A dynamic coupled fluid-semikinetic model for ionosphere-magnetosphere plasma transport: effects of ionization by soft electron precipitation, EOS Trans., Vol. 79, No. 17, April 28, 1998/Supplement.
  • Wu, X. -Y., and J. L. Horwitz, Dynamic coupled fluid semi-kinetic modeling of plasma outflow, EOS Trans., Vol. 79, No. 17, April 28, 1998/Supplement.
  • Caton, R. G., Y. -J. Su, J. L. Horwitz, and P. G. Richards, Systematic modeling of soft-electron precipitation effects on high-latitude f- region, EOS Trans., Vol. 79, No. 17, April 28, 1998/Supplement.
  • Horwitz, J. L., Y. -J. Su, T. E. Moore, B. L. Giles, P. D. Craven, M. O. Chandler, M. Hirahara, and C. J. Pollock, Survey of the polar wind near 1 and 8 RE with POLAR. In program for the Cambridge Symposium: Multiscale Plasmas, Cascais, Portugal, 1998.
  • Horwitz, J. L., and Y. - J. Su, Modeling ionospheric outflows, EOS Trans., Vol. 79, No. 24, June 16, 1998/Supplement.
  • Hirahara, P. M., J. L., Horwitz, T. E. Moore, M. O. Chandler, B. L. Giles, P. D. Craven, and C. L. Pollock, POLAR observations of properties of H + and O + conics in the cusp near ~ 5300 km altitude, EOS Trans., Vol. 79, No. 24, June 16, 1998/Supplement.
  • Su, Y. -J., J. L. Horwitz, T. E. Moore, B. L. Giles, M. O. Chandler, P. D. Craven, S. -W. Chang, and J. D. Scudder, POLAR wind and low-energy electron variations on POLAR, EOS Trans., Vol. 79, No. 24, June 16, 1998/Supplement.
  • Horwitz, J. L., Y. -J. Su, E. Dors, T. E. Moore, B. L. Giles, M. O. Chandler, P. D. Craven, S. -W. Chang, and J. D. Scudder, Polar wind measurements with TIDE/PSI and HYDRA on the POLAR spacecraft, EOS Trans., Vol. 79, No. 24, June 16, 1998/Supplement.
  • Stevenson, B. A., J. L. Horwitz, Y. -J. Su, H. A. Elliott, R. H. Comfort, P. D. Craven, M. O. Chandler, T. E. Moore, B. L. Giles, and C. J. Pollock, POLAR/TIDE perigee observations of thermal O+ characteristics in the polar cap region. In program for the Huntsville Workshop: The New Millennium Magnetosphere: Integrating Imaging, Discrete Observations and Global Simulations, Guntersville, AL, 1998.
  • Stevenson, B. A., J. L. Horwitz, Y. -J. Su, H. A. Elliott, R. H. Comfort, P. D. Craven, M. O. Chandler, T. E. Moore, B. L. Giles, and C. J. Pollack, POLAR/TIDE survey of thermal O+ characteristics near 5000 km altitude over the POLAR cap, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Moore, T. E., and J. L. Horwitz, Thirty years of ionospheric outflow I: Causes, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Moore, T. E., and J. L. Horwitz, Thirty years of ionospheric outflow II: Consequences, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Borovsky, J. E., R. A. Greenwald, T. J. Hallinan, J. L. Horwitz, M. C. Kelley, D. M. Klumpar, R. L. Lysak, B. H. Mauk, T. E. Moore, G. D. Reeves, H. J. Singer, and M. Thomsen, The magnetosphere-ionosphere facility: A satellite cluster in geosynchronous orbit magnetically connected to ground-based observatories, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Watanabe, S., M. Hirahara, T. Abe, E. Sagawa, C. Buchert, J. L. Horwitz, T. E. Moore, J. S. Pickett, A. Persoon, D. A. Gurnett, A. W. Yau, Y. Kasahara, T. Mukai, R. Fujii, S. C. Buchert, T. E. Moore, J. S. Pickett, A. M., Persoon, and D. A. Gurnett, Coordinated observations of thermal ion heating and outflow in and above the topside polar/Ionosphere, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Wu, X.-Y., J. L. Horwitz, and Y. H. Seo, Statistical analysis of F-region and topside ionospheric ion field-aligned flows at high latitudes, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Estep, G., X. -Y. Wu, J. L. Horwitz, Y. -J. Su, D. G. Brown, P. G. Richards, G. R. Wilson, Dynamic fluid kinetic (DyFK) modeling of auroral plasma outflow driven by soft electron precipitation and transverse ion heating, EOS Trans., Vol. 79, No. 45, November 10, 1998/Supplement.
  • Horwitz, J. L., Y. –J. Su, E.E. Dors, T. E. Moore, B. L. Giles, M. O. Chandler, P. D. Craven, S. -W. Chang, Low-energy electron effects of the polar wind by the POLAR spacecraft, EOS Trans., Vol 79, No. 45, November 10, 1998/Supplement.
  • Wu, X. -Y., J. L. Horwitz, Morphology of ionospheric ion field-aligned flows at high latitudes as observed with DE-2, EOS Trans., Vol. 80, No. 17, April 27, 1999/Supplement.
  • Stevenson, B. A., J. L. Horwitz, G. Germany, P. D. Craven, M. O. Chandler, T. E. Moore, B. L. Giles, G. K. Parks, C. J. Pollock, Y. -J. Su, POLAR/TIDE observations of field aligned O+ flows at 5000 km altitude over the auroral regions in comparison to UVI auroral images, EOS Trans., Vol. 80, No.17, April 27, 1999/Supplement.
  • Stevenson, B. A., J. L. Horwitz, G. Germany, P. D. Craven, M. O. Chandler, T. E. Moore, B. L. Giles, G. K. Parks, C. J. Pollock, Y. -J. Su, POLAR/TIDE observations of field aligned O+ flows at 5000 km altitude over the auroral regions in comparison to UVI auroral images. In program for the CEDAR Workshop, Boulder, CO, and the GEM workshop, Snowmass, CO. 1999.
  • Horwitz, J. L., G. Park, P. M. Banks, and N. Singh, Fluid and kinetic modeling of plasmasphere refilling processes. In program for the URSI Workshop, Toronto, Canada, 1999.
  • Horwitz, J. L., X. –Y. Wu, B. A. Stevenson, and T. E. Moore, High-latitude ionospheric field-aligned flows. In program for the Transport in the Magnetosphere Workshop, Yellowstone National Park, 1999.
  • Wu, X. -Y., J. L. Horwitz, Dynamic Fluid-Kinetic (DyFK) Modeling of auroral ion outflow: the pressure cooker and other effects of parallel electric fields, soft electron precipitation and transverse ion heating, EOS Trans. Vol. 81, No. 19, May 9, 2000/Supplement.
  • Stevenson, B. A., J. L. Horwitz, G. A. Germany, P. D. Craven, T. E. Moore, B. L. Giles, G. K. Parks, and Y. -J. Su, Relation of field aligned O+ flows at 5000 km altitude to auroral structure and brightness, EOS Trans., Vol. 81, No. 19, May 9, 2000/Supplement.
  • Wu, X. -Y., and J. L. Horwitz, Dynamic fluid-kinetic (DyFK) modeling of auroral ion outflow: the pressure cooker and other effects of parallel electric fields, soft electron precipitation and transverse ion heating, EOS Trans., Vol. 81, No. 19, May 9, 2000/Supplement.
  • Zeng, W., J. L. Horwitz, B. A. Stevenson, X. Y. Wu, Y. -J. Su, P. D. Craven, F. J. Rich, and T. E. Moore, Near-simultaneous POLAR and DMSP measurements of topside ionospheric up and down flows at high latitudes, EOS Trans., Vol. 81, No. 19, May 9, 2000/Supplement.
  • Horwitz, J. L., W. Zeng, B. A. Stevenson, X. –Y. Wu, and G. A. Germany, Investigating the role of the Earth's ionosphere in space weather: Modeling and observations of high-latitude ionospheric outflows. In program for the NATO, Advanced Study Institute on Space Storms and Space Weather Hazards, Crete, Greece, 2000.
  • Horwitz, J. L., W. Zeng, B. A. Stevenson, X. -Wu, G. A. Germany, P. D. Craven, F. J. Rich, and T. E. Moore, Multiple satellite observations of high-latitude ionospheric outflows. In program for the S-RAMP Conference, Sapporo, Japan, 2000.
  • Zeng, W., J. L. Horwitz, B. A. Stevenson, G. A. Germany, P. D. Craven, F. Rich, T. E. Moore, Topside ionosphere parameters observed by POLAR and DMSP at high latitudes, EOS Trans., Vol. 82, No. 19, November 9, 2000/Supplement.
  • Tu, J. -N., X. -Y. Wu, J. L. Horwitz, B. A. Stevenson, and V. C. Coffey, DyFK simulation of field-aligned ion flows observed by POLAR within convecting flux tubes over the polar ionosphere, EOS Trans., Vol. 82, November 9, 2000/Supplement.
  • Tu, J. -N., J. L. Horwitz, X. -Y. Wu, B. A. Stevenson, T. E. Moore, and V. C. Coffey, Polar ionospheric outflow simulations and observations, EOS Trans., Vol. 82, No. 20, May 9, 2001/Supplement.
  • Zeng, W., J. L. Horwitz, X. -Y. Wu, P. D. Craven, F. J. Rich, and T. E. Moore, Relationship of vertical ion flows and topside electron temperature, EOS Trans., Vol. 82, No. 20, May 9, 2001/Supplement.
  • Horwitz, J. L., Fluid transport simulation on plasmaspheric density profiles observed by IMAGE RPI, EOS Trans., Vol. 82, No. 47, November 20, 2001/Supplement.
  • Tu, J. -N., J. L. Horwitz, V. K. Henize, S. F. Fung, and B. W. Reinisch, Dynamic fluid-kinetic simulations on high plasma densities at polar latitudes observed by IMAGE RPI during magnetic storms, EOS Trans., Vol. 82, No. 47, November 20, 2001/Supplement.
  • J. L. Horwitz, and P. Song, The Physics of the Plasmasphere and its coupling to the ionosphere and ring current III, EOS Trans., Vol. 83, No. 19, May 7, 2002/Supplement.
  • Tu, J. -N., J. L. Horwitz, P. Song, X. Huang, B. W. Reinisch, and P. G. Richards, Simulating plasmasphere field-aligned density profiles measured with IMAGE/RPI: Effects of ion heating and refilling, EOS Trans., Vol. 83, No. 19, May 7, 2002/Supplement.
  • Horwitz, J. L., J. -N. Tu, P. Song, X. Huang, B. W. Reinisch, and P. G. Richards, Simulation of plasmaspheric density distributions along plasmaspheric field lines as measured by IMAGE/RPI EOS Trans., Vol. 83, No. 22, May 28, 2002/Supplement.
  • Tu, J. -N., J. L. Horwitz, V. Henize, S. Fung, and B. W. Reinisch, Dynamic Fluid-Kinetic (DyFK) simulation of density distributions along high-latitude magnetospheric field lines as measured by IMAGE/RPI, EOS Trans., Vol. 83, No. 22, May 28, 2002/Supplement.
  • Huang, X., B. W. Reinisch, P. Song, G. S. Sales, P. Nsumei, J. J. Green, P. F. Benson, S. Fung, D. L. Gallagher, J. -N. Tu, and J. L. Horwitz, Emperical models of the plasma density in the plasmasphere and polar cap. In program for the XXVIIth URSI General Assembly, Maastricht, Netherlands, 2002.
  • Reinisch, B., X. Huang, P. Song, G. Sales, I. A. Galkin, R. Benson, S. Fung, J. Green, RPI observations of the magnetostorm effects on the plasmaspheric density distribution. In program for the XXVIIth URSI General Assembly, Maastricht, Netherlands, 2002.
  • Tu, J. -N., J. L. Horwitz, and T. E. Moore, Modeling of high latitude field-aligned ion flows within convecting flux tubes associated with polar perigee passes. In program for the Huntsville Workshop: Astrophysical Particle Acceleration in Geospace and Beyond, Chattanooga, TN, 2002.
  • Zeng, W., J. L. Horwitz, P. D. Craven, F. J. Rich, and T. E. Moore, The O+ density trough at 5000 km altitude over the southern polar cap region of the magnetosphere/ionosphere observed by POLAR/TIDE. In program for the Huntsville Workshop: Astrophysical Particle Acceleration in Geospace and Beyond, Chattanooga, TN, 2002.
  • Zeng, W., J. L. Horwitz, P. D. Craven, F. J. Rich, and T. E. Moore, The O+ density trough at 5000 km altitude in the polar cap. In program for the American Geophysical Union Fall Meeting, December 8-12, 2003, Vol. 84, No. 46, November 18, 2003/Supplement.
  • Tu, J. -N., J. L. Horwitz, P. A. Nsumei, P. Song, X. -Q. Huang, B. W. Reinisch, W. Zeng, Modeling polar cap field-aligned electron density profiles measured with IMAGE Radio Plasma Imager. In program for the American Geophysical Union Fall Meeting, Vol. 84, No. 46, November 18, 2003/Supplement.
  • Zeng, W., J. L. Horwitz, P. D. Craven, F. J. Rich, and T. E. Moore, Satellite observations of the polar cap trough at 5000 km altitude. In preparation for the 2004 Joint Assembly, Montreal, Canada, May 15-22, 2004.
  • Tu, J., J. L. Horwitz, P. Nsumei, P. Song, X. Q. Huang, and B. W. Reinisch, Simulations of polar cap field-aligned electron density profiles measured with IMAGE Radio Plasma Imager. In preparation for the 1004 Joint Assembly, Montreal, Canada, May 15-22, 2004.
  • Zeng, W., J. L. Horwitz, and J.-N. Tu,  Characteristic Ion Distributions in the Dynamic Auroral Transition Region,  EOS Transactions abstract book, presented at Spring 2005 AGU meeting, New Orleans, Louisiana,  May 2005. 
  • Horwitz, J. L., Origin of O+ in the Polar Cap Magnetosphere,  invited presentation, 2006 CEDAR-GEM meeting, Santa Fe, New Mexico, June 2005.
  • Horwitz, J. L., Multiscale Coupling Processes in Ionospheric Plasma Transport, invited presentation to Conference on Earth-Sun System Exploration: Energy Transfer, Kona, Hawaii, January, 2006.
  • Horwitz, J. L., and Y.-J. Su, Plasmaspheric Density Profiles and Loss at the Magnetopause, invited presentation, 2006 CEDAR-GEM meeting, Santa Fe, New Mexico, June 2005.
  • Horwitz, J. L., W. Zeng, and J.-N. Tu,  Characteristic Ion Distribution Functions in the Dynamic Auroral Ionosphere-Magnetosphere Transition Region, invited presentation, 2006 CEDAR-GEM meeting, Santa Fe, New Mexico, June 2005.
  • Horwitz, J. L., Multiscale coupling processes in ionospheric plasma transport, invited presentation to Conference on Earth-Sun System Exploration: Energy Transfer, Kona, Hawaii, January 2006.
  • Horwitz, J. L., W. Zeng, H. A. Elliott, and T. E. Moore, DyFK simulation of the geomagnetic spectrometer observed by POLAR/TIDE, presented to American Geophysical Union meeting,Baltimore, MD, May 2006.
  • Moore, T. E., J. L. Horwitz, R. J. Strangeway, and Y. Zheng, Auroral ionosphere as a source of magnetospheric plasma, COSPAR, 36th COSPAR Scientific Assembly, Beijing, China, July 16-23, 2006.
  • Jaafari, F. J. L. Horwitz, and W. Zeng, Simulation of the formation of O+ troughs in the polar cap magnetosphere using the UT Arlington DyFK model, p. 25 of program for Fall 2006 Joint meeting of Texas Section of American Physical Society, October 5-7, 2006.
  • Zeng, W., J. L. Horwitz, T. E. Moore, and H. E. Elliott, The geomagnetic spectrometer observed by POLAR/TIDE and simulated by the UT Arlington DyFK transport model, p. 26 of program for Fall 2006 Joint meeting of Texas Section of American Physical Society, October 5-7, 2006.
  • Horwitz, J. L., W. Zeng, DyFK-simulation-based formulaic representation of the effects of wavedriven ion heating and electron precipitation on ionospheric outflow, p. 7 of program for Fall 2006 Joint meeting of Texas Section of American Physical Society, October 5-7, 2006.
  • Horwitz, J. L., W. Zeng, DyFK-simulation-based formulaic representation of the effects of wavedriven ion heating and electron precipitation on ionospheric outflows, p. 7 of program for Fall 2006 Joint meeting of Texas Section of American Physical Society, October 5-7, 2006.
  • Horwitz, J. L., Space Physics and Astrophysics at UT Arlington, abstract for invited talk presented to Astronomy League Conference (ALCON) Expo, University of Texas at Arlington, Arlington, TX, August 4-5, 2006.
  • Horwitz, J. L., Simulations of high-latitude ionospheric plasma transport into the magnetosphere using the UT Arlington Dynamic Fluid-Kinetic (DyFK) model", abstract for invited presentation to Department of Physics, University of Houston, September 26, 2006.
  • J. L. Horwitz, Dynamic Fluid Kinetic simulations of high-latitude ionospheric outflow, abstract for invited colloquium to Department of Space Physics and Astronomy, Rice University, November 20, 2006.
  • Elliott, H. A., J. Jahn, C. J. Pollock, T. E. Moore, O+ transport across the polar cap, presentation and abstract for Fall American Geophysical Union meeting, San Francisco, California, December 11-15,2006.
  • Jaafari, F., J. L. Horwitz, and W. Zeng, DyFK Simulation of the O+ density trough at 5000 km altitude in the polar cap, presentation and abstract for Fall American Geophysical Union meeting, San Francisco, California, December 11-15, 2006.
  • Horwitz, J. L., and W. Zeng, DyFK-simulation-based formulaic representation of the effects of wavedriven ion heating and electron precipitation on ionospheric outflows, presentation and abstract for Fall American Geophysical Union meeting, San Francisco, California, December 11-15, 2006.

Non-local Invited Talks:    
  • The latitudinal distribution of transverse electric fields related to E11, large scale auroral features and to ground and interplanetary magnetic field variations. Presented at the Chatanika Radar Advisory Group, Stanford, CA, February, 1977.
  • Recent advances in low-energy plasmas in the earth's magnetosphere. Presented at the UAB Physics Colloquium, February, 1980.
  • Low-energy plasma composition results from the ISEE-1 and SCATHA satellites. Presented at the Assembly of International Association of Geomagnetism and Aeronomy Workshop, Edinburgh, Scotland, August, 1981.
  • Thermal plasmas in the earth's magnetosphere. Presented at the University of Mississippi, Physics Colloquium, March, 1982.
  • Composition and dynamics of < 1 keV plasmas in the earth's magnetosphere. Presented at the American Geophysical Union Fall Meeting, San Francisco, December, 1982.
  • Menu of DE-1 low-energy plasma phenomena for Finnish collaboration. Presented at the U.S. Finland Auroral Workshop, University of Maryland, October, 1983.
  • Recent satellite measurements of low-energy plasmas in the magnetosphere and ionosphere. Presented at the National Ionosphere and Astronomy Center Workshop, July, 1984.
  • The new thermal ion composition measurements of the plasmasphere and plasmasphere region: Important questions for modelers. Presented at the American Geophysical Union Spring Meeting, Baltimore, MD, June, 1985.
  • Plasmasphere and plasmapause characteristics as measured by DE-1. Presented at the COSPAR Symposium: Physics of Thermal Plasma in the Magnetosphere, Toulouse, France, July, 1986.
  • The kinetic approach in global plasma transport modeling: Advantages and difficulties. Presented at the Huntsville Workshop: Magnetosphere-Ionosphere Models, Guntersville, AL, October, 1986.
  • Simulation and measurements of low-energy ionospheric plasmas in the magnetosphere. Presented at the International Symposium on Space Physics, Beijing, China, November, 1986.
  • Core plasmas in the earth's magnetosphere. Presented at the University of Maryland, Space Science Seminar, 1986.
  • Acceleration and transport of ionospheric ions in magnetosphere-ionosphere coupling processes. Presented at the International Symposium: Quantitative modeling of magnetosphere-ionosphere coupling processes, Tokyo, Japan, March, 1987.
  • Plasmasphere-ionosphere coupling measurements in the vicinity of trough flux tubes. Presented at the International Association of Geomagnetism and Aeronomy General Assembly Symposium: Physical Processes in Flux Tubes at Trough Latitudes, Vancouver, August, 1987.
  • Kinetic models for ionospheric ion transport into the magnetosphere. Presented at the Cambridge Workshop: Polar cap dynamics and high latitude ionospheric turbulence, Cambridge, June, 1988.
  • Kinetic features of core plasmas in the magnetosphere: A new generation of observations and simulations. Presented at the COSPAR Symposium: International Solar-Terrestrial Physics, Hague, Netherlands, June, 1990.
  • Plasma transport in the ionosphere-magnetosphere system using semi-kinetic models. Presented at the 18th Rarefied Gas Dynamics Symposium (RGD 18) held at the University of British Columbia, July, 1992.
  • Plasma transport in plasmasphere refilling/closed field lines. Presented at the 1992 Cambridge Workshop: Theoretical Geoplasma Physics: Controversial issues and new frontier research in Geoplasmas. Massachusetts Institute of Technology, Boston, MA, August, 1992.
  • Generalized semikinetic (GSK) models for space plasma transport. Presented at the American Geophysical Union Spring Meeting, Baltimore, MD, May, 1993.
  • The ionosphere as a source for the low-latitude boundary layer. Presented at the Geospace Environment ModelingWorkshop, Snowmass, CO, July, 1993.
  • Generalized semikinetic (GSR) transport modeling: science highlights. Presented at the American Geophysical Union Fall Meeting, San Francisco, CA, December, 1993.
  • Multiscale processes in ionospheric outflows. Presented at the Cambridge Symposium, Bermuda, February, 1995.
  • Formation of low-energy trapped and field-aligned ion distributions in substorm dipolarization events. Presented at the American Geophysical Union Spring Meeting, Baltimore, MD, May, 1995.
  • Contemporary issues in ionospheric outflows. Presented at the International Space Science Institute Meeting, Bern Switzerland, March, 1996.
  • Kinetic features of high-latitude plasma outflows. Presented at the American Geophysical Union Spring Meeting, Baltimore, MD, May, 1996.
  • The dynamics of core plasmas in the inner magnetosphere: What we (think) we know and what we might learn in the next five years (tutorial.) Presented at the Geospace Environment Modeling Workshop, Snowmass, Colorado, June, 1996.
  • High-and low-altitude observations of the polar cusp by the TIDE/PSI suite on Polar. Presented at the Geospace Environment ModelingWorkshop, Snowmass, CO, June, 1996.
  • Computer simulation of multiple scale processes in space plasmas. Presented at the XXV General Assembly of the International Union of Radio Science, Lille, France, September, 1996.
  • Plasmasphere refilling questions. Presented at the Geospace Environment ModelingWorkshop, Snowmass, CO, June, 1997.
  • Flow of ionospheric core plasmas into the magnetosphere: Recent simulations and observations from the Thermal Ion Dynamics Experiment/Plasma Source instrument onboard the POLAR spacecraft. Presented at the International Symposium: Solar-Terrestrial Coupling Processes, Paros, Greece, June, 1997.
  • Survey of the polar wind near 1 and 8 RE with POLAR. Presented at the Cambridge Symposium: Multiscale Plasmas Phenomenal workshop, Lisbon, Portugal, June, 1998.
  • Modeling ionospheric outflows. Presented at the American Geophysical Union, Western Pacific Meeting, Taipei, Taiwan, July, 1998.
  • POLAR/TIDE observations of field aligned 0+ flows at 5000 km altitude over the auroral regions in Comparison to UVI Auroral Images. Presented at the Geospace Environment ModelingWorkshop,  Snowmass, CO, June, 1999.
  • Kinetic modeling of plasmasphere refilling processes. Presented at the General Assembly of the International Union of Radio Science Assembly, Toronto, Canada, August, 1999.
  • Fluid and kinetic modeling of plasmasphere refilling processes. Presented at the Transport in the Magnetosphere Workshop, Yellowstone National Park, September, 1999.
  • High latitude ionospheric field-aligned flows. Presented at the Transport in the Magnetosphere Workshop, Yellowstone National Park, September, 1999.
  • Modeling and observations of high-latitude ionospheric outflows. Presented at the NATO Advanced Study Institute on Space Storms and Space Weather Hazards Workshop, Crete, Greece, June of 2000.
  • Multiple satellite observations of high-latitude ionospheric outflows. Presented at the STEP Results, Applications, and Modeling Phase Conference, Sapporo, Japan, October of 2000.
  • Recent studies of ionospheric outflow: Response to various influences. Presented at the Geospace Enviromental Modeling Workshop, Snowmass, CO, June of 2001.
  • Observations and simulations of high-latitude ionospheric outflows. Presented to University of Texas at Arlington, Physics Department, March 11, 2004.
  • Space plasma research at the University of Texas at Arlington. Presented to Texas Astronomical  Society, Richland College, January 28, 2005.
  • Space plasma research at the University of Texas at Arlington. Presented to the Department of Physics,  University of North Texas, March 8, 2005.
  • Space plasma research at the University of Texas at Arlington. Presented to the Department of Physics,  University of Texas at Dallas, March 23, 2005.
  • Origin of O+ in the Polar Cap Magnetosphere,  invited presentation, 2006 CEDAR-GEM meeting, Santa Fe, New Mexico, June 2005.
  • Plasmaspheric Density Profiles and Loss at the Magnetopause, invited presentation, 2006 CEDAR-GEM meeting, Santa Fe, New Mexico, June 2005.
  • Characteristic Ion Distribution Functions in the Dynamic Auroral Ionosphere-Magnetosphere Transition Region, invited presentation, 2006 CEDAR-GEM meeting, Santa Fe, New Mexico, June 2005.
  • Multiscale Coupling Processes in Ionospheric Plasma Transport, invited presentation to Conference on Earth-Sun System Exploration: Energy Transfer, Kona, Hawaii, January 2006.
  • "Space Physics and Astrophysics at UT Arlington," invited talk presented to Astronomy League Conference (ALCON) Expo, University of Texas at Arlington, Arlington, TX, August 4-5, 2006.
  • "Simulations of high-latitude ionospheric plasma transport into the magnetosphere using the UT Arlington Dynamic Fluid-Kinetic (DyFK) model", invited colloquium to Department of Physics, University of Houston, September 26, 2006.
  • "Dynamic Fluid Kinetic simulations of high-latitude ionospheric outflow ", invited colloquium to Department of Space Physics and Astronomy, Rice University, November 20, 2006.
  • "Ionospheric plasma supply to magnetosphere", invited talk presented to 8th International School for Space Simulations (ISSS-8), Kauai, Hawaii, February 25 - March 3, 2007.
  • "Dynamic Fluid-Kinetic Simulations of High-Latitude Ionospheric Outflows and their Compact Parameterization for Use in Global Magnetospheric Modeling", invited talk presented to High-Altitude Observatory, Boulder, Colorado, April 4, 2007.
  • "LWS TR&T T3b Project : Auroral Ionosphere-Magnetosphere Plasma Transport with Alfvén Kinetic Effects"; invited presentation at LWS TR&T T3b meeting, Boulder, Colorado, August 1-2, 2007.
  • "Astrophysics and Space Physics at the University of Texas at Arlington", presented to Changwon International Symposium on Advanced Science and Technology (CISAS), Changwon National University, Changwon, South Korea, November, 2007.
  • “Simulations of High-Latitude Ionospheric Plasma Transport into the Magnetosphere using the UT Arlington Dynamic Fluid-Kinetic (DyFK) Model”, invited colloquium to Department of Physics, University of Texas at San Antonio, February 15, 2008.
  • “Simulations of High-Latitude Ionospheric Plasma Transport into the Magnetosphere using the UT Arlington Dynamic Fluid-Kinetic (DyFK) Model”, presented to joint CNU-UTA Symposium, Changwon National University, Changwon, South Korea, May, 2008.

Conference Organizing:    
  • Convener, Special American Geophysical Union Session: "Thermal plasma in the ionosphere and magnetosphere", Fall,1978.
  • Convener, Huntsville, Chairman, Local Arrangements Committee, Alabama Academy and Junior Academy of Sciences Annual Meeting, and Chair, Special Session:
  • "Fundamental magnetospheric processes in the plasmapause region", Huntsville, AL, March of 1985.
  • Convener, COSAR Symposium: "Distribution of low-energy plasma in earth space: theory, experimental models", Helsinki, Finland; July, 1988.
  • Co-Convener, Huntsville Workshop: "Plasmasphere Refilling", Huntsville, AL; October, 1990.
  • Co-Convener, Huntsville workshop: "Magnetospheric plasma models", Guntersville, AL, October ,1992.
  • Co-Convener, Huntsville Workshop: "Coupling of Micro- and Mesoscale Processes in Space Plasma Transport", Guntersville, AL, October, 1994.
  • Co-Convener, Huntsville Workshop: "Encounter between Global Models and Observations in the ISTP Era", Guntersville, AL, September, 1996.
  • Co-Chair, International Space Science Institute, Inner Magnetosphere Group: Magnetospheric Plasma, Sources and Losses, Bern Switzerland, 1996-1999.
  • Co-Chair, Geospace Environment Modeling Workshop (GEM) Working Group: Plasmasphere and Ring Current Committee, Snowmass CO, June, 1996-1999.
  • Co-Convener, "Huntsville Workshop: Astrophysical Particle Acceleration in Geospace and Beyond", Chattanooga, TN, October, 2002.

 Appointments
DurationRankDepartment / SchoolCollege / OfficeUniversity / Company
2004-presentProfessor and ChairDepartment of Physics The University Texas at Arlington
1987-2004Associate DirectorCenter for Space Plasma and Aeronautic Research The University of Alabama in Huntsville
1978-2004ProfessorDepartment of Physics The University of Alabama in Huntsville
1976-1978Post-Doctoral FellowNational Academy of Sciences, National Research Council NASA, Marshall Space Flight Center, MSFC, AL
1970-1976Research Assistant  University of California, San Diego
 Synergistic Activities
Editorships
Associate Editor, Geophysical Research Letters, January, 1986-1989.

Editor, Advances in Space Research, Volume on Distribution of low-energy plasma in earth space: Theory, experimental models, 1989.

Guest Editor, Journal of Geophysical Research, Special issue on “Plasmasphere Refilling”, February, 1992.

Space Physics and Aeronomy Section Editor, EOS, American Geophysical Union,1994-1997.

Associate Editor, Inner Magnetosphere Section, International Space Science Institute 1996-1999.

Co-Editor, Cross-Scale Coupling in Space Plasmas, American Geophysical Union Monograph, Vol. 93, 1996.

Space Physics Editor, Reviews of Geophysics, American Geophysical Union, 1997-2001.

Co-Editor, Geospace mass and energy flow: Results from the ISTP Program.

American Geophysical Union Monograph, Vol 104, Washington, DC, 1998.

Guest Editor, Special Issue: Thirty Years of Ionospheric Outflow Studies. Journal of Atmospheric and Solar-Terrestrial Physics, Vol. 62, No. 6, April of 2000.

Co-Editor, Particle Acceleration in Astrophysical Plasmas: Geospace and Beyond, Geophysical Monograph 156, American Geophysical Union, Washington, D. C., 2005.

 Support
 DurationTitleSponsorAmountStatus
2007-2010Auroral Ionosphere Magnetosphere Plasma Transport with Alfvén Kinetic EffectsNASA/Living With a Star (LWS) Targeted Research and Technology (TR&T)278,000Current
2005-2008UTA Analysis of TIDE/PSI Data for ISTP Solar Maximum Extended MissionNASA/GSFC250,000Current
2004-2005Field-Aligned Ion Transport in the High-Latitude Ionosphere-Magnetosphere SystemATM-033438839,561Previous
2003-2007Geospace Enviroment Modeling (GEM) Investigation of Field Aligned Ionospheric Plasma Transport at Polar LatitudesNSF242,434Current
2002-2005High Latitude Magnetospheric-Ionospheric CouplingNASA/GSFC274,082Previous
2002-2003Astrophysical Particle Acceleration in Geospace and BeyondNSF8,000Previous
2002-2003Astrophysical Particle Acceleration in Geospace & BeyondNASA/ASGC1,980Previous
2002-2003Astrophysical Particle Acceleration in Geospace & BeyondNASA/MSFC10,000Previous
2000-2004Field-Aligned Ion Transport in the High-Latitude Ionosphere-Magnetosphere SystemNSF250,454Previous
2000-2003Field-Aligned Ion Transport in the High latitude Ionosphere-Magnetosphere SystemNSF8,000Previous
1999-2001High Latitude Magnetospheric Ionospheric Coupling, UAH Analysis of TIDE/PSI Data for ISTP Solar Maximum Extended Mission (TIDE)NASA125,862Previous
1997-2000Coupling of the High Latitude F-region to Topside UpflowsNSF146,614Previous
1996-1998ISPAE, Space Plasma WorkshopNASA12,570Previous
1996-1997Encounter between Global Observations and Models in ISTP ERANASA14,715Previous
1996-1997Plasma Wave Generation in the Ionosphere and Plasmasphere by Super-thermal ElectronsNSF60,000Previous
1996-1997Encounter between Global Observations and Models in ISTP ERANASA5,000Previous
1995-2000Fundamental Research and Applied Technology in the Areas of Space Physics and Astrophysics Via Utilization of the Available Flight Experiments and Developments of Future ProgramsNASA60,078Previous
1995-1998Convection Effects on High Latitude Plasma OutflowsNASA66,000Previous
1995-1996Kinetic Space PlasmasNASA38,000Previous
1995-1996Plasma Wave GenerationNSF60,000Previous
1995-1996Kinetic space weather: A global hybrid model of polar ionosphere-lower magnetosphere plasma transportNASA38,000Previous
1994-1997Core Plasma Evolution on L=4-7 Flux TubesNSF218,696Previous
1994-1997The Outer Plasmasphere as a Source for Energetic Magnetospheric PlasmasNASA66,000Previous
1994-1997Mesoscale Auroral Plasma TransportNSF179,000Previous
1994-1995Coupling of Micro and Mesoscale Processes in Space Plasma TransportNASA5,000Previous
1994-1995Coupling of Micro-Mesoscale Processes in Space Plasma TransportNSF3,000Previous
1994-1995Observations of Magnetospheric Electron Micro-burstsNASA10,000Previous
1993-1996REU InstrumentationNSF75,450Previous
1992-1995Space Plasma InvestigationsNASA346,000Previous
1992-1993Huntsville Workshop on Magnetospheric PlasmaNSF5,000Previous
1990-1993The Role of Ionospheric Plasmas in the MagnetosphereNASA156,165Previous
1990-1992Radiative Transfer ModelsNASA18,196Previous
1990-1992Kinetic Plasma Processes Occurring in the Outer PlasmasphereNASA42,706Previous
1990-1990Inst. Measurement of Ionospheric Thermal Electron Distribution FunctionNASA22,000Previous
1989-1995Time-Dependent Polar Plasma Outflow: Modeling and ObservationsNASA418,548Previous
1989-1991Plasmasphere RefillingNSF41,085Previous
1989-1991A New Approach to Plasmasphere Refilling: Anomalous Plasma EffectsNSF81,085Previous
1989-1990Space Plasma PhysicsNASA197,281Previous
1986-1991Particles and Plasmas in SpaceNSF/EPSCoR1,977,177Previous
1986-1989Low-Energy Plasma Environment in the Inner – MagnetosphereNASA124,299Previous
1986-1989Investigation of Low-Energy Space PlasmasNASA899,993Previous
1986-1987Global Plasma Transport ModelingNASA18,000Previous
1985-1988Plasmasphere-Ionosphere Plasma InterchangeNSF50,000Previous
1985-1987Transport of Ionospheric Ions through the Magnetosphere:Two- and Three- Dimensional ModelingNSF45,000Previous
1985-1986Plasmasphere and Magnetosphere Plasma Structure from ISEE-1 and DE-1NASA42,959Previous
1985-1986Effect of Time and Space-Varying Electric Fields on the PlasmasphereNASA15,000Previous
1983-1985Plasmasphere- Ionosphere Plasma InterchangeNSF42,000Previous
1983-1984Torus of Thermal Heavy Ions in the Vicinity of the PlasmapauseNASA12,000Previous
1983-1984Relationship of Thermal Plasma Structure to Auroral Boundaries and Other Selected Topics in Plasmaspheric Thermal PlasmasNASA12,000Previous
1982-1983Thermal Plasma in the Polar CuspsNASA10,000Previous
1981-1983An Experimental Study of the Plasmasphere Filling ProcessNASA10,000Previous
1981-1982Assessment of the Solar-Terrestrial Data Base Management System (DBMS)NASA24,125Previous
1980-1989Plasma and Magnetospheric ResearchNASA1,349,998Previous
1980-1981Correlations between Auroral features and Low-Energy Ion Characteristics in the MagnetosphereNASA7,200Previous
1980Data Base Management System (DBMS) WorkshopNASA18,599Previous
1979-1980Plasma PhysicsNASA247,500Previous
1979-1980Pitch Angle Distributions of Thermal Ions in the Inner MagnetosphereNASA27,500Previous
 Teaching
 
PHYS 4324-001 - Advanced Electricity and Magnetism
Spring 2009
[ Show Additional Information ]
This course is primarily intended to provide physics majors at the junior/senior level with the tools and understanding of magnetic fields in matter, electrodynamics, electromagnetic waves and radiation. It is effectively the second semester of a two-semester course in Electricity and Magnetism, following PHYS 3321, Intermediate Electricity and Magnetism.   In this course we will cover chapters 6-11 of Introduction to Electrodynamics, 3rd Edition, by David J. Griffiths, published by Prentice-Hall.

There will be periodic postings of homework solutions and other relevant materials on the WebCT (http://www.uta.edu/webct/) site for this course.



For the Official List of Courses for registration, please visit MyMav - Schedule of Classes
 MavBalls Research
UT Arlington Physics Investigation of NBA Basketballs
MavBalls Research

From Mark Cuban's Blog on NBA Balls:

I asked the University of Texas at Arlington Physics department to take a look at both the new and old NBA basketballs. I asked them to compare the 2 and let me know what they thought. No preconceived notions. No prejudice. Just science.

Below is their data and response. Before you get to it, i wanted to give my conclusions.

1. Keep the ball. Its not perfect, but it would create more hassles than it solves to change.
2. Check every floor in the NBA for "dead spots" and make sure the floors are consistent. This ball will be more impacted by soft spots on the floor.
3. Rather than waiting to see how moisture impacts play and if it creates turnovers, recognize the properties and advantages of the ball, that it is the same regardless of how old or new, and change out the balls at halftime, at the end of quarters, or when it gets wet. Just like they do in baseball and football.
4. The balls retain dirt. Lots of it. By the end of a game or two, the nets look like there have geen kids throwing dirt at them. We need to find a way to keep the balls clean and let every team know so if a fan touches one after a game they dont get grossed out. Changing the balls can help alleviate this problem.
5. AFter this season, look at the embossing and layout on the ball and see if there is a better option. This will make the new ball bounce "true" when compared to the old ball.

Here is the report and a big THANK YOU to UTA and all the hard work they did. They are a first class program and did a wonderfully thorough job


Results

October 26, 2006: MavBalls Investigation

Executive Summary:

Thus far, over the period October 14-present, through various tests, we have determined four major performance differences between the old leather balls and the new synthetic balls provided to us by the Dallas Mavericks organization. It should be noted that the leather balls provided were not new, but rather had been used for extended periods, whereas the synthetic balls provided were brand new.

(1) The two types of balls have different heights of return bounce when inflated to the same pressures and dropped from identical heights. The new synthetic balls display measurably reduced return height than the leather balls - about 5% less on average, when dropped from about four feet. Our compression measurements also indicate differences in elasticity. The difference in bounce heights may translate to effects on players' reactions and handling in terms of dribbling, passing, rebounding off the backboard, bouncing off the rim, etc.

(2) The surface of the synthetic balls display a factor of two higher coefficient of static friction when both leather and synthetic balls are dry. This characteristic would make the synthetic balls easier to grip (stickier) than the leather balls, when dry.

(3) However, with a few drops of added moisture on the surface of each type of ball, the new synthetic balls have a coefficient of friction which is at least 30% smaller than similarly moistened leather balls. We have also measured the moisture absorption rate, which confirms that the synthetic ball absorbs moisture at a much slower rate, leaving more of the moisture on the surface. Therefore, when wet, the synthethic balls are much harder to grip and handle (slippery). By contrast, our measurements indicate that the grip of the leather ball improves after similar moistening.

(4) The synthetic balls bounce more erratically (i.e., at a wider range of angles) off floors. Preliminary measurements suggest about 30% greater deviation in the position of the synthetic ball after a bounce. More tests are scheduled to quantify this precisely.

All the above conclusions should be considered preliminary and subject to revision since we are still actively testing.

Details of Measurements:

(1) We have measured the size and weight of the two types of balls - they are essentially identical in these base characteristics (less than 1% difference). The conditioned leather balls and synthetic balls have similar patterns on the surface. However, prior to use/conditioning, the leather balls display a spherical appearance to the "pebbling" -- instead of the flatter apperance seen in conditioned leather balls and synthetic balls.

(2) Tests have shown that the synthetic ball bounces back

lower by 5-8% when dropped from a height of little over four feet, depending on the hardness of the floor. Specifically, for a hard linoleum floor with concrete underneath, the leather ball bounced back an average distance of 2.2 inches higher compared to the synthetic ball, when dropped from a height of 4 feet 3.7 inches. The coefficient of restitution is 0.81 for the leather ball at this height, increasing monotonically to 0.85 for successive bounces till they reach approximately one third of the drop height. The coefficient of restitution for the synthetic ball was 0.79-0.84 over the same range of heights. The difference in bounce was more pronounced (increasing to 4 inches) on softer, more pliant floors.

(3) In order to compensate for the difference in bounce, we re-tested the basketballs by overinflating the synthetic balls. The synthetic ball had the same bounce characteristic as a conditioned leather ball when overinflated to 14 psi (the required overinflation depends on the hardness of the floor). The leather ball was inflated to the recommended pressure of 8.5 psi for comparison.

(4) The bounce test was repeated with a new (unconditioned) leather ball. We found that the unconditioned leather ball had similar coefficient of restitution to the synthetic ball at same inflation -- that is, both bounced back essentially to the same height. We conclude that the conditioning of leather balls increases their bounce. However, thus far, we have not attempted to condition our new leather ball and repeat the tests.

(5) The synthetic balls absorb water at a much slower rate, averaging 8.6 grams per minute. The conditioned leather balls will absorb water more rapidly, about 70 grams within a minute. After quasi-saturation at these water masses, the leather balls absorb water at a much slower rate than the synthetic balls, averaging 3.3 grams per minute.

(6) We have performed compression tests of all the balls. The data is being analyzed. Qualitatively, we find that the leather balls compress more easily under the same load, compared to the synthetic balls. The compression is linear over reasonable range of forces; we are in the process of quantitatively determining the elasticity.

(7) Initial friction tests show a much higher coefficient of friction for the synthetic ball when dry. The coefficient of friction between the surface of the synthetic ball and a silicon surface (medical literature shows silicon to have a friction coefficient similar to the human palm) is about 3.2, for our experimental setup. The friction coefficient is 1.69 for the leather ball, using the same procedure.

(8) Friction tests with liquids such as Visine (which has viscosity higher than water, similar to human tear drop, possibly closer to sweat) applied to the silicon (one drop per 2"x2" area) show that the coefficient of friction increases for the leather ball. After repeated application of drops, the coefficient increased gradually by at least 30% for the leather ball, thereby making it more "gripable". After quasi-saturation. adding drops reduced the coefficient by 20%, relative to a dry ball. However, for the synthetic ball, the coefficient of friction reduces immediately by 55% with the first drop of liquid. A larger reduction is seen with repeated application of liquid. In conclusion, the wet synthetic ball is significantly more slippery compared to wet leather balls.

(9) During our bounce tests, we observed that the synthetic ball bounced more erratically compared to the leather ball. Preliminary data shows an average horizontal deviation (near the apex after the bounce) of 15 mm for the leather ball, and 22 mm for the synthetic ball, after bouncing off the floor. Examination of the surface characteristics of the synthetic ball showed that more than 20% of the surface is embossed with text and logos to a depth of a few millimeters. We speculate that the more uneven surface of the strongly embossed synthetic balls is the principal cause for the erratic bounces in our tests. The surface of the leather ball is far more consistently spherical and even. We are continuing to improve these measurements.

Future tests:

(a) Continuing studies of friction to quantify the loss of

grip when the synthetic ball is wet.

(b) Wind tunnel test of aerodynamic drag is scheduled for

later this week.

(c) Futher quantitative measurement of erratic bounce is scheduled for next week.

(d) Repeat the bounce test (coefficient of restitution) at the American Airlines Center, if possible.

(e) All other tests are being repeated or redone with

increased precision.

Preliminary recommendations:

Based on our measurements so far, we would recommend that the embossing of the synthetic ball should be discontinued, to reduce erratic bounces. The material of the synthetic ball should be made more moisture absorbent, to increase friction and associated "gripability" when the surface is wet. The thickness of the rubber backing could be reduced to increase bounce. These relatively minor changes in manufacturing, it seems to us, would meet the dual needs of a more uniform low maintenance ball desired by the league with the performance characteristics approximating those which the players are accustomed to and prefer.

General comments about our measurements:

All tests were done with the balls inflated at 8 or 8.5 lbs. For comparisons shown above, old and new balls had the same inflation. Every measurement has been or will be repeated multiple times. We will include an estimate of errors in the next report. We used the following sample of balls for our studies: three conditioned leather balls provided by the

Dallas Mavericks, three new synthetic balls provided by the Dallas Mavericks, two new (not conditioned) official NBA leather balls purchased by us, and one new official NBA synthetic ball purchased by us. At this stage, please note that all measurements should be considered preliminary.

Kaushik De and Jim Horwitz
and the UT Arlington MavBalls Team

Department of Physics
The University of Texas at Arlington


News Related to MavBalls Research
Media Coverage, Blogs, and More


NBA Balls - Mark Cuban's Blog Post with Executive Summary

Read More
I asked the University of Texas at Arlington Physics department to take a look at both the new and old NBA basketballs. I asked them to compare the 2 and let me know what they thought. No preconceived notions. No prejudice. Just science.

As NBA season gets ready to open, all eyes are on new ball
Fort Worth Star-Telegram
Based on preliminary data gathered by two physicists at the University of Texas at Arlington, the bounce of the new basketball is considerably more erratic, and it becomes slick during play

UTA involved in NBA ball test
The Shorthorn
It's the NBA vs. its players, and now the university is playing the role of moderator. Physics professors and students are intensely experimenting with the NBA's new official basketball made by Spalding, released this summer. The changes are the first since 1970, when the ball went from four panels to eight, and are only the second in 60 seasons

Hoops, sweat and tears Physicists help a US basketball team get to grips with its new ball.
Nature.com
This year, the US National Basketball Association (NBA) is switching from using a leather to a synthetic, microfibre ball. The animal-welfare group People for the Ethical Treatment of Animals is thrilled, but basketball players complain that the new ball is slippery and doesn't handle as well as the old one.

Coming to grips with new NBA ball
Dallas Morning News
It took Dirk Nowitzki to come up with a positive spin on the NBA's new basketball, which has been ripped by players coast to coast.
The Mavericks' star zeroed in on the synthetic ball's consistent feel as a selling point.
"If it's played with for two months or if it's brand new, it feels bad," Nowitzki says. "So at least they accomplished that."

The physics of basketballs
The University of Texas at Arlington
When UT Arlington Department of Physics chair Jim Horwitz was asked to do a study of the new NBA basketball, you might say he jumped at the chance.


 Additional Information
Professional Memberships and Honors:
  • Member, American Geophysical Union, 1970-Present.
  • Awarded, Highest Honors with B.A., University of California, San Diego, 1970.
  • Member, International Sun-Earth Explorer Science Team, 1978-1982.
  • Member, Dynamics Explorer Science Team, 1979-1988.
  • Awarded, Huntsville's Outstanding Young Educator by the Huntsville Jaycees 1983.
  • Awarded, Researcher of the Year by Huntsville's Sigma Xi Research Society, 1983.
  • Member, IUGG Magnetospheric Quadrennial Reporting Team, 1983-1986.
  • President, Alabama Academy of Sciences, Huntsville Chapter, 1984-1985.
  • Member, International Commission on Physics of Thermal Plasma Regions in the Magnetosphere, 1996-Present.
  • Member, NASA Data Systems Users Working Group 1985-1990.
  • Member, Assistant State Project Director for Physics and Astronomy, Alabama EPSCoR, 1986-1989
  • Member, ISTP/POLAR/TIDE Science Team, IUGG Magnetospheric Quadrennial Reporting Team 1991-1995, 1992-Present.
  • Awarded, UAH Foundation winner for Research in Physical/Mathematical Sciences, 1996.
  • Core Member, Working Group Co-Chair, Sources and Losses of Magnetospheric Plasmas, International Space Science Institute Campaign, 1996-1999.
  • Member, Co-Chair, Geophysical Environmental Modeling campaign, Plasmasphere refilling and ring current decay working group, 1996-1999.
  • Member, UAH Awards Committee, College of Science, 2000-2004.
  • Space Physics Representative, AGU Book Committee, 2002-2006.
  • Member, American Physical Society, 2007- present.
  • Member at Large (elected) of Texas Section of American Physical Society (2008-   Present)
  • Chair(elected) , UT Arlington Association of Academic Directors and Chairs(AADC), 2008-2009.

Graduate Students Supported/Supervised: M.S.

W. K. Cobb, M.S. Physics, 1982.

J. T. Turnley, M.S. Computer Science, 1984.

W. T. Roberts, M.S. Physics, 1985, "Heavy Ion Torus in the Earth's Outer Plasmasphere".

K. Liou, M.S. Physics, 1988.  

J. Lin, Physics, M.S. Physics, 1990.

B. L. Giles, M.S. Physics, 1990.

T. R. Reyes, M.S. Physics, 1993, with Thesis: "The Acceleration of Ionospheric Ions Through Three-Dimensional Electric Field Structures".

M. L. Adrian, M.S. Physics 1995

R. Caton, M.S. Physics, 1994 

D. M. Ober, M.S. Physics, 1995

J. Lee, M.S. Physics, 1995    

Y. -H. Seo, M.S. Physics, 1997, with Thesis: "Statistical Relationships for Ionospheric F-Region/Topside Ion Upflows Based on Satellite Measurements".

G. M. Estep, M.S. Physics, 1997, with Thesis: "A Coupled Fluid-Generalized Semi-Kinetic Model for Treating Time Dependent Ionospheric Outflows".

B. A. Stevenson, M.S. Physics, 2000, with Thesis: "Relationship of Polar Field-Aligned O+ Flows at 5000 KM Altitude to Convection and Auroral Forms".


Graduate Students Supported/Supervised: Ph.D.

C. W. Ho, PhD. Physics, 1993, "The high altitude polar wind: simulation and observation".

D. G. Brown, PhD. Physics, 1993, "A generalized semikinetic (GSK) model for mesoscale auroral plasma transport".

F. J. Lin, PhD. Physics, 1993, "Equatorial heating effects on outer plasmasphere evolution".

D. M. Ober, PhD. Physics, 1997, "The outer plasmasphere as a source for magnetospheric plasmas".

Y. -J. Su, Ph.D Physics, 1998, "The photoelectron-driven polar wind: A coupled fluid-semikinetic simulations and measurements by the Thermal Ion Dynamics Experiment (TIDE) on the POLAR spacecraft".

X. -Y. Wu, PhD. Physics, 2000, "Auroral plasma upflows: Dynamic Fluid-Kinetic (DyFK) simulations and ionospheric observations".

M. L. Adrian, PhD. Physics, 2000, "Rocket measurements of ionospheric thermal and superthermal electron distributions in the pre-noon dayside cleft".

J. -N. Tu, PhD. Physics,  May 2004, "Simulation Study of Plasmaspheric Density Distributions and High-Latitude Ion Transport Observed by Satellites".

W. Zeng, PhD. Physics,  July,  2004, "Multi-Spacecraft Observations of O+ Flows in the Polar Topside Ionosphere and Lower Magnetosphere".

F. Jaafari, Ph. D. Physics, expected in May 2009.


Undergraduate Senior Theses

S. Lee, “The lunar wake and the plasma expansion phenomenon”, 1983.

B. L. Giles, “The auroral ion fountain: magnetic latitude, MLT and Kp dependencies”, 1986.

J. Foy, “An empirical model of plasma density and temperature in the magnetosphere projection speeds for MDH waves”, 1988.


 
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