U. S. Report to the IUGG, 1979-1982: Solar-Planetary Relationships-Aeronomy (Paper 3R0391)

U.S. contributions to auroral aeronomy, 1979-1982

Ultra High Energy Cosmic Rays (UHECRs) Acceleration by Large Amplitude Electro Magnetic Waves (LAEMWs)

Ultra High Energy Cosmic Rays: Signature of Extragalactic Component

Ultradense Matter

Ultraviolet and VUV sources for in-flight calibration of space experiments

Ultraviolet Radiation Scattering (λ 1300 Å) in the Upper Atmosphere of the Earth (Summary)

Ultraviolet stimulated electron source for use with low energy plasma instrument calibration

UN/ESA Workshops on Basic Space Science: An Update on Their Achievements

Unified D-region ion composition models

Unique Observations of a Geomagnetic SI^+ -- SI^- Pair: Solar Sources and Associated Solar Wind Fluctuations

United Nations Basic Space Science Initiative: 2011 Status Report on the International Space Weather Initiative

Update on the Sun-Earth Connection Chains Observed during the Solar Storm Events of April 2002: New Science & Outreach Aspects

Updating the Near-Earth Neutral Line Model

Upper Atmosphere Layers which Radiate in the Infrared Spectral Region

Upper limit of electron-neutral collision frequency in E- and F-layers

Use of coated silicon field emitters as neutralisers for fundamental physics missions in space

Using solar radio burst integrated fluxes to predict energetic proton flux increases

Using the 630.0-nm nightglow emission as a surrogate for the ionospheric Pedersen conductivity

Utilization of Artificial Earth Satellite Orbital Data to Determine the Wind Velocity in the Thermosphere