Results 171 to 180 of about 2,463,978 (199)
Some of the next articles are maybe not open access.
Semi-annual Variation in Thermospheric Density
Nature, 1968KING-HELE1 has reported a semi-annual variation in thermospheric density at about 190 km with a maximum to minimum ratio of 1.45. Cook's hypothesis2 that the semi-annual variation is caused by the modulation of the helium content of the lower thermosphere, originally coined to account for the variation at 1,100 km, clearly cannot be applied to explain ...
openaire +1 more source
Midlatitude neutral thermosphere density and temperature measurements
Journal of Geophysical Research, 1969Midlatitude neutral thermosphere density and temperature measurements, noting effect of atomic oxygen adsorption by ...
David T. Pelz, George P. Newton
openaire +1 more source
Accuracy of Earth's Thermospheric Neutral Density Models
AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 2006[Abstract] Atmospheric drag remains the dominant uncertainty for low altitude satellite precision orbit determination . Empirical models are used to estimate satellite drag. Model accuracies have shown little improvement in the past 35 years. A new Ja cchia -Bowman 2006 (JB2006) empirical model has been developed as part of the Air Force Space Command ...
Frank Marcos +2 more
openaire +1 more source
On thermospheric neutral density and wind estimation
The neutral mass density of the upper thermosphere can be determined by orbit and accelerometer data from Low Earth Orbit (LEO) satellites. Especially the accelerometers of geodetic satellites, measuring the non-gravitational accelerations acting on these satellites, are a very useful observation for precise density estimation also on very short time ...Florian Wöske +2 more
openaire +1 more source
Density variations in the lower thermosphere.
1974Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1974. ; Vita. ; Bibliography: leaves 155-160. ; Ph.D.
openaire +1 more source
A solar cycle of upper thermosphere density observations from the EISCAT Svalbard Radar : thermospheric density over Svalbard [PDF]
, 2014 We exploit a recently developed technique, based on ion-neutral coupling, which allows estimations of the upper thermospheric neutral density using measurements of ionospheric plasma parameters made by the European Incoherent Scatter (EISCAT) Svalbard Radar (ESR).
Vickers, H. +5 more
openaire
Thermospheric Density Variability and Forecast Model Development.
1997Abstract : Thermospheric densities derived from SETA-1, SETA-2 and SETA-3 accelerometer data, and cross track winds from SETA-1, were analyzed to determine the nature of latitudinal structures at latitudes greater than 45 degrees. Distinct dependencies on magnetic activity level, local time, hemisphere and season are revealed.
Timothy Fuller-Rowell, Jeffrey M. Forbes
openaire +1 more source
Satellite Aerodynamics and Determination of Thermospheric Density and Wind
AIP Conference Proceedings, 2011At present several satellites for earth gravity field measurement are in low polar orbits. These satellites have slender shapes and are equipped with highly sensitive accelerometer packages. Accelerometer data of these satellites can be used to determine local atmospheric density and winds.
openaire +1 more source
The “thermospheric spoon”: A mechanism for the semiannual density variation
Journal of Geophysical Research: Space Physics, 1998A mechanism is proposed to explain the cause of the global, semiannual thermospheric density variation. It is suggested that the global‐scale, interhemispheric circulation at solstice acts like a huge turbulent eddy in mixing the major thermospheric species.
openaire +1 more source
Air density in the lower thermosphere
2nd Annual Meeting, 1965R. POE, H. SMALL
openaire +1 more source