The physical behavior of the upper atmosphere deduced from satellite drag data

1967 ◽  
Vol 6 (6) ◽  
Author(s):  
W. Priester ◽  
M. Roemer ◽  
H. Volland
Keyword(s):  
Upper Atmosphere ◽  
Physical Behavior ◽  
Satellite Drag

scholarly journals Inferring thermospheric composition from ionogram profiles: A calibration with the TIMED spacecraft

2019 ◽  
Author(s):  
Christopher J. Scott ◽  
Shannon Jones ◽  
Luke A. Barnard
Keyword(s):  
Dissociative Recombination ◽  
Temporal Variations ◽  
Molecular Ions ◽  
Upper Atmosphere ◽  
Global Network ◽  
G Factor ◽  
Satellite Drag ◽  
Important Region ◽  
Ion Production ◽  
Sensitive Function

Abstract. Measurements of thermospheric composition via ground-based instrumentation are challenging to make and so details about this important region of the upper atmosphere are currently sparse. We present a technique that deduces quantitative estimates of thermospheric composition from ionospheric data, for which there is a global network of stations. The visibility of the F1 peak in ionospheric soundings from ground-based instrumentation is a sensitive function of thermospheric composition. The ionospheric profile in the transition region between F1 and F2 peaks can be expressed by the G factor, a function of ion production rate and loss rates via ion-atom interchange reactions and dissociative recombination of molecular ions. This in turn can be expressed as the square of the ratio of ions lost via these processes. We compare estimates of the G factor obtained from ionograms recorded at Kwajalein (9° N, 167.2° E) for 25 times during which the TIMED spacecraft recorded approximately co-located measurements of the neutral thermosphere. We find a linear relationship between √G and the molecular: atomic composition ratio, with a gradient of 2.23 ± 0.17 and an offset of 1.66 ± 0.19. This relationship reveals the potential for using ground-based ionospheric measurements to infer quantitative variations in the composition of the neutral thermosphere. Such information can be used to investigate spatial and temporal variations in thermospheric composition which in turn has applications such as understanding the response of thermospheric composition to climate change and the efficacy of the upper atmosphere on satellite drag.

scholarly journals Solar flares as proxy for the young Sun: satellite observed thermosphere response to an X17.2 flare of Earth's upper atmosphere

2012 ◽  
Vol 30 (8) ◽  
pp. 1129-1141 ◽  
Author(s):  
S. Krauss ◽  
B. Fichtinger ◽  
H. Lammer ◽  
W. Hausleitner ◽  
Yu. N. Kulikov ◽  
...  
Keyword(s):  
Solar Flares ◽  
Radiation Flux ◽  
Extreme Ultraviolet ◽  
Upper Atmosphere ◽  
Radiation Environment ◽  
The Sun ◽  
Satellite Drag ◽  
Grace Satellites ◽  
Early Phases ◽  
Activity Indices

Abstract. We analyzed the measured thermospheric response of an extreme solar X17.2 flare that irradiated the Earth's upper atmosphere during the so-called Halloween events in late October/early November 2003. We suggest that such events can serve as proxies for the intense electromagnetic and corpuscular radiation environment of the Sun or other stars during their early phases of evolution. We applied and compared empirical thermosphere models with satellite drag measurements from the GRACE satellites and found that the Jacchia-Bowman 2008 model can reproduce the drag measurements very well during undisturbed solar conditions but gets worse during extreme solar events. By analyzing the peak of the X17.2 flare spectra and comparing it with spectra of young solar proxies, our results indicate that the peak flare radiation flux corresponds to a hypothetical Sun-like star or the Sun at the age of approximately 2.3 Gyr. This implies that the peak extreme ultraviolet (EUV) radiation is enhanced by a factor of about 2.5 times compared to today's Sun. On the assumption that the Sun emitted an EUV flux of that magnitude and by modifying the activity indices in the Jacchia-Bowman 2008 model, we obtain an average exobase temperature of 1950 K, which corresponds with previous theoretical studies related to thermospheric heating and expansion caused by the solar EUV flux.

Estimation of secular density variations in the upper atmosphere from 1964–2007 satellite drag data

2011 ◽  
Vol 45 (5) ◽  
pp. 420-432
Author(s):  
I. I. Volkov ◽  
A. I. Semenov ◽  
V. V. Suevalov
Keyword(s):  
Upper Atmosphere ◽  
Satellite Drag

Influence of the hot oxygen corona on the satellite drag in the Earth’s upper atmosphere

2011 ◽  
Vol 45 (3) ◽  
pp. 231-239 ◽  
Author(s):  
V. I. Shematovich ◽  
D. V. Bisikalo ◽  
S. Krauss ◽  
W. Hausleitner ◽  
H. Lammer
Keyword(s):  
Upper Atmosphere ◽  
Satellite Drag ◽  
Hot Oxygen

Remaining Issues in Upper Atmosphere Satellite Drag

2021 ◽  
pp. 111-140
Author(s):  
Jeffrey P. Thayer ◽  
W. Kent Tobiska ◽  
Marcin D. Pilinski ◽  
Eric K. Sutton
Keyword(s):  
Upper Atmosphere ◽  
Satellite Drag
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