On the annual and semiannual variations of the thermospheric density

Volland, H.; Wulf-Mathies, C.; Priester, Wolfgang

doi:10.1016/0021-9169(72)90094-3

Cited by 18 publications

(6 citation statements)

References 14 publications

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“…He was among the first to use such signals to derive physical models of the Earth's atmosphere, particularly as it is affected by solar activity. This work that led to a second article in Naturwissenschaften [17] as well as many other papers [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37], including four in Nature. Of these publications, and Wolf's guiding roles in bodies such as COSPAR (the Committee for Space Research) during these years, probably no contribution has proved more influential than a detailed model of the upper atmosphere that he developed together with Isadore Harris during his years in the U.S.A. [38][39][40][41][42][43][44][45][46][47].…”

Section: Early Career(s)mentioning

confidence: 99%

Wolfgang Priester: from the big bounce to the $\Lambda$-dominated universe

Overduin

Blome

Hoell

2006

Naturwissenschaften

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Wolfgang Priester was one of Germany's most versatile and quixotic astrophysicists, re-inventing himself successively as a radio astronomer, space physicist and cosmologist, and making a lasting impact on each field. We focus in this personal account on his contributions to cosmology, where he will be most remembered for his association with quasars, his promotion of the idea of a nonsingular "big bounce" at the beginning of the current expansionary phase, and his recognition of the importance of dark energy (Einstein's cosmological constant Λ) well before this became the standard paradigm in cosmology.

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Section: Early Career(s)mentioning

confidence: 99%

Wolfgang Priester: from the big bounce to the $\Lambda$-dominated universe

Overduin

Blome

Hoell

2006

Naturwissenschaften

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“…Since early sixties, the existence of SAV in atmospheric densities and composition together with its implications for the ionosphere is well established [ Bhatnagar , 1971; Bhatnagar and Shepherd , 1989; Rishbeth et al , 2000; Volland et al , 1972]. The semiannual amplitude (SAA) is minimum in solstices (mid July, mid January) and maximum in equinoxes (March/April, late October), with July minimum deeper than the January one.…”

Section: Semiannual Variations (Sav)mentioning

confidence: 99%

Satellite ballistic coefficients and the lower thermosphere

Bhatnagar

Tan

2005

Geophysical Research Letters

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[1] Observed variations in the estimated ballistic coefficients (B 0 ) for satellites in the lower thermosphere during 2001, have been used to study its implications for atmospheric densities with respect to changes in the solar and geomagnetic activities. It is shown that the steady state density models predict the true densities within 10% as a function of solar activity, except during strong geomagnetic storms, when true densities are underestimated by about 15%. The variations in B 0 with days point to a semiannual variation (SAV) in the scaling factor required to correctly predict SAV in the true densities from steady state models. The calculations also show that changes in density ratios during some major geomagnetic storms can not be explained by steady state models. The Ncar-Tigcm models may be used to see if these bring B 0 closer to true ballistic coefficients than the steady state models.Citation: Bhatnagar, V. P., G. A. Germany, and A. Tan (2005), Satellite ballistic coefficients and the lower thermosphere, Geophys. Res. Lett., 32, L03109,

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“…Soon after its discovery in the upper thermosphere, the SAO was found in the lower thermosphere and near the mesopause (e.g., G. E. Cook, 1969a, 1969b; Groves, 1972; King‐Hele & Kingston, 1968; King‐Hele & Walker, 1969). Waves propagating up from the lower atmosphere can couple linearly and nonlinearly with the background atmosphere or with each other and significantly affect the T‐I SAO (Newell, 1966; Volland et al., 1972). Eddy diffusion has historically been used in atmospheric models to parametrize the effects of subgrid‐scale gravity wave mixing and breaking on the background densities, temperature and winds (Hodges, 1969).…”

Section: Introductionmentioning

confidence: 99%

“…Among the long‐term variations, the thermospheric and ionospheric annual oscillation (T‐I AO) and the semiannual oscillation (T‐I SAO) have the largest magnitudes and were initially observed in neutral densities derived from satellite drag measurements by Paetzold and Zschörner (1961). The global T‐I AO has a minimum in neutral densities in July and has partially been attributed to the changing distance between the Sun and the Earth (Volland et al., 1972), and is still under investigation (e.g., Qian et al., 2009). In this study, we mainly focus on the T‐I SAO.…”

Section: Introductionmentioning

confidence: 99%

Impacts of Lower Thermospheric Atomic Oxygen and Dynamics on the Thermospheric Semiannual Oscillation Using GITM and WACCM‐X

2022

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The Earth's atmosphere is an open system with complex interplay between internal and external drivers resulting in complicated nonlinear coupling mechanisms. The region above 100 km is usually referred to as the Earth's upper atmosphere with the neutral thermosphere coexisting with the partly ionized ionosphere. Both the thermosphere and ionosphere exhibit several periodic variations in densities and temperature across an array of timescales ranging from minutes to a few years (Rishbeth, 2007). These include variations due to gravity waves (e.g.,

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On the annual and semiannual variations of the thermospheric density

Cited by 18 publications

References 14 publications

Wolfgang Priester: from the big bounce to the $\Lambda$-dominated universe

Wolfgang Priester: from the big bounce to the $\Lambda$-dominated universe

Satellite ballistic coefficients and the lower thermosphere

Impacts of Lower Thermospheric Atomic Oxygen and Dynamics on the Thermospheric Semiannual Oscillation Using GITM and WACCM‐X

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