Difference between the spectra of acoustic gravity waves in daytime and nighttime hours due to nonequilibrium effects in the atmosphere

First GPS-TEC evidence for the wave structure excited by the solar terminator

“…The obtained results concerning the LS structure agree with theoretical indications of ST effects (Cot and Teitelbaum, 1980;Somsikov, 1983Somsikov, , 1987Somsikov and Ganguly, 1995;Dungenbaeva and Ganguly, 2004;Antonova et al, 2006) and do not contradict the experimental results obtained by Mishin et al (1991), Beley et al (1995), and Galushko et al (1998Galushko et al ( , 2003. In particular, these results confirm the conclusion by Galushko et al (1998) that ST-generated AGWs can be observed at sunrise better than at sunset (corresponding data will be presented in future publications).…”

“…Recent investigations have shown that movement of the solar terminator (ST) causes the generation of acousticgravity waves (STAGW), turbulence, and instabilities in the ionosphere plasma (Beer, 1978;Cot and Teitelbaum, 1980;Somsikov, 1983Somsikov, , 1987Somsikov and Ganguly, 1995;Dungenbaeva and Ganguly, 2004;Antonova et al, 2006). It is worth noting that among all of the sources of gravity waves, the moving ST has a special status, since it is a predictable phenomenon, whose characteristics are well known.…”

Solar radiation and atmospheric dynamics

“…It is directed towards the high-frequency region in the day time and caused by the solar radiation absorption and atmospheric emission of the radiations. These results are confirmed experimentally by the spectral analysis of the data of the pressure perturbation obtained during the period of August, September, and January in Antarctica [13]. This clearly demonstrates the fundamental role of coupling the gas and radiation.…”

“…Since the effects due to non-equilibrium atmosphere and openness were significant it became apparent that for getting a real picture of the processes in the atmosphere, the atmosphere should be viewed as a GRS [12][13][14]21]. But to construct an evolutionary model of the atmosphere, the Eqs.1, 2, 4, 7-9 need to be modified in view of the more exactly nature of the energy exchange between the gas and radiation.…”

“…Studies were carried out on the basis of the linearized empirical equations of non-equilibrium thermodynamics written for atmosphere as a GRS [12,13]. As a result, a significant shift of the spectrum of natural oscillations has been detected, determined by the interaction of radiation with the atmosphere.…”