Where does the Thermospheric Ionospheric GEospheric Research (TIGER) Program go?

Schmidtke, G.; Avakyan, S. V.; Berdermann, Jens; Bothmer, V.; Cessateur, Gaël; Ciraolo, L.; Didkovsky, L. V.; Wit, T. Dudok de; Eparvier, F.; Gottwald, Alexander; Haberreiter, M.; Hammer, R.; Jacobi, Ch.; Jakowski, N.; Kretzschmar, M.; Lilensten, Jean; Pfeifer, Marcel; Radicella, S. M.; Schäfer, Robert; Schmidt, W.; Solomon, Stanley C.; Thuillier, G.; Tobiska, W. Kent; Wieman, Seth; Woods, Thomas N.

doi:10.1016/j.asr.2015.07.043

Cited by 13 publications

(6 citation statements)

References 90 publications

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“…The interaction of solar radiation with the ionosphere is complicated due to several mechanisms with the potential to modulate the thermosphere-ionosphere (T-I) system at different timescales ranging from the 11-year solar cycle down to minutes (e.g., Liu et al, 2003;Afraimovich et al, 2008;Liu and Chen, 2009;Chen et al, 2012). The ionosphere plasma response to solar EUV and UV variations has been widely studied using ground-and space-based observations (e.g., Jakowski et al, 1991;Jacobi et al, 2016;Schmölter et al, 2018;Jakowski et al, 1999), as well as by numerical and empirical modeling (e.g., Ren et al, 2018;Vaishnav et al, 2018a, b). These studies have shown that the response of the ionosphere to solar EUV radiation variations is delayed by 1-2 d at the 27 d solar rotation period (e.g., Jakowski et al, 1991;Afraimovich et al, 2008;Jakowski et al, 2002;Min et al, 2009;Jacobi et al, 2016;Lee et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Long-term trends in the ionospheric response to solar extreme-ultraviolet variations

2019

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Abstract. The thermosphere–ionosphere system shows high complexity due to its interaction with the continuously varying solar radiation flux. We investigate the temporal and spatial response of the ionosphere to solar activity using 18 years (1999–2017) of total electron content (TEC) maps provided by the international global navigation satellite systems service and 12 solar proxies (F10.7, F1.8, F3.2, F8, F15, F30, He II, Mg II index, Ly-α, Ca II K, daily sunspot area (SSA), and sunspot number (SSN)). Cross-wavelet and Lomb–Scargle periodogram (LSP) analyses are used to evaluate the different solar proxies with respect to their impact on the global mean TEC (GTEC), which is important for improved ionosphere modeling and forecasts. A 16 to 32 d periodicity in all the solar proxies and GTEC has been identified. The maximum correlation at this timescale is observed between the He II, Mg II, and F30 indices and GTEC, with an effective time delay of about 1 d. The LSP analysis shows that the most dominant period is 27 d, which is owing to the mean solar rotation, followed by a 45 d periodicity. In addition, a semi-annual and an annual variation were observed in GTEC, with the strongest correlation near the equatorial region where a time delay of about 1–2 d exists. The wavelet variance estimation method is used to find the variance of GTEC and F10.7 during the maxima of the solar cycles SC 23 and SC 24. Wavelet variance estimation suggests that the GTEC variance is highest for the seasonal timescale (32 to 64 d period) followed by the 16 to 32 d period, similar to the F10.7 index. The variance during SC 23 is larger than during SC 24. The most suitable proxy to represent solar activity at the timescales of 16 to 32 d and 32 to 64 d is He II. The Mg II index, Ly-α, and F30 may be placed second as these indices show the strongest correlation with GTEC, but there are some differences in correlation during solar maximum and minimum years, as the behavior of proxies is not always the same. The indices F1.8 and daily SSA are of limited use to represent the solar impact on GTEC. The empirical orthogonal function (EOF) analysis of the TEC data shows that the first EOF component captures more than 86 % of the variance, and the first three EOF components explain 99 % of the total variance. EOF analysis suggests that the first component is associated with the solar flux and the third EOF component captures the geomagnetic activity as well as the remaining part of EOF1. The EOF2 captures 11 % of the total variability and demonstrates the hemispheric asymmetry.

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Section: Introductionmentioning

confidence: 99%

Long-term trends in the ionospheric response to solar extreme-ultraviolet variations

2019

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“…The ultraviolet, and particularly EUV, irradiance is intrinsically linked to solar cycle magnetic variation, and so is the galactic cosmic ray flux, which is again exhibiting record highs, as it did prior to solar cycle #24 (e.g., http://neutronm.bartol.udel.edu). Whether this serves as a bellwether for broader solar changes may be discoverable by the ongoing program of comprehensive space‐based observations of total and spectral solar irradiance (e.g., Dudok de Wit et al, ; Haberreiter et al, ; Schmidtke et al, ).…”

Section: Discussionmentioning

confidence: 99%

Ionospheric Electron Content During Solar Cycle 23

2018

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The solar minimum period between solar cycles 23 and 24 has generated extensive study, in part because the changes in the upper atmosphere and ionosphere were so dramatic. Thermospheric density during 2008-2009, at the benchmark 400-km altitude, was shown to be approximately 30% lower than the previous solar minimum during 1996, in observations and in model simulations. Ionospheric densities were also estimated to be lower, by 10% to 20%. However, earlier analyses using data from the global network of Global Navigation Satellite System receivers did not find any significant reduction in global mean total electron content. Recent work reexamining those data using a limited set of receivers, but with consistent processing, identified a 19% reduction (Emmert et al., 2017, https://doi.org/10.1002/2016JA023680). In this study, we compare model simulations of the thermosphere-ionosphere system during the 2008-2009 solar minimum to its predecessor and estimate a 16% reduction in global mean total electron content. This is consistent with the neutral thermosphere density change seen in model simulations and in satellite drag observations. In the model simulations, the primary driver is a 10% reduction in solar extreme ultraviolet irradiance, with a smaller contribution from lower geomagnetic activity, and a very small decrement due to increase in atmospheric carbon dioxide.Plain Language Summary The Sun goes through 11-year activity cycles, best known with regard to the number of sunspots. At solar minimum, when sunspots mostly vanish, the extreme ultraviolet region of the solar spectrum also diminishes. This causes lower temperature and density in the ionosphere and upper atmosphere above 100 km, where the extreme ultraviolet radiation is absorbed. Past solar minimum periods have seemed basically similar with regard to extreme ultraviolet radiation, and other manifestations of solar activity. However, the solar minimum during 2008-2009 was longer and had fewer sunspots than its predecessor during 1996, or than any minimum period in the past century. The thermosphere was also lower in density, and the ionosphere also appeared to be lower in density, but there were some contradictory measurements. Recent reanalysis of ionospheric measurements found better agreement with the thermospheric measurements. Modeling studies attempting to explain the changes in the ionosphere and thermosphere have suggested that they were caused by a decrease of about 10% in solar extreme ultraviolet radiation. Here we show that the model results and the ionospheric measurements are now in good agreement. This demonstrates that solar minima are not all the same and may have implications for understanding the Sun during extended periods of very low activity.

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“…Why was it necessary to take into account the microwave fluxes from the ionosphere? The fact is that in numerous space experiments, by now, the efforts of world science have determined the variations of all energy flows associated with solar and geomagnetic activity [30,31]. The results obtained indicate that these flows do not reach the lower atmosphere and, therefore, the direct impact of the effects of solar flares and magnetic storms on the biosphere and the lower layers of the atmosphere (the troposphere and its weather and climate char-acteristics) is impossible.…”

Section: Associate Formation In Aqueous Biosolutions Under Microwave ...mentioning

confidence: 99%

Microwave radiations of environment: On the possibility of inhibition of malignant mitosis

SV¹,

LA²

2022

J Clin Images Med Case Rep

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From the standpoint of fundamental physical optics, clinical images and medical cases of a number of human viral diseases are considered under the influence of the environment on a sick organism, namely: Solar-geomagnetic disturbances and modern anthropogenic background. Microwave emission of the terrestrial ionosphere disturbed by flares on the Sun and during periods of magnetic storms was determined to be the agent of such an impact, and the anthropogenic influence is associated with the continuously increasing radiation of the microwave flux during the development of mobile cellular communications. Separately, new experimental results on the effect of weightlessness on the mitosis of cancer cells, including those created artificially are being studied. A unified interpretation of these results within the framework of supramolecular physics of the generation of supramolecular structures (water-containing associates) in a living organism is presented.

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Where does the Thermospheric Ionospheric GEospheric Research (TIGER) Program go?

Cited by 13 publications

References 90 publications

Long-term trends in the ionospheric response to solar extreme-ultraviolet variations

Long-term trends in the ionospheric response to solar extreme-ultraviolet variations

Ionospheric Electron Content During Solar Cycle 23

Microwave radiations of environment: On the possibility of inhibition of malignant mitosis

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