Solar activity control of ionospheric and thermospheric processes

Jakowski, N.; Fichtelmann, Bernd; Jungstand, A.

doi:10.1016/0021-9169(91)90061-b

Cited by 60 publications

(64 citation statements)

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“…8d) This lag (of about 2 days) of the 27-day GEC variations, as compared with the corresponding changes in the EUV and radio 10.7-cm solar emissions (Figs. 7 and 8), is in agreement with the data presented by Jakowski et al (1991Jakowski et al ( , 1998Jakowski et al ( , 2002. Figure 7d shows the envelopes EdG(t), EdF(t) and EdU(t) of the maximal values of the 27-day variations of the dG(t), dF(t) and dU(t) presented in Figs.…”

Section: -Day Variations Of Gec -Comparison With Variations Of Solasupporting

confidence: 89%

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Global electron content: a new conception to track solar activity

et al. 2008

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Abstract. We developed a method and programs for estimation of the global electron content (GEC) from GPS measurements, using the ionosphere models IRI-2001 and NeQuick. During the 23rd cycle of solar activity, the value of GEC varied from 0.8 to 3.2×10 32 electrons, following changes in the solar extreme ultra violet (EUV) radiation and solar radio emission at 10.7-cm wavelength. We found a strong resemblance of these variations, with discernible 11-year and 27-day periodicities. A saturation effect of GEC is found when F10.7 increases. We found that GEC is characterized by strong seasonal (semiannual) variations with maximum relative amplitude at about 10% during the rising and falling parts of the solar activity and up to 30% during the period of maximum. It was found that the relative difference between model and experimental GEC series increase as the smoothing time window decreases. We found that GEC-IRI seasonal variations are out-of-phase with experimental GEC values. The lag between model and experimental maximum of GEC values can reach several tens of days. The variations of GEC lag, on average, 2 days after those of F10.7 and UV. GEC completely reflects the dynamics of the active regions on the solar surface. The amplitude of the 27-day GEC variations decreases from 8% at the rising and falling solar activity to 2% at the maximum and at the minimum. We also found that the lifetime of contrast long-living active formations on the Sun's surface in EUV range for more than 1 month exceeds the one in radio range (10.7 cm).

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Section: -Day Variations Of Gec -Comparison With Variations Of Solasupporting

confidence: 89%

“…Many works have been devoted to researching of this factor (Akasofu and Chapmen, 1972;Ivanov-Kholodny and Nikolsky, 1969;Vitinsky et al, 1986;Jakowski et al, 1991Jakowski et al, , 1998Jakowski et al, , 2002. However, quasi 27-day modulation of local ionosphere parameters can be masked by many other factors.…”

Section: Introductionmentioning

confidence: 99%

Global electron content: a new conception to track solar activity

et al. 2008

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“…Although TEC is subjected to a clear seasonal modulation, the general behavior of TEC is highly correlated with F10.7 (e.g., Jakowski et al 1991Jakowski et al , 2011. Whereas the dynamic ratio between TEC maximum and minimum is about 8 at day-time over Europe, the same ratio is about 5-6 for night-time conditions during solar cycle 23 (see Fig.…”

Section: Latitude-dependent Response Of Tec To Solar Euv Changesmentioning

confidence: 98%

Solar activity impact on the Earth’s upper atmosphere

Kutiev

Tsagouri

Perrone

et al. 2013

J. Space Weather Space Clim.

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The paper describes results of the studies devoted to the solar activity impact on the Earth's upper atmosphere and ionosphere, conducted within the frame of COST ES0803 Action. Aim: The aim of the paper is to represent results coming from different research groups in a unified form, aligning their specific topics into the general context of the subject. Methods: The methods used in the paper are based on data-driven analysis. Specific databases are used for spectrum analysis, empirical modeling, electron density profile reconstruction, and forecasting techniques. Results: Results are grouped in three sections: Medium-and long-term ionospheric response to the changes in solar and geomagnetic activity, storm-time ionospheric response to the solar and geomagnetic forcing, and modeling and forecasting techniques. Section 1 contains five subsections with results on 27-day response of low-latitude ionosphere to solar extreme-ultraviolet (EUV) radiation, response to the recurrent geomagnetic storms, long-term trends in the upper atmosphere, latitudinal dependence of total electron content on EUV changes, and statistical analysis of ionospheric behavior during prolonged period of solar activity. Section 2 contains a study of ionospheric variations induced by recurrent CIR-driven storm, a case-study of polar cap absorption due to an intense CME, and a statistical study of geographic distribution of so-called E-layer dominated ionosphere. Section 3 comprises empirical models for describing and forecasting TEC, the F-layer critical frequency foF2, and the height of maximum plasma density. A study evaluates the usefulness of effective sunspot number in specifying the ionosphere state. An original method is presented, which retrieves the basic thermospheric parameters from ionospheric sounding data.

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“…The high correlation between the variations of the solar radiation (EUV, energetic pearticle flux) and the variation of the total Correspondence to: C. Borries (claudia.borries@dlr.de) electron content (TEC) of the ionosphere has been demonstrated in many publications (e.g., Jakowski et al, 1991;Forbes et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Storm induced large scale TIDs observed in GPS derived TEC

Borries¹,

Jakowski²,

Wilken³

2009

Ann. Geophys.

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105

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Abstract. This work is a first statistical analysis of large scale traveling ionospheric disturbances (LSTID) in Europe using total electron content (TEC) data derived from GNSS measurements. The GNSS receiver network in Europe is dense enough to map the ionospheric perturbation TEC with high horizontal resolution. The derived perturbation TEC maps are analysed studying the effect of space weather events on the ionosphere over Europe.Equatorward propagating storm induced wave packets have been identified during several geomagnetic storms. Characteristic parameters such as velocity, wavelength and direction were estimated from the perturbation TEC maps. Showing a mean wavelength of 2000 km, a mean period of 59 min and a phase speed of 684 ms −1 in average, the perturbations are allocated to LSTID. The comparison to LSTID observed over Japan shows an equal wavelength but a considerably faster phase speed. This might be attributed to the differences in the distance to the auroral region or inclination/declination of the geomagnetic field lines.The observed correlation between the LSTID amplitudes and the Auroral Electrojet (AE) indicates that most of the wave like perturbations are exited by Joule heating. Particle precipitation effects could not be separated.

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Solar activity control of ionospheric and thermospheric processes

Cited by 60 publications

References 10 publications

Global electron content: a new conception to track solar activity

Global electron content: a new conception to track solar activity

Solar activity impact on the Earth’s upper atmosphere

Storm induced large scale TIDs observed in GPS derived TEC

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