scholarly journals Solar cycle effects in planetary geomagnetic activity: Analysis of 36-year long OMNI dataset

2000 ◽  
Vol 27 (17) ◽  
pp. 2797-2800 ◽  
Author(s):  
V. O. Papitashvili ◽  
N. E. Papitashvili ◽  
J. H. King
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Activity Analysis

scholarly journals Extremely low geomagnetic activity during the recent deep solar cycle minimum

2011 ◽  
Vol 7 (S286) ◽  
pp. 200-209 ◽  
Author(s):  
E. Echer ◽  
B. T. Tsurutani ◽  
W. D. Gonzalez
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Solar Minimum ◽  
Solar Wind Speed ◽  
Sunspot Cycle ◽  
Cycle Minimum ◽  
Current Minimum ◽  
Solar Wind Parameters ◽  
Xix Century

AbstractThe recent solar minimum (2008-2009) was extreme in several aspects: the sunspot number, Rz, interplanetary magnetic field (IMF) magnitude Bo and solar wind speed Vsw were the lowest during the space era. Furthermore, the variance of the IMF southward Bz component was low. As a consequence of these exceedingly low solar wind parameters, there was a minimum in the energy transfer from solar wind to the magnetosphere, and the geomagnetic activity ap index reached extremely low levels. The minimum in geomagnetic activity was delayed in relation to sunspot cycle minimum. We compare the solar wind and geomagnetic activity observed in this recent minimum with previous solar cycle values during the space era (1964-2010). Moreover, the geomagnetic activity conditions during the current minimum are compared with long term variability during the period of available geomagnetic observations. The extremely low geomagnetic activity observed in this solar minimum was previously recorded only at the end of XIX century and at the beginning of the XX century, and this might be related to the Gleissberg (80-100 years) solar cycle.

scholarly journals The 22-year cycle in the geomagnetic 27-day recurrences reflecting on the F2-layer ionization

2004 ◽  
Vol 22 (4) ◽  
pp. 1171-1176 ◽  
Author(s):  
E. M. Apostolov ◽  
D. Altadill ◽  
M. Todorova
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Activity Index ◽  
Solar Rotation ◽  
Rotation Period ◽  
Sunspot Cycle ◽  
Solar Cycles ◽  
Solar Radio Flux ◽  
Critical Frequency Fof2 ◽  
Northern And Southern Hemispheres

Abstract. Solar cycle variations of the amplitudes of the 27-day solar rotation period reflected in the geomagnetic activity index Ap, solar radio flux F10.7cm and critical frequency foF2 for mid-latitude ionosonde station Moscow from the maximum of sunspot cycle 18 to the maximum of cycle 23 are examined. The analysis shows that there are distinct enhancements of the 27-day amplitudes for foF2 and Ap in the late declining phase of each solar cycle while the amplitudes for F10.7cm decrease gradually, and the foF2 and Ap amplitude peaks are much larger for even-numbered solar cycles than for the odd ones. Additionally, we found the same even-high and odd-low pattern of foF2 for other mid-latitude ionosonde stations in Northern and Southern Hemispheres. This property suggests that there exists a 22-year cycle in the F2-layer variability coupled with the 22-year cycle in the 27-day recurrence of geomagnetic activity. Key words. Ionosphere (mid-latitude ionosphere; ionosphere- magnetosphere interactions) – Magnetospheric physics (solar wind-magnetosphere interactions)

A Search for Periodic Variations in Geomagnetic Activity and Their Solar Cycle Dependence

1973 ◽  
Vol 7 (3) ◽  
pp. 135-140 ◽  
Author(s):  
H Hauska ◽  
S Abdel-Wahab ◽  
E Dyring
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Cycle Dependence

A prediction of geomagnetic activity for solar cycle 23

1999 ◽  
Vol 104 (A4) ◽  
pp. 6871-6876 ◽  
Author(s):  
E. W. Cliver ◽  
A. G. Ling ◽  
J. E. Wise ◽  
L. J. Lanzerotti
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Solar Cycle 23

scholarly journals The correlation between solar and geomagnetic activity – Part 3: An integral response model

2011 ◽  
Vol 29 (6) ◽  
pp. 1005-1018 ◽  
Author(s):  
Z. L. Du
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Correlation Coefficient ◽  
Geomagnetic Activity ◽  
Decay Time ◽  
Response Model ◽  
Integral Response ◽  
Lag Times ◽  
The Relationship ◽  
Aa Index

Abstract. An integral response model is proposed to describe the relationship between geomagnetic activity (aa index) and solar activity (represented by sunspot number Rz): The aa at a given time t is the integral of Rz at past times (t'≤t) multiplied by an exponential decay factor of the time differences (e−(t−t')/τ), where τ is the decay time scale (~40 months). The correlation coefficient of aa with the reconstructed series based on this model (rf=0.85) is much higher than that of aa with Rz (r0=0.61). If this model is applied to each solar cycle, the correlation coefficient will be higher (rf=0.95). This model can naturally explain some phenomena related to aa and Rz, such as (i) the significant increase in the aa index (and its baseline) over the twentieth century; (ii) the longer lag times of aa to Rz at solar cycle maxima than at minima; and (iii) the variations in the correlations related to solar and Hale cycles. These results demonstrate that aa depends not only on the present Rz but also on past values. The profile of aa can be better predicted from Rz by this model than by point-point correspondence.

scholarly journals Variation of the foF2 parameter during fluctuating activity: Prediction with IRI-2012 compared to measured data from Ouagadougou inosonde station during solar cycles 21 and 22

2019 ◽  
Vol 41 (1) ◽  
pp. 59-68
Author(s):  
Abidina Diabaté ◽  
Jean Louis Zerbo ◽  
Frédéric Ouattara
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Equatorial Electrojet ◽  
International Reference Ionosphere ◽  
Theoretical Physics ◽  
Solar Cycles ◽  
Quiet Time ◽  
Iri Model ◽  
Equatorial Station ◽  
International Reference

In this paper, we review on diurnal variations of the foF2 ionospheric parameter predicted by the IRI-2012 model, and data from Ouagadougou ionosonde station located in the crest of the Equatorial Anomaly (Lat: 12.5°N; Long: 358.5°E, dip: 1.43°) during fluctuating geomagnetic activity conditions for the solar cycles 21 and 22. Our investigations are focused on the electrodynamic aspects, the influence of the ionospheric electric currents as well as the variations of the hourly values given by model and experimental measurements. A comparative study pointed out that the IRI-2012 model, through its URSI and CCIR subroutines, gives a good prediction of the critical frequency of the F2 layer between 0700 TL and 0000 TL. In addition, IRI -2012 tries to reproduce, as best as possible, the vertical drift E × B during minimum, decreasing phase, winter, and autumn. However, there is no effect of drift during the other seasons and solar cycle phases. A last, the model does not take into account the PRE phenomenon observed in autumn and the influence of the equatorial electrojet in this ionospheric zone.ReferencesAcharya R., Roy B., Sivaraman M.R., 2010. Dasgupta A. An empirical relation of daytime equatorial total electron content with equatorial electrojet in the Indian zone. J Atmos Terr Phys, 72(10), 774–780.Acharya R., Roy B., Sivaraman M.R.; Dasgupta A., 2011. On conformity of the EEJ based Ionospheric model to the Fountain effect and resulting improvements. J Atmos Terr Phys, 73, 779-784.Adeniyi J.O., Oladipo O.A., Radicella S.M., 2005. Variability of fof2 and comparison with iri model for an equatorial station. The Abdus Salam International Centre for Theoretical Physics, IC/2005/085, http://www.ictp.it/~pub_off.Adeniyi1 J.O., Oladjipo O.A., Radicella S.M., 2005. Variability of foF2 and comparison with IRI model for an equatorial station. The Abdus Salam International Centre for Theoretical Physics, IC/2005/085.Bilitza D., et al., 2014. The International Reference Ionosphere 2012-a model of international collaborationI.  J. Space Weather Space Clim, 4, A07.Bilitza D., Reinisch B.W., 2008. International Reference Ionosphere 2007: Improvements and new parameters. Adv. Space Res, 42, 599–609.Farley D.T., Bonell E., Fejer B.G., Larsen M.F., 1986. The Prereversal Enhancement of the Zonal Electric Field in the Equatorial Ionosphere. J Geophys Res, 91(A12), 13,723–13,728.Faynot J.M., Villa P., 1979. F region at the magnetic equator. Ann Geophys, 35, 1–9.Fejer B.G., 1981. The equatorial ionospheric electric fields: A review. J Atmos Terr Phys, 43, 377.Fejer B.G., Farley D.T., Woodman R.F., Calderon C., 1979. Dependence of equatorial F region vertical drifts on season and solar cycle. J Geophys Res, 84, 5792.Legrand J.P., Simon P.A., 1989. Solar cycle and geomagnetic activity: A review for geophysicists. Part I. The contributions to geomagnetic activity of shock waves and of the solar wind. Ann. Geophys, 7, 565–578.Obrou K.O., 2008. Contribution à l’amélioration du modèle "International Reference Ionosphere" (IRI) pour l’ionosphère équatoriale. Thèse de doctorat Université de Cocody,  Abidjan, Côte d’Ivoire.Ouattara F., 2009. Contribution à l’étude des relations entre les deux composantes du champ magnétique solaire et l’Ionosphère Equatoriale. Thèse de Doctorat d’Etat ès Sciences, Université Cheikh Anta Diop, Dakar, Sénégal.Ouattara F., 2013. IRI-2007 foF2 Predictions at Ouagadougou Station during Quiet Time Periods from 1985 to 1995. Archives of Physics Research, 4, 12–18.Ouattara F., Amory-Mazaudier C., 2009. Solar–geomagnetic activity and Aa indices toward a Standard.  J. Atmos. Terr. Phys, 71, 1736–1748.Ouattra F., Nanéma, 2014. Quiet Time foF2 Variation at Ouagadougou Station and Comparison with TIEGCM and IRI-2012 Predictions for 1985 and 1990. Physical Science International Journal, 4(6), 892–902.Oyekola  O.S., Fagundes P.R., 2012. Equatorial F2-layer variations: Comparison between F2 peak parameters at Ouagadougou with the IRI-2007 model.  Earth, Planets Space, 64, 553–566.Rishbeth H., 1971. The F-layer dynamo. Planet, Space Sci, 19, 263.Vassal J.A., 1982. The variation of the magnetic field and its relationship with the equatorial electrojet in Senegal Oriental. Annals of Geophysics, Tome French, 38.Zerbo J.L., Amory-Mazaudier C. Ouattara F., Richardson J., 2012. Solar Wind and Geomagnetism, toward a Standard Classification 1868-2009.  Ann Geophys, 30, 421–426. http://dx.doi.org/10.5194/angeo-30-421-2012.Zerbo J.L., Amory-Mazaudier C., Ouattara F., 2013. Geomagnetism during solar cycle 23: Characteristics. J. Adv. Res, 4(3), 265–274. Doi:10.1016/j.jare.2013.08.010.Zerbo J.L., Ouattara F., Zoundi C., Gyébré A., 2011. Solar cycle 23 and geomagnetic activity since 1868. Revue CAMES serie A, 12(2), 255–262.

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