Kp index correlations with solar-wind parameters during the first and second stages of a recurrent geomagnetic storm

Bobrov, M. S.

doi:10.1016/0032-0633(73)90188-8

Cited by 24 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Different explanations have been presented for the geomagnetic activity associated with CIRs. Bobrov [1973] suggested it was due to the highly fluctuating southward component of IMF. Burlaga and Lepping [1977] considered that the electric field, Ey, was the determinant parameter for geomagnetic activity.…”

Section: Results Of Statistical Analysismentioning

confidence: 99%

Geoeffectiveness of corotating interaction regions as measured by Dst index

Alves¹,

Echer²,

González³

2006

J. Geophys. Res.

128

View full text Add to dashboard Cite

[1] Corotating interaction regions (CIRs) are structures formed when high-speed solar wind streams overtake slow solar wind streams as they propagate outward. These structures produce regions of enhanced density and magnetic field strength in the solar wind near the ecliptic plane. In this paper, the geoeffectiveness of CIRs, as measured by the geomagnetic Dst index, is assessed during the solar wind observational period . A catalogue of CIRs is constructed by consulting high-speed plasma streams (HSPS) lists present in the literature and by analyzing solar wind parameters for each HSPS event. The geoeffectiveness of CIRs is analyzed by determining the number of intense (Dst À100 nT), moderate (À100 < Dst À50 nT), or weak (À50 < Dst À30 nT) magnetic storms that followed each CIR event. Statistical distributions of CIR parameters (maximum solar wind speed, maximum convection electric field, southward magnetic field peak) and geoeffectiveness (Dst peak) are obtained. Correlation analyses of Dst index with various solar wind parameters are presented. A comparison with the geoeffectiveness of other interplanetary structures such as shocks, magnetic clouds, and sector boundaries is performed. Our results show that 33% of CIRs are followed by moderate/intense magnetic activity (Dst < À50 nT), i.e., approximately one third of the CIR events observed near Earth are geoeffective.

show abstract

Section: Results Of Statistical Analysismentioning

confidence: 99%

Geoeffectiveness of corotating interaction regions as measured by Dst index

Alves¹,

Echer²,

González³

2006

J. Geophys. Res.

128

View full text Add to dashboard Cite

show abstract

“…As suggested by Borovsky and Gosling [2001], if there is an enhanced viscous interaction controlled by the amplitude of the turbulence in the solar wind, then there should be correlations between the solar wind turbulence amplitude and the geomagnetic indices. Although largely ignored at present, such correlations have been found in the past [ Ballif et al , 1967, 1969; Hirshberg and Colburn , 1969; Bobrov , 1973; Garrett , 1974; Garrett et al , 1974]. Two physical interpretations of these correlations have been given.…”

Section: Eddy‐viscosity Hypothesismentioning

confidence: 99%

Role of solar wind turbulence in the coupling of the solar wind to the Earth's magnetosphere

2003

View full text Add to dashboard Cite

[1] The correlation between the amplitude of the MHD turbulence in the upstream solar wind and the amplitude of the Earth's geomagnetic activity indices AE, AU, AL, Kp, ap, Dst, and PCI is explored. The amplitude of the MHD turbulence is determined by the fluctuation amplitude of the solar wind magnetic field. This ''turbulence effect'' in solar wind/magnetosphere coupling is more easily discerned when the interplanetary magnetic field (IMF) is northward, but the effect is also present when the IMF is southward. The magnitude of the effect is the same for northward and southward IMF, accounting for about 150 nT of the variability of the AE index. Tests are performed that conclude (1) that the turbulence effect is not caused by the turbulence amplitude acting as a proxy for jBj in the solar wind and (2) that reversals of the IMF from northward to southward in the turbulent fluctuations is not the cause of the correlations. An expression is derived for the total viscous-shear force on the surface of the magnetosphere; improved solar wind/ magnetosphere correlations result when this expression is used. With insight from fluidflow experiments, the turbulence effect is interpreted as an enhanced viscous coupling of the solar wind flow to the Earth's magnetosphere caused by an eddy viscosity that is controlled by the amplitude of MHD turbulence in the upstream solar wind: more upstream turbulence means more momentum transfer from the magnetosheath into the magnetosphere, resulting in more stirring of the magnetosphere, which produces enhanced geomagnetic activity indices.

show abstract

“…It is now established that statistical properties of the solar wind are dominated by large-amplitude fluctuations at small scales and present signatures of intermittency [Marsch andTu, 1994, 1997;Sorriso-Valvo et al, 1999;Alexandrova et al, 2008;Uritsky et al, 2011;Osman et al, 2012;Alexandrova et al, 2013]. Even though the possible influence of solar wind turbulence on geomagnetic activity has been long recognized Journal of Geophysical Research: Space Physics 10.1002/2015JA021505 with studies investigating possible coupling between solar wind fluctuations and geomagnetic activity [Ballif et al, 1967[Ballif et al, , 1969Hirshberg and Colburn, 1969;Garrett et al, 1974;Garrett, 1974;Bobrov, 1973], statistical, comprehensive observational, and numerical studies of the impact of solar wind fluctuations on magnetospheric dynamic (as compared to steady state) processes are less frequent [Tsurutani and Gonzalez, 1987;Chen et al, 1993Chen et al, , 1994Borovsky and Funsten, 2003;Pulkkinen et al, 2006aPulkkinen et al, , 2006bD'Amicis et al, 2007;Jankoviċovà et al, 2008;D'Amicis et al, 2009;Huang et al, 2010;Claudepierre et al, 2010;Ilie et al, 2010aIlie et al, , 2010bLiemohn et al, 2011;McGregor et al, 2014].…”

Section: Introductionmentioning

confidence: 99%

The impact of solar wind ULFB_zfluctuations on geomagnetic activity for viscous timescales during strongly northward and southward IMF

et al. 2015

View full text Add to dashboard Cite

We analyze more than 17 years of OMNI data to statistically quantify the impact of IMF Bz fluctuations on AL by using higher‐order moments in the AL‐distribution as a proxy. For strongly southward interplanetary magnetic field (IMF), the AL distribution function is characterized by a decrease of the skewness, a shift of its peak from −30 nT to −200 nT, and a broadening of the distribution core. During northward IMF, the distribution of AL is characterized by a significant reduction of the standard deviation and weight in the tail. Following this characterization of AL for southward and northward IMF, we show that IMF fluctuations enhance the driving on timescales smaller than those of substorms by shifting the peak of the probability distribution function by more than 150 nT during southward IMF, and by narrowing the distribution function by a factor of 2 during northward IMF. For both southward and northward IMF, we demonstrate that high power fluctuations in Bz systematically result in a greater level of activity on timescales consistent with viscous processes. Our results provide additional quantitative evidence of the role of the solar wind fluctuations in geomagnetic activity. The methodology presented also provides a framework to characterize short timescale magnetospheric dynamics taking place on the order of viscous timescales τ ≪ 1 hour.

show abstract

Kp index correlations with solar-wind parameters during the first and second stages of a recurrent geomagnetic storm

Cited by 24 publications

References 12 publications

Geoeffectiveness of corotating interaction regions as measured by Dst index

Geoeffectiveness of corotating interaction regions as measured by Dst index

Role of solar wind turbulence in the coupling of the solar wind to the Earth's magnetosphere

The impact of solar wind ULFB_zfluctuations on geomagnetic activity for viscous timescales during strongly northward and southward IMF

Contact Info

Product

Resources

About

Kp index correlations with solar-wind parameters during the first and second stages of a recurrent geomagnetic storm

Cited by 24 publications

References 12 publications

Geoeffectiveness of corotating interaction regions as measured by Dst index

Geoeffectiveness of corotating interaction regions as measured by Dst index

Role of solar wind turbulence in the coupling of the solar wind to the Earth's magnetosphere

The impact of solar wind ULFBzfluctuations on geomagnetic activity for viscous timescales during strongly northward and southward IMF

Contact Info

Product

Resources

About

The impact of solar wind ULFB_zfluctuations on geomagnetic activity for viscous timescales during strongly northward and southward IMF