scholarly journals Solar Wind Parameters and Its Geoefficiency During Minimums of Four Solar Cycles

2021 ◽  
Vol 31 (4) ◽  
pp. 508-514
Author(s):  
Vitalii Degtyarev ◽  
Georgy Popov ◽  
Svetlana Chudnenko
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Activity ◽  
Geomagnetic Activity ◽  
Statistical Processing ◽  
Magnetic Activity ◽  
Solar Cycles ◽  
Deep Minimum ◽  
Significant Difference ◽  
Solar Wind Parameters

Recently a number of publications have appeared on the long and deep minimum in cycle 23 of solar activity. This interest is due to the fact that it turned out to be the longest and deepest in terms of the number of sunspots in the entire era of space exploration. The features of the minimum of cycle 23 of solar activity and the beginning of cycle 24 made it possible to assume that in the coming decades, a minimum of solar activity similar to the Dalton or Maunder minimum, leading to a global change in the earth's climate, may occur. Such assumptions make a detailed study of the influence of the minimum of solar cycle 23 on the parameters of the solar wind and the interplanetary magnetic field, as well as a comparison of this influence with similar manifestations in the three previous cycles very urgent. The work carried out statistical processing and analysis of data available in print and on the Internet on the indices of solar activity (W and F10.7), on geomagnetic activity, as well as on the parameters of the solar wind and interplanetary field. In contrast to other similar studies, when choosing time intervals for all cycles, only one — 12 months was used, which made it possible to exclude annual and semi-annual variations in solar wind parameters. For the considered minima of solar activity, the geoeffectiveness of the disturbed fluxes ICME, CIR, and Sheath was considered. A monotonic and very significant decrease in the geoeffectiveness of the ICME streams was found. Data processing on the hourly average values of the solar wind parameters at the minima of geomagnetic activity for 4 cycles confirmed the significant difference between cycle 23 and the previous ones in the behavior of the magnetic field. The cycle-by-cycle decrease in the geoeffectiveness of coronal ejections discussed in the press deserves a more detailed analysis using extensive data on magnetic activity indices.

scholarly journals Reconstruction of geomagnetic activity and near-Earth interplanetary conditions over the past 167 yr – Part 2: A new reconstruction of the interplanetary magnetic field

2013 ◽  
Vol 31 (11) ◽  
pp. 1979-1992 ◽  
Author(s):  
M. Lockwood ◽  
L. Barnard ◽  
H. Nevanlinna ◽  
M. J. Owens ◽  
R. G. Harrison ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Activity ◽  
Flow Speed ◽  
Range Data ◽  
Solar Wind Flow ◽  
Annual Means ◽  
Solar Wind Parameters ◽  
The Imf

Abstract. We present a new reconstruction of the interplanetary magnetic field (IMF, B) for 1846–2012 with a full analysis of errors, based on the homogeneously constructed IDV(1d) composite of geomagnetic activity presented in Part 1 (Lockwood et al., 2013a). Analysis of the dependence of the commonly used geomagnetic indices on solar wind parameters is presented which helps explain why annual means of interdiurnal range data, such as the new composite, depend only on the IMF with only a very weak influence of the solar wind flow speed. The best results are obtained using a polynomial (rather than a linear) fit of the form B = χ · (IDV(1d) − β)α with best-fit coefficients χ = 3.469, β = 1.393 nT, and α = 0.420. The results are contrasted with the reconstruction of the IMF since 1835 by Svalgaard and Cliver (2010).

scholarly journals Seasonal features of geomagnetic activity: a study on the solar activity dependence

2021 ◽  
Vol 39 (5) ◽  
pp. 929-943
Author(s):  
Adriane Marques de Souza Franco ◽  
Rajkumar Hajra ◽  
Ezequiel Echer ◽  
Mauricio José Alves Bolzan
Keyword(s):  
Solar Wind ◽  
Solar Activity ◽  
Geomagnetic Activity ◽  
Annual Variation ◽  
Geomagnetic Storms ◽  
Solar Wind Speed ◽  
Solar Cycles ◽  
Annual Variations ◽  
Long Duration ◽  
Activity Dependence

Abstract. Seasonal features of geomagnetic activity and their solar-wind–interplanetary drivers are studied using more than five solar cycles of geomagnetic activity and solar wind observations. This study involves a total of 1296 geomagnetic storms of varying intensity identified using the Dst index from January 1963 to December 2019, a total of 75 863 substorms identified from the SuperMAG AL/SML index from January 1976 to December 2019 and a total of 145 high-intensity long-duration continuous auroral electrojet (AE) activity (HILDCAA) events identified using the AE index from January 1975 to December 2017. The occurrence rates of the substorms and geomagnetic storms, including moderate (-50nT≥Dst>-100nT) and intense (-100nT≥Dst>-250nT) storms, exhibit a significant semi-annual variation (periodicity ∼6 months), while the super storms (Dst≤-250 nT) and HILDCAAs do not exhibit any clear seasonal feature. The geomagnetic activity indices Dst and ap exhibit a semi-annual variation, while AE exhibits an annual variation (periodicity ∼1 year). The annual and semi-annual variations are attributed to the annual variation of the solar wind speed Vsw and the semi-annual variation of the coupling function VBs (where V = Vsw, and Bs is the southward component of the interplanetary magnetic field), respectively. We present a detailed analysis of the annual and semi-annual variations and their dependencies on the solar activity cycles separated as the odd, even, weak and strong solar cycles.

scholarly journals Seasonal features of geomagnetic activity: evidence for solar activity dependence?

2021 ◽  
Author(s):  
Adriane Marques de Souza Franco ◽  
Rajkumar Hajra ◽  
Ezequiel Echer ◽  
Mauricio José Alves Bolzan
Keyword(s):  
Solar Wind ◽  
Solar Activity ◽  
Geomagnetic Activity ◽  
Annual Variation ◽  
Geomagnetic Storms ◽  
Solar Wind Speed ◽  
Solar Cycles ◽  
Annual Variations ◽  
Long Duration ◽  
Activity Dependence

Abstract. Seasonal features of geomagnetic activity and their solar wind-interplanetary drivers are studied using more than 5 solar cycles of geomagnetic activity and solar wind observations. This study involves a total of 1239 geomagnetic storms of varying intensity identified using the Dst index from January 1963 to December 2019, a total of 75863 substorms identified from the SML index from January 1976 to December 2019, a total of 145 high-intensity long-duration continuous auroral electrojet (AE) activity (HILDCAA) events identified using the AE index from January 1975 to December 2017. The occurrence rates of the substorms, geomagnetic storms, including moderate (−50 nT ≥ Dst > −100 nT) and intense (−100 nT ≥ Dst > −250 nT), exhibit a significant semi-annual variation (periodicity ~ 6 months), while the super storms (Dst ≤ −250 nT) and HILDCAAs do not exhibit any clear seasonal feature. The geomagnetic activity indices Dst and ap exhibit a semi-annual variation while AE exhibits an annual variation (periodicity ~ 1 year). The annual and semi-annual variations are found to be driven by the annual variation of the solar wind speed Vsw and the semi-annual variation of the coupling function V Bs (where V = Vsw, and Bs is the southward component of the interplanetary magnetic field), respectively. We present a detailed analysis of the annual and semi-annual variations and their dependencies on the solar activity cycles separated as the odd, even, weak and strong solar cycles.

scholarly journals Long‐Term Variations in Solar Wind Parameters, Magnetopause Location, and Geomagnetic Activity Over the Last Five Solar Cycles

2019 ◽  
Vol 124 (6) ◽  
pp. 4049-4063 ◽  
Author(s):  
A. A. Samsonov ◽  
Y. V. Bogdanova ◽  
G. Branduardi‐Raymont ◽  
J. Safrankova ◽  
Z. Nemecek ◽  
...  
Keyword(s):  
Solar Wind ◽  
Geomagnetic Activity ◽  
Solar Cycles ◽  
Solar Wind Parameters ◽  
Long Term Variations

scholarly journals A 22-year cycle in the F layer ionization of the ionosphere

1997 ◽  
Vol 15 (8) ◽  
pp. 1015-1027 ◽  
Author(s):  
E. Feichter ◽  
R. Leitinger
Keyword(s):  
Solar Activity ◽  
Geomagnetic Activity ◽  
Annual Variation ◽  
Sunspot Cycle ◽  
Statistical Processing ◽  
High Solar Activity ◽  
Electron Content ◽  
Solar Cycles ◽  
Total Electron ◽  
Cycle Variation

Abstract. The double-sunspot-cycle variation in terrestrial magnetic activity has been well known for about 30 years. In 1990 we examined and compared the low-solar-activity (LSA) part of two consecutive cycles and predicted from this database and from published results the existence of a double-sunspot-cycle variation in total electron content (TEC) of the ionosphere too. This is restricted to noontime when the semi-annual component is well developed. Since 1995 we have had enough data for the statistical processing for high-solar-activity (HSA) conditions of two successive solar cycles. The results confirm the LSA findings. The annual variation of TEC shows a change from an autumn maximum in cycle 21 to a spring maximum during the next solar cycle. Similar to the aa indices for geomagnetic activity the TEC data show a phase change in the 1-year component of the Fourier transform of the annual variation. Additionally we found the same behaviour in the F-layer peak electron density (Nmax) over four solar cycles. This indicates that there exists a double-sunspot-cycle variation in the F-layer ionization over Europe too. It is very likely coupled with the 22-year cycle in geomagnetic activity.

scholarly journals Long-term correlations in solar proxies and solar wind parameters

2021 ◽  
Author(s):  
Luca Giovannelli ◽  
Raffaele Reda ◽  
Tommaso Alberti ◽  
Francesco Berrilli ◽  
Matteo Cantoresi ◽  
...  
Keyword(s):  
Solar Wind ◽  
Time Lag ◽  
Magnetic Activity ◽  
Time Shift ◽  
Time Interval ◽  
Solar Cycles ◽  
K Index ◽  
The Earth ◽  
Solar Wind Parameters

<p>The long-term behaviour of the Solar wind and its impact on the Earth are of paramount importance to understand the framework of the strong transient perturbations (CMEs, SIRs). Solar variability related to its magnetic activity can be quantified by using synthetic indices (e.g. sunspots number) or physical ones (e.g. chromospheric proxies). In order to connect the long-term solar activity variations to solar wind properties, we use Ca II K index and solar wind OMNI data in the time interval between 1965 and 2019, which almost entirely cover the last 5 solar cycles. A time lag in the correlation between the parameters is found. This time shift seems to show a temporal evolution over the different solar cycles.</p><div> </div>

Correlation Of Geomagnetic Activity With The Solar Wind

1996 ◽  
Author(s):  
Charles F. Kennel
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Geomagnetic Activity ◽  
Global Scale ◽  
Auroral Zone ◽  
Time Dependent ◽  
Solar Cycles ◽  
Wind Variability ◽  
Ae Index ◽  
The Difference

Even if a steady convection state could exist in principle, the magnetosphere will be rarely in it, since the interplanetary magnetic field is hardly ever stationary over the 2-4 hour convection cycle (Rostoker et al., 1988). Indeed, the hourly average north-south component of the interplanetary field retained the same sign for two consecutive hours only 12.2% of the time during solar cycles 20 and 21 (Hapgood et al., 1991). If only for this reason, we cannot avoid dealing with time-dependent convection. In this section, we take up one method of coping with the issue. Correlation studies take advantage of solar wind variability without ever needing to consider the precise nature of the time-dependent response of the magnetosphere. Though laborious, they are a procedurally straightforward way to test the viscous and reconnection models of convection. Geomagnetic activity, the response of geomagnetic field to currents flowing in the ionosphere and in space, has been monitored in an increasingly systematic way since the beginning of the eighteenth century. Today, a worldwide network of ground stations provides continuous records of the magnetic field at many different locations on the earth’s surface. Before computational data displays enabled large quantities of data to be summarized at a glance, the complex multi-station records were combined into single parameters called geomagnetic indices, which were designed to characterize one aspect or another of geomagnetic activity on a global scale. We will refer frequently to the auroral electrojet (AE) index, which was designed by Davis and Sugiura (1966) as a measure of electrojet activity in the auroral zone. The index is derived from the horizontal, northern component of the geomagnetic perturbation field measured at a number of observatories in the northern hemisphere. The number of observing stations contributing to the index is occasionally indicated in parentheses as AE(12) or AE(32), and so on. The maximum and minimum perturbations recorded at any given time at the stations in the AE network are called the AU and AL indices, respectively, for “upper” and “lower.” These provide a measure of the westward and eastward electrojet strengths. The difference between AU and AL is the AE index.

scholarly journals Prediction of solar activity cycles by assimilating sunspot data into a dynamo model

2009 ◽  
Vol 5 (S264) ◽  
pp. 202-209 ◽  
Author(s):  
Irina N. Kitiashvili ◽  
Alexander G. Kosovichev
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Solar Cycle ◽  
Sunspot Number ◽  
Magnetic Activity ◽  
Magnetic Helicity ◽  
Dynamo Model ◽  
Solar Cycles ◽  
Sunspot Data ◽  
Cycle 24

AbstractSolar activity is a determining factor for space climate of the Solar system. Thus, predicting the magnetic activity of the Sun is very important. However, our incomplete knowledge about the dynamo processes of generation and transport of magnetic fields inside Sun does not allow us to make an accurate forecast. For predicting the solar cycle properties use the Ensemble Kalman Filter (EnKF) to assimilate the sunspot data into a simple dynamo model. This method takes into account uncertainties of both the dynamo model and the observed sunspot number series. The method has been tested by calculating predictions of the past cycles using the observed annual sunspot numbers only until the start of these cycles, and showed a reasonable agreement between the predicted and actual data. After this, we have calculated a prediction for the upcoming solar cycle 24, and found that it will be approximately 30% weaker than the previous one, confirming some previous expectations. In addition, we have investigated the properties of the dynamo model during the solar minima, and their relationship to the strength of the following solar cycles. The results show that prior the weak cycles, 20 and 23, and the upcoming cycle, 24, the vector-potential of the poloidal component of magnetic field and the magnetic helicity substantial decrease. The decrease of the poloidal field corresponds to the well-known correlation between the polar magnetic field strength at the minimum and the sunspot number at the maximum. However, the correlation between the magnetic helicity and the future cycle strength is new, and should be further investigated.

scholarly journals On the scaling of waiting-time distributions of the negative IMF <i>B<sub>z</sub></i> component

2006 ◽  
Vol 24 (10) ◽  
pp. 2735-2741 ◽  
Author(s):  
R. D'Amicis ◽  
R. Bruno ◽  
B. Bavassano ◽  
V. Carbone ◽  
L. Sorriso-Valvo
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Activity ◽  
Solar Cycle ◽  
Interplanetary Magnetic Field ◽  
Power Law ◽  
Waiting Time ◽  
The Sun ◽  
Activity Phase ◽  
Solar Wind Parameters

Abstract. Statistics associated with the fluctuations in solar wind parameters show a remarkable dependence on the solar activity phase. In particular, we focus our attention on the waiting-time statistics governing the MHD fluctuations of the z-component of the interplanetary magnetic field, which are important within the framework of the Sun-Earth connections, and briefly discuss the preliminary results. Data from several spacecrafts, covering different phases of the solar cycle and different radial distances, are used. We found that propagating Alfvénic fluctuations and convected structures strongly influence the statistics which vary from quasi-Poissonian to power law.

Sign in / Sign up

Export Citation Format

Share Document