scholarly journals High speed solar wind streams over the last four solar cycles

2018 ◽  
Author(s):  
Yana Asenovska ◽  
Simeon Asenovski
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Solar Cycles ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

scholarly journals Rapid solar wind and geomagnetic variability during the ascendant phases of the 11-yr solar cycles

2009 ◽  
Vol 5 (S264) ◽  
pp. 359-362 ◽  
Author(s):  
G. Maris ◽  
O. Maris
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Solar Wind Velocity ◽  
Interplanetary Space ◽  
Solar Cycles ◽  
Geomagnetic Disturbances ◽  
Geomagnetic Indices ◽  
Terrestrial Magnetosphere ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

AbstractSolar activity and its consequences for the interplanetary space are governing and perturbing the Earth's magnetosphere. The response of the terrestrial magnetosphere displayed as geomagnetic disturbances is measured by several geomagnetic indices. This paper analyses the geomagnetic variability during the ascendant phases of the last four solar cycles (nos. 20-23) under the influence of the high speed solar wind. The ascendant phase of a solar cycle is a proper interval of the irrespective cycle during which the influences of the solar cycles adjacent to it (the precedent and the following ones) are not present. The correlation between the geomagnetic indices and the high speed stream intensity during the analysed intervals was examined. Lomb-Scargle method of spectral analysis was applied on the solar wind velocity series during the ascendant phases.

scholarly journals Solar cycle by a look of high speed solar wind streams variation

2018 ◽  
Vol 30 ◽  
pp. 26-32
Author(s):  
Simeon Asenovski
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
High Speed ◽  
Solar Cycles ◽  
Speed Solar Wind ◽  
Solar Wind Parameters ◽  
High Speed Solar Wind

In this paper are presented variation of the solar wind parameters during last four solar cycles (21-24) with focus on the high speed solar wind streams (HSS) condition. The averaged values of the parameters for every cycle are calculated and discussed. The results show that Earth is under the HSS influence more than 50% of the total time in each of the last four solar cycles. This fact determines the importance of the studding the behavior of the HSS.

scholarly journals The influence of solar wind on extratropical cyclones – Part 1: Wilcox effect revisited

2009 ◽  
Vol 27 (1) ◽  
pp. 1-30 ◽  
Author(s):  
P. Prikryl ◽  
V. Rušin ◽  
M. Rybanský
Keyword(s):  
Time Series ◽  
Solar Wind ◽  
Northern Hemisphere ◽  
High Speed ◽  
Coronal Holes ◽  
Extratropical Cyclones ◽  
Sector Boundary ◽  
Speed Solar Wind ◽  
The Mean ◽  
High Speed Solar Wind

Abstract. A sun-weather correlation, namely the link between solar magnetic sector boundary passage (SBP) by the Earth and upper-level tropospheric vorticity area index (VAI), that was found by Wilcox et al. (1974) and shown to be statistically significant by Hines and Halevy (1977) is revisited. A minimum in the VAI one day after SBP followed by an increase a few days later was observed. Using the ECMWF ERA-40 re-analysis dataset for the original period from 1963 to 1973 and extending it to 2002, we have verified what has become known as the "Wilcox effect" for the Northern as well as the Southern Hemisphere winters. The effect persists through years of high and low volcanic aerosol loading except for the Northern Hemisphere at 500 mb, when the VAI minimum is weak during the low aerosol years after 1973, particularly for sector boundaries associated with south-to-north reversals of the interplanetary magnetic field (IMF) BZ component. The "disappearance" of the Wilcox effect was found previously by Tinsley et al. (1994) who suggested that enhanced stratospheric volcanic aerosols and changes in air-earth current density are necessary conditions for the effect. The present results indicate that the Wilcox effect does not require high aerosol loading to be detected. The results are corroborated by a correlation with coronal holes where the fast solar wind originates. Ground-based measurements of the green coronal emission line (Fe XIV, 530.3 nm) are used in the superposed epoch analysis keyed by the times of sector boundary passage to show a one-to-one correspondence between the mean VAI variations and coronal holes. The VAI is modulated by high-speed solar wind streams with a delay of 1–2 days. The Fourier spectra of VAI time series show peaks at periods similar to those found in the solar corona and solar wind time series. In the modulation of VAI by solar wind the IMF BZ seems to control the phase of the Wilcox effect and the depth of the VAI minimum. The mean VAI response to SBP associated with the north-to-south reversal of BZ is leading by up to 2 days the mean VAI response to SBP associated with the south-to-north reversal of BZ. For the latter, less geoeffective events, the VAI minimum deepens (with the above exception of the Northern Hemisphere low-aerosol 500-mb VAI) and the VAI maximum is delayed. The phase shift between the mean VAI responses obtained for these two subsets of SBP events may explain the reduced amplitude of the overall Wilcox effect. In a companion paper, Prikryl et al. (2009) propose a new mechanism to explain the Wilcox effect, namely that solar-wind-generated auroral atmospheric gravity waves (AGWs) influence the growth of extratropical cyclones. It is also observed that severe extratropical storms, explosive cyclogenesis and significant sea level pressure deepenings of extratropical storms tend to occur within a few days of the arrival of high-speed solar wind. These observations are discussed in the context of the proposed AGW mechanism as well as the previously suggested atmospheric electrical current (AEC) model (Tinsley et al., 1994), which requires the presence of stratospheric aerosols for a significant (Wilcox) effect.

scholarly journals Influence of heavy ions on the high-speed solar wind

1997 ◽  
Vol 102 (A8) ◽  
pp. 17419-17432 ◽  
Author(s):  
Xing Li ◽  
Ruth Esser ◽  
Shadia R. Habbal ◽  
You-Qiu Hu
Keyword(s):  
Solar Wind ◽  
Heavy Ions ◽  
High Speed ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

scholarly journals High‐Speed Solar Wind Streams in 2007–2008: Turning on the Russell‐McPherron Effect

2019 ◽  
Vol 124 (11) ◽  
pp. 8913-8927 ◽  
Author(s):  
C. Munteanu ◽  
A. Hamada ◽  
K. Mursula
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

North-south cosmic ray asymmetry and high speed solar wind

1997 ◽  
Vol 19 (6) ◽  
pp. 929-932 ◽  
Author(s):  
A.K. Svirzhevskaya ◽  
G.A. Bazilevskaya ◽  
N.S. Svirzhevsky ◽  
M.B. Krainev
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Cosmic Ray ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

scholarly journals Cosmic Ray and Geomagnetic Response to High Speed Solar Wind Streams

2014 ◽  
Vol 6 (3) ◽  
pp. 42-49
Author(s):  
N.K Sharma ◽  
◽  
Tufail Ahmad
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Cosmic Ray ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

scholarly journals Interplanetary Response to Solar Long Time-Scale Phenomena

1980 ◽  
Vol 91 ◽  
pp. 105-125
Author(s):  
C. D'Uston ◽  
J. M. Bosqued
Keyword(s):  
Solar Wind ◽  
Time Scale ◽  
High Speed ◽  
Coronal Holes ◽  
Observational Evidence ◽  
Solar Wind Flow ◽  
Speed Solar Wind ◽  
Long Time ◽  
Outer Corona ◽  
High Speed Solar Wind

In this paper, we briefly review the experimental knowledge gained in the recent years on the interplanetary response to solar long-time scale phenomena such as the coronal magnetic structure and its evolution. Observational evidence that solar wind flow in the outer corona comes from the unipolar diverging magnetic regions of the photosphere is discussed along with relations to coronal holes. High-speed solar wind streams observed within the boundary of interplanetary magnetic sectors are associated with these structures. Their boundaries appear as very narrow velocity shears.

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