Nonlinear Processes in Geophysics
www.nonlin-processes-geophys.net
1023-5809
1607-7946
15
4
2008
10.5194/npg-15-523-2008
http://www.nonlin-processes-geophys.net/15/523/2008/
http://www.nonlin-processes-geophys.net/15/523/2008/npg-15-523-2008.html
http://www.nonlin-processes-geophys.net/15/523/2008/npg-15-523-2008.pdf
523
529
2008-07-02
The effect of upstream turbulence and its anisotropy on the efficiency of solar wind – magnetosphere coupling
D. Jankovičová
dja@ufa.cas.cz
Z. Vörös
J. Šimkanin
Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
Institute of Astro- and Particle Physics, University of Innsbruck, Innsbruck, Austria
Geophysical Institute, Academy of Sciences of the Czech Republic, Prague, Czech Republic
The importance of space weather and its forecasting is growing as
interest in studying geoeffective processes in the Sun – solar wind
– magnetosphere – ionosphere coupled system is increasing. This
paper introduces the proper selection criteria for solar wind
magnetic turbulence events during duskward electric field and
southward <i>B<sub>z</sub></i> driven geomagnetic storms. Two measures for the
strength of solar wind fluctuations were investigated: the standard
deviations of magnetic field components and a proxy for the
so-called Shebalin anisotropy angles. These measures were compared
to the strength of geomagnetic storms obtained from a SYM-H index
time series. We found a weak correlation between standard deviation
of interplanetary magnetic field GSM component <i>B<sub>z</sub></i> and SYM-H
index, and a strong correlation between Shebalin anisotropy angle
and the SYM-H index, which can be the result of an increase of
probability of magnetic reconnection in fluctuating magnetic fields.
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