Publication Date:
2017-04-04
Description:
One of the most interesting aspects of the global magnetospheric response to solar
wind changes is the relationship between storms and substorms. Here we present new
results on the relationship between these two different classes of magnetospheric
phenomena by approaching the problem on the side of information theory. Using the
Auroral Electrojet AL and SYM‐H indices as representative proxies of magnetic substorms
and storms, we investigate the transfer of information by means of transfer entropy
analysis (Schreiber, 2000). The obtained results seem, on average, to indicate the presence
of a net transfer of information from AL to SYM‐H on time scales shorter than 10 h. On the
basis of this result, geomagnetic substorms may act as a driver for the occurrence of
geomagnetic storms. However, carrying out a more careful analysis which takes into
account the global geomagnetic daily activity, we suggest that the direction of information
flow between substorms and storms depends on the global activity level. Indeed, if it is
true that a sequence of magnetospheric substorms may drive a moderate storm, it is also
true that very large storms may dominate and drive the occurrence of magnetospheric
substorms.
Description:
Published
Description:
A08225
Description:
3.9. Fisica della magnetosfera, ionosfera e meteorologia spaziale
Description:
JCR Journal
Description:
restricted
Keywords:
Storm-substorm relationship
;
Information theory
;
01. Atmosphere::01.03. Magnetosphere::01.03.02. Magnetic storms
;
01. Atmosphere::01.03. Magnetosphere::01.03.03. Magnetospheric physics
;
05. General::05.01. Computational geophysics::05.01.04. Statistical analysis
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
