Publikationsdatum:
2017-04-04
Beschreibung:
The geomagnetic field is chaotic and can be characterized by a mean exponential time scale〈t〉after which it is no longer predictable. It is also ergodic, so time analyses can substitute the more difficult phase space analyses. Taking advantage of these two properties of the Earth’s magnetic field, a scheme of processing global geomagnetic models in time is presented, to estimate fluctuations of the time scale t. Here considering that the capability to predict the geomagnetic field is reduced over periods of geomagnetic jerks, we propose a method to detect these events over a long time span. This approach considers that epochs characterized by relative
minima of fluctuations in time scale t, i.e., those periods when a geomagnetic field is less predictable, are possible jerk occurrence dates. We analyze the last 400 years of the geomagnetic field (covered by the Gufm1 model) to detect minima of fluctuations, i.e., epochs characterized by low values of the time scale.Most of the
well known jerks are confirmed through this method and a few others have been suggested. Finally, we also identify some short periods when the field is less chaotic (more predictable) than usual, naming these periods
as steady state geomagnetic regime, to underline their opposite behavior with respect to jerks.
Beschreibung:
Published
Beschreibung:
839–850
Beschreibung:
3.4. Geomagnetismo
Beschreibung:
JCR Journal
Beschreibung:
restricted
Schlagwort(e):
geomagnetic field
;
geomagnetic jerks
;
ergodicity
;
chaos
;
04. Solid Earth::04.05. Geomagnetism::04.05.02. Geomagnetic field variations and reversals
Repository-Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Materialart:
article
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