 |
| Titel |
Complexity signatures in the geomagnetic H component recorded by the Tromsø magnetometer (70° N, 19° E) over the last ¼ century |
| VerfasserIn |
C. M. Hall |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
2198-5634
|
| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics Discussions ; 1, no. 1 ; Nr. 1, no. 1 (2014-05-13), S.895-915 |
| Datensatznummer |
250115096
|
| Publikation (Nr.) |
 copernicus.org/npgd-1-895-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Solar disturbances, depending on the orientation of the interplanetary
magnetic field, typically result in perturbations of the geomagnetic field as
observed by magnetometers on the ground. Here, the geomagnetic field's
horizontal component, as measured by the ground-based observatory-standard
magnetometer at Tromsø (70° N, 19° E) is examined for
signatures of complexity. 25 year-long 10 s resolution datasets are
analysed, but for fluctuations with timescales less than 1 day.
Quantile-quantile (Q-Q) plots are employed first, revealing the fluctuations
are better represented by Cauchy rather than Gaussian distributions.
Thereafter, both spectral density and detrended fluctuation analysis methods
are used to estimate values of the generalized Hurst exponent, α. The
results are then compared with independent findings. Inspection and
comparison of the spectral and detrended fluctuation analyses reveals that
timescales between 1 h and 1 d are characterized by
fractional Brownian motion with a generalized Hurst exponent of ~1.4
whereas including timescales as short as 1 min suggests fractional
Brownian motion with a generalized Hurst exponent of ~1.6. This is
consistent with changes in the position of the auroral electrojet that can be
considered rapid during the course of an evening, whereas from
minute-to-minute the electrojet moves more persistently in geomagnetic
latitude. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|