scholarly journals Magnetic field modelling from scalar-only data: Resolving the Backus effect with the equatorial electrojet

2005 ◽  
Vol 57 (12) ◽  
pp. 1203-1209 ◽  
Author(s):  
R. Holme ◽  
M. A. James ◽  
H. Lühr
Keyword(s):  
Magnetic Field ◽  
Equatorial Electrojet ◽  
Field Modelling ◽  
Backus Effect

Monte Carlo Modelling of Phase Transitions in Quasi-One-Dimensional Multiferoic

2016 ◽  
Vol 845 ◽  
pp. 158-161
Author(s):  
S.J. Lamekhov ◽  
Dmitry A. Kuzmin ◽  
Igor V. Bychkov ◽  
I.A. Maltsev ◽  
V.G. Shavrov
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Monte Carlo ◽  
Phase Transitions ◽  
Monte Carlo Method ◽  
External Magnetic Field ◽  
Periodic Potential ◽  
One Dimensional ◽  
Field Modelling ◽  
Energy Components

Behavior of quasi-one-dimensional multiferoic Ca3CoMnO6 in external magnetic field was investigated. Modelling by Monte Carlo method was performed to show influence of external magnetic field on appearance of polarization and temperature of phase transition in electric subsystem. Magnetization, polarization and energy components for magnetic and electric subsystems dependencies were achieved for different values of external magnetic field. Modelling showed that periodic potential in form of Frenkel-Kontorova makes influence on maximal values and temperature of phase transitions for magnetization and polarization.

Magnetic Field Modelling of an Ironless Wind Power Microgenerator

2018 ◽  
Author(s):  
V. Verdum ◽  
R. P. Homrich ◽  
A. F. Flores Filho ◽  
M. A. Silveira ◽  
D. G. Dorrell
Keyword(s):  
Magnetic Field ◽  
Wind Power ◽  
Field Modelling

scholarly journals Search for magnetically quiet CHAMP polar passes and the characteristics of ionospheric currents during the dark season

2006 ◽  
Vol 24 (11) ◽  
pp. 2997-3009 ◽  
Author(s):  
P. Ritter ◽  
H. Lühr
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Transverse Field ◽  
Transverse Component ◽  
Local Times ◽  
Time Interval ◽  
Polar Regions ◽  
Ionospheric Currents ◽  
Ionospheric Conductivity ◽  
Field Modelling

Abstract. The magnetic activity at auroral latitudes is strongly dependent on season. During the dark season, when the solar zenith angle in the polar region is larger than 100° at all local times, the ionospheric conductivity is much reduced, and generally low activity is encountered. These time intervals are of special interest for the main field modelling, because then the geomagnetic field readings, in particular the field magnitude, are only slightly affected by ionospheric currents. Based on CHAMP data, this study examines how these quiet periods are reflected in the different magnetic field components. The peak FAC density is used as a possible proxy for the deviation of the total field. As a second option, the transverse field component, which is aligned with the auroral oval, is investigated, because it presents a measure for the FAC total current. Correlation analyses with the scalar residuals are performed and both proxies are tested for their suitability of predicting the intensity of the auroral electrojet during the dark polar seasons. The indicators based on the local FAC strength or on the amplitude of the transverse component show a reasonable correlation with the electrojet intensity for these periods, but fail when limited to small amplitudes. The predictability improves considerably if the time sector is limited to dayside hours (08:00–16:00 MLT). As the activity at high latitudes is strongly controlled by the solar wind input, we also consider IMF quantities which may support very quiet conditions. Correlations of the magnetic field scalar residuals with the merging electric field are strongest if only passes in the dayside sector are considered. Best selection results for quiet passes are obtained by combining four conditions: dark season, small average merging electric field, Em<0.8 mV/m, absence of peak values of Em>1.2 mV/m during a time interval of 40 min centred at the polar crossing, and limitation to the dayside sector (08:00–16:00 MLT). The set of quiet polar passes identified by these criteria may be used beneficially in crustal field modelling of the polar regions.

scholarly journals Use of along-track magnetic field differences in lithospheric field modelling

2014 ◽  
Vol 200 (2) ◽  
pp. 880-889 ◽  
Author(s):  
S. Kotsiaros ◽  
C. C. Finlay ◽  
N. Olsen
Keyword(s):  
Magnetic Field ◽  
Field Modelling ◽  
Along Track
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