Secular variation and geomagnetic normal field modelling in Brazil

1988 ◽  
Vol 41 (3-6) ◽  
pp. 199-209
Author(s):  
Luiz Muniz Barreto
Keyword(s):  
Secular Variation ◽  
Normal Field ◽  
Field Modelling

scholarly journals Crustal geomagnetic field and secular variation by regional and global models for Austria

2018 ◽  
Vol 111 (1) ◽  
pp. 48-63
Author(s):  
Klaudio Peqini ◽  
Bejo Duka ◽  
Ramon Egli ◽  
Barbara Leichter
Keyword(s):  
Secular Variation ◽  
Geomagnetic Field ◽  
Rate Of Change ◽  
Aeromagnetic Data ◽  
Model Bias ◽  
Global Models ◽  
Normal Field ◽  
Core Field ◽  
Crustal Field ◽  
Predicted Values

Abstract Using 12-year-long series of data (2001-2012) from geomagnetic observatories and repeat stations in Austria and its neighboring countries, a regional spatial-temporal (ST) model is developed based on the polynomial expansion consisting of latitude, longitude, and time of the geomagnetic field components and total magnetic field F. Additionally, we have used three different global models (CHAOS-5, POMME-9, and EMM2015), which are built on spherical harmonics up to a maximum degree Lmax and give the core field and crustal field separately. The normal field provided by the ST model and its “model bias”, which comprise the residuals of the differences between measured and predicted values, are calculated and the respective maps are shown. The residuals are considered an estimate of the local crustal field. In the case of global models, we have applied for each of these three methods to calculate the “model bias”: residuals of the differences between observed values and predicted values of the model, residuals of the differences between observed values and core field values of the model, and the average bias for the period 2001-2012. The normal field of the region of Austria provided by each global model is also calculated. Generally, the regional and global models yield relatively similar crustal fields for the Austrian region, especially when the first method is used. The normal fields calculated by them are in good agreement with each other. Each of the global models directly provides the crustal field, and they are compared with the aeromagnetic data provided by aeromagnetic surveys over the Austrian region. The ST model is in better agreement with aeromagnetic data. We have also analyzed the secular variation over the region, which is calculated from the rate of change of normal field given by the ST and global models.

scholarly journals The 1990.0 magnetic repeat station survey and normal reference fields for Italy

1994 ◽  
Vol 37 (5) ◽  
Author(s):  
A. Meloni ◽  
O. Battelli ◽  
A. De Santis ◽  
G. Dominici
Keyword(s):  
Secular Variation ◽  
Data Reduction ◽  
Measuring Equipment ◽  
Field Data ◽  
Data Mapping ◽  
Reduction Procedure ◽  
Normal Field ◽  
Repeat Station ◽  
Magnetic Network ◽  
Reference Fields

A survey of 116 repeat stations of the Italian Magnetic Network was carried out between 1989 and 1992. We describe the characteristics of the selected network repeat station sites, the characteristics of the measuring equipment, the data reduction procedure and the analysis in terms of normal field, data mapping and secular variation. Together with the values from our previous campaigns, we also determined, for all elements, the normal fields of secular variation. The new repeat station data are listed. Results, maps and normal fields are discussed with respect to previous work and future survey plans.

On refinement of the normal field

2018 ◽  
Vol 62 (2) ◽  
pp. 127-131
Author(s):  
L.S. Sugaipova ◽  
Keyword(s):  
Normal Field

Investigation and Mean-Field Modelling of Microstructural Mechanisms Driving the Tensile Properties of Dual-Phase Steels

2020 ◽  
Author(s):  
Alexandre Mathevon ◽  
Damien Fabrègue ◽  
Véronique Massardier ◽  
Sophie Cazottes ◽  
Philippe Rocabois ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Mean Field ◽  
Dual Phase ◽  
Dual Phase Steels ◽  
Field Modelling

THETYS SUBDUCTION AND CONTINENTAL COLLISION FROM POTENTIAL FIELD MODELLING

2018 ◽  
Author(s):  
Hans Thybo ◽  
◽  
Vahid Teknik ◽  
Vahid Teknik ◽  
Abdolreza Ghods ◽  
...  
Keyword(s):  
Potential Field ◽  
Continental Collision ◽  
Field Modelling ◽  
Potential Field Modelling

Ion flow field modelling based on lattice Boltzmann method and its mesh refinement

2020 ◽  
Vol 14 (20) ◽  
pp. 4539-4546
Author(s):  
Ting Zhu ◽  
Song Wang ◽  
Naming Zhang ◽  
Shuhong Wang ◽  
Shuya Ning
Keyword(s):  
Flow Field ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Mesh Refinement ◽  
Ion Flow ◽  
Field Modelling ◽  
Boltzmann Method
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