Abstract The geomagnetic field is chaotic and can be characterized by a mean exponential time scale < τ > after which it no longer predictable. It also ergodic, so analyses substitute the more difficult phase space analyses. Taking advantage of these two properties Earth's magnetic field, scheme processing global models in presented, to estimate fluctuations τ. Here considering that capability predict reduced over periods jerks, we propose method detect events long span. This approach...

Here we present a revised geomagnetic reference model for the region comprising Albanian territory, southeast part of Italian Peninsula and Ionian Sea from 1990 to 2010 with prediction 2012. This study is based on datasets magnetic measurements taken during different campaigns in Albania Italy time concern, together total intensity data set ∅rsted CHAMP satellite missions. The designed represent Cartesian components, X, Y, Z F main field (and its secular variation SV) period interest. To...

Abstract. In this study we have applied spectral techniques to analyze geomagnetic field time-series provided by observatories, and compared the results with those obtained from analogous analyses of synthetic data estimated models. Then, an algorithm is here proposed detect jerks in time-series, mainly occurring eastern component field. Applying such analysis generated global models has allowed us depict most important space-time features all over globe, since beginning XXth century....

Taking advantage of the measurements undertaken during Albanian and Italian magnetic repeat station networks since 1990, as well a selected set Ørsted satellite total field measurements, reference model for region comprising territory, southern part Peninsula, Ionian Sea is presented. The model, designed to components main geomagnetic epochs between 1990 2005, has been developed by means spherical cap harmonic analysis applied semiangle 8°, larger than that investigated take into account...

Until recently there has been nothing in the geomagnetic literature giving Gauss coefficients (equivalent to magnetic multipole moments) for scalar potential produced outside a finite-sized region of electric current. Nor an expression corresponding vector potential. This paper presents simple terms volume integral over current, and also series expansion these coefficients. We show how our result is related classical expressions given by spherical current sheet, results recent papers Engels...

For a vector field defined by scalar potential outside surface enclosing all the sources, it is well known that uniquely if either itself, or its derivative normal to surface, everywhere on surface. spherical radial component of field: horizontal (vector) also gives uniqueness (except for any monopole contribution). This paper discusses way other partial information can give unique, almost knowledge external potential/field, bringing together and correcting previous work. convenience results...

study their time evolution in years. In order to find the best NN for predictions, we tested many different kinds of and ways training, when inputs targets are long annual series synthetic geomagnetic field values. The found was used predict values means components beyond registration periods a Geomagnetic Observatory. global over Earth, considered 105 Observatories, chosen have more than 30 years (1960.5-2005.5) be well distributed Earth. Using technique, created 137 «virtual observatories»...

To provide insights on the paleosecular variation of geomagnetic field and mechanism reversals, long time series dipolar magnetic moment are generated by two different stochastic models, known as “domino” model inhomogeneous Lebovitz disk dynamo model, with initial values taken from paleomagnetic data. The former considers mutual interactions N macrospins embedded in a uniformly rotating medium, where random forcing dissipation act each macrospin. With an appropriate set model’s parameters...

A new national geomagnetic network of repeat stations for total field F, horizontal component H, vertical Z and declination D has been established in a collaboration between the Albanian Geological Society (Center Geochemistry Geophysics), Tirana University (Albania) Istituto Nazionale di Geofisica (Italy). From observed magnetic elements all were referred to Epoch 1994.75 normal reference fields computed form 1st order polynomials latitude longitude. An overview work, including brief...

<p>The differences between monthly mean values of the observed geomagnetic field and predicted by different models internal (named “model biases”) for time period 2000-2015 at several observatories are analyzed. We notice that increasing maximum degree model is not always followed decrease such bias”. The series these biases” reduced their average resulted to be approximately same all should represent external (non-modeled) contribution field. These (close or away each other) compared...

Aiming to recover the fluid flow at Earth's Core–Mantle Boundary (CMB) and possible relation with geomagnetic jerks, we use global "gufm1" model which makes of expansion each element field in spherical harmonics, covering last 400 years. Under frozen–flux approximation, induction equation for radial component (Br) is employed due continuity this through CMB. The velocity CMB essentially two-dimensional separated into toroidal poloidal parts. Then these parts as well its secular variation are...

Abstract Using 12-year-long series of data (2001-2012) from geomagnetic observatories and repeat stations in Austria its neighboring countries, a regional spatial-temporal (ST) model is developed based on the polynomial expansion consisting latitude, longitude, time field components total magnetic F. Additionally, we have used three different global models (CHAOS-5, POMME-9, EMM2015), which are built spherical harmonics up to maximum degree L max give core crustal separately. The normal...

The aim of this study is to construct the fluid flow at Earth's Core–Mantle Boundary (CMB). We employ global "gufm1" model which describes dipolar geomagnetic field for last 400 years. work under frozen–flux approximation. Using continuity radial component (Br) through CMB, we obtain respective equation. two-dimensional velocity CMB separated into toroidal and poloidal parts. Then these parts as well its secular variation are expanded in spherical harmonics series substituted induction...

Different methods of analysis have been applied to satellite geomagnetic data that are claimed be representative the crustal field Italian area. The compared with each other concluding SCHA is best one. downward continuation by different gives results, most realistic those and RHA methods. Some remarks about method their results for area presented.

Abstract. In this study we have applied spectral techniques to analyze geomagnetic field time-series provided by observatories, and compared the results with those obtained from analogous analyses of synthetic data estimated models. Then, an algorithm is here proposed detect jerks in time-series, mainly occurring Eastern component field. Applying such analysis generated global models has allowed us depict most important space-time features all over globe, since beginning XXth century....

The steady state of a perfect conductive fluid in laminar flow resulting from the 'Hall effect' is studied. Using Maxwell equations, spatial variation magnetic field calculated for three cases different geometries: between two infinite parallel planes, coaxial infinite-long cylinders and concentric spheres. According to our calculation cases, depends on velocity. strengthened layers where velocity greater, but this dependency negligible non relativistic flows. Our approach study provides an...

Abstract. In this study we have applied two spectral techniques in terms of Fourier and wavelet analysis to geomagnetic field time series compared the results with those obtained from analogous analyses synthetic data. Then, an algorithm has been proposed detect jerks series, mainly being considered by Eastern component secular variation. Applying such generated global models allowed us depict most important space-time features on scale, since beginning XXth century. Finally, a spherical...