Two strong magnetic storms observed during CME events in November 2001 and 2003 are considered in this study. Magnetic field data from L’Aquila (Italy), Bay St Louis and Boulder (USA), Alibag (India) and other observatories are analyzed where amplitude, possible time lag and expansion characteristics of the geomagnetic field variations among observatories at middle and low latitudes are examine...

S U M M A R Y Combining CHAMP satellite magnetic measurements with aeromagnetic and marine magnetic data, the global geomagnetic field has now been modelled to spherical harmonic degree 720. An important tool in field modelling is the geomagnetic power spectrum. It allows the comparison of field models estimated from different data sets and can be used to identify noise levels and systematic er...

The rapid decrease of the geomagnetic field intensity in the last centuries has led to speculations that an attempt to a reversal or an excursion might be under way. Here we investigate this hypothesis by examining past records of geomagnetic field intensity obtained from sedimentary cores and from the study of cosmogenic nuclides. The selected records describe geomagnetic changes with an unpre...

Geomagnetic field is a one of the candidates for creation of anisotropy in azimuth distribution of extensive air showers over the entered cosmic rays to the atmosphere. Here we present the question: Is there any azimuth anisotropy flux in the upper level of the atmosphere due to the geomagnetic field over the entered cosmic-rays? The obtained answer is: yes. This investigation showed an agreeme...

The largest geomagnetic storms of solar cycle 24 so far occurred on 2015 March 17 and June 22 with Dst minima of 223 and 195 nT, respectively. Both of the geomagnetic storms show a multi-step development. We examine the plasma and magnetic field characteristics of the driving coronal mass ejections (CMEs) in connection with the development of the geomagnetic storms. A particular effort is to re...

[1] The daily variation of the geomagnetic field during quiet time at equinox features a longitudinal dependence, which is observed in the dip-latitude/longitude frame. Two explanations are considered: (1) the longitudinal changes of the geomagnetic latitude at constant dip-latitude and (2) the longitudinal variations of the main field, which modulates the ionospheric dynamo e.m.f. and determin...

The discussion in the preceding paper is restricted to the uncertainties in magnetic-field-line tracing in the magnetosphere resulting from published standard errors in the spherical harmonic coefficients that define the axisymmetric part of the internal geomagnetic field (i.e. gn dg 0 n). Numerical estimates of these uncertainties based on an analytic equation for axisymmetric field lines are ...

This paper evaluates methods for the long-range navigation of autonomous underwater vehicles (AUVs) at a middle depth of deep water from the viewpoint of spatial fields-aided navigation. Motivated by experimental works on the geomagnetic field-aided navigation of aquatic animals, we focus on the application of inertia systems with reference to maps of geomagnetic and bathymetric fields of the E...

Investigations of the paleosecular variation of the geomagnetic field on geological timescales depend on globally distributed data sets from lava flows. We report new paleomagnetic results from lava flows of the East Carpathian Mountains (23.6°E, 46.4°N) erupted between 4 and 6 Ma. The average virtual geomagnetic pole position (76 sites) includes the North Geographic Pole and the dispersion of ...

Magnetotactic bacteria are microorganisms that orient and migrate along magnetic field lines. The classical model of polar magnetotaxis predicts that the field-parallel migration velocity of magnetotactic bacteria increases monotonically with the strength of an applied magnetic field. We here test this model experimentally on magnetotactic coccoid bacteria that swim along helical trajectories. ...