Next, we investigated the global distribution of correlation coefficients between the magnetic field intensity, inclination, and residual Sq amplitude obtained from 40 geomagnetic stations.
The geomagnetic parameters, i.e. total field intensity, inclination and declination, were calculated by GEOMAGIX based on the model for the World Magnetic Model (WMM 2005) for the test site at 1 September 2008.
The intensity and inclination data from the simulations are shown in Fig. 7c, d.
Similar to treatment steps containing measurement data, the deconvolved data include X-, Y-, and Z-axis intensity, declination, inclination, and total intensity.
Alternatively, X-, Y-, and Z-axis intensity, declination, inclination, or total intensity can be shown on a single large plot to view multiple step data in more detail (Fig. 3c).
Figure 9 shows the relationship between the residual Sq amplitude and the ambient magnetic field parameters (total intensity and inclination) at the Addis Ababa (left panels a and b) and Chambon-La-Foret (right panels a and b) stations.
Relationship between the residual Sq amplitude and the ambient magnetic field parameters (total intensity and inclination) at the Addis Ababa (left panels a and b) and Chambon-La-Foret (right panels c and d) stations.
Note that the exported file only contains the optimized deconvolution data including X-, Y-, Z-axis intensity, declination, inclination, total intensity, the errors associated with these data, and the optimized ABIC values as well as the optimized ln u), position shift, and length correction that yield the minimum ABIC.
In order to confirm whether the changes in both the magnetic field intensity and inclination are strongly related to the long-term variation in the residual Sq amplitude or not, we investigated the relationship using the long-term magnetic field data calculated with the IGRF-11 model [Finlay et al. [2010].
The present study attempts to establish a global picture of the long-term trend in the Sq amplitude and to clarify the mechanism in comparison with the long-term trend in the magnetic field intensity and inclination derived from the International Geomagnetic Reference Field (IGRF -11 model [FIGRF -11 al. [2010].
However, all birds need to find their way over some distance and a magnetic compass and/or a magnetic map in particular [58] could be very useful at all navigation scales - provided that such a sense would be sensitive to minuscule changes in magnetic field intensity and inclination.
