Time filter

Source Type

Tozzi R.,Italian National Institute of Geophysics and Volcanology | De Santis A.,Italian National Institute of Geophysics and Volcanology | De Santis A.,University of Chieti Pescara | Gaya-Pique L.-R.,Comprehensive Nuclear Test Ban Treaty Organization PrepCom
Tectonophysics | Year: 2013

The Antarctic Reference Model (ARM) has been here updated using recent geomagnetic data measured over the Antarctic continent from both ground observatories and satellites. This regional geomagnetic model is based on a Spherical Cap Harmonic Analysis (SCHA) of geomagnetic field measurements over a polar cap of 30° half-angle centred at the geographic South Pole, fixing the maximum spatial expansion index kmax=8 and the maximum temporal order of polynomials qmax=4.The importance of updating ARM model lies, for instance, in its usefulness for the reduction of magnetic surveys, performed during the period of model validity over the Antarctica, or for geomagnetic anomaly field estimations. Moreover, so far, ARM still remains the only regional reference magnetic model specifically constructed for the Antarctic continent. The present updated version can be considered valid from 1955.5 to 2010.0 with predictive coefficients up to 2012.0. The model includes the most recent available data but, in contrast to previous versions not only does it take advantage of a stricter selection of satellite data in order to consider even quieter periods of external magnetic activity, but it also includes ground observatory data previous to 1960 going back to 1955.8. Like the previous versions, the new updated model has been tested and compared with major global models to show its reliability over the region under investigation. © 2012 Elsevier B.V.


Qamili E.,Italian National Institute of Geophysics and Volcanology | Qamili E.,University of Siena | De Santis A.,Italian National Institute of Geophysics and Volcanology | Cianchini G.,Italian National Institute of Geophysics and Volcanology | And 5 more authors.
Earth, Planets and Space | Year: 2010

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 to 2012. This study is based on the datasets of magnetic measurements taken during different campaigns in Albania and Italy in the time of concern, together with a total intensity data set from the Ørsted and CHAMP satellite missions. The model is designed to represent the Cartesian components, X, Y, Z and the total intensity F of the main geomagnetic field (and its secular variation SV) for the period of interest. To develop the model, we applied a Spherical Cap Harmonic Analysis (SCHA) of the geomagnetic potential over a 16° cap with most of the observations concentrated in the central 4° half-angle. The use of a larger cap than that containing the data was made to reduce the typical problems in SV modelling over small regions. Also a new technique, called "Radially Simplified Spherical Cap Harmonic Analysis" (RS-SCHA), was developed to improve the model especially in the radial variation of the geomagnetic field components. Both these models provide an optimal representation of the geomagnetic field in the considered region compared with the International Geomagnetic Reference Field model (IGRF-11) and can be used as reference models to reduce magnetic surveys undertaken in the area during the time of validity of the model, or to extrapolate the field till 2012. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS).

Loading Comprehensive Nuclear Test Ban Treaty Organization PrepCom collaborators
Loading Comprehensive Nuclear Test Ban Treaty Organization PrepCom collaborators