Earth Planets Space, Vol. 62 (No. 10), pp. 833-841, 2010
Enkelejda Qamili1,2, Angelo De Santis1, Gianfranco Cianchini1,2, Bejo Duka3, Luis R. Gaya-Piqué4, Guido Dominici1, and Niko Hyka3
1Istituto Nazionale di Geofisica e Vulcanologia, Roma 2, Roma, Italy
2Scuola di Dottorato in Scienze Polari, Universitá degli studi di Siena, Siena, Italy
3Department of Physics, Faculty of Natural Sciences, University of Tirana, Albania
4On-Site Inspection Division, Comprehensive Nuclear-Test Ban Treaty Organization PrepCom, Vienna, Austria
(Received March 18, 2010; Revised June 23, 2010; Accepted July 20, 2010; Online published December 31, 2010)
Here we present a revised geomagnetic reference model for the region comprising Albanian territory, south-east 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.
Key words: Regional geomagnetic modelling, spherical cap harmonic analysis, magnetic ground and satellite data.