Quiet-time magnetic variations at high latitude observatories
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2004
Received: 27 March 2003
Accepted: 27 December 2003
Published: 24 June 2014
The quiet-time geomagnetic variations at high latitudes have not been systematically studied so far. Here we present quiet-time variation results from more than two years of continuous magnetic observations in Fennoscandia and Svalbard using the IMAGE magnetometer network. The CHAMP CO2 model is found to yield an excellent secular variation correction with a simple linear trend. The effect of the magnetospheric ring current on the quiet-time field values for each component is presented with the coefficients for the expected linear correlation with the DST index. A general trend for these coefficients is found for the CGM latitudes from 54 to 68 degrees. In this area the diurnal variation is well in accordance with the expected seasonal Sq behaviour. North of the Fennoscandian mainland the DST coefficients and the diurnal variations show an unexpected behaviour and additional current systems are presented as a likely cause. An objective, automated baseline method used in this study is also introduced as a method useful for various applications.