- Open Access
Analyzing and correcting for contaminating magnetic fields at the Brorfelde geomagnetic observatory due to high voltage DC power lines
Earth, Planets and Space volume 61, pages1233–1241(2009)
The magnetic field observations made at the geomagnetic observatory Brorfelde (BFE), Denmark, are subject to disturbances of several nT caused by two single wire high-voltage DC power lines connecting Scandinavia with Central Europe. We have analysed how the magnetic disturbances relate to the currents in the power lines and found a linear relationship. Using linear regression on carefully selected parts of the available data series we have determined the factors of proportionality. Based on the simple relationship between the currents in the power lines and the observed magnetic disturbances, we have derived a method to correct the observatory data for a significant part of the disturbances. In addition we have investigated the influence of the disturbances on the determination of the K-index of the observatory. We found that the K-index based on the original disturbed data compared to the K-indices calculated from corrected data was different in 4% of the 3-hour intervals for the investigated period.
Bartels, J., The technique of scaling indices K and Q of geomagnetic activity, Ann. Intern. Geophys., Year 4, 215–226, 1957a.
Bartels, J., The geomagnetic measures for the time-variations of solar corpuscular radiation, described for use in correlation studies in other geophysical fields, Ann. Intern. Geophys., Year 4, 227–236, 1957b.
Ebisuzaki, W., A method to estimate the statistical significance of a correlation when the data are serially correlated, J. Clim., 10(9), 2147–2153, 1997.
Fuenzalida, H. and B. Rosenblüth, Prewhitening of climatological time series, J. Clim., 3(3), 382–393, 1990.
Jankowski, J. and C. Sucksdorf, Guide for magnetic measurements and observatory practice, 235 pp, IAGA, 1996.
Lowes, F. J., DC railways and the magnetic fields they produce—the geomagnetic context, Earth Planets Space, 61, i–xv, 2009.
Matzka, J., L. W. Pedersen, C. Fox Maule, A. Neska, J. Reda, A. Nilsson, and H.-J. Linthe, The effect of high-voltage DC power lines on the geomagnetic measurements at BFE, Proceedings of XIII IAGA Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing, in press.
Mayaud, P. N., Derivation, meaning, and use of geomagnetic indices, in Geophys. Monogr. Ser., 22, American Geophysical Union, Washington DC, 1980.
Menvielle, M. and A. Berthelier, The K-derived planetary indices: description and availability, Rev. Geophys., 29(3), 415–432, 1991.
Neska, A., Remote Reference versus Signal-Noise Separation: A least-square based comparison between magnetotelluric processing techniques, PhD thesis, Freie Universitt Berlin, Fachbereich Geowissenschaften, available at http://www.diss.fu-berlin.de/2006/349, 2006.
Nowozynski, K., T. Ernst, and J. Jankowski, Adaptive smoothing method for computer derivation of K-indices, Geophys. J. Int., 104, 85–93, 1991.
Oettinger, G., V. Haak, and J. C. Larsen, Noise reduction in magnetotelluric time-series with a new signal-noise separation method and its application to a field experiment in the Saxonian Granit Massif, Geophys. J. Int., 146, 659–669, 2001.
Pirjola, R., L. Newitt, D. Boteler, L. Trichtchenko, P. Fernberg, L. McKee, D. Danskin, and G. Jansen van Beek, Modelling the disturbance caused by a dc-electrified railway to geomagnetic measurements, Earth Planets Space, 59, 943–949, 2007.
Schmucker, U., Anomalies of Geomagnetic variations in the Southwestern United States, University of California Press, Berkeley, 1970.
Soyer, W. and H. Brasse, Investigation of anomalous magnetic field variations in the central Andes of N Chile and SW Bolivia, Geophys. Res. Lett., 28(15), 3023–3026, 2001.
Varentsov, Iv. M. and EMTESZ WG, Joint robust inversion of quasi-2D MT/GDS data sets, in Protokol of the 21. kolloquium “Elektromagnetisch Tiefenforschung” Wohldenberg, edited by O. Ritter, 111–123, http://bib.gfz-potsdam.de/emtf/2005/pdf/Varentsov_EMTF2005.pdf, 2005.
von Storch, H. and F. Zwiers, Statistical Analysis in Climate Research, p. 373, 496 pp, Cambridge University Press, 1999.
Wienert, K. A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, UNESCO Paris, 1970.
About this article
Cite this article
Maule, C.F., Thejll, P., Neska, A. et al. Analyzing and correcting for contaminating magnetic fields at the Brorfelde geomagnetic observatory due to high voltage DC power lines. Earth Planet Sp 61, 1233–1241 (2009). https://doi.org/10.1186/BF03352976
- magnetic observatory
- power lines