Skip to main content

Analyzing and correcting for contaminating magnetic fields at the Brorfelde geomagnetic observatory due to high voltage DC power lines

Abstract

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.

References

  • Bartels, J., The technique of scaling indices K and Q of geomagnetic activity, Ann. Intern. Geophys., Year 4, 215–226, 1957a.

    Google Scholar 

  • 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.

    Google Scholar 

  • 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.

    Article  Google Scholar 

  • Fuenzalida, H. and B. Rosenblüth, Prewhitening of climatological time series, J. Clim., 3(3), 382–393, 1990.

    Article  Google Scholar 

  • Jankowski, J. and C. Sucksdorf, Guide for magnetic measurements and observatory practice, 235 pp, IAGA, 1996.

    Google Scholar 

  • Lowes, F. J., DC railways and the magnetic fields they produce—the geomagnetic context, Earth Planets Space, 61, i–xv, 2009.

    Article  Google Scholar 

  • 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.

    Google Scholar 

  • Menvielle, M. and A. Berthelier, The K-derived planetary indices: description and availability, Rev. Geophys., 29(3), 415–432, 1991.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Article  Google Scholar 

  • Schmucker, U., Anomalies of Geomagnetic variations in the Southwestern United States, University of California Press, Berkeley, 1970.

    Google Scholar 

  • 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.

    Article  Google Scholar 

  • 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.

    Google Scholar 

  • von Storch, H. and F. Zwiers, Statistical Analysis in Climate Research, p. 373, 496 pp, Cambridge University Press, 1999.

    Google Scholar 

  • Wienert, K. A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, UNESCO Paris, 1970.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Cathrine Fox Maule.

Rights and permissions

Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.

Reprints and Permissions

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

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03352976

Key words

  • Geomagnetism
  • magnetic observatory
  • power lines
  • K-index