Effects of substorm electrojet on declination along concurrent geomagnetic latitudes in the northern auroral zone

Abstract

The geomagnetic field often experiences large fluctuations, especially at high latitudes in the auroral zones. We have found, using simulations, that there are significant differences in the substorm signature, in certain coordinate systems, as a function of longitude. This is confirmed by the analysis of real, measured data from comparable locations. Large geomagnetic fluctuations pose challenges for companies involved in resource exploitation since the Earth's magnetic field is used as the reference when navigating drilling equipment. It is widely known that geomagnetic activity increases with increasing latitude and that the largest fluctuations are caused by substorms. In the auroral zones, substorms are common phenomena, occurring almost every night. In principle, the magnitude of geomagnetic disturbances from two identical substorms along concurrent geomagnetic latitudes around the globe, at different local times, will be the same. However, the signature of a substorm will change as a function of geomagnetic longitude due to varying declination, dipole declination, and horizontal magnetic field along constant geomagnetic latitudes. To investigate and quantify this, we applied a simple substorm current wedge model in combination with a dipole representation of the Earth's magnetic field to simulate magnetic substorms of different morphologies and local times. The results of these simulations were compared to statistical data from observatories and are discussed in the context of resource exploitation in the Arctic. We also attempt to determine and quantify areas in the auroral zone where there is a potential for increased space weather challenges compared to other areas.

Regional 3‐D Modeling of Ground Electromagnetic Field Due To Realistic Geomagnetic Disturbances

“…These real‐time magnetic survey tools rely on the principle of measuring the direction of the wellbore relative to the direction of the local geomagnetic and gravity fields. During periods of enhanced geomagnetic activity significant deviations can be experienced (Edvardsen et al, ; Reay et al, ). Thus, accurate modeling of the near‐surface geomagnetic field is essential for reducing the drilling errors and directional uncertainty.…”

Estimating external magnetic field differences at high geomagnetic latitudes from a single station

“…Accurately estimating the full field magnetic vector across the Earth has many useful scientific and practical applications, for example in reduction to quiet-time values in repeat station surveying, space weather nowcasting (Gaunt 2016), aeromagnetic surveying (Reeves 1993) or commercial activities such as directional drilling (Reay et al 2005;Edvardsen, Johnsen and Lovhaug 2016). In many of these scenarios, the location of interest is typically remote from a geomagnetic observatory or variometer.…”