مؤسسه ژئوفیزیک دانشگاه تهران فیزیک زمین و فضا 2538-371X 51 4 2026 03 17 Geomagnetic Disturbance Impact on Magnetic Survey Tool Errors in High-Latitude Directional Drilling Geomagnetic Disturbance Impact on Magnetic Survey Tool Errors in High-Latitude Directional Drilling 65 73 106274 10.22059/jesphys.2026.404857.1007734 FA Andrei V. Vorobev The Geophysical Center of the Russian Academy of Sciences, Moscow, Russia. Gulnara R. Vorobeva Department of Informatics, Ufa University of Science and Technology, Ufa, Russia. Journal Article 2025 10 23 This paper presents an approach to develop a proactive probabilistic model for assessing extreme errors in magnetic surveying tools caused by geomagnetic disturbances in the Arctic aurora zone, with the aim of enhancing the efficiency of directional drilling and accounting for risks that go beyond reactive compensation methods.<br />Analysis of high-resolution geomagnetic data (2004-2005) from 12 auroral observatories reveals that the absolute additional error in magnetic declination (|Δ<em>D</em>|) follows a composite statistical law. The core of the distribution (~84% of data) is lognormal (shape parameter s = 0.87 for |Δ<em>D</em>_mean| and <em>s</em> = 1.02 for |Δ<em>D</em>_max|), indicating error formation via multiplicative ionospheric processes. Critically, the tails (~16%) are heavy and obey a Pareto distribution, signaling a substantial risk of extreme events. We quantify that the maximum synchronous error (|Δ<em>D</em>_max|) exceeds 5.67° with a 1% probability, even during the solar cycle's declining phase. A distinct diurnal pattern with dual maxima suggests an optimal time windows for precision drilling operations.<br />The established lognormal-Pareto model facilitates a paradigm shift towards proactive risk management in high-latitude drilling. Our findings underscore the statistical insufficiency of mean-error approaches and quantify a significant probability of extreme azimuthal errors due to space weather. This study provides a foundation for developing decision-support systems, optimizing operational schedules, and informing stricter metrological standards for Arctic drilling equipment. This paper presents an approach to develop a proactive probabilistic model for assessing extreme errors in magnetic surveying tools caused by geomagnetic disturbances in the Arctic aurora zone, with the aim of enhancing the efficiency of directional drilling and accounting for risks that go beyond reactive compensation methods.<br />Analysis of high-resolution geomagnetic data (2004-2005) from 12 auroral observatories reveals that the absolute additional error in magnetic declination (|Δ<em>D</em>|) follows a composite statistical law. The core of the distribution (~84% of data) is lognormal (shape parameter s = 0.87 for |Δ<em>D</em>_mean| and <em>s</em> = 1.02 for |Δ<em>D</em>_max|), indicating error formation via multiplicative ionospheric processes. Critically, the tails (~16%) are heavy and obey a Pareto distribution, signaling a substantial risk of extreme events. We quantify that the maximum synchronous error (|Δ<em>D</em>_max|) exceeds 5.67° with a 1% probability, even during the solar cycle's declining phase. A distinct diurnal pattern with dual maxima suggests an optimal time windows for precision drilling operations.<br />The established lognormal-Pareto model facilitates a paradigm shift towards proactive risk management in high-latitude drilling. Our findings underscore the statistical insufficiency of mean-error approaches and quantify a significant probability of extreme azimuthal errors due to space weather. This study provides a foundation for developing decision-support systems, optimizing operational schedules, and informing stricter metrological standards for Arctic drilling equipment. https://jesphys.ut.ac.ir/article_106274_bc66052711790be9ef4f7b3836f949f8.pdf