Analytical Insights into Inaccurate Normal Vector Determination by Minimum Variance Analysis of Magnetic Fields
Year: 2025
Type: article
Abstract: It has been widely recognized that the minimum variance analysis of magnetic fields (MVAB) often fails to accurately predict the direction normal to a discontinuity or current sheet, compared with multiple-spacecraft methods. However, there is a lack of analytical proof to support this claim. In this paper, the accuracy of MVAB is tested using an analytical tangential and rotational discontinuity, where the exact normal is known. To evaluate the performance of MVAB, random fluctuations generated from a normal distribution, with varying magnitudes of variance ( σ 2 ), are imposed on the B x component. Results show that the MVAB normal is misaligned with the exact normal when σ 2 is comparable to or larger than λ 2 * . Here, λ 2 * is the eigenvalue of the intermediate variance direction at σ 2 = 0. To achieve good accuracy, it is required that λ 2 / λ 3 > 4.0, λ Nc 0 / λ 2 < 0.3, and λ Ncp / λ 2 < 0.3, where λ 2 and λ 3 are the eigenvalues of the intermediate and minimum variance directions, and
Source: The Astrophysical Journal
Author: Wai-Leong Teh
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funder: Universiti Kebangsaan Malaysia
Award: G2234174163
OpenAlex ID: W4408326652