Non-linear Least Square Fitting Technique for the Determination of Field Line Resonance Frequency in Ground Magnetometer Data: Application to Remote Sensing of Plasmaspheric Mass Density Journal Article uri icon

Overview

abstract

  • The accurate determination of the Field Line Resonance (FLR) frequency; of a resonating geomagnetic field line is necessary to remotely monitor; the plasmaspheric mass density during geomagnetic storms and quiet times; alike. Under certain assumptions the plasmaspheric mass density at the; equator is inversely proportional to the square of the FLR frequency.; The most common techniques to determine the FLR frequency from ground; magnetometer measurements are the amplitude ratio and phase difference; techniques, both based on geomagnetic field observations at two; latitudinally separated ground stations along the same magnetic; meridian. Previously developed automated techniques have used; statistical methods to pinpoint the FLR frequency using the amplitude; ratio and phase difference calculations. We now introduce a; physics-based automated technique, using non-linear least square fitting; of the ground magnetometer data to the analytical resonant wave; equations, that reproduces the wave characteristics on the ground, and; from those determine the FLR frequency. One of the advantages of the new; technique is the estimation of physics-based errors of the FLR; frequency, and as a result of the equatorial plasmaspheric mass density.; We present analytical results of the new technique, and test it using; data from the Inner-Magnetospheric Array for Geospace Science (iMAGS); ground magnetometer chain along the coast of Chile and the east coast of; the United States. We compare the results with the results of previously; published statistical automated techniques.

publication date

  • July 15, 2020

has restriction

  • hybrid

Date in CU Experts

  • February 1, 2021 2:36 AM

Full Author List

  • Boudouridis A; Yizengaw E; Moldwin M; Zesta E

author count

  • 4

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