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Geomagnetism Program

We monitor the Earth's magnetic field. Using ground-based observatories, we provide continuous records of magnetic field variations; disseminate magnetic data to various governmental, academic, and private institutions; and conduct research into the nature of geomagnetic variations for purposes of scientific understanding and hazard mitigation.

News

The Monitor Newsletter - Vol. 12 | Issue July 2023 - Vol. 12 | Issue July 2023

The Monitor Newsletter - Vol. 11 | Issue May 2023

The Monitor Newsletter - Vol. 10 | Issue February 2023

Publications

Hybrid CPU-GPU solution to regularized divergence-free curl-curl equations for electromagnetic inversion problems

The Curl-Curl equation is the foundation of time-harmonic electromagnetic (EM) problems in geophysics. The efficiency of its solution is key to EM simulations, accounting for over 95% of the computation cost in geophysical inversions for magnetotelluric or controlled-source EM problems. However, most published EM inversion codes are still central processing unit (CPU)-based and cannot utilize rece
Authors
Hao Dong, Kai Sun, Gary D. Egbert, Anna Kelbert, Naser Meqbel

Modeling geomagnetic induction in submarine cables

Submarine cables have become a vital component of modern infrastructure, but past submarine cable natural hazard studies have mostly focused on potential cable damage from landslides and tsunamis. A handful of studies examine the possibility of space weather effects in submarine cables. The main purpose of this study is to develop a computational model, using Python, of geomagnetic induction on su
Authors
Shibaji Chakraborty, David H. Boteler, Xueling Shi, Benjamin Scott Murphy, Michael D. Hartinger, Xuan Wang, Greg M. Lucas, Joseph B. H. Baker

Synthesizing ground magnetic disturbance using dipole-aligned loop elementary currents and Biot-Savart relationship

This report presents a method for constructing a simplified numerical description of the electric current distributions in the ionosphere and gap region based on dipole-aligned loop elementary currents (DALECs). A theoretical basis for DALECs is presented, along with a prototypical algorithm for constructing an elementary numerical DALEC. The algorithm is verified and validated by combining DALECs
Authors
E. Joshua Rigler, Michael Wiltberger

Science

Auroras and Earthquakes: Strange Companions

Release Date: JULY 6, 2020 In 1722 and 1723 a London clockmaker, George Graham, observed daily and consistent variations on one of his instruments, a “Needle upon the Pin” (a compass), for which he had no explanation. Swedish scientists obtained some of Graham’s instruments to record what is now known to be the variations in Earth’s magnetic field. In 1741, they noticed a significant deflection of...
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Auroras and Earthquakes: Strange Companions

Release Date: JULY 6, 2020 In 1722 and 1723 a London clockmaker, George Graham, observed daily and consistent variations on one of his instruments, a “Needle upon the Pin” (a compass), for which he had no explanation. Swedish scientists obtained some of Graham’s instruments to record what is now known to be the variations in Earth’s magnetic field. In 1741, they noticed a significant deflection of...
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August 25, 2018 Magnetic Disturbance - Peak Dst 174 nT

Space Weather Events of August 25, 2018
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June 23, 2015 Magnetic Disturbance - Peak Dst -195 nT

Space Weather Events of June 23, 2015
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