Geomagnetism Program
Publications
Geomagnetism publications.
Geomagnetism Program research plan, 2020–2024
The Geomagnetism Program of the U.S. Geological Survey (USGS) monitors geomagnetic field variation through operation of a network of observatories across the United States and its territories, and it pursues scientific research needed to estimate and assess geomagnetic and geoelectric hazards. Over the next five years (2020–2024 inclusive) and in...
Love, Jeffrey J.; Kelbert, Anna; Murphy, Benjamin S.; Rigler, E. Joshua; Lewis, Kristen A.
Adjusted geomagnetic data—Theoretical basis and validation
Adjusted geomagnetic data are magnetometer measurements with provisional correction factors applied such that vector quantities are oriented in a local Cartesian frame in which the X axis points north, the Y axis points east, and the Z axis points down. These correction factors are determined from so-called absolute measurements, which are “ground...
Rigler, E. Joshua; Claycomb, Abram E.
Intensity and impact of the New York Railroad superstorm of May 1921
Analysis is made of low‐latitude ground‐based magnetometer data recording the magnetic superstorm of May 1921. By inference, the storm was driven by a series of interplanetary coronal mass ejections, one of which produced a maximum pressure on the magnetopause of ~64.5 nPa, sufficient to compress the subsolar magnetopause radius to ~5.3 Earth...
Love, Jeffrey J.; Hayakawa, Hisashi; Cliver, Edward W. Data sharing in magnetotellurics
Here, we introduce the first openly available comprehensive database of magnetotelluric (MT) and related electromagnetic data that we developed and matured over the past decade, explain how to access the data, and describe the challenges that had to be overcome to make MT data sharing possible. The database is a helpful tool for MT scientists, and...
Kelbert, Anna; Erofeeva, Svetlana; Trabant, Chad; Karstens, Rich; Van Fossen, Mickey C. The extreme space weather event in September 1909
We evaluate worldwide low-latitude auroral activity associated with the great magnetic storm of September 1909 for which a minimum Dst value of −595 nT has recently been determined. From auroral observations, we calculate that the equatorward boundary of the auroral oval in the 1909 event was in the range from 31°–35° invariant latitude (...
Hayakawa, Hisashi; Ebihara, Yusuke; Cliver, Edward W.; Hattori, Kentaro; Toriumi, Shin; Love, Jeffrey J.; Umemura, Norio; Namekata, Kosuke; Sakaue, Takahito; Takahashi, Takuya; Shibata, Kazunari Extreme‐value geoelectric amplitude and polarization across the northeast United States
Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey,...
Love, Jeffrey J.; Lucas, Greg M.; Bedrosian, Paul A.; Kelbert, Anna On the intensity of the magnetic superstorm of September 1909
Analysis is made of solar observations and ground‐based magnetometer data recording space weather before and during the magnetic superstorm of 25 September 1909. From these data, it is inferred that the storm was initiated by an interplanetary coronal‐mass ejection having a mean Sun‐to‐Earth velocity of ~1,679 km/s. The commencement pressure...
Love, Jeffrey J.; Hayakawa, Hisashi; Cliver, Edward W.
Honolulu Magnetic Observatory
Tucked in a grove of thorny mesquite trees, on an ancient coral reef on the south side of the Hawaiian island of Oahu, west of Pearl Harbor, a small unmanned observatory quietly records the Earth’s time-varying magnetic field. The Honolulu Magnetic Observatory is 1 of 14 that the U.S. Geological Survey Geomagnetism Program operates at various...
Love, Jeffrey J.; Finn, Carol Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with...
Love, Jeffrey J.; Lucas, Greg M.; Kelbert, Anna; Bedrosian, Paul A.
On the feasibility of real-time mapping of the geoelectric field across North America
A review is given of the present feasibility for accurately mapping geoelectric fields across North America in near-realtime by modeling geomagnetic monitoring and magnetotelluric survey data. Should this capability be successfully developed, it could inform utility companies of magnetic-storm interference on electric-power-grid systems. That real...
Love, Jeffrey J.; Rigler, E. Joshua; Kelbert, Anna; Finn, Carol A.; Bedrosian, Paul A.; Balch, Christopher C. Operational nowcasting of electron flux levels in the outer zone of Earth's radiation belt
We describe a lightweight, accurate nowcasting model for electron flux levels measured by the Van Allen probes. Largely motivated by Rigler et al. (2004, https://doi.org/10.1029/2003SW000036), we turn to a time‐varying linear filter of previous flux levels and Kp. We train and test this model on data gathered from the 2.10 MeV channel of...
Coleman, Tim; McCollough, James P.; Young, Shawn L.; Rigler, E. Joshua Geoelectric hazard assessment: the differences of geoelectric responses during magnetic storms within common physiographic zones
Geomagnetic field data obtained through the INTERMAGNET program are convolved with with magnetotelluric surface impedance from four EarthScope USArray sites to estimate the geoelectric variations throughout the duration of a magnetic storm. A duration of time from June 22, 2016, to June 25, 2016, is considered which encompasses a...
Cuttler, Stephen W.; Love, Jeffrey J.; Swidinsky, Andrei