Identification

Title

Multi‐scale intense geoelectric and geomagnetic field perturbations observed after an interplanetary magnetic field turning

Abstract

Intense geoelectric fields during geomagnetic storms generate geomagnetically induced currents in power grids and other infrastructure, necessitating an understanding of their causes, for example, through coordinated space and ground observations. This study investigates localized intense geoelectric ( E ) and geomagnetic ( B ) field perturbations following an Interplanetary Magnetic Field (IMF) turning during a geomagnetic storm on 25 October 2011. Observations from EarthScope magnetotelluric sites in the upper Midwest United States revealed shorter period (1 min) ultra‐low‐frequency (ULF) waves superimposed on longer period (10 min) perturbations in both E and B fields. These sites, located at 19 hr magnetic local time and magnetic latitude, recorded large amplitude E and B perturbations. Ground‐based all‐sky imagers showed auroral brightening with sunward and poleward propagation, while upstream spacecraft linked the perturbations to an IMF turning and solar wind dynamic pressure impulse. The longer‐period E and B field perturbations likely stem from localized ionospheric currents tied to substorm auroral activity post‐IMF turning. The combination of ionospheric currents, ULF waves, and the Earth's varying conductivity produces intense geoelectric fields of 2 V/km in the upper Midwest. A comparison using input data and software compatible with the NOAA/USGS geoelectric field nowcast model revealed its limitations in capturing such events due to the temporal and spatial resolution of the underlying data. Using 1‐s geomagnetic field data can improve geoelectric field models by capturing short‐period and large spatial scale waves, although localized magnetic perturbations remain underestimated due to insufficient ground magnetometer density.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7zk5n1w

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2025-02-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

<span style="font-family:Arial;font-size:10pt;font-style:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span>

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact