[ghsc-seminars] GHSC Seminar, TOMORROW, Thursday, Aug 22th @ 10 am - Xueling Shi, Virginia Tech

[Rigler, Erin (Josh)]

*Characterization of Geoelectric Fields Associated with Ultra-Low Frequency
Waves*

*Xueling Shi*
*Virginia Tech (visiting NCAR/HAO)*

Geomagnetic perturbations related to a variety of phenomena in the
near-Earth space environment induce electric fields at the Earth’s surface.
These "geoelectric" fields in turn drive potentially damaging
geomagnetically induced currents (GIC) in technological infrastructures
such as railroads, pipelines, submarine cables and power grids. The
spatio-temporal specification of geoelectric fields is needed to improve
forecasts of GIC, and the combination of ground conductivity measurements
and the time rate of change of the magnetic field (dB/dt) can be used to
estimate the geoelectric field. Pulsations, or waves, at the lower end of
the Ultra-Low Frequency (ULF) band in the coupled magnetosphere- ionosphere
(M-I) generate periodic ground magnetic perturbations and dB/dt that have
been linked to geoelectric fields and GIC. A better understanding of the
role of ULF waves in generating geoelectric fields is thus needed to
improve GIC models and forecasting capabilities. We use a coordinated
investigation using satellite measurements, coherent scatter radars
(SuperDARN), ground magnetic and geoelectric field measurements, and
magneto-telluric impedance measurements to address the over-arching science
question, "How do ULF waves in the M-I system couple to geoelectric field
variations relevant to GIC?"

*Thursday, August 22th**, 2019*
*10-11am*
*  (Mountain Time)*
*USGS, 1711 Illinois Street, Golden, CO*
*Entry Level Seminar Room (204)*

*Note: Please arrive *~5 minutes early* and *bring photo ID* for
airport-style security measures now in place at the USGS building.

Thank you,
GHSC Seminar Committee

Ben
Mirus - bbmirus at usgs.gov
Josh Rigler - erigler at usgs.gov
Oliver Boyd - olboyd at usgs.gov <oboyd at usgs.gov>
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