Community:Email 02Aug13b

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From Jeffrey Love (jlove at usgs.gov) on 02 August 2013.


Please post to CEDAR, SPA, and GEM email announcements:

I'd like to draw your attention to a Mendenhall post-doctoral opportunity at the USGS. Developing regional to national 3D conductivity models from MT data is an important component of this work.

More information about this opportunity can be found at:

http://geology.usgs.gov/postdoc/opps/2014/14-28%20Gannon.htm

General information on the Mendenhall post-doctoral program can be found at:

http://geology.usgs.gov/postdoc/opps/research.html

Applications will be accepted through Sep 20, 2013 and include a research proposal to be developed in coordination with the research advisors. Interested applicants having received their PhD within the last 5 years are encouraged to apply.

Weathering the storm: The ground-level response to geomagnetic disturbance - GICs and critical infrastructure

We seek a postdoctoral fellow with strong quantitative skills to advance USGS research related to Geomagnetically Induced Currects (GIC).The goal of this project is to extend and improve existing electric field models for GIC applications using this data, as well as pursue relevant scientific questions on the nature and statistics of electric fields induced by geomagnetic disturbances such as magnetic storms and substorms.

Direct measurement of electric fields for GIC studies is difficult due to the wide range of geological structure and variable nature of the induced fields over areas of interest. However, local or regional estimates are critical to providing accurate hazard assessments to end users who may be affected by ground-level electric field variation (for example, power utilities).

The following data are available and may help in the pursuit of research under this Opportunity:

  • Directly-measured GIC values from SUNBURST network monitors
  • Directly-measured GIC values from interested power grid operators (e.g., Dominion Power in the Virginia/East Coast region)
  • Electric field values calculated from system models based on the SUNBURST GIC data;

3-D crustal-scale conductivity structure for the northwestern U.S., derived from EarthScope USArray magnetotelluric data.

  • Long-term historical and real-time preliminary magnetic field data from USGS magnetic observatories
  • Local magnetic field information from variometer and academic magnetometer arrays across the United States.

Electric field estimates are typically calculated in the frequency domain using surface impedance estimates, derived from local ground conductivity models, and the spectral characteristics of the magnetic field driver. Some of the uncertainties and scientific topics the successful applicant may choose to pursue might include:

  • How accurate is a local estimate of the magnetic field based on observatory inputs; how important are spatial variations in the magnetic field to GIC calculations?
  • How well do interpolation methods work for magnetic field inputs to electric field calculations?
  • Are the existing one-dimensional conductivity models sufficient? Where are more advanced models needed?
  • How significant are coastal and other transverse variations in conductivity to GIC calculations?
  • What are the possible electric field values and GIC impacts of extreme geomagnetic events?

Research Advisors: Jeffrey Love, +1 303 273 8540, jlove@usgs.gov, Paul Bedrosian, +1 303 236 4834, pbedrosian@usgs, Jennifer Gannon, +1 303 666 6738, gannonjl@gmail.com, Andrei Swidinsky (Colorado School of Mines), +1 303 273 3934, aswidins@mines.edu

-- Jeffrey J. Love

USGS Advisor for Geomagnetic Research

303-273-8540

jlove@usgs.gov, profile.usgs.gov/jlove


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