Quantifying the Electric Grid Risk from Geomagnetic Storms: AER at Space Weather Workshop

Space Weather Workshop; Boulder, CO
April 16, 2013 - April 19, 2013

Atmospheric and Environmental Research's (AER) Space Weather research scientists are showcasing their research on geomagnetic disturbances and solar energetic proton flux levels, at this year's Space Weather Workshop in Boulder, Colorado, hosted by NOAA, NASA and UCAR. 

Tuesday at 9:45AM Nicole Homeier, PhD, is presenting on Quantifying the Electric Grid Risk from Geomagnetic Storms. AER is creating geomagnetic disturbance (GMD) stress test scenarios to assess the impact of GMDs on power grid infrastructure. Our model is developed using a database of historical magnetic storms. Surface electric fields are derived from interpolated magnetic fields and surface impedances from the United States Geological Survey. The overall goal is a realistic simulation of surface electric fields over the continental United States during extreme storms. Nicole will describe the model and show how it can be used to understand GMD impacts on grid infrastructure.

AER also has the following as poster presentations.

Surface Electric Fields for North America During Geomagnetic Storms. AER is developing surface electric field scenarios for the continental U.S. to better understand the impact of geomagnetic disturbances (GMDs) on the electric grid. These surface electric field time-series are created for both historical and simulated extreme geomagnetic storms. Using the spherical elementary current system method (SECS), we interpolate the sparsely distributed magnetometer data across North America. This interpolated magnetic field data is combined with surface impedances from the United States Geological Survey for physiographic regions to create a database of horizontal, orthogonal surface electric field maps in one-minute time steps during each storm. The induced surface electric field strongly depends on the local surface impedance –we discuss the relative response of different physiographic regions to different sets of magnetic field inputs. We also discuss our current implementation of the coastal enhancement effect of the surface electric field.

Solar Energetic Proton Nowcast for Low Earth Orbits. Solar energetic proton flux levels above > 10 pfu can damage spacecraft and pose a hazard to astronauts as well as passengers and crew on polar commercial flights. While the GOES satellites provide real-time data of SEP levels in geosynchronous orbit, it is also important to determine the risk to objects in lower altitude orbits. To assess this risk in real-time, we created a web-based nowcast of SEP flux. The tool determines the current solar energetic proton flux level given input position (latitude, longitude, and altitude) and energy of the protons (e.g., > 10 MeV). The effective cutoff energy is calculated for the location and current geomagnetic storm level (i.e., the Kp value from SWPC) using the Shea & Smart (e.g., Smart et al. 1999abc, 2000) geomagnetic cutoff model, which uses a trajectory tracing technique through the Tsyganenko magnetospheric model for the geomagnetic field. With the cutoff energy and GOES proton flux measurements, a map of the current predicted proton flux level at the input energy is displayed along with the calculated integral spectrum for the input position.