Geoelectric Field Maps: Progress on NOAA's Operational Near-Real-Time Geoelectric Field Estimation Capability

Estimation of ground-level geoelectric fields has been identified by the electrical power industry as a key capability in assessment and mitigation of the impacts of space weather on electrical power infrastructure. The development of a capability to provide this information has involved a multi-disciplinary, multi-agency approach to bring together the various required technical expertise. We describe the components of an operational system for near real-time (no more than several minutes latency) estimation of spatially variable ground-level geoelectric fields. This system has been in development at NOAA’s Space Weather Prediction Center (SWPC) in collaboration with the USGS Geomagnetism Program and the NASA Community Coordinated Modeling Center (CCMC). Initial experimental capability is now available to the public at SWPC’s website (http://www.swpc.noaa.gov/).

Two operational products are provided: 1D Geoelectric Field Maps based on the Fernberg (2012) 1D conductivity model compilation, and 3D Geoelectric Field Maps which employ the best available three-dimensional Earth conductivity models in the US (Meqbel et al., 2014; Yang et al., 2015; Murphy & Egbert, 2017 and others) obtained through a USGS compilation of magnetotelluric community inversion results based on NSF’s Earthscope USArray impedances (Schultz et al., 2006-2018). The work on the 3D conductivity models is ongoing as new USArray data are obtained, and new methods for improved magnetotelluric inversion are developed. The maps also use the best available observatory magnetic field data (operated by USGS and Natural Resources, Canada) interpolated in real time using the method of spherical elementary currents (SECs; e.g., Amm & Viljanen, 1999; Pulkkinen et al., 2003).

The deployment of these maps represents a significant advance in the specification of space weather hazards compared to what was previously available, i.e. global geomagnetic indices, providing the electric power industry with a tool to assess regional space weather hazards in near real-time. An emphasis will also be made to identify key priorities for future improvements of this product. We encourage the community to make use of these operational tools to assist us in cross-comparison and validation.