Topical Discussion Meeting - Polar Cap (PC) indices for Space Weather monitoring

Peter Stauning (Danish Meteorological Institute)
Friday 22/11, 15:15-16:30

Earlier investigations have used the Polar Cap (PC) indices to demonstrate the close relation of GIC-related power grid disturbances to enhanced PC index levels (e.g., Stauning, 2012). A remarkable feature of most of the examined cases is the lengthy intervals, ranging up to several hours of PC index values elevated above “alert level” (10 mV/m), preceding GIC-related power grid disruptions. The main reason for this feature is considered to be the time it takes the enhanced merging processes at the front of the magnetosphere, and the subsequent transpolar convection of plasma and embedded magnetic fields into the tail region, to shift the substorm processes responsible for violent GIC events to the subauroral latitudes where the vulnerable power grids reside. If available in real time, the PC indices may provide advance warning with lead times of several hours, of major substorm-related GIC events that may threaten vulnerable power grids in North America and Northern Europe.

In order to provide adequate structuring of the discussions it is suggested to subdivide the session into specific topics, such as:
- The use of real-time on-line Polar Cap indices to forecast substorm-related major GIC events that may threaten power grids.
- Adding multiple geomagnetic data sources to enhance forecast reliability. Potential candidates are Resolute Bay and Concordia Dome-C magnetometers to provide back-up for Thule and Vostok magnetometer data.
- Organisation to distribute on-line real-time PC indices.
- Monitoring the accuracy and reliability of delivered PC index values.
- Agreement on index derivation procedures and documentation of calculation methods.
Summary of discussions