Author: Robert A. Morris, Richard A. Quinn and Steven O'Malley
Space Weather Workshop
Operational Dst from Real-time Data Streams and Forecast Algorithms; W.K. Tobiska, D. Knipp, D. Bouwer, R. Shelley, J. Bailey, B. Burke, P. Hagan, D. Odstrcil, J. Love, J. Gannon, P. Friberg, V. Eccles, B. Schunk, D. Intriligator, M. Hesse, M. Kuznetsova, R. Morris, R. Quinn, S. O’Malley, and B. Bowman; Space Weather Workshop; Boulder CO, 24-27 May 2012.
Dst, the disturbance storm-time index for the magnetospheric ring current, is a ground-measured indicator of the perturbation to Earth’s main magnetic field. Its variability derives from changes in the ring current energy density driven by solar wind coupling with the terrestrial magnetosphere. This coupling energizes plasma captured from solar wind and ionospheric sources, producing a temporarily trapped particle population that forms the variable ring current. Coupling tends to be most effective during the passage of fast interplanetary coronal mass ejections. However, less energetic ejecta associated with moderate and large X-ray, non-CME, flaring events, i.e., the inhomogenous strings and density filaments in coronagraph imagery, can also produce significant ring current variability. We report on the successful implementation of multiple streams of real-time Dst from several institutions and we also describe significant advances in forecasting Dst. In addition to Dst derived from ENLIL/CONE modeling (Stream A), the Anemomilos data-driven, deterministic algorithm uses three observables to provide information about solar ejecta geoeffectiveness as it departs the Sun (Stream B). The Anemomilos forecast algorithm has been tested for most of its components for every hour in 6-month time frames in 2001 and in 2005, i.e., for active and quiet solar conditions. An operational system derived from these methods is being developed to enable current epoch specification and forecast Dst to 6 days in the future. Dst is one of the geomagnetic drivers to the JB2008 thermosphere density model that has greatly improved the specification of mass density for low Earth orbit satellite operations; the real-time and forecast Dst described here supports the operational implementation of JB2008.