Charles J. Wetterer (Pacific Defense Solutions, LLC)
Keywords: space weather, atmospherics
Abstract:
The Disturbed Storm Time (Dst) index is a measure of the magnetic field (in nT) created by the ring current, an electric current carried by charged particles trapped in the Earths magnetosphere. The index is calculated from measurements at 4 magnetometer stations near the equator and referenced to zero on internationally designated quiet days. As with other geomagnetic indices, the Dst index exhibits a high degree of correlation from one value to the next. In fact, existing forecast models that strictly use solar wind and interplanetary magnetic field data as inputs have a difficult time matching the performance of simple persistence when evaluating the model by the linear correlation coefficient and the root mean square error between forecast values and actual values. A model using the unscented Kalman filter (UKF) as the forecast engine was developed in an attempt to improve on simple persistence and existing models. This UKF model is very similar to the model we used to forecast the planetary geomagnetic index (Kp) last year (Wetterer et al. [2010]) that outperformed all other existing Kp forecast models. Initial results using this UKF forecast model to forecast Dst shows a similar performance and are detailed in this paper. The UKFbased model offers the opportunity for further forecast improvement by adding new inputs and refining the state and measurement functions in the filter.
Date of Conference: September 13-16, 2011
Track: Poster