Validation of Geomagnetic Index Forecast and Specification Models

Specification and forecast of geomagnetic indices is an important capability for space weather operations. The University Partnering for Operational Support (UPOS) effort at the Applied Physics Laboratory of Johns Hopkins University (JHU/APL) produced many space weather models, including the Kp/Dst Predictor and Kp Estimator. We perform a validation of index forecast products against definitive indices from the National Geophysical Data Center (NOAA/NGDC), US Geological Survey (USGS), and the World Data Center for Geomagnetism, Kyoto (WDC). We compute continuous predictant skill scores, as well as 2x2 contingency tables and associated scalar quantities for different index thresholds. We discuss differences between validations of directly observable data and validations of geomagnetic indices and factors to consider when choosing a "definitive" index data set.