Conditional Climatology of Ap: The Relationship between Solar Flares and Geomagnetic Storms
Abstract
This report documents a study of USAFETAC's optical solar flare database and its relationship to Gottingen's planetary geomagnetic index (Ap). The study was based on solar flare data with an 11-year period of record (1975 to 1986--Solar Cycle 21). After solar flares and Ap indices were studied separately, more than 27,000 flare reports were merged with 3-hour Ap values for 7 days after each flare. The resultant dataset was analyzed with respect to certain flare characteristics (such as importance, brightness, duration, solar location, and phase of the solar cycle) to find the best predictor of geomagnetic storming. The results were summarized in contingency tables (provided in Appendix B) for use as solar forecasting aids. Some flares were found to have more of an influence on the Earth's geomagnetic field than others. Of all the features studied, a flare's importance and location on the disk seemed to be best predictors of geomagnetic storming. Keywords: Climatology, Solar flares, Solar disturbances, Sunsports, Solar activity, Solar atmosphere, Solar forecasting, Geomagnetic storm.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1990
- Accession Number
- ADA222574
Entities
People
- Donald L. Wilson
- Roger T. Edson
Organizations
- Air Force Technical Applications Center