A Comparative Verification of Forecasts from Two Operational Solar Wind Models
Abstract
The solar wind (SW) and interplanetary magnetic field (IMF) have a significant influence on the near-earth space environment. In this study we evaluate and compare forecasts from two models that predict SW and IMF conditions: The Hakamada-Akasofu-Fry (HAF) version 2. operational at the Air Force Weather Agency, and Wang-Shecley-Arge (WSA) version l.6, executed routinely at the Space Weather Prediction Center SW speed (V(sw)) and IMF polarity (Bpoi) forecasts at LI were compared with Wind and Advanced Composition Explorer satellite observations. Verification statistics were computed by study year and forecast day. Results revealed that both models' mean V(sw) are slower than observed. The HAF slow bias increases with forecast duration WSA had lower V,w forecastobservation difference (F-O) absolute means and standard deviations than HAF. HAF and WSA V(sw) forecast standard deviations were less than observed V(sw) F-0 mean square skill rarely exceeds that of recurrence forecasts. Bpoi is correctly predicted 65%-85% of the time in both models. Recurrence beats the models in Ppol skill in nearly every year forecast day category Verification by "event" (flare events less than or equal to 5 days before forecast start) and "nonevent" (no flares) forecasts showed that most HAF V(sw) bias growth, F-O standard deviation decrease, and forecast standard deviation decrease were due to the event forecasts Analysis of single time step V(sw) increases of greater than or equal to 20% in the nonevent forecasts indicated that both models predicted too many occurrences and missed many observed incidences. Neither model had skill above a random guess in predicting V(sw) increase arrival time at LI.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 16, 2010
- Accession Number
- ADA547784
Entities
People
- Donald C. Norquist
- Warner C. Meeks
Organizations
- Air Force Research Laboratory