Accession Number:

ADA510181

Title:

A Technique for Short-Term Warning of Solar Energetic Particle Events Based on Flare Location Flare Size and Evidence of Particle Escape

Descriptive Note:

Journal article

Corporate Author:

AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE

Report Date:

2009-04-01

Pagination or Media Count:

20.0

Abstract:

We have developed a technique to provide short-term warnings of solar energetic proton SEP events that meet or exceed the Space Weather Prediction Center threshold of J 10 MeV 10 prsq cmssr. The method is based on flare location, flare size, and evidence of particle accelerationescape as parameterized by flare longitude, time-integrated soft X-ray intensity, and time-integrated intensity of type III radio emission at 1 MHz, respectively. In this technique, warnings are issued 10 min after the maximum of or M2 soft X-ray flares. For the solar cycle 23 1995-2005 data on which it was developed, the method has a probability of detection of 63 4775, a false alarm rate of 42 3481, and a median warning time of 55 min for the 19 events successfully predicted by our technique for which SEP event onset times were provided by Posner 2007. These measures meet or exceed verification results for competing automated SEP warning techniques but, at the present stage of space weather forecasting, fall well short of those achieved with a human aided by techniques such as ours making the ultimate yesno SEP event prediction. We give some suggestions as to how our method could be improved and provide our flare and SEP event database in the auxiliary material to facilitate quantitative comparisons with techniques developed in the future.

Subject Categories:

  • Astrophysics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE