Prediction is difficult, especially the future
---variously attributed
March 2006: The daily predictions on these pages are no longer being updated.
Recently I have been working on a
Bayesian method of solar flare
prediction. The idea is to use the information in the numbers and
sizes of solar flares already observed from the Sun
together with the known phenomenological rules of flare
statistics to make a prediction for the occurrence of a flare within a
given period, or to improve an existing prediction.
A paper on the theory of the method was published in the
Astrophysical Journal (Wheatland 2004, ApJ 609, 1134-1139). A version of
the paper is also
available online from astro-ph.
The method has been applied to X-ray flare observations from the
Geostationary Observational Environmental Satellites (GOES).
GOES events (flares) are characterised by their peak soft X-ray
flux in the 1-8 Angstrom band. Moderate-sized events are M class flares,
which have a peak flux greater than 0.00001 Watts per square metre at the
satellite. Large events are X class flares, which have a peak flux greater
than 0.0001 Watts per square metre. There is interest in predicting M and
X class events, in particular because of the effect of the enhanced flux of
soft X-rays on the upper atmosphere. The GOES implementation is described
in detail in a second paper on the method (Wheatland 2005, Space Weather
Vol. 3, No. 7, S07003, 10.1029/2004SW000131). A version of this paper is
also available from
astro-ph.
An experimental automated prediction system for GOES flares is also
being developed.
Below are the current predictions for the occurrence of M
and X class flares within 24 hours (the times are in Universal Time),
based on a year's data prior to the stated time. This page should
have new predictions each day. (For more information on how these
predictions were made, see this page.
For more information on the
reliability of these predictions, see
this page and this
page.)
Prediction for the probability of occurrence of a large flare on the Sun within 24 hours, based on the previous year of GOES events. Prob. of at least one flare of size M to X = 0.050+/-0.011 Prob. of at least one flare of X size or greater = 0.008+/-0.002 Prediction made at 2006/03/16 00:02:00 (UT)
Previous prediction:
Prediction for the probability of occurrence of a large flare on the Sun within 24 hours, based on the previous year of GOES events. Prob. of at least one flare of size M to X = 0.050+/-0.011 Prob. of at least one flare of X size or greater = 0.008+/-0.002 Prediction made at 2006/03/15 00:02:00 (UT)
Additional information:
Summary of all predictions made to date
Automatic check of the reliability of the predictions
The prediction for 4 November 2003
A test of the method on historical data
Links to other pages related to flare prediction
Mike Wheatland's home page
Acknowledgement:
The predictions given here are based on
information from the Space Environment Center, Boulder, CO,
National Oceanic and Atmospheric Administration (NOAA), US Dept. of
Commerce. The GOES plot is obtained from the same source.