A test of the method on historical data 
The method has been tested using historical GOES observations for 19752003, and the results are briefly presented here. Predictions were made for each day of the GOES observations for the occurrence of M and X flares within a day, based on a year of data prior to the day. The resulting predictions were compared with the actual historical record of flaring. The test is described in the Space Weather article (Wheatland 2005, Space Weather, Vol. 3, No. 7, S07003 10.1029/2004SW000131). A version is available from astroph. Figure 1 shows year by year plots of the number of days on which MX class events occurred, i.e. events above the M level but below X level (histogram, upper panel), and of the number of days on which X class events occurred (histogram, lower panel), for 19762003. The numbers of event days predicted by the method are shown by diamonds.


Figure 1: Top panel: Numbers of observed (histogram) and predicted (diamonds) event days for MX flares. Bottom: The same, but for X flares. 
Figure 2 shows "reliability plots" for the prediction of MX events (upper panel), and of X events (lower panel), for 19762003, together with associated statistics. An explanation of these plots is given here. Briefly the predictions are on the horizontal axis and the observations are on the vertical axis, and the 45 degree solid line is perfect prediction. In these plots (and in Figure 1) it is evident that there is some overprediction, in particular of MX events. These plots may be compared with similar plots for predictions issued by the US National Oceanic and Atmospheric Administration, available here and here.

Total days: 10226 Event days: 2600 Mean (f): 0.282 Mean (x): 0.254 Median (f): 0.218 Std dev (f): 0.251 Std dev (x): 0.435 Mean (fx=1): 0.508 Mean (fx=0): 0.204 Median (fx=1): 0.565 Median (fx=0): 0.116 Std dev (fx=1): 0.216 Std dev (fx=0): 0.212 Discrimination: 0.304 ME: 0.027 MAE: 0.277 MSE: 0.138 Linear assoc: 0.528 Skill: 0.272 
Total days: 10226 Event days: 365 Mean (f): 0.040 Mean (x): 0.036 Median (f): 0.017 Std dev (f): 0.058 Std dev (x): 0.186 Mean (fx=1): 0.120 Mean (fx=0): 0.038 Median (fx=1): 0.105 Median (fx=0): 0.016 Std dev (fx=1): 0.084 Std dev (fx=0): 0.055 Discrimination: 0.082 ME: 0.005 MAE: 0.068 MSE: 0.032 Linear assoc: 0.262 Skill: 0.066 
Figure 2: Reliability plots for MX event and X event prediction, and associated statistics. 

Main flare prediction page
More detail on how today's predictions were made Summary of all predictions made to date Automatic check of the reliability of the predictions Prediction for 4 November 2003 Links to other pages related to flare prediction Mike Wheatland's home page 


Page maintained by m.wheatland@physics.usyd.edu.au  Page last updated Thursday, 18Aug2005 10:41:25 AEST 