Sudden Ionospheric Disturbances (SID) Recorded During February 2001

The events listed above meet at least one of the following criteria

Reported in at least two observer reports Visually analyzed with definiteness rating = 5 Reported by overseas observers with high definiteness rating

Solar Events

February was indeed a very quiet month as far as solar flares go. As can be seen by the SID event listing there were only 13 events detected by observers. The Goes-8 satellite registered only 100 events. None of these were M-Class events, in fact the strongest X-Ray event registered was a C8.2 on the 5th of February. This was detected by most observers.

The 19th to the 21st was the most active period as far as reported events. There were 3 on the first day, one on the second and 2 on the third. Other than that it was a very sparse month for solar flares. I have started working on a way to graphically show the flare activity for the month. At first showing the SIDs, as detected by observers, was considered but it was decided that, for now, that was too dependant on the number of observers, and the ability of individual setups to detect smaller flares. Clearly we are not detecting all the flares that occur so it was decided, since it is readily available, to plot the number of flares registered each day by the Goes satellite instead. An example of such a plot is provided below.

It has not been decided yet how this data will be presented on a regular basis in the future. It will be provided, however, in order to compare the flare activity directly to the sunspot activity. I will be preparing a similar chart for the past 8 months and continue to prepare a chart each month from now on.

• Back to February Solar Bulletin
• Editor's Note
• Sudden Ionospheric Disturbances Supplement