The above graph is real time data coming from my solar flare monitor. When a solar flare is released, its energy reaches Earth about 8.3 minutes later. One of its effects is to disturb the ionosphere. We use the ionosphere to bounce radio signals over long distances. These Sudden Ionic Disturbances (SIDs) affect the strength of certain radio signals and we can measure these changes.
A solar flare starts very quickly and fades slowly and it leaves this signature on the ionosphere. We see our radio signal strength follow the same pattern when a solar flare hits (I think it looks like a shark fin coming out of the sea). Also, during sunrise and sunset, the radio signal is "bounced around" and this should not be confused with solar activity. It is only possible to take data while the Sun is above the horizon. During the night I'll leave a plot of the days activity.
The lower plot shows a number of differnt radio stations, the upper only shows 2 for clarity. The "Surfing the Sun" Blog Will give details as to what type of flare, from which sunspot it came etc. Below is a diagram showing what to look out for.