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FORECAST SOL: Moderate yellow MAG: Moderate yellow ION: Moderate yellow
HomeWorld Data CentreData Display and DownloadSpectrographSolar Radio Burst Classifications Friday, Feb 23 2024 10:03 UT
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Spectrograph: Solar Radio Burst Classifications

Type Characteristics Duration Frequency range Associated phenomena
I Short, narrow-bandwidth bursts. Usually occur in large numbers with underlying continuum. Single burst:
~ 1 second
hours - days
80 - 200 MHz Active regions, flares, eruptive prominences.
IISlow frequency drift bursts. Usually accompanied by a (usually stronger intensity) second harmonic.3 - 30 minutesFundamental:
20 - 150 MHz
Flares, proton emission, magnetohydrodynamic shockwaves.
III Fast frequency drift bursts. Can occur singularly, in groups, or storms (often with underlying continuum). Can be accompanied by a second harmonic Single burst:
1 - 3 seconds
1 - 5 minutes
minutes - hours
10 kHz - 1 GHz Active regions, flares.
IV Stationary Type IV: Broadband continuum with fine structure Hours - days 20 MHz - 2 GHz Flares, proton emission.
Moving Type IV: Broadband, slow frequency drift, smooth continuum. 30 mins - 2 hours 20 - 400 MHz Eruptive prominences, magnetohydrodynamic shockwaves.
Flare Continua: Broadband, smooth continuum. 3 - 45 minutes 25 - 200 MHz Flares, proton emission.
V Smooth, short-lived continuum. Follows some type III bursts. Never occur in isolation. 1 - 3 minutes 10 - 200 MHz Same as type III bursts.


In nearly all cases, drifting bursts drift from high to low frequencies.

The Frequency Range is the typical range in which the bursts appear - not their bandwidth.

The sub-types of type IV are not universally agreed upon and are thus open to debate.

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