HF communications are affected by sunspots. Their number is growing with the new solar cycle #25. There are eight classifications of sunspots. You will find them below.
The different classifications
- α – Alpha:
A unipolar sunspot group. - β – Bèta:
A sunspot group that has a positive and a negative polarity (or bipolar) with a simple division between the polarities. - γ – Gamma:
A complex region in which the positive and negative polarities are so irregularly distributed that they can’t be classified as a bipolar Sunspot group. - β-γ – Bèta-Gamma:
A bipolar sunspot group but complex enough so that no line can be drawn between spots of opposite polarity. - δ – Delta:
The umbrae of opposite polarity in a single penumbra. - β-δ – Bèta-Delta:
A sunspot group with a general beta magnetic configuration but contains one (or more) delta sunspots. - β-γ-δ – Bèta-Gamma-Delta:
A sunspot group with a beta-gamma magnetic configuration but contains one (or more) delta sunspots. - γ-δ – Gamma-Delta
A sunspot group with a gamma magnetic configuration but contains one (or more) delta sunspots.
Check out more info on sunspots at