Category Archives: HF Development

Sunspots, CMEs and HF

27 Aug

If the prognosticators for increasing numbers of sunspots and the ramp up of the new sunspot cycle are correct, then those radio amateurs who enjoy HF will be dusting off their rigs, keys and microphones in anticipation of good DX.

Here’s a link to the Sunspot Index and Long-term Solar Observations which gives us a taste of what’s to come for sunspot numbers. Today’s numbers can be found at Space Weather Live.

There’s always a possible fly in the sunspot ointment and they’re called Coronal Mass Ejections (CMEs) which can disrupt communications. A nice CME was observed on Tuesday August 4th. Check out this GIF.

The magnetic classification of sunspots

7 Dec

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 classificationssunspot with magnetic classification

  1. α – Alpha:
    A unipolar sunspot group.
  2. β – Bèta:
    A sunspot group that has a positive and a negative polarity (or bipolar) with a simple division between the polarities.
  3. 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.
  4. β-γ – Bèta-Gamma:
    A bipolar sunspot group but complex enough so that no line can be drawn between spots of opposite polarity.
  5. δ – Delta:
    The umbrae of opposite polarity in a single penumbra.
  6. β-δ – Bèta-Delta:
    A sunspot group with a general beta magnetic configuration but contains one (or more) delta sunspots.
  7. β-γ-δ – Bèta-Gamma-Delta:
    A sunspot group with a beta-gamma magnetic configuration but contains one (or more) delta sunspots.
  8. 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