At ~34ppt the Southern Ocean is significantly less saline than other major water bodies (Arctic Ocean excluded). The Southern Continent also shares proximity to the South Atlantic Anomaly - where the Earth's inner Van Allen radiation belt comes closest to the Earth's surface. The Antartica itself is also (apparently) lots of ice, ice, and more ice.

As the temporary home to several scientific expeditions - these usually include one, or more, ham radio stations - one wonders about the HF band propagation in Antarctica.

How does the South Atlantic Anomaly affect propagation in the HF bands?


2 Answers 2


To answer the question posed in the final paragraph, it looks like the South Atlantic Anomaly doesn't affect HF propagation much if at all. The Near-Real-Time MUF Map seems to show MUF contours consistent with the time of day (and the southern hemisphere late spring) with nothing specific to the SAA area. I also found the following statement:

At last, recall that the F2 region is also the home of the South Atlantic Anomaly (SAA), the lower limit of Van Allen belts that goes down to 200 km of altitude between South America and South Atlantic ocean. Constituted of fast electrons and heavy protons released by the solar wind trapped by the geomagnetic field, during quiet days, the SAA doesn't affect radio propagation in this region of the world.

From The radio propagation

  • $\begingroup$ PROLAB-PRO's Near-Real-Time MUF Map is only a simulation. Who says it takes the South Atlantic Anomaly into account? I could not find any reference in support of this assumption. $\endgroup$
    – on4aa
    Commented Nov 14, 2013 at 9:42

Good question!

May I stir it up a bit?

The SAA is a bit of concern to LEO satellites -- including the ISS -- because the bottom of a "radiation bubble" dips down into that area, thus its name. It is a region or volume where the frequency of Single Event Effects on Integrated Circuits is slightly higher than other points at that altitude. Or, conversely, matches the frequency of upsets that you would expect at a slightly higher altitude.

The "bubble" bottom and overall volume (roughly donut shaped) I speak of are part of the lower Van Allen radiation belt and of course is related to the ionosphere that influences our terrestrial radio wave propagation. But, my best guess is that on a global scale, the bubble bottom has negligible effect if any at all on signals NOT passing through that particular volume, and likely little affect on signals through that volume. I've made contact with McMurdo station several times but not enough to notice any SAA effects that I know of. I am interested in such observations by others.

My contribution to this discussion is limited to helping describe how the SAA volume is only a small part of a much larger volume(s) surrounding our planet. FWIW, I work with electronics that pass through the SAA on a regular basis, and have also done simulations and testing on ICs w.r.t. SEE/SEU bit flips, latch up and related phenomena. And I still enjoy HF ops to boot.

  • $\begingroup$ FYI — signatures are not the done thing on Stack Exchange. Your usercard in the bottom right functions as your signature for posts. You can include personal information in your profile, or if it's relevant to the answer (as I assume 'amsat area coordinator' is) you could mention it (say in your second paragraph). $\endgroup$
    – Kevin Reid AG6YO
    Commented Nov 12, 2013 at 19:39

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