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Why is it so difficult to make a contact with Greenland?

If you are even a casual DXer, you’ve noticed that talking to Japan and even Alaska from the Australian East coast is easy. Despite the path of 12,000km Alaskans are loud and clear. Yet trying to make it further, over the North Pole, seems almost impossible. Here is a personal statistic: out of 91,000 contacts made in the past two years, and thousands of hours on air, on all HF bands, I’ve only made two contacts with Greenland!

To an amateur, it seems that there is a physical barrier which prevents signal from passing directly over the North Pole. And yes there is. A nasty one for that matter.

Most of what we know about polar path propagation goes back to scientific studies and experimental data from the early 1960s. Deviation, attenuation, absorption, Auroral disturbance: the physics is complex and propagation are both unpredictable and highly unreliable.

In the HF spectrum that concerns us, Auroral zone absorption is quite ‘patchy’ in spatial and temporal behaviour and probably attenuates HF signals up to 60 dB in severe cases. Polar cap absorption, although a relatively rare event, can attenuate HF signals up to 100 dB at times. Scary!

In other words, the polar barrier is there on most days and nights. And only occasionally, on a quiet, undisturbed day, the barrier disappears.

Yesterday, just past sunset, I decoded an unbelievably strong OX5DM on 10.136 MHz, FT8 mode. He was making local contacts with North Americans and Scandinavians. Full of hope, I put out a call. Then another one, and one more. He got back to me with +14 report, meaning, my 100W signal was so loud it was like I was sitting in the same room, having a conversation! I literally fell off the chair. The magic happened. A few minutes later, he faded away, never to be decoded again. My third contact with Greenland!

Yes, HF is still full of exciting surprises. Ham radio is a sophisticated hobby that handsomely rewards curious, persistent and sophisticated chasers.

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