Greyline Analysis

3Y0K Bouvet Island · Solar terminator and day/night propagation

Bouvet Island — Extreme Latitude Lighting

At 54°S latitude, Bouvet Island experiences dramatically different day/night cycles compared to mid-latitude stations. During the March 1-14 operation window (austral autumn), Bouvet had approximately:

Daylight

~12.5h

Darkness

~11.5h

Twilight

~1.5h

Path Classification

Paths from Bouvet to worldwide receivers are classified by solar illumination at both endpoints:

38%Both Day

Both Bouvet and receiver in daylight. Best for 10m-15m F2 propagation.

35%Cross-Terminator

One end in day, one in night. Greyline enhancement possible — signals follow the terminator.

27%Both Dark

Both ends in darkness. Low bands (40m-160m) dominate. Long-path possible.

Greyline Windows

The solar terminator crosses Bouvet twice daily. During early March, approximate greyline windows at JD04:

Sunrise Greyline

~05:30 UTC

EU stations in early morning, NA in late evening

Sunset Greyline

~18:00 UTC

JA/VK stations near local sunrise, optimal for 40m/80m

Average Kp during operation: 2.3 — geomagnetically quiet, with a storm event around March 8-9 that would have degraded greyline enhancement on the higher bands.

Future Enhancement

Full greyline visualization with interactive solar terminator overlay and per-path SNR comparison (greyline vs non-greyline) will be added when real 3Y0K observation data is available.