ARRL International DX Contest — SSB¶
SSB · ARRL · March 07–07, 2026
Storm Impact: Geomagnetic storm developed during the contest
Kp rose from quiet (1.0) on Saturday morning to active (4.67) by Sunday afternoon. This provided a natural experiment — same bands, same operators, changing geomagnetic conditions. The storm's impact on high-band propagation is the centerpiece of this analysis.
Kp trajectory: 1.0 → 4.67 (Sunday morning)
Contest Overview¶
| Contest Window | 2026-03-07 00:00 — 2026-03-08 23:59 UTC |
| Analysis Window | 2026-03-06 — 2026-03-09 (±24h) |
| Mode | SSB |
| SFI | 135–143 |
| Kp Range | 1.0–4.67 |
| Primary Source | PSKR signatures |
Key Findings¶
- 20m was the dominant band both days — strong worldwide propagation at SFI 135+
- Storm onset visible in high-band SNR degradation Sunday afternoon
- 15m and 10m showed clear sensitivity to rising Kp — openings shortened on Day 2
- 40m and 80m relatively unaffected by the storm — low bands more resilient to Kp disturbance
- Higher SFI (135 vs 110 for CW weekend) improved high-band openings before the storm hit
- SFI 135–143 still below March 2023–2025 average (~159) — cycle declining but high bands well-supported
Band Activity Summary¶
PSKR signature counts during the contest window, aggregated by band.
| Band | Signatures | Median SNR | Avg Distance (km) | Peak Hour (UTC) |
|---|---|---|---|---|
| 160m | 17,496 | -4 dB | 1,972 | 20:00 |
| 80m | 79,585 | -6 dB | 2,137 | 1:00 |
| 60m | 16,436 | -4 dB | 2,737 | 4:00 |
| 40m | 323,562 | -8 dB | 3,123 | 21:00 |
| 30m | 164,626 | -7 dB | 4,012 | 7:00 |
| 20m | 399,505 | -7 dB | 3,679 | 12:00 |
| 17m | 166,346 | -7 dB | 4,025 | 15:00 |
| 15m | 264,366 | -8 dB | 4,466 | 8:00 |
| 12m | 116,988 | -8 dB | 4,727 | 12:00 |
| 10m | 281,951 | -9 dB | 5,365 | 9:00 |
Hourly Activity Profile¶
Spot density by hour (UTC) across all contest bands — PSKR source.
| Hour | 20m | 15m | 10m | 40m | 80m |
|---|---|---|---|---|---|
| 00:00 | 45,327 | 42,098 | 71,002 | 57,707 | 19,772 |
| 01:00 | 40,502 | 47,829 | 61,582 | 59,652 | 23,936 |
| 02:00 | 30,523 | 42,271 | 47,374 | 60,755 | 22,657 |
| 03:00 | 28,846 | 31,741 | 29,387 | 61,750 | 21,693 |
| 04:00 | 41,964 | 36,814 | 29,895 | 68,341 | 22,106 |
| 05:00 | 61,751 | 40,478 | 37,440 | 68,636 | 18,913 |
| 06:00 | 80,674 | 46,381 | 44,018 | 70,243 | 10,711 |
| 07:00 | 91,216 | 75,170 | 70,423 | 60,356 | 4,768 |
| 08:00 | 82,635 | 92,226 | 88,899 | 46,155 | 2,878 |
| 09:00 | 70,144 | 88,547 | 100,973 | 43,911 | 3,256 |
| 10:00 | 82,631 | 80,949 | 87,346 | 51,142 | 4,368 |
| 11:00 | 90,820 | 60,747 | 67,289 | 58,786 | 4,217 |
| 12:00 | 111,027 | 59,069 | 73,039 | 68,124 | 3,012 |
| 13:00 | 110,166 | 59,259 | 78,526 | 63,479 | 2,458 |
| 14:00 | 101,911 | 61,882 | 73,926 | 52,854 | 1,134 |
| 15:00 | 97,822 | 65,726 | 65,884 | 49,681 | 961 |
| 16:00 | 92,975 | 62,126 | 65,092 | 55,860 | 3,395 |
| 17:00 | 94,345 | 58,482 | 56,758 | 65,979 | 8,989 |
| 18:00 | 96,610 | 43,304 | 38,902 | 75,308 | 17,492 |
| 19:00 | 59,795 | 22,432 | 24,334 | 62,155 | 18,345 |
| 20:00 | 48,470 | 13,935 | 20,011 | 76,911 | 21,172 |
| 21:00 | 45,035 | 15,098 | 24,325 | 90,000 | 19,753 |
| 22:00 | 42,962 | 20,954 | 32,195 | 67,674 | 18,966 |
| 23:00 | 38,912 | 28,977 | 44,078 | 47,710 | 19,705 |
Solar Conditions Timeline¶
Solar indices over the analysis window (Mar 06–Mar 09).
| Date | SFI | SSN | Kp | Ap | Conditions |
|---|---|---|---|---|---|
| 2026-03-06 | 142.8 | 88.0 | 1.0 | 4.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 2.33 | 9.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 2.0 | 7.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 1.0 | 4.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 1.67 | 6.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 1.0 | 4.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 1.0 | 4.0 | Quiet |
| 2026-03-06 | 142.8 | 88.0 | 3.33 | 18.0 | Unsettled |
| 2026-03-07 | 135.4 | 82.0 | 4.0 | 27.0 | Active |
| 2026-03-07 | 135.4 | 82.0 | 3.33 | 18.0 | Unsettled |
| 2026-03-07 | 135.4 | 82.0 | 3.0 | 15.0 | Unsettled |
| 2026-03-07 | 135.4 | 82.0 | 2.0 | 7.0 | Quiet |
| 2026-03-07 | 135.4 | 82.0 | 1.67 | 6.0 | Quiet |
| 2026-03-07 | 135.4 | 82.0 | 3.0 | 15.0 | Unsettled |
| 2026-03-07 | 135.4 | 82.0 | 4.0 | 27.0 | Active |
| 2026-03-07 | 135.4 | 82.0 | 4.0 | 27.0 | Active |
| 2026-03-08 | 134.5 | 79.0 | 4.67 | 39.0 | Active |
| 2026-03-08 | 134.5 | 79.0 | 3.67 | 22.0 | Unsettled |
| 2026-03-08 | 134.5 | 79.0 | 4.0 | 27.0 | Active |
| 2026-03-08 | 134.5 | 79.0 | 3.0 | 15.0 | Unsettled |
| 2026-03-08 | 134.5 | 79.0 | 3.67 | 22.0 | Unsettled |
| 2026-03-08 | 134.5 | 79.0 | 4.0 | 27.0 | Active |
| 2026-03-08 | 134.5 | 79.0 | 3.0 | 15.0 | Unsettled |
| 2026-03-08 | 134.5 | 79.0 | 2.33 | 9.0 | Quiet |
Geographic Reach¶
Distance distribution of observed paths — PSKR source.
| Band | Min (km) | Median (km) | Max (km) | Paths |
|---|---|---|---|---|
| 160m | 0 | 1,972 | 15,473 | 9,524 |
| 80m | 0 | 2,137 | 19,583 | 31,928 |
| 60m | 0 | 2,737 | 19,610 | 8,106 |
| 40m | 0 | 3,123 | 20,015 | 111,748 |
| 30m | 0 | 4,012 | 20,015 | 65,883 |
| 20m | 0 | 3,679 | 20,015 | 134,609 |
| 17m | 0 | 4,025 | 20,015 | 70,284 |
| 15m | 0 | 4,466 | 19,904 | 104,364 |
| 12m | 0 | 4,727 | 19,814 | 56,486 |
| 10m | 0 | 5,365 | 19,904 | 115,960 |
Resources¶
| Resource | Link |
|---|---|
| Full Analysis Notebook | View on GitHub |
| Contest Dataset | Download SQLite |
| IONIS Jupyter | All Notebooks |
The notebook contains the complete analysis with interactive charts: solar timeline, band activity heatmaps, geographic reach maps, day/night classification, SNR distributions, and historical context. The SQLite dataset contains all PSKR signatures from the analysis window — download it to run the notebook locally or explore the data yourself.
Analysis powered by IONIS — 14 billion propagation observations, 71 MCP tools, and a neural network that learned HF physics from the data.