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 | 178,831 | -6 dB | 2,550 | 20:00 |
| 80m | 530,309 | -7 dB | 3,093 | 4:00 |
| 60m | 183,048 | -6 dB | 3,011 | 20:00 |
| 40m | 1.7M | -9 dB | 4,213 | 21:00 |
| 30m | 1.1M | -9 dB | 4,748 | 21:00 |
| 20m | 2.1M | -9 dB | 4,856 | 15:00 |
| 17m | 1.1M | -9 dB | 4,890 | 16:00 |
| 15m | 1.5M | -9 dB | 5,197 | 16:00 |
| 12m | 822,868 | -10 dB | 5,256 | 12:00 |
| 10m | 1.4M | -10 dB | 5,818 | 13:00 |
Hourly Activity Profile¶
Spot density by hour (UTC) across all contest bands — PSKR source.
| Hour | 20m | 15m | 10m | 40m | 80m |
|---|---|---|---|---|---|
| 00:00 | 751,263 | 421,143 | 548,868 | 897,954 | 321,615 |
| 01:00 | 658,401 | 387,912 | 409,089 | 1.0M | 376,563 |
| 02:00 | 547,434 | 292,227 | 278,910 | 1.0M | 364,386 |
| 03:00 | 436,890 | 191,556 | 166,818 | 1.0M | 385,563 |
| 04:00 | 470,895 | 192,561 | 170,163 | 1.1M | 413,595 |
| 05:00 | 593,931 | 230,613 | 220,539 | 1.0M | 328,206 |
| 06:00 | 850,575 | 302,151 | 285,969 | 999,447 | 222,945 |
| 07:00 | 963,363 | 560,340 | 488,412 | 756,540 | 107,919 |
| 08:00 | 883,716 | 773,349 | 689,409 | 621,717 | 74,880 |
| 09:00 | 789,045 | 772,857 | 816,006 | 567,996 | 84,579 |
| 10:00 | 889,275 | 702,876 | 817,539 | 587,967 | 104,628 |
| 11:00 | 974,565 | 597,462 | 730,128 | 592,407 | 82,647 |
| 12:00 | 1.1M | 645,627 | 858,108 | 645,624 | 59,313 |
| 13:00 | 1.3M | 739,497 | 974,709 | 576,759 | 35,823 |
| 14:00 | 1.3M | 813,153 | 920,817 | 472,965 | 17,913 |
| 15:00 | 1.3M | 890,790 | 873,744 | 468,183 | 18,642 |
| 16:00 | 1.2M | 892,788 | 891,993 | 552,606 | 44,850 |
| 17:00 | 1.3M | 872,769 | 766,503 | 675,327 | 119,316 |
| 18:00 | 1.3M | 752,271 | 559,002 | 803,301 | 205,434 |
| 19:00 | 1.2M | 579,396 | 436,056 | 1.1M | 307,908 |
| 20:00 | 1.1M | 458,799 | 389,994 | 1.2M | 365,697 |
| 21:00 | 1.0M | 436,374 | 383,106 | 1.2M | 370,260 |
| 22:00 | 1.0M | 463,719 | 508,854 | 1.1M | 358,140 |
| 23:00 | 812,262 | 430,875 | 595,068 | 846,381 | 347,304 |
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 | 83.0 | 4.0 | 27.0 | Active |
| 2026-03-07 | 135.4 | 83.0 | 3.33 | 18.0 | Unsettled |
| 2026-03-07 | 135.4 | 83.0 | 3.0 | 15.0 | Unsettled |
| 2026-03-07 | 135.4 | 83.0 | 2.0 | 7.0 | Quiet |
| 2026-03-07 | 135.4 | 83.0 | 1.67 | 6.0 | Quiet |
| 2026-03-07 | 135.4 | 83.0 | 3.0 | 15.0 | Unsettled |
| 2026-03-07 | 135.4 | 83.0 | 4.0 | 27.0 | Active |
| 2026-03-07 | 135.4 | 83.0 | 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 | 2.67 | 12.0 | Quiet |
| 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 |
| 2026-03-09 | 128.4 | 85.0 | 2.0 | 7.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 1.33 | 5.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 1.0 | 4.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 1.33 | 5.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 1.67 | 6.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 1.67 | 6.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 1.67 | 6.0 | Quiet |
| 2026-03-09 | 128.4 | 85.0 | 2.33 | 9.0 | Quiet |
Geographic Reach¶
Distance distribution of observed paths — PSKR source.
| Band | Min (km) | Median (km) | Max (km) | Paths |
|---|---|---|---|---|
| 160m | 0 | 2,550 | 19,818 | 73,229 |
| 80m | 0 | 3,093 | 20,015 | 178,921 |
| 60m | 0 | 3,011 | 19,904 | 67,123 |
| 40m | 0 | 4,213 | 20,015 | 508,443 |
| 30m | 0 | 4,748 | 20,015 | 370,292 |
| 20m | 0 | 4,856 | 20,015 | 615,334 |
| 17m | 0 | 4,890 | 20,015 | 393,661 |
| 15m | 0 | 5,197 | 20,015 | 514,153 |
| 12m | 0 | 5,256 | 20,015 | 341,759 |
| 10m | 0 | 5,818 | 20,015 | 523,567 |
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, 80 MCP tools, and a neural network that learned HF physics from the data.