[CQ-Contest] Listen to what happens when a X4.0 Solar Flare hitsyour contest operation - P40E CQWW CW 2000
Randy Thompson K5ZD
k5zd at charter.net
Thu Dec 31 16:27:17 PST 2009
I recall this contest and the flare as well. I was operating SOAB from my
home station. The bands seemed to go dead and then slowly recover. This is
difficult to process when you have already been awake for 40 something
hours. With the bands broken, I began to tune around and see what I could
find. I "discovered" that 10 meters seemed to be where I could find QSOs.
It was weird to tune through big empty patches when the bands had been
packed just moments before.
My rate sheet tells some of the story:
12Z - - - 3/1 54/2 85/4 142/7 3588/622
13Z - - - - 6/3 134/3 140/6 3728/628
14Z - - - - 37/3 82/4 119/7 3847/635
15Z - - - - 96/4 18/3 114/7 3961/642
16Z --+-- --+-- --+-- --+-- 73/1 14/2 87/3 4048/645 <<<
17Z - - - - - 78/7 78/7 4126/652
18Z - - - - 89/0 17/3 106/3 4232/655
19Z - - - 58/1 30/1 5/5 93/7 4325/662
20Z - - - 51/4 9/7 - 60/11 4385/673
The log snippet doesn't look that bad, until you realize how good the rate
was during the first half of the 16z hour.
21048 CW 2000-11-26 1636 K5ZD 599 05 9A3GO 599 15
21048 CW 2000-11-26 1637 K5ZD 599 05 UA1ZCX 599 16
28131 CW 2000-11-26 1638 K5ZD 599 05 DK2OY 599 14
21048 CW 2000-11-26 1638 K5ZD 599 05 OK2BGK 599 15
21048 CW 2000-11-26 1639 K5ZD 599 05 DL5NO 599 14
21048 CW 2000-11-26 1639 K5ZD 599 05 DL2ANM 599 14
21048 CW 2000-11-26 1640 K5ZD 599 05 RX6AUE 599 16
21048 CW 2000-11-26 1641 K5ZD 599 05 EW5O 599 16
21048 CW 2000-11-26 1643 K5ZD 599 05 LA7MFA 599 14 <<time to tune
28139 CW 2000-11-26 1644 K5ZD 599 05 HB2FAP 599 14
28144 CW 2000-11-26 1647 K5ZD 599 05 OK2ZC 599 15
28149 CW 2000-11-26 1647 K5ZD 599 05 IZ0AIS 599 15
28152 CW 2000-11-26 1648 K5ZD 599 05 SP6NIC 599 15
21028 CW 2000-11-26 1651 K5ZD 599 05 YL2SM 599 15
28009 CW 2000-11-26 1656 K5ZD 599 05 SN5N 599 15
28019 CW 2000-11-26 1659 K5ZD 599 05 OM3NY 599 15
28020 CW 2000-11-26 1700 K5ZD 599 05 G4ODV 599 14
28021 CW 2000-11-26 1700 K5ZD 599 05 IT9AF 599 15
28031 CW 2000-11-26 1702 K5ZD 599 05 P40E 599 9
28040 CW 2000-11-26 1705 K5ZD 599 05 GM3POI 599 14
28050 CW 2000-11-26 1708 K5ZD 599 05 OK2PKY 599 15 <<recovery
begins
28050 CW 2000-11-26 1708 K5ZD 599 05 HA8YU 599 15
28050 CW 2000-11-26 1709 K5ZD 599 05 HA0HH 599 15
28050 CW 2000-11-26 1710 K5ZD 599 05 VE3OTL 599 4
These really big contests do give us some great data points to study the
impact of sudden solar disturbances.
Randy, K5ZD
> -----Original Message-----
> From: cq-contest-bounces at contesting.com
> [mailto:cq-contest-bounces at contesting.com] On Behalf Of José
> Nunes CT1BOH
> Sent: Thursday, December 31, 2009 12:44 AM
> To: cq-contest at contesting.com
> Subject: [CQ-Contest] Listen to what happens when a X4.0
> Solar Flare hitsyour contest operation - P40E CQWW CW 2000
>
> I had the idea for this post after reading K9LA's article
> "Solar Flares at ZF2RR.
> http://mysite.verizon.net/k9la/Solar_Flares_at_ZF2RR.pdf
>
> K9LA in his article explains the impact on ZF2RR operation of
> Solar Flares:
>
> "(...) Dan, N9XX, was at ZF for CQ WW CW in 2000, and he did
> a single band 10m low power effort as ZF2RR. Overall he did
> very well (he won the World for 10m low power), but he
> noticed several hours with significantly reduced rates that
> he suspected were tied to flare activity.
> There are four periods that stand out where the rate dropped
> significantly – during the 18-19 UTC period on day 1, and
> during the 16-17 UTC, 19-20 UTC, and 22-23 UTC periods on day
> 2. The rate drop during the 18-19 UTC period on day 1
> coincides with an X1.9 flare that erupted at 1836 UTC. The
> rate drop during the 16-17 UTC period on day 2 coincides with
> an X4.0 flare that erupted at 1638 UTC. Those were the only
> two class X flares during the contest weekend(...)"
>
> It just happens that while operating P40E during the 2000
> CQWW CW Contest, I was recording the event. And I still
> remember the black-out that followed the big X4.0 Solar
> Flare. I thought it would be interesting to share the story
> and the audio clip of the impact of the solar flare.
>
> First take a look at the Goes Xray Flux (5 minute data) on
> the 25 and 26 November 2002
> http://qsl.net/ct1boh/audio/20001127_xray.PNG
> I marked with an arrow the big solar X4.0 flare that occurred
> at 16:38 on 26 November, Sunday of the contest.
>
> P40E was QRV on 21 Mhz (21050)
> In the 40 minutes before the Solar Flare impacted P40E
> operation, 16:00 - 16:39, I had worked 107 QSOs at a rate of
> 160.5 QSOs per hour.
> In the 20 minutes after the Solar Flare impacted P40E
> operation 16:40 -
> 16:59 first there was a 7 minute black-out and then I managed
> to work 10 QSOs at a rate of 30 QSOs per hour.
>
> Another interesting aspect to mention is that K9LA notes in
> his article:
>
> "(...)The duration of the blackout depends on the magnitude
> of the flare.
> And since absorption is proportional to the inverse of
> frequency squared, 28MHz will be the least affected of our HF
> bands. (...)"
> Note that P40E reaction right after the flare, is first to
> tune up and down looking for signals, and then QSY from 15 to
> 10 meters, and resume activity as the band returns to normal.
>
> Very interesting is the surge of noise right after the Solar
> Flare until almost total black-out of the bands and during
> the 7 minute black-out. You will listen to a a vanishing
> pile-up, to a dead band, and then the recovery of activity.
>
> You can check P40E log here to follow audio clip from 16:36z
> until 17:02z http://www.qsl.net/ct1boh/audio/flare.txt
>
> And you can listen here to the26 minutes of audio clip here.
> http://www.qsl.net/ct1boh/audio/flare.wav
> Note that this was an SO2R operation so you should use
> headphones. You will listen on the left ear to radio 1 (RUN
> radio) on 21MHZ and right ear to radio 2 (S&P radio) on 28
> Mhz before the QSY to 10.
>
> Happy New year to all
> --
> --
> José Nunes
> CONTEST CT1BOH - http://www.qsl.net/ct1boh
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