Per W0AH's query:
I have the following on my propagation website at
http://www.kn4lf.com/kn4lf5.htm . Read #4 and #5.
Here are some general guidelines concerning correlation of propagation indices
to actual expected HF/MF propagation conditions.
1.) Dropping indices numbers are better, except solar flux for HF.
2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best
for E layer multi hop. Keep in mind though that the 10.7 cm (2800 mhz) solar
flux index is not a "reliable" gauge of ionization in our atmosphere, as the
energy of photons at this frequency is to low on the order of one million
times.
2a.) For high frequencies a solar flux of 100 is okay, 150 better, above 200
best for F layer multi hop.
3.) Solar flux of at least 100 for E valley-F layer ducting mechanism.
4.) Previous 24 hour Ap index under 10, under 7 for several days consecutively
is best.
5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for high
latitude paths, 0-1 for several days consecutively is best.
6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and no
greater then (10-1) on MF broadcast band.
7.) Background x-ray flux levels less than C1 for several days consecutively
for 160/120 meters and less then B9 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a (+) sign, indicates a lesser chance of high latitude path
auroral absorption/unpredictable refraction or scattering of MF RF signals,
when the Kp is above 3.
Then look at the propagation data below. You can see that the K index was very
low for several days, allowing the Aurora Oval to retract latitudinally and
allow the high latitude path to open up between Colorado and northern Europe.
At last check the Aurora index is now a 10, at the top of the scale and the Kp
is a 6 which is a moderate geomagnetic storm.
Kp
Boulder K
20031013 94.4 12 25 14.5 13 8-25 33233334 32234434 316-537
20031012 97.8 23 35 7.0 6 4-11 12132222 00113311 286-369
20031011 105.8 51 77 6.0 5 5-9 21212212 00111321 350-433
20031010 111.8 85 79 6.1 5 4-8 21122212 00003221 408-517
Also I posted the following on other E-Lists on Friday October 10th. Topband
propagation conditions can be forecasted.
----- Original Message -----
From: "Thomas Giella KN4LF" <kn4lf@tampabay.rr.com>
To: "a RSGB PSC E-List" <PSC.Committee@rsgb.org.uk>; "a HCDX Prop Channel"
<propagation@hard-core-dx.com>; "a NRC AM E-List" <am@nrcdxas.org>; "a HCDX
E-List" <hard-core-dx@hard-core-dx.com>; "a Cumbre DX E-List"
<cumbredx@cs2.ralabs.com>; "a ABDX E-List" <ABDX@topica.com>
Sent: Friday, October 10, 2003 11:15 AM
Subject: Propagation Outlook
> I would expect HF/MF radio propagation conditions to worsen beginning in the
> October 13-14th window. Recurrent Coronal Hole #063 will become geoeffective
> (Earth facing) by the 13th.
During a previous geoeffective pass as #057 it produced a peak Kp index of 7
> and a peak Ap index of 129. As #052 it produced a 7/122.
73,
Thomas F. Giella, KN4LF
Plant City, FL, USA
EL87WX
KN4LF 160 Meter Amateur Radio Resources & More:
http://www.kn4lf.com/kn4lf.htm
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive:
http://www.kn4lf.com/kn4lf5.htm
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